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Dean NS, Krambeck AE. Contemporary Use of Computed Tomography (CT) Imaging in Suspected Urolithiasis in Pregnancy. Curr Urol Rep 2023; 24:443-449. [PMID: 37314612 DOI: 10.1007/s11934-023-01171-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/08/2023] [Indexed: 06/15/2023]
Abstract
PURPOSE OF REVIEW We aimed to examine the role of low-dose CT (LDCT) in the diagnostic work-up for suspected urolithiasis in pregnancy. We reviewed contemporary urologic recommendations for CT in pregnancy, its utilization for suspected urolithiasis, and explored barriers to its use. RECENT FINDINGS National urologic guidelines and the American College of Obstetricians and Gynecologists recommend the judicious use of LDCT imaging in pregnancy when necessary. We noted inconsistencies in review article management pathways and recommendations for CT imaging for suspected urolithiasis in pregnancy. Overall CT utilization in pregnancy for suspected urolithiasis is low. Proposed barriers to LDCT use in pregnancy include fears of litigation and misperceptions of the harm of diagnostic radiation. Recent advancements in imaging technologies for urolithiasis in pregnancy are limited. More specific diagnostic pathway recommendations from national urologic guideline bodies for when to use LDCT to investigate renal colic in pregnancy may reduce diagnostic and intervention delays.
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Affiliation(s)
- Nicholas S Dean
- Department of Urology, Northwestern University, 676 N. St. Clair, Suite 2300, Chicago, IL, 60611, United States.
| | - Amy E Krambeck
- Department of Urology, Northwestern University, 676 N. St. Clair, Suite 2300, Chicago, IL, 60611, United States
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Grunz JP, Halt D, Schüle S, Beer M, Hackenbroch C. Thermoluminescence Dosimetry in Abdominal CT for Urinary Stone Detection: Effective Radiation Dose Reduction With Tin Prefiltration at 100 kVp. Invest Radiol 2023; 58:231-238. [PMID: 36070523 DOI: 10.1097/rli.0000000000000924] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVES Spectral shaping via tin prefiltration has gained recognition for dose saving in high-contrast imaging tasks. The aim of this phantom dosimetry study was to investigate whether the use of tin filters can also reduce the effective radiation dose in 100 kVp abdominal computed tomography (CT) compared with standard low-dose scans for suspected urolithiasis. METHODS Using a third-generation dual-source CT scanner, 4 scan protocols each were used on a standard (P1-P4) and a modified obese Alderson-Rando phantom (P5-P8), in which 11 urinary stones of different compositions were placed. Hereby 1 scan protocol represented standard low-dose settings (P1/P5: 110 kVp/120 kVp), whereas 3 experimental protocols used low-kilovoltage spectral shaping (P2/P3/P4 and P6/P7/P8: 100 kVp with tin prefiltration). Radiation dose was recorded by thermoluminescent dosimeters at 24 measurement sites. For objective assessment of image quality, dose-weighted contrast-to-noise ratios were calculated and compared between scan protocols. Additional subjective image quality analysis was performed by 2 radiologists using equidistant 5-point scales for estimation image noise, artifacts, kidney stone detectability, and delineation of bone and soft tissue. RESULTS Both conventional low-dose protocols without tin prefiltration were associated with the highest individual equivalent doses and the highest effective radiation dose in the experimental setup (P1: 0.29-6.43 mGy, 1.45-1.83 mSv; P5: 0.50-9.35 mGy, 2.33-2.79 mSv). With no false-positive diagnoses, both readers correctly detected each of the 11 urinary calculi irrespective of scan protocol and phantom configuration. Protocols using spectral shaping via tin prefiltration allowed for effective radiation dose reduction of up to 38% on the standard phantom and 18% on the modified obese phantom, while maintaining overall diagnostic image quality. Effective dose was approximately 10% lower in a male versus female anatomy and could be reduced by another 10% if gonadal protection was used ( P < 0.001). CONCLUSIONS Spectral shaping via tin prefiltration at 100 kVp is a suitable means to reduce the effective radiation dose in abdominal CT imaging of patients with suspected urolithiasis. The dose reduction potential is slightly less pronounced in a modified phantom emulating an obese body composition compared with a standard phantom.
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Affiliation(s)
| | - Daniel Halt
- From the Department of Radiology, German Armed Forces Hospital Ulm, Ulm
| | - Simone Schüle
- From the Department of Radiology, German Armed Forces Hospital Ulm, Ulm
| | - Meinrad Beer
- Department of Radiology, University Hospital Ulm, Ulm, Germany
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Glover XG, Ballon-Landa EC, Sawyer MD. Ultralow-Dose Intraoperative Computed Tomography During Endoscopic Stone Surgery: A Quality Improvement Project. J Endourol 2023; 37:428-442. [PMID: 36458465 DOI: 10.1089/end.2022.0503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Objectives: To improve care in patients with large kidney stones using advanced intraoperative imaging techniques to reduce perioperative radiation exposure, improve stone-free rates (SFRs), and reduce the number of surgical interventions in a quality improvement project. Patients and Methods: Patients with kidney stones appropriate for percutaneous nephrolithotomy (PCNL) treatment were scheduled into a hybrid operating room for endoscopic surgery (PCNL and/or ureteroscopy) with intent to perform intraoperative CT (ICT). Imaging was performed using an Artis Zeego Care+Clear™ (Siemens) robotic-armed multiplanar fluoroscopy system with collimation to the level of the affected kidney(s). After the initial case, the proprietary CARE™ (combined applications to reduce exposure) protocol was used. When the hybrid room was unavailable, a mobile CT scanner (O-Arm; Medtronics) was used in the traditional room (n = 2). Results: Thirty-one ICTs were performed in 23 consecutive patients during endoscopic stone procedures with a median effective radiation dose of 1.39 mSv per scan, significantly less than the preoperative noncontrast CT (12.02 mSv) in the same patients (p < 0.001). Longitudinal radiation exposure associated with stone treatment significantly decreased by 83% (15.80 to 2.68 mSv, p < 0.001) compared with a similar historical PCNL cohort. Clinically significant residual stones (≥3 mm) were identified at initial ICT in eight patients (35%) and further treated in six patients. One patient had missed residual stone diagnosed 34 days after surgery, which was apparent on re-review of the ICT. Thus, final verified SFR was 87% for all stages. Mean number of procedures improved from 1.77 to 1.30 (p = 0.05) and rate of postoperative CT scans improved from 82% to 26% (p < 0.001). Conclusion: Ultralow-dose ICT was demonstrated to simultaneously improve SFR and number of staged treatments, and greatly reduce the perioperative radiation dose for our patients. The findings support the continued use of this modality to benefit all patients with large stones.
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Affiliation(s)
- Xavier G Glover
- Surgical Services, Rocky Mountain Regional VA Medical Center, VA Eastern Colorado Health Care System, Aurora, Colorado, USA.,Division of Urology, Department of Surgery, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Eric C Ballon-Landa
- Surgical Services, Rocky Mountain Regional VA Medical Center, VA Eastern Colorado Health Care System, Aurora, Colorado, USA.,Division of Urology, Department of Surgery, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Mark D Sawyer
- Surgical Services, Rocky Mountain Regional VA Medical Center, VA Eastern Colorado Health Care System, Aurora, Colorado, USA.,Division of Urology, Department of Surgery, University of Colorado School of Medicine, Aurora, Colorado, USA
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Rawashdeh M, Saade C. Establishment of diagnostic reference levels in low-dose renal computed tomography. Acta Radiol 2023; 64:829-836. [PMID: 35505591 DOI: 10.1177/02841851221095238] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND Increased radiation doses from computed tomography (CT) examinations is well known with proven risks of inducing cancers for effective dose >100 mSv (according to some studies >50 mSvs). PURPOSE To establish the diagnostic reference level (DRL) for low-dose renal CT examinations in the evaluation of renal stones. MATERIAL AND METHODS Patient demographics, CT parameters, and dosimetric indices (CTDIvol and dose length product [DLP]) were collected from 12 tertiary hospitals that routinely perform renal CT in the detection and evaluation of renal stones over a period of 12 weeks. Data obtained from 1418 average-sized patients in each category were recorded. The median values of dosimetric indices for each site were calculated. The DRL values were defined as the 75th percentile of the distribution of the median values of CTDIvol and DLP. RESULTS There were no significant differences between patient demographics. Mean kVp and mAs for protocols were 121.67 ± 11.56 and 226.91 ± 78.44, respectively. The CTDIvol values were in the range of 2-36.2 mGy, while the DLP values were in the range of 43-1942 mGy.cm. The DRL for the CTDIvol was 16.15 mGy and for the DLP 851.77 mGy.cm. The local median values of CDTIvol and DLP are higher than DRL in two hospitals. CONCLUSION Comparison of local median values of CDTIvol and DLP with DRL suggests the needs of an optimization strategy in some hospitals.
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Affiliation(s)
- Mohammad Rawashdeh
- Department of Allied Medical Sciences, 108612Jordan University of Science and Technology, Irbid, Jordan
| | - Charbel Saade
- Medical Imaging Sciences, Faculty of Health Sciences, University College Cork, Cork, Ireland
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Tin-filtered 100 kV Ultra-low-dose Abdominal CT for Calculi Detection in the Urinary Tract: A Comparative Study of 510 Cases. Acad Radiol 2022; 30:1033-1038. [PMID: 35963837 DOI: 10.1016/j.acra.2022.07.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 07/14/2022] [Accepted: 07/14/2022] [Indexed: 11/23/2022]
Abstract
OBJECTIVES For detection of urinary calculi, unenhanced low-dose computed tomography is the method of choice, outperforming radiography and ultrasound. This retrospective monocentric study aims to compare a clinically established, dedicated low-dose imaging protocol for detection of urinary calculi with an ultra-low-dose protocol employing tin prefiltration at a standardized tube voltage of 100 kVp. METHODS Two study arms included a total of 510 cases. The "low-dose group" was comprised of 290 individuals (96 women; age 49 ± 16 years; BMI 27.23 ± 5.60 kg/m2). The "ultra-low-dose group" with Sn100 kVp consisted of 220 patients (84 women; age 47 ± 17 years; BMI 26.82 ± 5.62 kg/m2). No significant difference was ascertained for comparison of age (p = 0.132) and BMI (p = 0.207) between cohorts. For quantitative assessment of image quality, image noise was assessed. RESULTS No significant difference regarding frequency of calculi detection was found between groups (p = 0.596). Compared to the low-dose protocol (3.08 mSv; IQR 2.22-4.02 mSv), effective dose was reduced by 62.35% with the ultra-low-dose protocol employing spectral shaping (1.16 mSv; IQR 0.89-1.54 mSv). Image noise was calculated at 18.90 (IQR 17.39-21.20) for the low-dose protocol and at 18.69 (IQR 17.30-21.62) for the ultra-low-dose spectral shaping protocol. No significant difference was ascertained for comparison between groups (p = 0.793). CONCLUSION For urinary calculi detection, ultra-low-dose scans utilizing spectral shaping by means of tin prefiltration at 100 kVp allow for considerable dose reduction of up to 62% over conventional low-dose CT without compromising image quality.
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Raynor R, Rajesh A. Adopting low dose CT in evaluating renal calculi-progress from 2008-18 in a large UK tertiary hospital. JOURNAL OF CLINICAL UROLOGY 2022. [DOI: 10.1177/20514158221082876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Background: Computed tomography (CT) of the urinary tract is a commonly performed investigation and it is crucial to adhere to low dose protocols to avoid unnecessary radiation burden. Aims: To review the adoption of low-dose techniques over time, defined as a dose length product (DLP) < 200mGy.cm, in a large teaching hospital over three locations with 12 CT scanners. Methods: Data were obtained from the radiology information system for exams completed under the coding for unenhanced CT evaluation for renal calculi between 14 Feb 2008 and 31 December 2018. Examinations where the DLP was not correctly recorded, was below 40mGy.cm, or where the equipment used could not be identified were excluded. The distribution of doses and the median DLP per scanner was calculated. Results: In all, 20,080 studies were available across 12 CT scanners in the 10- year period. The average Median DLP has reduced from 501mGy.cm in 2008 to 178mGy.cm in 2018. Conclusions: Improvements in CT technology and implementation of low-dose protocols have resulted in significantly lower doses for evaluation of kidney stones since 2008. Although this study demonstrates significant variation between scanners, the overall adoption of low dose techniques is excellent. Level of evidence: Not applicable
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Affiliation(s)
- Richard Raynor
- Medical Physics, University Hospitals of Leicester NHS Trust, UK
| | - Arumugam Rajesh
- Department of Radiology, University of Leicester and University Hospitals of Leicester NHS Trust, Leicester, UK
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Haubold J, Zensen S, Erfanian Y, Guberina N, Opitz M, Sawicki LM, Forsting M, Umutlu L, Theysohn JM. ULTRA-LOW-DOSE COMPUTED TOMOGRAPHY IN UROLITHIASIS-EFFECT OF AN ADDITIONAL TIN FILTER ON IMAGE QUALITY AND RADIATION DOSE. RADIATION PROTECTION DOSIMETRY 2021; 197:146-153. [PMID: 34952539 DOI: 10.1093/rpd/ncab180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 11/12/2021] [Accepted: 12/01/2021] [Indexed: 06/14/2023]
Abstract
To compare radiation dose and image quality of three CT-scanners using optimal dose protocols in patients with suspected urolithiasis regarding additional hardware (tin filter) and software (iterative reconstruction). Examinations from a single-source CT-scanner (A2) and a dual-source CT-scanner (DSCT) (A1) were compared to a tin filter DSCT (B) regarding dose-length product (DLP) and volume-weighted CT dose-index (CTDIvol). DLP of B was 51 and 53% lower in comparison to A1 and A2 (78.62, 159.20 and 165.80 mGy·cm, respectively; P < 0.0001). CTDIvol of B was 53% and 56% significantly lower compared to A1 and A2, respectively (1.52 vs. 3.22 vs. 3.46 mGy; P < 0.0001). Image quality in B proved to be similar to A1 and A2 (3.57, 3.51 and 3.60, respectively; P > 0.05). Inter-rater agreement regarding image quality was good for all CT-scanners (κ = 0.62). Modern CTs with a built-in tin filter allow a significant reduction of radiation exposure in patients with suspected urolithiasis by optimizing the X-ray spectrum.
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Raskolnikov D, Hall MK, Ngo SD, Dighe M, Kanal KM, Harper JD, Gore JL. Strategies to Optimize Nephrolithiasis Emergency Care (STONE): Prospective Evaluation of an Emergency Department Clinical Pathway. Urology 2021; 160:60-68. [PMID: 34757049 DOI: 10.1016/j.urology.2021.09.028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 08/16/2021] [Accepted: 09/08/2021] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To convene a multi-disciplinary panel to develop a pathway for Emergency Department (ED) patients with suspected nephrolithiasis and then prospectively evaluate its effect on patient care. MATERIALS AND METHODS The STONE Pathway was developed and linked to order sets within our Electronic Health Record in April 2019. Records were prospectively reviewed for ED patients who underwent ultrasound or Computerized Tomography (CT) to evaluate suspected nephrolithiasis between January 2019 and August 2019 within our institution. The primary outcome measure was the proportion of patients whose ED CT was low dose (<4 mSv). Secondary outcome measures included receipt of pathway-concordant pain medications and urine strainers. Order set utilization was evaluated as a process measure. Balance measures assessed included repeat ED visits, imaging, hospitalizations, and a urologic clinic visit or surgery within 30 days of discharge. RESULTS 441 patients underwent ED imaging, of whom 261 (59%) were evaluated for suspected nephrolithiasis. The STONE Pathway was used in 50 (30%) eligible patients. Patients treated with the Pathway were more likely to undergo low-dose CTs (49% vs. 23%, p<0.001), and receive guideline-concordant pain medications such as NSAIDs (90% vs. 62%, p<0.001), and were less likely to return to the ED within 30 days (13% vs. 2%, p=0.01). These measures demonstrated special cause variation following Pathway release. CONCLUSIONS Clinical pathways increase compliance with evidence-based practices for pain control and imaging in nephrolithiasis emergency care and may improve the delivery of value-based care.
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Affiliation(s)
| | - M Kennedy Hall
- Department of Emergency Medicine, University of Washington, Seattle, WA
| | - Steven D Ngo
- School of Medicine, University of Washington, Seattle, WA
| | - Manjiri Dighe
- Department of Radiology, University of Washington, Seattle, WA
| | - Kalpana M Kanal
- Department of Radiology, University of Washington, Seattle, WA
| | | | - John L Gore
- Department of Urology, University of Washington, Seattle, WA
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Eddy FK, Ngano SO, Jervé FA, Serge A. Optimization of the scan length of head traumas on the pediatric and adult CT scan and proposition of a new acquisition limit. Sci Rep 2021; 11:10958. [PMID: 34040095 PMCID: PMC8155083 DOI: 10.1038/s41598-021-90529-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Accepted: 05/10/2021] [Indexed: 11/15/2022] Open
Abstract
To propose a new method of reducing the scan length of head trauma while keeping the diagnostic efficiency of the examination in order to develop DRL in an African context. This is a retrospective single-center study including 145 patients who had cranial examinations on a 64-barettes scanner. All head trauma cases were selected. The interpretations of these CT scanners by the three radiologists of the service were noted to determine the acquisition limit. All patient acquisition lengths have been recorded. The acquisition limit for head trauma ended in clinical routine at cervical spine 4 (C4). The average scan length was 23.03 cm. Out of the CT scan results for 145 patients, only 2 (1.37%) had a C3 level cervical spine fracture and 2 (1.37%) at C4. By respecting the principles of radiation protection, this result has shown us that it is possible to limit the acquisition length of the CT scanners indicated for head trauma. The limit of the optimized scan length that we proposed is at cervical spine 2 (98.62%). Now, all head trauma are limited on cervical vertebra 2 in our hospital. The use of this new method is beneficial when the clinical indication of the examination and the type of trauma (multi-trauma) are taken into account. Based on the principles of radiation protection and the clinical indication for the examination, reducing the scan length from C4 to C2 is an effective way to reduce the dose absorbed by the patient.
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Affiliation(s)
- Fotso Kamdem Eddy
- Unité de Recherche de la Matière Condensée, d'Electronique et de Traitement du Signal, Department of Physics, Faculty of Science, University of Dschang, Dschang, Cameroon.
| | - Samba Odette Ngano
- Unité de Recherche de la Matière Condensée, d'Electronique et de Traitement du Signal, Department of Physics, Faculty of Science, University of Dschang, Dschang, Cameroon
- Department of Radiography, Yaoundé General Hospital, Yaoundé, Cameroon
| | - Fotue Alain Jervé
- Unité de Recherche de la Matière Condensée, d'Electronique et de Traitement du Signal, Department of Physics, Faculty of Science, University of Dschang, Dschang, Cameroon
| | - Abogo Serge
- Department of Radiology, National Social Insurance Fund Hospital, Yaoundé, Cameroon
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Cheng Y, Han Y, Li J, Fan G, Cao L, Li J, Jia X, Yang J, Guo J. Low-dose CT urography using deep learning image reconstruction: a prospective study for comparison with conventional CT urography. Br J Radiol 2021; 94:20201291. [PMID: 33571034 DOI: 10.1259/bjr.20201291] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
OBJECTIVES To compare the image quality of low-dose CT urography (LD-CTU) using deep learning image reconstruction (DLIR) with conventional CTU (C-CTU) using adaptive statistical iterative reconstruction (ASIR-V). METHODS This was a prospective, single-institutional study using the excretory phase CTU images for analysis. Patients were assigned to the LD-DLIR group (100kV and automatic mA modulation for noise index (NI) of 23) and C-ASIR-V group (100kV and NI of 10) according to the scan protocols in the excretory phase. Two radiologists independently assessed the overall image quality, artifacts, noise and sharpness of urinary tracts. Additionally, the mean CT attenuation, signal-to-noise ratio (SNR) and contrast-to-noise (CNR) in the urinary tracts were evaluated. RESULTS 26 patients each were included in the LD-DLIR group (10 males and 16 females; mean age: 57.23 years, range: 33-76 years) and C-ASIR-V group (14 males and 12 females; mean age: 60 years, range: 33-77 years). LD-DLIR group used a significantly lower effective radiation dose compared with the C-ASIR-V group (2.01 ± 0.44 mSv vs 6.9 ± 1.46 mSv, p < 0.001). LD-DLIR group showed good overall image quality with average score >4 and was similar to that of the C-ASIR-V group. Both groups had adequate and similar attenuation value, SNR and CNR in most segments of urinary tracts. CONCLUSION It is feasibility to provide comparable image quality while reducing 71% radiation dose in low-dose CTU with a deep learning image reconstruction algorithm compared to the conventional CTU with ASIR-V. ADVANCES IN KNOWLEDGE (1) CT urography with deep learning reconstruction algorithm can reduce the radiation dose by 71% while still maintaining image quality.
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Affiliation(s)
- Yannan Cheng
- Department of Radiology, the First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, Shaanxi province, PR China
| | - Yangyang Han
- Department of Radiology, the First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, Shaanxi province, PR China
| | - Jianying Li
- GE Healthcare, Computed Tomography Research Center, Beijing, 100176, PR China
| | - Ganglian Fan
- Department of Radiology, the First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, Shaanxi province, PR China
| | - Le Cao
- Department of Radiology, the First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, Shaanxi province, PR China
| | - Junjun Li
- Department of Radiology, the First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, Shaanxi province, PR China
| | - Xiaoqian Jia
- Department of Radiology, the First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, Shaanxi province, PR China
| | - Jian Yang
- Department of Radiology, the First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, Shaanxi province, PR China
| | - Jianxin Guo
- Department of Radiology, the First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, Shaanxi province, PR China
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Thakur APS, Sharma V, Ramasamy V, Choudhary A, Patel P, Singh S, Parol S. Management of ureteric stone in pregnancy: a review. AFRICAN JOURNAL OF UROLOGY 2020. [DOI: 10.1186/s12301-020-00070-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Urolithiasis in pregnancy is a major health concern and is one of the most common causes for non-obstetrical abdominal pain and subsequent hospital admission during pregnancy. The incidence of urinary calculi during pregnancy varies in the range of 1/200 to 1/2000. Acute ureteric colic in pregnancy is associated with significant potential risks to both mother and fetus. Significant anatomic and functional changes occur in pregnancy which not only lead to stone formation but also create diagnostic dilemma. The diagnosis of ureteric calculi can be incorrect in about 28% of pregnant patients.
Main body
Management of ureteric stone during pregnancy is remaining to be a challenge for the treating urologist. Because of the inability to use good imaging options for the diagnosis confirmation and more invasive approach for the treatment, management continues to be difficult. The main threats are preterm labor with delivery and premature rupture of membranes. Other pregnancy complications are obstructive uropathy, gestational diabetes mellitus, recurrent abortions and pre-eclampsia. Management of diagnosed ureteric stone is unique in the pregnant population and requires multi-disciplinary care. It should be individualized for each patient and moves preferably from conservative to invasive approaches sequentially. With continued advancements in endourological techniques, few definitive treatment options are also available for such patients.
Conclusion
There are several lacunae related with the diagnostic imaging, medical expulsive therapy, reliability of ureteral stent/percutaneous nephrostomy insertions and safety of ureteroscopy during pregnancy. Herein, we review the management of ureteric stone during pregnancy, the various diagnostic modalities and treatment options with their advantages and disadvantages. We also proposed our management algorithm to deal with such clinical scenario in this particular population.
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Shim YS, Park SH, Choi SJ, Ahn SJ, Pak SY, Jung H, Park SH. Comparison of submillisievert CT with standard-dose CT for urolithiasis. Acta Radiol 2020; 61:1105-1115. [PMID: 31795730 DOI: 10.1177/0284185119890088] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
BACKGROUND Patients with renal stones receive multiple computed tomography (CT) examinations. We investigated whether submillisievert (sub-mSv) CT for stone detection could reduce radiation dose at exposure levels comparable to kidney, ureter, and bladder (KUB) radiography. PURPOSE To evaluate the radiation dose exposure, diagnostic performance, and image quality of sub-mSv non-contrast CT using advanced modelled iterative reconstruction algorithm with spectral filtration for the detection of urolithiasis. MATERIAL AND METHODS A total of 145 consecutive patients underwent non-contrast CT using a third-generation dual-source scanner to obtain two datasets, i.e. 16.7% (sub-mSv CT, tube detector A) and 100% (standard-dose CT, combination of tube detector A and B) tube loads with spectral filtration. The performance of sub-mSv CT for the detection of stones was analyzed by two readers and compared with that of standard-dose CT. Image quality was measured subjectively and objectively. RESULTS In total, 171 stones were detected in 79 patients. The mean effective radiation doses of sub-mSv CT was 0.3 mSv. The sensitivity and specificity values for diagnosis of stones measuring ≥3 mm was 95.1% and 100% for sub-mSv CT. The sensitivity and specificity for all stone detection was 74.9% and 97.8%, respectivey, for sub-mSv CT. The image quality was lower for sub-mSv CT than for standard-dose CT (P < 0.01). CONCLUSION Sub-mSv CT can be achieved with radiation doses close to KUB radiography. Sub-mSv CT with spectral filtration can be used to detect stones measuring ≥3 mm and be used as a follow-up imaging modality as an alternative to KUB radiography.
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Affiliation(s)
- Young Sup Shim
- Department of Radiology, Gil Medical Center, Gachon University College of Medicine, Incheon, Republic of Korea
| | - So Hyun Park
- Department of Radiology, Gil Medical Center, Gachon University College of Medicine, Incheon, Republic of Korea
| | - Seung Joon Choi
- Department of Radiology, Gil Medical Center, Gachon University College of Medicine, Incheon, Republic of Korea
| | - Su Joa Ahn
- Department of Radiology, Gil Medical Center, Gachon University College of Medicine, Incheon, Republic of Korea
| | - Seong Yong Pak
- Healthcare Diagnostic Imaging Division, Siemens-healthineers, Seoul, Republic of Korea
| | - Han Jung
- Department of Urology, Gil Medical Center, Gachon University College of Medicine, Incheon, Republic of Korea
| | - Seong Ho Park
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea
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Uldin H, McGlynn E, Cleasby M. Using the T11 vertebra to minimise the CT-KUB scan field. Br J Radiol 2020; 93:20190771. [PMID: 32208971 PMCID: PMC10993226 DOI: 10.1259/bjr.20190771] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 03/12/2020] [Accepted: 03/16/2020] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES Computed tomography scans of the kidney, ureters, and bladder (CT-KUB) are crucial in investigating urinary calculi but impart a substantial radiation doses. Radiation can be limited by minimising the scanning field to the necessary area (i.e. from the kidneys to urethra). Before auditing, the superior limit of CT-KUB scans had not been formally clarified at our trust. Consistently ensuring the upper limit of scans is at or below T10 has been shown to be a viable method of performing CT-KUB scans. This study aimed to assess the overscan length of CT-KUB investigations and modify practice accordingly to minimise it. There were two standards that were set for CT-KUB scanning. First, the mean percentage overscan length (i.e. percentage of the scan above the kidneys) should be <15%. Second, all scans should include the superior borders of both kidneys. METHODS 90 consecutive CT-KUB scans for ureteric calculus were retrospectively investigated using IMPAX software in the first phase of data collection. After these data were analysed, a newly devised protocol using T11 as the superior scan limit was delivered to radiographers in the department. and 105 in the second phase (re-audit). The analysis parameters were: percentage overscan length, distance between diaphragm and upper border of kidneys, vertebral level at which the scan commenced, and whether both kidneys were fully included. RESULTS In the first phase, overscan of >15% was present in 94.4% of scans. The mean percentage overscan length was 28.2%. The superior vertebral limit of 59% of scans was at T10 or below and a lower superior vertebral limit correlated with decreasing overscan. 99% of scans fully included both kidneys. In the second phase (3 months later), the mean overscan percentage reduced to 10.6% (standard deviation = 4.4%). Excessive overscan affected 35.2% of scans. The superior vertebral limit of 8% of scans was at T10 or below. 100% of scans fully included both kidneys. CONCLUSION Excessive overscanning was due to inconsistent technique in capturing CT-KUB scans. Before this audit, the superior limit of CT-KUB scans had not been formally clarified at our trust. By successfully standardising the process with a reproducible method, the overscan target was comfortably met. Therefore, patient dose was minimised without compromising scan quality. ADVANCES IN KNOWLEDGE This audit has successfully shown a feasible standardised protocol for CT-KUB investigations which can be used to minimise overscanning of patients.
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Affiliation(s)
- Hasaam Uldin
- Heartlands, Good Hope, and Solihull Hospitals, University
Hospitals Birmingham NHS Foundation Trust,
Birmingham, United Kingdom
| | - Eunan McGlynn
- Heartlands, Good Hope, and Solihull Hospitals, University
Hospitals Birmingham NHS Foundation Trust,
Birmingham, United Kingdom
| | - Morgan Cleasby
- Heartlands, Good Hope, and Solihull Hospitals, University
Hospitals Birmingham NHS Foundation Trust,
Birmingham, United Kingdom
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Substantial radiation dose reduction with consistent image quality using a novel low-dose stone composition protocol. World J Urol 2020; 38:2971-2979. [PMID: 31993735 DOI: 10.1007/s00345-020-03082-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Accepted: 01/06/2020] [Indexed: 10/25/2022] Open
Abstract
PURPOSE To assess a novel low-dose CT-protocol, combining a 150 kV spectral filtration unenhanced protocol (Sn150 kVp) and a stone-targeted dual-energy CT (DECT) in patients with urolithiasis. METHODS 232 (151 male, 49 ± 16.4 years) patients with urolithiasis received a low-dose non-contrast enhanced CT (NCCT) for suspected urinary stones either on a third-generation dual-source CT system (DSCT) using Sn150 kVp (n = 116, group 1), or on a second-generation DSCT (n = 116 group 2) using single energy (SE) 120 kVp. For group 1, a subsequent dual-energy CT (DECT) with a short stone-targeted scan range was performed. Objective and subjective image qualities were assessed. Radiation metrics were compared. RESULTS 534 stones (group 1: n = 242 stones; group 2: n = 292 stones) were found. In group 1, all 215 stones within the stone-targeted DECT-scan range were identified. DE analysis was able to distinguish between UA and non-UA calculi in all collected stones. 11 calculi (5.12%) were labeled as uric acid (UA) while 204 (94.88%) were labeled as non-UA calculi. There was no significant difference in overall Signal-to-noise-ratio between group 1 and group 2 (p = 0.819). On subjective analysis both protocols achieved a median Likert rating of 2 (p = 0.171). Mean effective dose was significantly lower for combined Sn150 kVp and stone-targeted DECT (3.34 ± 1.84 mSv) compared to single energy 120 kVp NCCT (4.45 ± 2.89 mSv) (p < 0.001), equaling a 24.9% dose reduction. CONCLUSION The evaluated novel low-dose stone composition protocol allows substantial radiation dose reduction with consistent high diagnostic image quality.
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15
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Hsiao CC, Chen PC, Kuo PC, Ho CH, Jao JC. Assessment of image quality and dose in contrast-enhanced head and neck CT angiography of New Zealand rabbit. JOURNAL OF X-RAY SCIENCE AND TECHNOLOGY 2020; 28:739-750. [PMID: 32597826 DOI: 10.3233/xst-200669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
BACKGROUND Although computed tomography (CT) is a powerful diagnostic imaging modality for diagnosing vascular diseases, it is some what risky to human health due to the high radiation dosage. Thus, CT vendors have developed low dose computed tomography (LDCT) aiming to solve this problem. Nowadays, LDCT has gradually become a main stream of CT examination. OBJECTIVE This study aimed to assess the feasibility of LDCTAin an animal model and compare the imaging features and doses in two clinical scanners. METHODS Twenty-two New Zealand rabbit head and neck CTA images pre- and post-contrast agent injection were performed using256-sliceand 64-slice CT scanners. The tube voltages used in the 256-slice and the 64-slice CTA were 70 kVp and 80 kVp, respectively. Quantitative images indices and radiation doses obtained from CTA in these two scanners were compared. RESULTS More neck arterial vessels could be visualized in multi-planar reconstruction (MPR) CTA on the 256-slice CT scanner than on the 64-slice CT scanner. After contrast agent injection, all observed neck arterial vessels had higher CT numbers in 256-slice CTA than in 64-slice CTA. There was no significant difference in contrast-to-noise (CNR) of CTA images between these two scanners. CT dose index (CTDI) and dose length product (DLP) for the 256-slice CTA were lower than those for the 64-slice CTA. CONCLUSIONS Low dose CTA of rabbits with 70 or 80 kVp is feasible in a 256-slice or a 64-slice CT scanner. The radiation dose from the 256-slice CTA was much lower than that from the 64-slice CTA with comparable SNR and CNR. The technique can be further applied in longitudinal monitoring of an animal stroke model in the future.
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Affiliation(s)
- Chia-Chi Hsiao
- Department of Radiology, Kaohsiung Veterans General Hospital, Taiwan, R.O.C
| | - Po-Chou Chen
- Department of Biomedical Engineering, I-Shou University, Taiwan, R.O.C
| | - Pei-Chi Kuo
- Department of Biomedical Engineering, I-Shou University, Taiwan, R.O.C
| | - Chih-Hao Ho
- Department of Medical Imaging, Taipei City Hospital (Yangming Branch), Taiwan, R.O.C
| | - Jo-Chi Jao
- Department of Medical Imaging and Radiological Sciences, College of Health Sciences, Kaohsiung Medical University, Taiwan, R.O.C
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Increased urinary bladder volume improves the detectability of urinary stones at the ureterovesical junction in non-enhanced computed tomography (NECT). Eur Radiol 2019; 29:6953-6964. [PMID: 31209621 DOI: 10.1007/s00330-019-06279-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 05/08/2019] [Accepted: 05/17/2019] [Indexed: 10/26/2022]
Abstract
OBJECTIVES To evaluate the influence of the urinary bladder volume on the detectability of urolithiasis at the ureterovesical junction (UVJ) using a low-dose CT (LD-CT) with iterative reconstruction (IR) and a standard-dose CT (SD-CT) without IR in a large cohort. METHODS Four hundred patients (278 males (69.5%), mean 44.6 ± 14.7 years) with urolithiasis at the UVJ were investigated either by an LD-CT with IR (n = 289, 72%) or an SD-CT without IR (n = 111, 28%) protocol. The detectability of distal urolithiasis was assessed by a dichotomous assessment (definite or questionable) by two radiologists in consensus and by a quantitative analysis of the signal density distribution across a line drawn parallel to the distal ureter. Based on the resulting graph, minimum/maximum density values and mean/maximum upslopes and downslopes were derived and calculated automatically. In all patients, the total bladder volume was calculated by a slice-by-slice approach on axial CT images. RESULTS Patients with definite stones showed significantly higher urinary bladder volumes compared to patients with questionable stones in both LD-CT and SD-CT (p < 0.01). These results were independent of stones' length and patients' BMI values. Using cutoffs of 92 ml for LD-CT and 69 ml for SD-CT, high positive predictive values/accuracy rates of 96%/85% (LD-CT) and 98%/86% (SD-CT) were observed to identify definite urinary stones. CONCLUSIONS Urinary bladder volume has a significant impact on the detectability of distal urolithiasis. Moderate bladder filling by pre-CT hydration with subsequent CT scan at the time of high urge to void increases the detectability of urinary stones at the UVJ in clinical routine. KEY POINTS • Urinary bladder volume significantly affects the detectability of distal urolithiasis • Higher bladder volumes are associated with improved detectability of distal urinary stones • Oral pre-CT hydration for urolithiasis is easily applicable and cost-effective.
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17
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Tzou DT, Zetumer S, Usawachintachit M, Taguchi K, Bechis SK, Duty BD, Harper JD, Hsi RS, Sorensen M, Sur RL, Reliford-Titus S, Chang HC, Isaacson D, Bayne DB, Wang ZJ, Stoller ML, Chi T. Computed Tomography Radiation Exposure Among Referred Kidney Stone Patients: Results from the Registry for Stones of the Kidney and Ureter. J Endourol 2019; 33:619-624. [PMID: 31030576 DOI: 10.1089/end.2019.0091] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Purpose: Kidney stone patients routinely have CT scans during diagnostic work-up before being referred to a tertiary center. How often these patients exceed the recommended dose limits for occupational radiation exposure of >100 mSv for 5 years and >50 mSv in a single year from CT alone remains unknown. This study aimed to quantify radiation doses from CTs received by stone patients before their evaluation at a tertiary care stone clinic. Methods: From November 2015 to March 2017, consecutive new patients enrolled into the Registry for Stones of the Kidney and Ureter (ReSKU™) had the dose-length product of every available CT abdomen/pelvis within 5 years of their initial visit recorded, allowing for an effective dose (EDose) calculation. Multivariate logistic regression analysis identified factors associated with exceeding recommended dose limits. Models were created to test radiation reducing effects of low-dose and phase-reduction CT protocols. Results: Of 343 noncontrast CTs performed, only 29 (8%) were low-dose CTs (calculated EDose <4 mSv). Among 389 total patients, 101 (26%) and 25 (6%) had an EDose >20 mSv and >50 mSv/year, respectively. Increased body mass index, number of scans, and multiphase scans were associated with exceeding exposure thresholds (p < 0.01). The implementation of a low-dose CT protocol decreased the estimated number of scans contributing to overexposure by >50%. Conclusions: Stone patients referred to a tertiary stone center may receive excessive radiation from CT scans alone. Unnecessary phases and underutilization of low-dose CT protocols continue to take place. Enacting new approaches to CT protocols may spare stone patients from exceeding recommended dose limits.
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Affiliation(s)
- David T Tzou
- 1 Department of Urology, University of California, San Francisco, San Francisco, California.,2 Division of Urology, Department of Surgery, University of Arizona College of Medicine, Tucson, Arizona
| | - Samuel Zetumer
- 1 Department of Urology, University of California, San Francisco, San Francisco, California
| | - Manint Usawachintachit
- 1 Department of Urology, University of California, San Francisco, San Francisco, California.,3 Division of Urology, Faculty of Medicine, King Chulalongkorn Memorial Hospital, Chulalongkorn University, The Thai Red Cross Society, Bangkok, Thailand
| | - Kazumi Taguchi
- 1 Department of Urology, University of California, San Francisco, San Francisco, California.,4 Department of Nephro-urology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Seth K Bechis
- 5 Department of Urology, University of California, San Diego, San Diego, California
| | - Brian D Duty
- 6 Department of Urology, Oregon Health & Science University, Portland, Oregon
| | - Jonathan D Harper
- 7 Department of Urology, University of Washington, Seattle, Washington
| | - Ryan S Hsi
- 8 Department of Urology, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Mathew Sorensen
- 7 Department of Urology, University of Washington, Seattle, Washington
| | - Roger L Sur
- 5 Department of Urology, University of California, San Diego, San Diego, California
| | | | - Helena C Chang
- 7 Department of Urology, University of Washington, Seattle, Washington
| | - Dylan Isaacson
- 1 Department of Urology, University of California, San Francisco, San Francisco, California
| | - David B Bayne
- 1 Department of Urology, University of California, San Francisco, San Francisco, California
| | - Zhen J Wang
- 9 Department of Radiology, University of California, San Francisco, San Francisco, California
| | - Marshall L Stoller
- 1 Department of Urology, University of California, San Francisco, San Francisco, California
| | - Thomas Chi
- 1 Department of Urology, University of California, San Francisco, San Francisco, California
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Dillman JR, Rigsby CK, Iyer RS, Alazraki AL, Anupindi SA, Brown BP, Chan SS, Dorfman SR, Falcone RA, Garber MD, Nguyen JC, Peters CA, Safdar NM, Trout AT, Karmazyn BK. ACR Appropriateness Criteria ® Hematuria-Child. J Am Coll Radiol 2019; 15:S91-S103. [PMID: 29724430 DOI: 10.1016/j.jacr.2018.03.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 03/04/2018] [Indexed: 02/01/2023]
Abstract
Hematuria is the presence of red blood cells in the urine, either visible to the eye (macroscopic hematuria) or as viewed under the microscope (microscopic hematuria). The clinical evaluation of children and adolescents with any form of hematuria begins with a meticulous history and thorough evaluation of the urine. The need for imaging evaluation depends on the clinical scenario in which hematuria presents, including the suspected etiology. Ultrasound and CT are the most common imaging methods used to assess hematuria in children, although other imaging modalities may be appropriate in certain instances. This review focuses on the following clinical variations of childhood hematuria: isolated hematuria (nonpainful, nontraumatic, and microscopic versus macroscopic), painful hematuria (ie, suspected nephrolithiasis or urolithiasis), and renal trauma with hematuria (microscopic versus macroscopic). The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.
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Affiliation(s)
| | - Jonathan R Dillman
- Principal Author, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio.
| | - Cynthia K Rigsby
- Panel Chair, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois
| | - Ramesh S Iyer
- Panel Vice Chair, Seattle Children's Hospital, Seattle, Washington
| | | | | | - Brandon P Brown
- Riley Hospital for Children Indiana University, Indianapolis, Indiana
| | | | | | - Richard A Falcone
- Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio; American Pediatric Surgical Association
| | - Matthew D Garber
- Wolfson Children's Hospital, Jacksonville, Florida; American Academy of Pediatrics
| | - Jie C Nguyen
- Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Craig A Peters
- UT Southwestern Medical Center, Dallas, Texas; Society for Pediatric Urology
| | | | - Andrew T Trout
- Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Boaz K Karmazyn
- Specialty Chair, Riley Hospital for Children Indiana University, Indianapolis, Indiana
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Comparison of Tin Filter-Based Spectral Shaping CT and Low-Dose Protocol for Detection of Urinary Calculi. AJR Am J Roentgenol 2019; 212:808-814. [PMID: 30673337 DOI: 10.2214/ajr.18.20154] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
OBJECTIVE The purpose of this study was to assess the performance of tin filter-based spectral shaping CT compared with routine low-dose CT for detection of urolithiasis. MATERIALS AND METHODS Unenhanced third-generation dual-source CT scans of 129 consecutively registered patients were retrospectively reviewed: 43 patients underwent CT for detection of renal stones with tin filtration (Sn150 kV); 43 patients underwent a routine low-dose CT protocol at 100 kV; and 43 patients underwent a routine CT protocol with automated tube potential selection (110-120 kV). Image quality was evaluated subjectively and objectively. Volume CT dose index (CTDIvol) and size-specific dose estimate (SSDE) were recorded. To prospectively compare the performances of the spectral shaping protocol (Sn150 kV) with the standard (120 kV) and routine low-dose (100 kV) protocols, a phantom (sheep kidneys) containing stones were also scanned with each protocol and evaluated by two radiologists. RESULTS CT with tin filtration resulted in 28% and 66% reduction in CTDIvol compared with CT performed with routine low-dose and standard-dose protocols (p < 0.05). Accordingly, it also led to 24% and 55% reduction in SSDE compared with the low-dose and standard protocols (p < 0.05). Subjective image quality and signal-to-noise ratio were similar between the tin filtration and the routine low-dose groups (p > 0.05). The objective image noise was similar in the three groups (p > 0.05). The phantom study showed no difference in detection of renal stones between the three tube potential settings. CONCLUSION Using spectral shaping with tin filtration can substantially reduce radiation dose compared with routine standard- and low-dose abdominal CT for urinary stone disease.
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20
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Chang DH, Slebocki K, Khristenko E, Herden J, Salem J, Große Hokamp N, Mammadov K, Hellmich M, Kabbasch C. Low-dose computed tomography of urolithiasis in obese patients: a feasibility study to evaluate image reconstruction algorithms. Diabetes Metab Syndr Obes 2019; 12:439-445. [PMID: 31114274 PMCID: PMC6497819 DOI: 10.2147/dmso.s198641] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 02/07/2019] [Indexed: 12/12/2022] Open
Abstract
Purpose: Retrospective evaluation and comparison of image quality generated by low-dose computed tomography (LDCT) from obese patients with urolithiasis using alternative reconstruction algorithms. Materials and methods: Twenty-five obese patients (body mass index [BMI]>25 kg/m2) underwent LDCT scans for suspected urolithiasis. The scans were recompiled using filtered-back projection (FBP), statistical iterative reconstruction (iDose) and iterative model-based reconstruction (IMR). Dose-length product (DLP) and patient details were obtained from the CT dose report and clinical charts, respectively. Objective image noise was assessed by measuring the SD of Hounsfield units (HUs) in defined locations. Additionally, subjective image evaluation was independently performed by two radiologists using a 3-point Likert scale. The inter-reviewer agreement of image quality was calculated. Results: Ureteral concretions were observed in all CT scans, two of which revealed bilateral stones. The assessed patients' mean BMI was 29.29±3.74 kg/m2, and the DLP of the CT scans was 100.04±10.00 mGy*cm. All scans were rated diagnostic with the iDose and iterative model-based reconstructions, whereas 41% of the scans performed with FBP reconstruction were nondiagnostic. With respect to image quality, IMR was superior to iDose and FBP, both in the objective (P<0.001) and overall subjective (P≤0.008) evaluation of the respective data sets. The inter-reviewer agreement for overall image quality was "almost perfect" for IMR, "substantial" for iDose and "moderate" for FBP (κ values of 1.0, 0.6 and 0.46, respectively). Conclusion: Using iterative image reconstruction algorithms, LDCT of urolithiasis is feasible in overweight patients with a BMI between 25 and 35 kg/m2. Due to higher image quality, IMR is the preferred algorithm for scan reconstruction as it may help to avoid repeated examinations due to initial nondiagnostic scans.
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Affiliation(s)
- De-Hua Chang
- Department of Diagnostic and Interventional Radiology, University Medical Center Heidelberg, Heidelberg, Germany
- Correspondence: De-Hua ChangIm Neuenheimer Feld 110, Heidelberg69120, GermanyEmail
| | - Karin Slebocki
- Department of Diagnostic and Interventional Radiology, University Hospital of Cologne, Cologne, Germany
| | - Ekaterina Khristenko
- Department of Diagnostic and Interventional Radiology, University Medical Center Heidelberg, Heidelberg, Germany
| | - Jan Herden
- Department of Urology, University Hospital of Cologne, Cologne, Germany
| | - Johannes Salem
- Department of Urology, University Hospital of Cologne, Cologne, Germany
| | - Nils Große Hokamp
- Department of Diagnostic and Interventional Radiology, University Hospital of Cologne, Cologne, Germany
| | - Kamal Mammadov
- Department of Diagnostic and Interventional Radiology, University Hospital of Cologne, Cologne, Germany
| | - Martin Hellmich
- Institute of Medical Statistics and Computational Biology (IMSB), Medical Faculty, University of Cologne, Cologne, Germany
| | - Christoph Kabbasch
- Department of Diagnostic and Interventional Radiology, University Hospital of Cologne, Cologne, Germany
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Effective Radiation Dose Reduction in Computed Tomography With Iterative Reconstruction in Patients With Urinary Stone. J Comput Assist Tomogr 2019; 43:877-883. [DOI: 10.1097/rct.0000000000000921] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Zhou Y, Liu D, Hou P, Zha KJ, Wang F, Zhou K, He W, Gao JB. Low-dose spectral insufflation computed tomography protocol preoperatively optimized for T stage esophageal cancer - preliminary research experience. World J Gastroenterol 2018; 24:4197-4207. [PMID: 30271084 PMCID: PMC6158477 DOI: 10.3748/wjg.v24.i36.4197] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 07/28/2018] [Accepted: 08/24/2018] [Indexed: 02/06/2023] Open
Abstract
AIM To evaluate the T stage of esophageal squamous cell carcinoma (ESCC) using preoperative low-dose esophageal insufflation computed tomography (EICT).
METHODS One hundred and twenty ESCC patients confirmed by surgery or esophagoscopy were divided into three groups. Groups B and C were injected with 300 mgI/kg contrast medium for automatic spectral imaging assist (GSI assist), while group A underwent a conventional 120 kVp computed tomography (CT) scan with a 450 mgI/kg contrast medium injection. EICT was performed in group C. Group A was reconstructed with filtered back projection, and groups B and C were reconstructed with 50% adaptive statistical iterative reconstruction. The contrast-to-noise ratio of lesion-to-mediastinal adipose tissue and the radiation dose were measured. Specific imaging features were observed, and T stage ESCCs were evaluated.
RESULTS The sensitivity and accuracy of the T1/2 stage were higher in group C than in groups A and B (sensitivity: 43.75% vs 31.82% and 33.33%; accuracy: 54.29% vs 46.67% and 52.50%, respectively). With regard to the T3 stage, the sensitivity and specificity in group C were higher than those in groups A and B (sensitivity: 56.25% vs 41.17% and 44.44%; specificity: 73.68% vs 67.86% and 63.64%, respectively). The diagnostic sensitivity, specificity and accuracy of the T4 stage were similar among all groups. There were no significant differences in volume CT dose index [(5.91 ± 2.57) mGy vs (3.24 ± 1.20) vs (3.65 ± 1.77) mGy], dose-length product [(167.10 ± 99.08) mGy•cm vs (113.24 ± 54.46) mGy•cm vs (117.98 ± 32.32) mGy•cm] and effective dose [(2.52 ± 1.39) vs (1.63 ± 0.76) vs (1.73 ± 0.44) mSv] among the groups (P > 0.05). However, groups B and C received similar effective doses but lower iodine loads than group A [(300 vs 450) mgI/kg].
CONCLUSION EICT combined with GSI assist allows differential diagnosis between the T1/2 and T3 stages. The ability to differentially diagnose the T3 and T4 stages of medullary ESCC can be improved by quantitatively and qualitatively analyzing the adipose tissue in front of the vertebral body.
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Affiliation(s)
- Yue Zhou
- Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan Province, China
| | - Dan Liu
- Department of Gastroenterology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan Province, China
| | - Ping Hou
- Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan Province, China
| | - Kai-Ji Zha
- Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan Province, China
| | - Feng Wang
- Department of Oncology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan Province, China
| | - Kun Zhou
- Department of Thoracic Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan Province, China
| | - Wei He
- Department of Oncology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan Province, China
| | - Jian-Bo Gao
- Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan Province, China
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Image Quality and Patient-Specific Organ Doses in Stone Protocol CT: A Comparison of Traditional CT to Low Dose CT with Iterative Reconstruction. BIOMED RESEARCH INTERNATIONAL 2018; 2018:5120974. [PMID: 30363655 PMCID: PMC6181004 DOI: 10.1155/2018/5120974] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 09/16/2018] [Indexed: 02/03/2023]
Abstract
Objective To compare organ specific radiation dose and image quality in kidney stone patients scanned with standard CT reconstructed with filtered back projection (FBP-CT) to those scanned with low dose CT reconstructed with iterative techniques (IR-CT). Materials and Methods Over a one-year study period, adult kidney stone patients were retrospectively netted to capture the use of noncontrasted, stone protocol CT in one of six institutional scanners (four FBP and two IR). To limit potential CT-unit use bias, scans were included only from days when all six scanners were functioning. Organ dose was calculated using volumetric CT dose index and patient effective body diameter through validated conversion equations derived from previous cadaveric, dosimetry studies. Board-certified radiologists, blinded to CT algorithm type, assessed stone characteristics, study noise, and image quality of both techniques. Results FBP-CT (n=250) and IR-CT (n=90) groups were similar in regard to gender, race, body mass index (mean BMI = 30.3), and stone burden detected (mean size 5.4 ± 1.2 mm). Mean organ-specific dose (OSD) was 54-62% lower across all organs for IR-CT compared to FBP-CT with particularly reduced doses (up to 4.6-fold) noted in patients with normal BMI range. No differences were noted in radiological assessment of image quality or noise between the cohorts, and intrarater agreement was highly correlated for noise (AC2=0.873) and quality (AC2=0.874) between blinded radiologists. Conclusions Image quality and stone burden assessment were maintained between standard FBP and low dose IR groups, but IR-CT decreased mean OSD by 50%. Both urologists and radiologists should advocate for low dose CT, utilizing reconstructive protocols like IR, to reduce radiation exposure in their stone formers who undergo multiple CTs.
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Jeong YJ, Choo KS, Nam KJ, Lee JW, Kim JY, Jung HJ, Lim SJ. Image quality and radiation dose of CT venography with double dose reduction using model based iterative reconstruction: comparison with conventional CT venography using filtered back projection. Acta Radiol 2018; 59:546-552. [PMID: 28766981 DOI: 10.1177/0284185117725780] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Background Computed tomography venography (CTV) at low kVp using model-based iterative reconstruction (MBIR) can enhance vascular enhancement with noise reduction. Purpose To evaluate image qualities and radiation doses of CTV at 80 kVp using MBIR and a small iodine contrast media (CM) dose and to compare these with those of CTV performed using a conventional protocol. Material and Methods Sixty-five patients (mean age = 58.1 ± 7.2 years) that underwent CTV for the evaluation of deep vein thrombosis (DVT) and varicose veins were enrolled in this study. Patients were divided into two groups: Group A (35 patients, 80 kVp, MBIR, automatic tube current modulation, CM = 270 mg/mL, 100 mL) and Group B (30 patients, 100 kVp, filtered back projection [FBP], 120 fixed mA, CM = 370 mg/mL, 120 mL). Objective and subjective image qualities of inferior vena cava (IVC), femoral vein (FV), and popliteal vein (PV) were assessed and radiation doses were recorded. Results Mean vascular enhancement in group A was significantly lower than in group B ( P < 0.01). Noise in group A was significantly lower than in group B except for PV and contrast-to-noise ratio were not significantly different in the two groups ( P > 0.05). In addition, radiation dose in group A was significantly lower than in group B ( P < 0.001). Subjective image quality comparison revealed group A was statistically inferior to group B except for subjective image noise. Conclusion CTV at 80 kVp using MBIR with small iodine contrast dose provided acceptable image quality at a lower radiation dose than conventional CTV using FBP.
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Affiliation(s)
- Yeo-Jin Jeong
- Department of Radiology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Hospital, Busan, Republic of Korea
| | - Ki Seok Choo
- Department of Radiology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Hospital, Busan, Republic of Korea
| | - Kyung Jin Nam
- Department of Radiology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Hospital, Busan, Republic of Korea
| | - Ji Won Lee
- Department of Radiology, Pusan National University Hospital, Pusan National University School of Medicine, Busan, Republic of Korea
| | - Jin You Kim
- Department of Radiology, Pusan National University Hospital, Pusan National University School of Medicine, Busan, Republic of Korea
| | - Hyuk Jae Jung
- Department of Vascular surgery, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Busan, Republic of Korea
| | - Soo Jin Lim
- Department of Cardiology, Kim Hae Gang-il Hospital, KyoungNam, Republic of Korea
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Li X, Shu H, Zhang Y, Li X, Song J, Du J, Qian Y, Liu B, Yu Y. Low-dose CT with adaptive statistical iterative reconstruction for evaluation of urinary stone. Oncotarget 2018; 9:20103-20111. [PMID: 29732006 PMCID: PMC5929449 DOI: 10.18632/oncotarget.25047] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 03/24/2018] [Indexed: 11/25/2022] Open
Abstract
Purpose To prospectively determine the diagnostic performance of low-dose CT (LDCT) with adaptive statistical iterative reconstruction (ASIR) technique for the detection of urinary stone disease. Results The average DLP and ED was 408.16 ± 119.04 mGy and 6.12 ± 1.79 mSv in CDCT, and 138.19 ± 76.87 mGy and 2.07 ± 1.15 mSv in LDCT, respectively. The dose reduction rate of LDCT was nearly 66.1% for both DLP and ED (P < 0.05). LDCT–80% ASIR images showed great image quality (mean score = 4.09), which was similar to CDCT-FBP images (mean score = 4.17) (P > 0.05), but higher than LDCT-FBP images (mean score = 2.77) (P < 0.05). Materials and Methods 70 consetutive patients with clinically suspected urolithiasis underwent non-enhanced CT. Followed by both conventional-dose CT (CDCT) and low-dose CT (LDCT) scans. Automatic tube current modulation (ATCM) scanning was used, with a noise index setting of 13 in CDCT and 25 in LDCT. Reconstructions were performed with filtered back projection (FBP) and different settings of adaptive statistical iterative reconstruction [ASIR(40%, 60%, 80%)]. Urinary calculi (size, location, number), image quality (scale 1–5), image noise (scale 1–3) and diagnostic confidence levels (scale 1–3) were evaluated and measured by two radiologists independently. Radiation dose was recorded by calculating dose length product (DLP) and effective dose (ED). Statistical analyses included Mann-Whitney U test and Paired t tests. Conclusions LDCT with ASIR can reduce the radiation dose while maintain relatively high image quality in the diagnosis of urinary stone diseases.
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Affiliation(s)
- Xiaohu Li
- Department of Radiology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Hongmin Shu
- Department of Radiology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Yifei Zhang
- Department of Urology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Xiaoshu Li
- Department of Radiology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Jian Song
- Department of Radiology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Junhua Du
- Department of Urology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Yinfeng Qian
- Department of Radiology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Bin Liu
- Department of Radiology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Yongqiang Yu
- Department of Radiology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
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Low-Dose CT for Evaluation of Suspected Urolithiasis: Diagnostic Yield for Assessment of Alternative Diagnoses. AJR Am J Roentgenol 2018; 210:557-563. [DOI: 10.2214/ajr.17.18552] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Wang T, Gong Y, Shi Y, Hua R, Zhang Q. Feasibility of dual-low scheme combined with iterative reconstruction technique in acute cerebral infarction volume CT whole brain perfusion imaging. Exp Ther Med 2017; 14:163-168. [PMID: 28672909 PMCID: PMC5488643 DOI: 10.3892/etm.2017.4451] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 03/27/2017] [Indexed: 12/22/2022] Open
Abstract
The feasibility of application of low-concentration contrast agent and low tube voltage combined with iterative reconstruction in whole brain computed tomography perfusion (CTP) imaging of patients with acute cerebral infarction was investigated. Fifty-nine patients who underwent whole brain CTP examination and diagnosed with acute cerebral infarction from September 2014 to March 2016 were selected. Patients were randomly divided into groups A and B. There were 28 cases in group A [tube voltage, 100 kV; contrast agent, iohexol (350 mg I/ml), reconstructed by filtered back projection] and 31 cases in group B [tube voltage, 80 kV; contrast agent, iodixanol (270 mg I/ml), reconstructed by algebraic reconstruction technique]. The artery CT value, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), dose length product, effective dose (ED) of radiation and brain iodine intake of both groups were measured and statistically analyzed. Two physicians carried out kappa (κ) analysis on the consistency of image quality evaluation. The difference in subjective image quality evaluation between the groups was tested by χ2. The differences in CT value, SNR, CNR, CTP and CT angiography subjective image quality evaluation between both groups were not statistically significant (P>0.05); the diagnosis rate of the acute infarcts between the two groups was not significantly different; while the ED and iodine intake in group B (dual low-dose group) were lower than group A. In conclusion, combination of low tube voltage and iterative reconstruction technique, and application of low-concentration contrast agent (270 mg I/ml) in whole brain CTP examination reduced ED and iodine intake without compromising image quality, thereby reducing the risk of contrast-induced nephropathy.
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Affiliation(s)
- Tao Wang
- CT Room, Xuzhou Central Hospital, Xuzhou, Jiangsu 221009, P.R. China
| | - Yi Gong
- Department of Ultrasound, Xuzhou Central Hospital, Xuzhou, Jiangsu 221009, P.R. China
| | - Yibing Shi
- CT Room, Xuzhou Central Hospital, Xuzhou, Jiangsu 221009, P.R. China
| | - Rong Hua
- CT Room, Xuzhou Central Hospital, Xuzhou, Jiangsu 221009, P.R. China
| | - Qingshan Zhang
- Department of Neurology, Xuzhou Central Hospital, Xuzhou, Jiangsu 221009, P.R. China
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Soenen O, Balliauw C, Oyen R, Zanca F. Dose and Image Quality in Low-dose CT for Urinary Stone Disease: Added Value of Automatic Tube Current Modulation and Iterative Reconstruction Techniques. RADIATION PROTECTION DOSIMETRY 2017; 174:242-249. [PMID: 27247446 DOI: 10.1093/rpd/ncw133] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Accepted: 05/06/2016] [Indexed: 06/05/2023]
Abstract
The aim of this study was to compare dose and image quality (IQ) of a baseline low-dose computed tomography (CT) (fix mAs) vs. an ultra-low-dose CT (automatic tube current modulation, ATCM) in patients with suspected urinary stone disease and to assess the added value of iterative reconstruction. CT examination was performed on 193 patients (103 baseline low-dose, 90 ultra-low-dose). Filtered back projection (FBP) was used for both protocols, and Sinogram Affirmed Iterative Reconstruction (SAFIRE) was used for the ultra-low-dose protocol only. Dose and ureter stones information were collected for both protocols. Subjective IQ was assessed by two radiologists scoring noise, visibility of the ureter and overall IQ. Objective IQ (contrast-to-noise ratio, CNR) was assessed for the ultra-low-dose protocol only (FBP and SAFIRE). The ultra-low-dose protocol (ATCM) showed a 22% decrease in mean effective dose (p < 0.001) and improved visibility of the pelvic ureter (p = 0.02). CNR was higher for SAFIRE (p < 0.0001). SAFIRE improves the objective IQ, but not the subjective IQ for the chosen clinical task.
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Affiliation(s)
- Olivier Soenen
- Department of Radiology, University Hospitals Leuven, KU Leuven, Herestraat 49, B-3000 Leuven, Belgium
| | - Christophe Balliauw
- Department of Radiology, University Hospitals Leuven, KU Leuven, Herestraat 49, B-3000 Leuven, Belgium
| | - Raymond Oyen
- Department of Radiology, University Hospitals Leuven, KU Leuven, Herestraat 49, B-3000 Leuven, Belgium
- Department of imaging and Pathology, University Hospitals Leuven, KU Leuven, Herestraat 49, B-3000 Leuven, Belgium
| | - Federica Zanca
- Department of Radiology, University Hospitals Leuven, KU Leuven, Herestraat 49, B-3000 Leuven, Belgium
- Department of imaging and Pathology, University Hospitals Leuven, KU Leuven, Herestraat 49, B-3000 Leuven, Belgium
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Tenant S, Pang CL, Dissanayake P, Vardhanabhuti V, Stuckey C, Gutteridge C, Hyde C, Roobottom C. Intra-patient comparison of reduced-dose model-based iterative reconstruction with standard-dose adaptive statistical iterative reconstruction in the CT diagnosis and follow-up of urolithiasis. Eur Radiol 2017; 27:4163-4172. [DOI: 10.1007/s00330-017-4783-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 02/13/2017] [Accepted: 02/16/2017] [Indexed: 01/24/2023]
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Gervaise A, Teixeira P, Hossu G, Blum A, Lapierre-Combes M. Optimizing z-axis coverage of abdominal CT scans of the urinary tract: a proposed alternative proximal landmark for acquisition planning. Br J Radiol 2016; 89:20160197. [PMID: 27653843 DOI: 10.1259/bjr.20160197] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE To evaluate an alternative method to reduce the acquisition coverage of urinary tract CT. METHODS This retrospective study included 365 abdominopelvic CT studies. Three radiographers simulated shortened acquisition coverages using three methods to determine the upper limit of the acquisition: Method 1 used the renal contours; Method 2 used the inferior margin of the 10th thoracic vertebra; and Method 3 used the point of intersection of the left diaphragmatic dome and the anterior margin of the vertebral bodies. Reductions in acquisition coverage and number of CT scans with a portion of the kidney excluded from the simulated reduced acquisition were compared between the three methods. RESULTS The mean ± standard deviation reduction of acquisition coverage for the three readers with Methods 1, 2 and 3 were 20.5 ± 4.8, 15.1 ± 6.5 and 18.2 ± 5.3%, respectively. Compared with Method 2, Method 3 allowed a mean scan length reduction of 3.6%. The proportions of CT scans with a portion of the kidney excluded from the simulated reduced acquisition with Methods 1, 2 and 3 and averaged over the three readers were 6.7, 0.7 and 1.4%, respectively, with no significant difference between Methods 2 and 3. Interreader and intrareader agreements were excellent with all methods, but interclass correlation coefficients were higher with Method 3. CONCLUSION The method using the renal contours should not be used owing to its high proportion of kidneys with a portion excluded from the acquisition. Using the intersection of the left diaphragmatic dome and the anterior margin of the vertebral bodies for proximal landmark for urinary tract CT represents a new alternative method with a better reduction of scan length compared with the method using the inferior margin of T10 and with no significant increase in the number of kidneys with a portion excluded from the reduced acquisition. Advances in knowledge: A new method using the point of intersection of the left diaphragmatic dome and the anterior border of the vertebral bodies on the lateral scout radiograph is introduced to reduce the z-axis coverage of urinary tract CT scans.
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Affiliation(s)
- Alban Gervaise
- 1 Service d'Imagerie Médicale, HIA Legouest, Metz, France.,2 Service d'Imagerie Guilloz, Hôpital Central, CHRU Nancy, Nancy, France.,3 U947, INSERM, Nancy, France.,4 IADI, Université de Lorraine, Nancy, France
| | - Pedro Teixeira
- 2 Service d'Imagerie Guilloz, Hôpital Central, CHRU Nancy, Nancy, France.,3 U947, INSERM, Nancy, France.,4 IADI, Université de Lorraine, Nancy, France
| | - Gabriela Hossu
- 5 CIC-IT 1433, INSERM, Nancy, France.,6 Pôle S2R, CHRU Nancy, Nancy, France.,7 CIC-IT, Université de Lorraine, Nancy, France
| | - Alain Blum
- 2 Service d'Imagerie Guilloz, Hôpital Central, CHRU Nancy, Nancy, France
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Prospective Comparison of Reduced-Iodine-Dose Virtual Monochromatic Imaging Dataset From Dual-Energy CT Angiography With Standard-Iodine-Dose Single-Energy CT Angiography for Abdominal Aortic Aneurysm. AJR Am J Roentgenol 2016; 207:W125-W132. [PMID: 27610820 DOI: 10.2214/ajr.15.15814] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
OBJECTIVE The purpose of this study was to compare the image quality of reduced-iodine-dose single-source dual-energy CT angiography (CTA) with that of standard-iodine-dose single-energy CTA in examinations of patients with abdominal aortic aneurysm and to assess the effect of the concentration of iodinated contrast medium on intravascular enhancement and image quality of reduced-iodine-dose CTA. SUBJECTS AND METHODS In a prospective randomized clinical trial, 66 consecutively registered patients with abdominal aortic aneurysm who had previously undergone single-energy CTA (30-37 g I) underwent follow-up CTA at a reduced dose (21-27 g I) of iodinated contrast medium of either 270 mg I/mL (n = 33) or 320 mg I/mL (n = 33). Two readers independently evaluated virtual monochromatic imaging datasets (40-140 keV) and single-energy CTA images for image quality and noise and their preference for optimal energy virtual monochromatic imaging dataset. A value of p < 0.05 was considered statistically significant. RESULTS All 66 dual-energy CTA examinations were rated diagnostic with mean image quality and image noise scores of 4.8 and 4.5 for reader 1 and 3.8 and 3.4 for reader 2 compared with single-energy CTA results of 4.5 and 4.2 for reader 1 and 4.5 and 4.1 for reader 2. Low-energy virtual monochromatic images (40-60 keV) from reduced-iodine-dose (28%) dual-energy CTA had significantly higher intravascular aortic attenuation (26-185%) and contrast-to-noise ratio (CNR) (20-25%) than standard-iodine-dose single-energy CTA images (p < 0.0001). No significant difference was found between patients who received 270 and those who received 320 mg I/mL with respect to intravascular aortic attenuation (p = 0.6331) or CNR (p = 0.9775). CONCLUSION Low-energy virtual monochromatic imaging datasets from reduced-iodine (24 g I) single-source dual-energy CTA of the abdomen provide up to 185% higher attenuation and 25% higher CNR than standard-iodine-dose (33.3 g I) single-energy CTA while offering a wide range of energy settings irrespective of the concentration of IV contrast medium used.
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Park SB, Kim YS, Lee JB, Park HJ. Knowledge-based iterative model reconstruction (IMR) algorithm in ultralow-dose CT for evaluation of urolithiasis: evaluation of radiation dose reduction, image quality, and diagnostic performance. ACTA ACUST UNITED AC 2016. [PMID: 26197735 DOI: 10.1007/s00261-015-0504-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
PURPOSE To evaluate the efficacy of a knowledge-based iterative model reconstruction (IMR) algorithm for reducing image noise in ultralow-dose (ULD) CT for urolithiasis. MATERIALS AND METHODS A total of 103 patients diagnosed with urinary stones (n = 276) were enrolled. Regular dose (RD) scans (120 kV and 150 mAs, maximal tube current in dose modulation) were reconstructed using filtered back-projection (FBP, RD-FBP), and ULD scans (100 kV and 20 mAs, fixed tube current) were reconstructed with FBP (ULD-FBP), statistical iterative reconstruction (IR; ULD-iDose), and a knowledge-based IMR algorithm (ULD-IMR). Prospective interpretations of the two scans were performed with respect to radiation dose, objective image noise, and subjective assessment. The subjective assessment was also evaluated with regard to each patient's body mass index (BMI, < 25 or ≥ 25 kg/m(2)). Using RD CT (RD-FBP) as the reference standard, two reviewers assessed the diagnostic performance and inter-observer agreement for ULD-IMR. RESULT The average effective doses with RD CT and ULD CT were 8.31 and 0.68 mSv, respectively, and the average radiation dose reduction rate was 91.82% (p < 0.01). The lowest objective image noise was observed with ULD-IMR (p < 0.01). Subjective assessment in ULD-IMR was comparable to that of RD-FBP, although RD-FBP remained statistically superior. For BMI, there was a statistically significant difference in subjective image quality between the normal (4.7 ± 0.54) and overweight or obese groups (4.2 ± 0.5) (p < 0.05). The ULD-IMR showed a greater than 75% concordant rate in overall stones and 100% in ureter stones larger than 3 mm. However, for stones <3 mm, neither reviewer had a good detection rate (45.5% and 56.9% for the general and genitourinary radiologist, respectively). Inter-observer agreement was almost perfect (κ = 0.82). CONCLUSION Despite a significant radiation dose reduction, ULD-IMR images were comparable in image quality and noise to RD-FBP images. Furthermore, the diagnostic performance of the ULD non-enhanced CT protocol was comparable to that of the RD scan for diagnosing urinary stones larger than 3 mm.
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Affiliation(s)
- Sung Bin Park
- Department of Radiology, Chung-Ang University Hospital, Chung-Ang University College of Medicine, 102, Heukseok-ro, Dongjak-gu, Seoul, 156-755, Korea.
| | - Yang Soo Kim
- Department of Radiology, Chung-Ang University Hospital, Chung-Ang University College of Medicine, 102, Heukseok-ro, Dongjak-gu, Seoul, 156-755, Korea
| | - Jong Beum Lee
- Department of Radiology, Chung-Ang University Hospital, Chung-Ang University College of Medicine, 102, Heukseok-ro, Dongjak-gu, Seoul, 156-755, Korea
| | - Hyun Jeong Park
- Department of Radiology, Chung-Ang University Hospital, Chung-Ang University College of Medicine, 102, Heukseok-ro, Dongjak-gu, Seoul, 156-755, Korea
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Park JH, Kim B, Kim MS, Kim HJ, Ko Y, Ahn S, Karul M, Fletcher JG, Lee KH. Comparison of filtered back projection and iterative reconstruction in diagnosing appendicitis at 2-mSv CT. Abdom Radiol (NY) 2016; 41:1227-36. [PMID: 27315093 DOI: 10.1007/s00261-015-0632-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
PURPOSE To compare radiologists' diagnostic performance and confidence, and subjective image quality between filtered back projection (FBP) and iterative reconstruction (IR) at 2-mSv appendiceal CT. METHODS The institutional review board approved this retrospective study and waived the requirement for informed consent. We included 107 adolescents and young adults (age, 29.8 ± 8.5 years; 64 females) undergoing 2-mSv CT for suspected appendicitis. Appendicitis was pathologically confirmed in 42 patients. Seven readers with different experience levels independently reviewed the CT images reconstructed using FBP and IR (iDose(4), Philips). They rated both the likelihood of appendicitis and subjective image quality on 5-point Likert scales. Diagnostic confidence was assessed using the likelihood of appendicitis, proportion of indeterminate interpretations, and 3-point normal appendix visualization score. We used receiver operating characteristic analyses, Wilcoxon's signed-rank tests, and McNemar's tests. RESULTS The pooled area under the receiver operating characteristic curve (AUC) was 0.96 for both FBP and IR (95% CI for the difference, -0.02, 0.02; P = 0.73). The AUC difference was not significant in any of the individual readers (P ≥ 0.21). For the majority of the readers, the diagnostic confidence was not significantly different between the two reconstruction methods. Subjective image quality tended to be higher with IR for all readers (P ≤ 0.70), showing significant differences for four readers (P ≤ 0.040). CONCLUSION When diagnosing appendicitis at 2-mSv CT in adolescents and young adults, FBP and IR were comparable in radiologists' diagnostic performance and confidence while IR exhibited higher subjective image quality than FBP.
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Hsi RS, Stoller ML, Miller NL. Ultrasonography is an Adequate Initial Screening Test for Urinary Calculi. J Urol 2016; 196:645-7. [PMID: 27312317 DOI: 10.1016/j.juro.2016.06.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/10/2016] [Indexed: 10/21/2022]
Affiliation(s)
- Ryan S Hsi
- Department of Urology, University of California, San Francisco, San Francisco, California
| | - Marshall L Stoller
- Department of Urology, University of California, San Francisco, San Francisco, California
| | - Nicole L Miller
- Department of Urologic Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
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Bernstein AL, Dhanantwari A, Jurcova M, Cheheltani R, Naha PC, Ivanc T, Shefer E, Cormode DP. Improved sensitivity of computed tomography towards iodine and gold nanoparticle contrast agents via iterative reconstruction methods. Sci Rep 2016; 6:26177. [PMID: 27185492 PMCID: PMC4868985 DOI: 10.1038/srep26177] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 04/27/2016] [Indexed: 01/13/2023] Open
Abstract
Computed tomography is a widely used medical imaging technique that has high spatial and temporal resolution. Its weakness is its low sensitivity towards contrast media. Iterative reconstruction techniques (ITER) have recently become available, which provide reduced image noise compared with traditional filtered back-projection methods (FBP), which may allow the sensitivity of CT to be improved, however this effect has not been studied in detail. We scanned phantoms containing either an iodine contrast agent or gold nanoparticles. We used a range of tube voltages and currents. We performed reconstruction with FBP, ITER and a novel, iterative, modal-based reconstruction (IMR) algorithm. We found that noise decreased in an algorithm dependent manner (FBP > ITER > IMR) for every scan and that no differences were observed in attenuation rates of the agents. The contrast to noise ratio (CNR) of iodine was highest at 80 kV, whilst the CNR for gold was highest at 140 kV. The CNR of IMR images was almost tenfold higher than that of FBP images. Similar trends were found in dual energy images formed using these algorithms. In conclusion, IMR-based reconstruction techniques will allow contrast agents to be detected with greater sensitivity, and may allow lower contrast agent doses to be used.
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Affiliation(s)
| | | | - Martina Jurcova
- Department of Radiology, University of Pennsylvania, 3400 Spruce St, 1 Silverstein, Philadelphia, PA 19104, USA
| | - Rabee Cheheltani
- Department of Radiology, University of Pennsylvania, 3400 Spruce St, 1 Silverstein, Philadelphia, PA 19104, USA
| | - Pratap Chandra Naha
- Department of Radiology, University of Pennsylvania, 3400 Spruce St, 1 Silverstein, Philadelphia, PA 19104, USA
| | | | | | - David Peter Cormode
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
- Department of Radiology, University of Pennsylvania, 3400 Spruce St, 1 Silverstein, Philadelphia, PA 19104, USA
- Division of Cardiovascular Medicine, University of Pennsylvania, Philadelphia, PA, USA
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Gervaise A, Gervaise-Henry C, Pernin M, Naulet P, Junca-Laplace C, Lapierre-Combes M. How to perform low-dose computed tomography for renal colic in clinical practice. Diagn Interv Imaging 2016; 97:393-400. [DOI: 10.1016/j.diii.2015.05.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Revised: 05/12/2015] [Accepted: 05/19/2015] [Indexed: 01/09/2023]
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Half-dose non-contrast CT in the investigation of urolithiasis: image quality improvement with third-generation integrated circuit CT detectors. ACTA ACUST UNITED AC 2016; 40:1255-62. [PMID: 25296996 DOI: 10.1007/s00261-014-0264-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
PURPOSE The objective of this study is to establish the effect of third-generation integrated circuit (IC) CT detector on objective image quality in full- and half-dose non-contrast CT of the urinary tract. METHODS 51 consecutive patients with acute renal colic underwent non-contrast CT of the urinary tract using a 128-slice dual-source CT before (n = 24) and after (n = 27) the installation of third-generation IC detectors. Half-dose images were generated using projections from detector A using the dual-source RAW data. Objective image noise in the liver, spleen, right renal cortex, and right psoas muscle was compared between DC and IC cohorts for full-dose and half-dose images reconstructed with FBP and IR algorithms using 1 cm(2) regions of interest. Presence and size of obstructing ureteric calculi were also compared for full-dose and half-dose reconstructions using DC and IC detectors. RESULTS No statistical difference in age and lateral body size was found between patients in the IC and DC cohorts. Radiation dose, as measured by size-specific dose estimates, did not differ significantly either between the two cohorts (10.02 ± 4.54 mGy IC vs. 12.28 ± 7.03 mGy DC). At full dose, objective image noise was not significantly lower in the IC cohort as compared to the DC cohort for the liver, spleen, and right psoas muscle. At half dose, objective image noise was lower in the IC cohort as compared to DC cohort at the liver (21.32 IC vs. 24.99 DC, 14.7% decrease, p < 0.001), spleen (19.33 IC vs. 20.83 DC, 7.20% decrease, p = 0.02), and right renal cortex (20.28 IC vs. 22.98 DC, 11.7% decrease, p = 0.005). Mean obstructing ureteric calculi size was not significantly different when comparison was made between full-dose and half-dose images, regardless of detector type (p > 0.05 for all comparisons). CONCLUSIONS Third-generation IC detectors result in lower objective image noise at full- and half-radiation dose levels as compared with traditional DC detectors. The magnitude of noise reduction was greater at half-radiation dose indicating that the benefits of using novel IC detectors are greater in low and ultra-low-dose CT imaging.
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Aissa J, Kohlmeier A, Rubbert C, Hohn U, Blondin D, Schleich C, Kröpil P, Boos J, Antoch G, Miese F. Diagnostic value of CT-localizer and axial low-dose computed tomography for the detection of drug body packing. J Forensic Leg Med 2016; 37:55-60. [DOI: 10.1016/j.jflm.2015.10.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Revised: 07/17/2015] [Accepted: 10/25/2015] [Indexed: 10/22/2022]
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Haubenreisser H, Bigdeli A, Meyer M, Kremer T, Riester T, Kneser U, Schoenberg SO, Henzler T. From 3D to 4D: Integration of temporal information into CT angiography studies. Eur J Radiol 2015; 84:2421-4. [DOI: 10.1016/j.ejrad.2015.06.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Accepted: 06/15/2015] [Indexed: 12/15/2022]
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How should patients with cystine stone disease be evaluated and treated in the twenty-first century? Urolithiasis 2015; 44:65-76. [PMID: 26614112 DOI: 10.1007/s00240-015-0841-x] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 11/05/2015] [Indexed: 02/02/2023]
Abstract
Cystinuria continues to be one of the most challenging stone diseases. During the latest decades our knowledge of the molecular basis of cystinuria has expanded. Today 160 different mutations in the SLC3A1 gene and 116 in the SLC7A9 gene are listed. The full implications of type A, B or AB status are not yet fully understood but may have implications for prognosis, management and treatment. Despite better understanding of the molecular basis of cystinuria the principles of recurrence prevention have remained essentially the same through decades. No curative treatment of cystinuria exists, and patients will have a life long risk of stone formation, repeated surgery, impaired renal function and quality of life. Therapy to reduce stone formation is directed towards lowering urine cystine concentration and increasing cystine solubility. Different molecules that could play a role in promoting nucleation and have a modulating effect on cystine solubility may represent new targets for cystinuria research. Investigation of newer thiol-containing drugs with fewer adverse effects is also warranted. Determining cystine capacity may be an effective tool to monitor the individual patient's response. Compliance in cystinuric patients concerning both dietary and pharmacological intervention is poor. Frequent clinical follow-up visits in dedicated centres seem to improve compliance. Cystinuric patients should be managed in dedicated centres offering the complete range of minimal invasive treatment modalities, enabling a personalized treatment approach in order to reduce risk and morbidity of multiple procedures.
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Villa L, Giusti G, Knoll T, Traxer O. Imaging for Urinary Stones: Update in 2015. Eur Urol Focus 2015; 2:122-129. [PMID: 28723526 DOI: 10.1016/j.euf.2015.10.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Revised: 10/14/2015] [Accepted: 10/29/2015] [Indexed: 10/22/2022]
Abstract
CONTEXT Imaging is essential for the diagnosis and the clinical decision-making process of patients with urinary stones. OBJECTIVE To assess the benefits and limitations of various imaging techniques by specifically focusing on different phases of stone patients' management. EVIDENCE ACQUISITION PubMed and Web of Science databases were used to identify studies published in the last 10 yr on this argument. Search terms included 'urolithiasis', nephrolithiasis', or 'urinary stones' in combination (AND) with the terms 'imaging', 'computer tomography', 'ultrasonography', 'intravenous pyelogram', or 'radiation exposure'. Study selection was based on an independent peer-review process of all the authors after the structured data search. EVIDENCE SYNTHESIS Noncontrast-enhanced computer tomography (CT) provides the highest value of diagnostic accuracy for urinary stones. Stone composition can be specifically assessed through the use of dual-energy CT. When information about the anatomy of the renal collecting system is required or alternative pathologies are suspected, CT with contrast injection is recommended. Low-dose protocols allowed a drastic reduction of the effective dose administered to the patient, thus limiting the biological risk due to ionising radiations. Other strategies to contain the radiation exposure include the dual-split bolus dual energy CT and the adaptive statistical image reconstruction. Abdomen ultrasound may be a valid alternative as an initial approach since it does not change the outcome of patients compared with CT, and should be the imaging of choice in children and pregnant women. CONCLUSIONS Noncontrast-enhanced CT is the most accurate imaging technique to identify urinary stones. Abdomen ultrasound seems to be a valid alternative in the initial evaluation of urinary colic. New low-dose protocols and strategies have been developed to contain radiation exposure, which is a major issue especially in specific circumstances. PATIENT SUMMARY Noncontrast-enhanced computer tomography has been increasingly used for the diagnosis and management of urinary stones. Low-dose protocols as well as alternative imaging should be considered by clinicians in specific circumstances to minimise radiation exposure.
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Affiliation(s)
- Luca Villa
- Division of Experimental Oncology/Unit of Urology, URI, IRCCS Ospedale San Raffaele, Milan, Italy.
| | - Guido Giusti
- Department of Urology, IRCCS Ospedale San Raffaele Ville Turro, Milan, Italy
| | - Thomas Knoll
- Department of Urology, Klinikum Sindelfingen-Boeblingen, University of Tuebingen, Sindelfingen, Germany
| | - Olivier Traxer
- Department of Urology, Tenon Hospital, Pierre et Marie Curie University, Paris, France
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Choi SY, Ahn SH, Choi JD, Kim JH, Lee BI, Kim JI, Park SB. Determination of optimal imaging settings for urolithiasis CT using filtered back projection (FBP), statistical iterative reconstruction (IR) and knowledge-based iterative model reconstruction (IMR): a physical human phantom study. Br J Radiol 2015; 89:20150527. [PMID: 26577542 DOI: 10.1259/bjr.20150527] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
OBJECTIVE The purpose of this study was to compare CT image quality for evaluating urolithiasis using filtered back projection (FBP), statistical iterative reconstruction (IR) and knowledge-based iterative model reconstruction (IMR) according to various scan parameters and radiation doses. METHODS A 5 × 5 × 5 mm(3) uric acid stone was placed in a physical human phantom at the level of the pelvis. 3 tube voltages (120, 100 and 80 kV) and 4 current-time products (100, 70, 30 and 15 mAs) were implemented in 12 scans. Each scan was reconstructed with FBP, statistical IR (Levels 5-7) and knowledge-based IMR (soft-tissue Levels 1-3). The radiation dose, objective image quality and signal-to-noise ratio (SNR) were evaluated, and subjective assessments were performed. RESULTS The effective doses ranged from 0.095 to 2.621 mSv. Knowledge-based IMR showed better objective image noise and SNR than did FBP and statistical IR. The subjective image noise of FBP was worse than that of statistical IR and knowledge-based IMR. The subjective assessment scores deteriorated after a break point of 100 kV and 30 mAs. CONCLUSION At the setting of 100 kV and 30 mAs, the radiation dose can be decreased by approximately 84% while keeping the subjective image assessment. ADVANCES IN KNOWLEDGE Patients with urolithiasis can be evaluated with ultralow-dose non-enhanced CT using a knowledge-based IMR algorithm at a substantially reduced radiation dose with the imaging quality preserved, thereby minimizing the risks of radiation exposure while providing clinically relevant diagnostic benefits for patients.
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Affiliation(s)
- Se Y Choi
- 1 Department of Urology, The Armed Forces Il-Dong Hospital, Pocheon, Republic of Korea.,2 Department of Urology, Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul, Republic of Korea
| | - Seung H Ahn
- 3 Department of Urology, KEPCO Medical Center, Seoul, Republic of Korea
| | - Jae D Choi
- 3 Department of Urology, KEPCO Medical Center, Seoul, Republic of Korea
| | - Jung H Kim
- 3 Department of Urology, KEPCO Medical Center, Seoul, Republic of Korea
| | - Byoung-Il Lee
- 4 Radiation Health Research Institute, Korea Hydro and Nuclear Power, Seoul, Republic of Korea
| | - Jeong-In Kim
- 4 Radiation Health Research Institute, Korea Hydro and Nuclear Power, Seoul, Republic of Korea
| | - Sung B Park
- 5 Department of Radiology, Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul, Republic of Korea
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Kim JH, Choo KS, Moon TY, Lee JW, Jeon UB, Kim TU, Hwang JY, Yun MJ, Jeong DW, Lim SJ. Comparison of the image qualities of filtered back-projection, adaptive statistical iterative reconstruction, and model-based iterative reconstruction for CT venography at 80 kVp. Eur Radiol 2015; 26:2055-63. [PMID: 26486938 DOI: 10.1007/s00330-015-4060-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 09/28/2015] [Accepted: 10/06/2015] [Indexed: 11/25/2022]
Abstract
PURPOSE To evaluate the subjective and objective qualities of computed tomography (CT) venography images at 80 kVp using model-based iterative reconstruction (MBIR) and to compare these with those of filtered back projection (FBP) and adaptive statistical iterative reconstruction (ASIR) using the same CT data sets. MATERIALS AND METHODS Forty-four patients (mean age: 56.1 ± 18.1) who underwent 80 kVp CT venography (CTV) for the evaluation of deep vein thrombosis (DVT) during 4 months were enrolled in this retrospective study. The same raw data were reconstructed using FBP, ASIR, and MBIR. Objective and subjective image analysis were performed at the inferior vena cava (IVC), femoral vein, and popliteal vein. RESULTS The mean CNR of MBIR was significantly greater than those of FBP and ASIR and images reconstructed using MBIR had significantly lower objective image noise (p < .001). Subjective image quality and confidence of detecting DVT by MBIR group were significantly greater than those of FBP and ASIR (p < .005), and MBIR had the lowest score for subjective image noise (p < .001). CONCLUSION CTV at 80 kVp with MBIR was superior to FBP and ASIR regarding subjective and objective image qualities. KEY POINTS • MBIR provides superior image quality compared with FBP and ASIR • CTV at 80kVp with MBIR improves diagnostic confidence in diagnosing DVT • CTV at 80kVp with MBIR presents better image quality with low radiation.
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Affiliation(s)
- Jin Hyeok Kim
- Department of Radiology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Pusan, Korea
| | - Ki Seok Choo
- Department of Radiology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Pusan, Korea.
| | - Tae Yong Moon
- Department of Radiology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Pusan, Korea
| | - Jun Woo Lee
- Department of Radiology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Pusan, Korea
| | - Ung Bae Jeon
- Department of Radiology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Pusan, Korea
| | - Tae Un Kim
- Department of Radiology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Pusan, Korea
| | - Jae Yeon Hwang
- Department of Radiology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Pusan, Korea
| | - Myeong-Ja Yun
- Department of Preventive and Occupational Medicine, School of Medicine, Pusan National University, Pusan, Korea
| | - Dong Wook Jeong
- Department of Family Medicine, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Pusan, Korea
| | - Soo Jin Lim
- Department of Cardiology, Kimhae Jungang Hospital, Gyeongsangnam-do, Korea
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Seyal AR, Arslanoglu A, Abboud SF, Sahin A, Horowitz JM, Yaghmai V. CT of the Abdomen with Reduced Tube Voltage in Adults: A Practical Approach. Radiographics 2015; 35:1922-39. [PMID: 26473536 DOI: 10.1148/rg.2015150048] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Recent innovations in computed tomographic (CT) hardware and software have allowed implementation of low tube voltage imaging into everyday CT scanning protocols in adults. CT at a low tube voltage setting has many benefits, including (a) radiation dose reduction, which is crucial in young patients and those with chronic medical conditions undergoing serial CT examinations for disease management; and (b) higher contrast enhancement. For the latter, increased attenuation of iodinated contrast material improves the evaluation of hypervascular lesions, vascular structures, intestinal mucosa in patients with bowel disease, and CT urographic images. Additionally, the higher contrast enhancement may provide diagnostic images in patients with renal dysfunction receiving a reduced contrast material load and in patients with suboptimal peripheral intravenous access who require a lower contrast material injection rate. One limitation is that noisier images affect image quality at a low tube voltage setting. The development of denoising algorithms such as iterative reconstruction has made it possible to perform CT at a low tube voltage setting without compromising diagnostic confidence. Other potential pitfalls of low tube voltage CT include (a) photon starvation artifact in larger patients, (b) accentuation of streak artifacts, and (c) alteration of the CT attenuation value, which may affect evaluation of lesions on the basis of conventional enhancement thresholds. CT of the abdomen with a low tube voltage setting is an excellent radiation reduction technique when properly applied to imaging of select patients in the appropriate clinical setting.
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Affiliation(s)
- Adeel R Seyal
- From the Department of Radiology, Northwestern University-Feinberg School of Medicine, 676 N Saint Clair St, Suite 800, Chicago, IL 60611
| | - Atilla Arslanoglu
- From the Department of Radiology, Northwestern University-Feinberg School of Medicine, 676 N Saint Clair St, Suite 800, Chicago, IL 60611
| | - Samir F Abboud
- From the Department of Radiology, Northwestern University-Feinberg School of Medicine, 676 N Saint Clair St, Suite 800, Chicago, IL 60611
| | - Azize Sahin
- From the Department of Radiology, Northwestern University-Feinberg School of Medicine, 676 N Saint Clair St, Suite 800, Chicago, IL 60611
| | - Jeanne M Horowitz
- From the Department of Radiology, Northwestern University-Feinberg School of Medicine, 676 N Saint Clair St, Suite 800, Chicago, IL 60611
| | - Vahid Yaghmai
- From the Department of Radiology, Northwestern University-Feinberg School of Medicine, 676 N Saint Clair St, Suite 800, Chicago, IL 60611
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Samim M, Goss S, Luty S, Weinreb J, Moore C. Incidental findings on CT for suspected renal colic in emergency department patients: prevalence and types in 5,383 consecutive examinations. J Am Coll Radiol 2015; 12:63-9. [PMID: 25557571 DOI: 10.1016/j.jacr.2014.07.026] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Accepted: 07/20/2014] [Indexed: 12/21/2022]
Abstract
PURPOSE This study aimed to determine the prevalence, importance, and types of incidental findings (IF) in non-enhanced CT scans performed for suspected renal colic, based on ACR white papers and other accepted radiographic recommendations. METHODS Retrospective review of 5,383 consecutive finalized reports of nonenhanced CT using renal colic protocol performed on adult patients at 2 emergency departments over a 5.5-year period. IF were defined as those unrelated to symptoms (as opposed to alternate causes of symptoms) and were categorized as "important" if follow-up was recommended based on recently published consensus recommendations. Subsets of reports of those with important IF were blindly re-reviewed to calculate inter-rater variability for presence and categorization of important IF. RESULTS Important IF were identified in 12.7% (95% confidence interval [CI]: 11.8%-13.6%) of scans. Prevalence of important IF increased with age: important IF in individuals age >80 years were 4 times more common than for those aged 18-30 years: 28.9% (95% CI: 22.4%-36.4%) versus 6.9% (95% CI: 5.5%-8.6%), respectively, P ≤ .05. Women had a higher prevalence of important IF compared with men: 13.4% (95% CI: 12.2%-14.7%) versus 11.9% (95% CI: 10.7%-13.2%), but the difference was not statically significant (P = .09). There was substantial inter-rater agreement (kappa ≥ 0.69) regarding presence and classification of important IFs using published guidelines. CONCLUSIONS Important IF occurred in 12.7% of non-enhanced CT scans performed for suspected renal colic in the emergency department and are more common in older individuals. Prospective studies that use radiographic recommendations to characterize IF and examine the outcome and cost of their workup are encouraged.
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Affiliation(s)
- Mohammad Samim
- Department of Radiology, Yale University School of Medicine, New Haven, Connecticut.
| | - Sarah Goss
- Department of Emergency Medicine, Yale University School of Medicine, New Haven, Connecticut
| | - Seth Luty
- Department of Emergency Medicine, Yale University School of Medicine, New Haven, Connecticut
| | - Jeffrey Weinreb
- Department of Radiology, Yale University School of Medicine, New Haven, Connecticut
| | - Christopher Moore
- Department of Emergency Medicine, Yale University School of Medicine, New Haven, Connecticut
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Abstract
Acute urinary tract disorders often manifest as flank pain and are a common complaint of patients who present to the emergency department. The pain is often a vague, poorly localized sensation that may have a variety of causes. Laboratory and clinical findings, such as hematuria, are neither sensitive nor specific for determining the cause of the flank pain. Accordingly, imaging is an important tool in determining a diagnosis and management plan. Patients with acute urinary tract disorders who present with pain include those with calculi as well as renal infection, vascular disorders, and hemorrhage.
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Affiliation(s)
- Rakhee H Goel
- Imaging Institute, Cleveland Clinic, 9500 Euclid Avenue, L10, Cleveland, OH 44195, USA
| | - Raman Unnikrishnan
- Glickman Urological and Kidney Institute, Cleveland Clinic, 9500 Euclid Avenue, Q10, Cleveland, OH 44195, USA
| | - Erick M Remer
- Imaging Institute, Glickman Urological and Kidney Institute, Cleveland Clinic, 9500 Euclid Avenue, A21, Cleveland, OH 44195, USA.
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Kim SH, Yoon JH, Lee JH, Lim YJ, Kim OH, Ryu JH, Son JH. Low-dose CT for patients with clinically suspected acute appendicitis: optimal strength of sinogram affirmed iterative reconstruction for image quality and diagnostic performance. Acta Radiol 2015; 56:899-907. [PMID: 25118330 DOI: 10.1177/0284185114542297] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Accepted: 06/12/2014] [Indexed: 12/31/2022]
Abstract
BACKGROUND As there is increased concern over the radiation exposure particularly in adolescents and young adults, computed tomography (CT) dose reduction is needed in the diagnosis of acute appendicitis. PURPOSE To evaluate the optimal strength of sinogram affirmed iterative reconstruction (SAFIRE) to obtain the best image quality on a 30-mAs applied low-dose CT (LDCT 30mAs) and to compare the diagnostic performances of the LDCT 30mAs with different SAFIRE strengths with that of the 100-mAs applied LDCT (LDCT 100mAs) for the diagnosis of acute appendicitis. MATERIAL AND METHODS A total of 102 consecutive patients (47 men, 55 women; mean age, 41.2 years; range, 15-82 years) with right lower quadrant pain underwent abdominal-pelvic CT, consisting of arterial phase LDCT 100mAs and portal venous phase LDCT30mAs under a fixed 120 kV. LDCT 30mAs images were reconstructed separately with five strength levels (S1-S5). Two blinded radiologists recorded scores for the subjective image quality of the LDCT 30mAs dataset (S0-S5) and confidence scores for the diagnosis of acute appendicitis on each dataset and LDCT 100mAs. CT image noise was measured for each set. RESULTS The study population consisted of 58 patients with confirmed appendicitis and 44 without appendicitis. There was no significant difference in diagnostic performance between LDCT 100mAs and LDCT 30mAs with any strength for both readers (AUC for reader 1, LDCT 30mAs with S0-S5 = 0.97, LDCT 100mAs = 0.93, P = 0.0936; for reader 2, LDCT 30mAs with S0-S5 = 0.96, LDCT 100mAs = 0.97, P = 0.128). The measured noise decreased as the strength increased from S0 to S5 (mean, 20.8 > 17.7 > 15.6 > 13.5 > 11.5 > 9.5, P < 0.0001). However, overall subjective image quality on S3 was better than the other strengths for both readers (S0 < S1 < S2 < S3 > S4 > S5, P < 0.0001). CONCLUSION Although measured noise declined as SAFIRE strength increased, S3 seems optimal for the best subjective image quality on LDCT 30mAs. The diagnostic performance of LDCT 30mAs with any strength is comparable to that of LDCT 100mAs for the diagnosis of acute appendicitis.
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Affiliation(s)
- Seung Ho Kim
- Department of Radiology, Inje University College of Medicine, Haeundae Paik Hospital, Busan, Republic of Korea
| | - Jung-Hee Yoon
- Department of Radiology, Inje University College of Medicine, Haeundae Paik Hospital, Busan, Republic of Korea
| | - Jang Hee Lee
- Department of Radiology, Inje University College of Medicine, Haeundae Paik Hospital, Busan, Republic of Korea
| | - Yun-Jung Lim
- Department of Radiology, Inje University College of Medicine, Haeundae Paik Hospital, Busan, Republic of Korea
| | - Ok Hwa Kim
- Department of Radiology, Inje University College of Medicine, Haeundae Paik Hospital, Busan, Republic of Korea
| | - Ji Hwa Ryu
- Department of Radiology, Inje University College of Medicine, Haeundae Paik Hospital, Busan, Republic of Korea
| | - Jung-Hee Son
- Department of Radiology, Inje University College of Medicine, Haeundae Paik Hospital, Busan, Republic of Korea
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Geyer LL, Schoepf UJ, Meinel FG, Nance JW, Bastarrika G, Leipsic JA, Paul NS, Rengo M, Laghi A, De Cecco CN. State of the Art: Iterative CT Reconstruction Techniques. Radiology 2015. [PMID: 26203706 DOI: 10.1148/radiol.2015132766] [Citation(s) in RCA: 383] [Impact Index Per Article: 42.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Lucas L Geyer
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - U Joseph Schoepf
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - Felix G Meinel
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - John W Nance
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - Gorka Bastarrika
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - Jonathon A Leipsic
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - Narinder S Paul
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - Marco Rengo
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - Andrea Laghi
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - Carlo N De Cecco
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
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