1
|
Ren Z, Zhang X, Hu Z, Li D, Liu Z, Wei D, Jia Y, Yu N, Yu Y, Lei Y, Chen X, Guo C, Ren Z, He T. Reducing Radiation Dose and Improving Image Quality in CT Portal Venography Using 80 kV and Adaptive Statistical Iterative Reconstruction-V in Slender Patients. Acad Radiol 2020; 27:233-243. [PMID: 31031186 DOI: 10.1016/j.acra.2019.02.022] [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: 01/16/2019] [Revised: 02/26/2019] [Accepted: 02/27/2019] [Indexed: 01/23/2023]
Abstract
OBJECTIVE To explore the feasibility of reducing radiation dose and improving image quality in CT portal venography (CTPV) using 80 kV and adaptive statistical iterative reconstruction-V(ASIR-V) in slender patients in comparison with conventional protocol using 120 kV and ASIR. METHODS Sixty slender patients for enhanced abdominal CT scanning were randomly divided into group A and group B. Group A used the conventional 120 kV tube voltage, 600 mgI/kg contrast dose and reconstructed with the recommended 40% ASIR. Group B used 80 kV tube voltage, 350 mgI/kg contrast dose and reconstructed with ASIR-V from 40% to 100% with 10% interval. The CT values and standard deviation (SD) values of the main portal vein, left branch, and right branch of portal vein, liver, and erector spinae at the same level were measured to calculate the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). The image quality was subjectively scored by two experienced radiologists blindly using a 5-point criterion. The contrast dose, volumetric CT dose index, and dose length product were recorded in both groups and the effective dose was calculated. RESULTS There was no significant difference in general data between the two groups (p > 0.05), the effective dose and contrast dose in group B were reduced by 63.3% (p < 0.001) and 39.7% (p < 0.001), respectively compared with group A. With the percentage of ASIR-V increased in group B, the CT values showed no significant difference, while the SD values gradually decreased and SNR values and CNR values increased accordingly. Compared with group A, group B demonstrated similar CT values (p > 0.05), while the SD values with 80% ASIR-V to 100% ASIR-V were significantly lower than those of 40% ASIR (p < 0.001), and the SNR values and CNR values with 70% ASIR-V to 100% ASIR-V were significantly higher than those of 40% ASIR (p < 0.001). The subjective image quality scores by the two radiologists had excellent consistency (kappa value>0.75, p < 0.001), and the final subjective image quality scores and the subjective scores in each of the 5 scoring categories with 60% ASIR-V to 100% ASIR-V were all significantly higher than those of 40% ASIR, and 80% ASIR-V obtained the highest subjective score among different reconstructions. CONCLUSION In CTPV, the application of 80 kV and ASIR-V reconstruction in slender patients can significantly reduce radiation dose (by 63.3%) and contrast agent dose (by 39.7%). Compared with the recommended 40% ASIR using 120 kV, ASIR-V with 80% to 100% percentages can further improve image quality and with 80% ASIR-V being the best reconstruction algorithm. ADVANCES IN KNOWLEDGE CTPV with 80 kV and ASIR-V algorithm in slender patients can significantly reduce radiation dose and contrast agent dose as well as improve image quality, compared with the conventional 120 kV protocol using 40% ASIR.
Collapse
|
2
|
Jia Y, Zhai B, He T, Yu Y, Yu N, Duan H, Yang C, Zhang X. The Application of a New Model-Based Iterative Reconstruction in Low-Dose Upper Abdominal CT. Acad Radiol 2019; 26:e275-e283. [PMID: 30660470 DOI: 10.1016/j.acra.2018.11.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 11/27/2018] [Accepted: 11/27/2018] [Indexed: 12/23/2022]
Abstract
RATIONALE AND OBJECTIVES To compare upper abdominal computed tomography (CT) image quality of new model-based iterative reconstruction (MBIR) with low-contrast resolution preference (MBIRNR40), conventional MBIR (MBIRc), and adaptive statistical iterative reconstruction (ASIR) at low dose with ASIR at routine-dose. MATERIALS AND METHODS Study included phantom and 60 patients who had initial and follow-up CT scans. For patients, the delay phase was acquired at routine-dose (noise index = 10 HU) for the initial scan and low dose (noise index = 20 HU) for the follow-up. The low-dose CT was reconstructed with 40% and 60% ASIR, MBIRc, and MBIRNR40, while routine-dose CT was reconstructed with 40% ASIR. CT value and noise measurements of the subcutaneous fat, back muscle, liver, and spleen parenchyma were compared using one-way ANOVA. Two radiologists used semiquantitative 7-scale (-3 to +3) to rate image quality and artifacts. RESULTS The phantom study revealed superior low-contrast resolution with MBIRNR40. For patient scans, the CT dose index for the low-dose CT was 3.00 ± 1.32 mGy, 75% lower than the 11.90 ± 4.75 mGy for the routine-dose CT. Image noise for the low-dose MBIRNR40 images was significantly lower than the low-dose MBIRc and ASIR images, and routine-dose ASIR images (p < 0.05). Subjective ratings showed higher image quality for low-dose MBIRNR40, with lower noise, better low-contrast resolution for abdominal structures, and finer lesion contours than those of low-dose MBIRc and ASIR images, and routine-dose ASIR images (p < 0.05). CONCLUSION MBIRNR40 with low-contrast resolution preference provides significantly lower noise and better image quality than MBIRc and ASIR in low-dose abdominal CT; significantly better objective and subjective image quality than the routine-dose ASIR with 75% dose reduction.
Collapse
|
3
|
Abstract
Imaging plays a crucial role in pre-transplant evaluation to enhance the probability of a successful outcome. Its aim is to define kidney and vascular anatomy and to assess potential pathologies. Each modality has advantages and disadvantages. Computed tomography angiography (CTA) is the most commonly used imaging modality, however, magnetic resonance angiography (MRA) can be used in selected cases. The purpose of this review article is to provide an overview of available imaging modalities, their benefits, risks, advantages, and disadvantages. Imaging findings that indicate particular anomalies and pathologies that may affect living renal donor selection will be discussed.
Collapse
Affiliation(s)
- Ayaz Aghayev
- Cardiovascular Imaging Program, Departments of Radiology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Sumit Gupta
- Cardiovascular Imaging Program, Departments of Radiology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Borna E Dabiri
- Cardiovascular Imaging Program, Departments of Radiology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Michael L Steigner
- Cardiovascular Imaging Program, Departments of Radiology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| |
Collapse
|
4
|
Böning G, Rotzinger RA, Kahn JF, Freyhardt P, Renz DM, Maurer M, Streitparth F. Tailored CT angiography in follow-up after endovascular aneurysm repair (EVAR): combined dose reduction techniques. Acta Radiol 2018; 59:1316-1325. [PMID: 29430936 DOI: 10.1177/0284185118756952] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Background Endovascular aneurysm repair (EVAR) requires lifelong surveillance by computed tomography angiography (CTA). This is attended by a substantial accumulation of radiation exposure. Iterative reconstruction (IR) has been introduced to approach dose reduction. Purpose To evaluate adaptive statistical iterative reconstruction (ASIR) at different levels of tube voltage concerning image quality and dose reduction potential in follow-up post EVAR. Material and Methods One hundred CTAs in 67 patients with EVAR were examined using five protocols: protocol A (n = 40) as biphasic standard using filtered back projection (FBP) at 120 kV; protocols B (n = 40), C (n = 10), and D1 (n = 5) biphasic using ASIR at 120, 100, and 80 kV, respectively; and protocol D2 (n = 5) with a monophasic splitbolus ASIR protocol at 80 kV. Image quality was assessed quantitatively and qualitatively. Applied doses were determined. Results Applied doses in ASIR protocols were significantly lower than FBP standard (up to 75%). Compared to protocol A, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) (e.g. arterial CNR intra-/extra-stent lumen: A = 35.4 ± 13.5, B = 34.2 ± 10.0, C = 29.6 ± 6.8, D1 = 32.1 ± 6.3, D2 = 40.8 ± 23.1) in protocol B were equal and in protocols C and D equal to partially inferior, however not decisive for diagnostic quality. Subjective image quality ratings in all protocols were good to excellent without impairments of diagnostic confidence (A-D2: 5), with high inter-rater agreement (60-100%). Conclusion ASIR contributes to significant dose reduction without decisive impairments of image quality and diagnostic confidence. We recommend an adapted follow-up introducing ASIR and combined low-kV in the long-term surveillance after EVAR.
Collapse
Affiliation(s)
- Georg Böning
- 1 Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Roman A Rotzinger
- 1 Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Johannes F Kahn
- 1 Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Patrick Freyhardt
- 1 Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Diane M Renz
- 2 Department of Radiology, Jena University Hospital, Jena, Germany
| | - Martin Maurer
- 3 Department of Radiology, Inselspital Bern, Bern, Switzerland
| | - Florian Streitparth
- 1 Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| |
Collapse
|
5
|
Abstract
Proper pre- and post-transplant diagnostic imaging work-up is fundamental in ensuring a successful outcome for renal transplantation. Despite exposure to ionizing radiation, CT has high spatial resolution and is a widely available and fast imaging technique. CT is performed routinely to delineate the anatomy of the kidney, relevant vasculature, and urinary collecting system in the living donor, to assess the iliac vessels in potential recipients prior to surgery, and to assess early and late-term post-transplant complications. The purpose of this article is to outline the optimal CT protocol and the main reportable findings for both the donor and the recipient diagnostic imaging work-up as well as to point out the main issues regarding ionizing radiation exposure and contrast medium injection in these subjects.
Collapse
|
6
|
CT-angiography of the aorta in patients with Marfan disease - High-pitch MDCT at different levels of tube voltage combined with Sinogram Affirmed Iterative Reconstruction. Clin Imaging 2018; 51:123-132. [DOI: 10.1016/j.clinimag.2018.02.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Revised: 01/20/2018] [Accepted: 02/06/2018] [Indexed: 01/16/2023]
|
7
|
Böning G, Kahn JF, Kaul D, Rotzinger R, Freyhardt P, Pavel M, Streitparth F. CT follow-up in patients with neuroendocrine tumors (NETs): combined radiation and contrast dose reduction. Acta Radiol 2018; 59:517-526. [PMID: 28786299 DOI: 10.1177/0284185117726101] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Background Frequent computed tomography (CT) follow-ups involve significant radiation related risks for patients with low-grade neuroendocrine tumors (NETs). Contrast agent (CA) application is essential for diagnostic evidence and has additional risks especially in patients with limited renal function. Purpose To investigate if a combination of dose and contrast agent (CA) reduction affects image quality and diagnostic evidence in neuroendocrine tumor (NET) patients. Material and Methods A total of 51 NET patients were enrolled in the study and 153 CT scans were analyzed. Patients underwent a baseline CT scan (A = 120 kVp, filtered back projection [FBP]) and two follow-up CTs (B = 120 kVp, adaptive statistical iterative reconstruction [ASIR] 40%; C1 = 100 kVp, ASIR 40%; C2 = 100 kVp, ASIR 60%; the latter two protocols were applied with a 30% reduction in CA volume). We evaluated image quality and applied dose. Results In C1/2, the combination of low kV (100 kVp) with ASIR 40%/60% reduced the mean applied dose significantly by 28% compared to B and by 57% compared to A. Signal-to-noise ratio (SNR) and contrast-to-noise ratios (CNR) of tumor to liver/muscle were significantly increased by using C1/2 compared to B and A. With respect to subjective image quality, a slight loss of diagnostic confidence in C1 could be counterbalanced by the higher ASIR blending in C2. Conclusion Combined dose reduction techniques can be used to reduce radiation dose and CA volume without sacrificing image quality and diagnostic confidence in staging CT of NET patients.
Collapse
Affiliation(s)
- G Böning
- Department of Radiology Charité, Humboldt-University Medical School, Berlin, Germany
| | - JF Kahn
- Department of Radiology Charité, Humboldt-University Medical School, Berlin, Germany
| | - D Kaul
- Department of Radiation Oncology Charité, Humboldt-University Medical School, Berlin, Germany
| | - R Rotzinger
- Department of Radiology Charité, Humboldt-University Medical School, Berlin, Germany
| | - P Freyhardt
- Department of Radiology Charité, Humboldt-University Medical School, Berlin, Germany
| | - M Pavel
- Department of Gastroenterology Charité, Humboldt-University Medical School, Berlin, Germany
| | - F Streitparth
- Department of Radiology Charité, Humboldt-University Medical School, Berlin, Germany
| |
Collapse
|
8
|
Selecting living donors for uterus transplantation: lessons learned from two transplantations resulting in menstrual functionality and another attempt, aborted after organ retrieval. Arch Gynecol Obstet 2017; 297:675-684. [PMID: 29270725 DOI: 10.1007/s00404-017-4626-z] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 12/11/2017] [Indexed: 12/25/2022]
Abstract
PURPOSE To contribute to establishing donor selection criteria based on our experience with two successful living-donor human uterus transplantations (UTx) and an aborted attempt. METHODS This interventional study included three patients with uterine agenesis, aged 23, 34, and 23 years, scheduled for UTx, and their uterus-donating mothers, aged 46, 61, and 46 years, respectively. Interventions included preoperative investigations, donor surgery, back-table preparation, and recipient surgery. Preoperative imaging, surgical data, histopathology, menstrual pattern, and uterine blood flow were the main outcome measures. RESULTS In the first case (46-year-old mother/23-year-old daughter), donor/recipient surgery took 12.12/5.95 h. Regular spontaneous menstruations started 6-week post-transplantation, continuing at 24-28-day intervals throughout the 6-month observation period. Repeated follow-up cervical biopsies showed no signs of rejection. In the second case (61-year-old donor), surgery lasted 13.10 h; attempts to flush the retrieved uterus failed due to extreme resistance of the left uterine artery (UA) and inability to perfuse the right UA. Transplantation was aborted to avoid graft vessel thrombosis or insufficient blood flow during potential pregnancy. Histopathology revealed intimal fibrosis and initial sclerosis (right UA), extensive intimal fibrosis (parametric arterial segments), and subtotal arterial stenosis (myometrial vascular network). In the third case (46-year-old mother/23-year-old daughter), donor/recipient surgery took 9.05/4.52 h. Menstruations started 6-week post-transplantation. Repeated cervical biopsies showed no signs of rejection during the initial 12-week follow-up period. CONCLUSIONS Meticulous preoperative evaluation of potential living uterus donors is essential. This may include selective contrast-enhanced UA angiograms and limitation of donor age, at least in donors with risk factors for atherosclerosis. CLINICAL TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT03048396.
Collapse
|
9
|
Schäfer ML, Lüdemann L, Böning G, Kahn J, Fuchs S, Hamm B, Streitparth F. Radiation dose reduction in CT with adaptive statistical iterative reconstruction (ASIR) for patients with bronchial carcinoma and intrapulmonary metastases. Clin Radiol 2016; 71:442-9. [PMID: 26970839 DOI: 10.1016/j.crad.2016.01.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Revised: 01/07/2016] [Accepted: 01/14/2016] [Indexed: 10/24/2022]
Abstract
AIM To compare the radiation dose and image quality of 64-row chest computed tomography (CT) in patients with bronchial carcinoma or intrapulmonary metastases using full-dose CT reconstructed with filtered back projection (FBP) at baseline and reduced dose with 40% adaptive statistical iterative reconstruction (ASIR) at follow-up. MATERIALS AND METHODS The chest CT images of patients who underwent FBP and ASIR studies were reviewed. Dose-length products (DLP), effective dose, and size-specific dose estimates (SSDEs) were obtained. Image quality was analysed quantitatively by signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) measurement. In addition, image quality was assessed by two blinded radiologists evaluating images for noise, contrast, artefacts, visibility of small structures, and diagnostic acceptability using a five-point scale. RESULTS The ASIR studies showed 36% reduction in effective dose compared with the FBP studies. The qualitative and quantitative image quality was good to excellent in both protocols, without significant differences. There were also no significant differences for SNR except for the SNR of lung surrounding the tumour (FBP: 35±17, ASIR: 39±22). DISCUSSION A protocol with 40% ASIR can provide approximately 36% dose reduction in chest CT of patients with bronchial carcinoma or intrapulmonary metastases while maintaining excellent image quality.
Collapse
Affiliation(s)
- M-L Schäfer
- Department of Radiology, Charité - Universitätsmedizin Berlin, Campus Virchow Klinikum, Augustenburger Platz 1, 13353 Berlin, Germany.
| | - L Lüdemann
- Department of Radiotherapy, Universitätsklinikum Essen, Hufelandstr. 55, 45147 Essen, Germany
| | - G Böning
- Department of Radiology, Charité - Universitätsmedizin Berlin, Campus Virchow Klinikum, Augustenburger Platz 1, 13353 Berlin, Germany
| | - J Kahn
- Department of Radiology, Charité - Universitätsmedizin Berlin, Campus Virchow Klinikum, Augustenburger Platz 1, 13353 Berlin, Germany
| | - S Fuchs
- Department of Radiology, Charité - Universitätsmedizin Berlin, Campus Virchow Klinikum, Augustenburger Platz 1, 13353 Berlin, Germany
| | - B Hamm
- Department of Radiology, Charité - Universitätsmedizin Berlin, Campus Virchow Klinikum, Augustenburger Platz 1, 13353 Berlin, Germany
| | - F Streitparth
- Department of Radiology, Charité - Universitätsmedizin Berlin, Campus Virchow Klinikum, Augustenburger Platz 1, 13353 Berlin, Germany
| |
Collapse
|
10
|
Kahn J, Grupp U, Kaul D, Böning G, Lindner T, Streitparth F. Computed tomography in trauma patients using iterative reconstruction: reducing radiation exposure without loss of image quality. Acta Radiol 2016; 57:362-9. [PMID: 25852193 DOI: 10.1177/0284185115580839] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 03/04/2015] [Indexed: 11/16/2022]
Abstract
BACKGROUND Rising numbers of computed tomography (CT) examinations worldwide have led to a focus on dose reduction in the latest developments in CT technology. Iterative reconstruction (IR) models bear the potential to effectively reduce dose while maintaining adequate image quality. PURPOSE To assess the impact of adaptive statistical iterative reconstruction (ASIR) technique on dose reduction and image quality in a dedicated whole body CT (WBCT) protocol for trauma patients. MATERIAL AND METHODS A total of 122 subjects with multiple trauma was prospectively included in our study. Subjects who had to undergo a WBCT following a severe trauma were randomly assigned to two different groups: Group A was examined with an ASIR protocol for the body series (n = 64), group B (n = 58) was examined using a standard filtered back projection (FBP) protocol. Image quality was assessed both quantitatively by calculating signal-to-noise ratio (SNR) and contrast-to-noise ratios (CNRs) and qualitatively by two observers who evaluated image quality using a 5-point scale system. Applied dose was analyzed as CTDIvol (mGy), total DLP (mGyxcm), and effective dose (mSv). RESULTS Applied dose for the body series in group A was about 23% lower than in group B (P < 0.05). SNR and CNRs for different tissues were not significantly different. Subjective image quality ratings were excellent and showed no significant difference, with a high inter-reader agreement. CONCLUSION ASIR contributes to a relevant dose reduction without any loss of image quality in a dedicated WBCT protocol for patients with multiple trauma.
Collapse
Affiliation(s)
| | - Ulrich Grupp
- Department of Radiology, Charité, Berlin, Germany
| | - David Kaul
- Department of Radiology, Charité, Berlin, Germany
| | - Georg Böning
- Department of Radiology, Charité, Berlin, Germany
| | - Tobias Lindner
- Department of Emergency Medicine, Charité, Berlin, Germany
| | | |
Collapse
|
11
|
Böning G, Schäfer M, Grupp U, Kaul D, Kahn J, Pavel M, Maurer M, Denecke T, Hamm B, Streitparth F. Comparison of applied dose and image quality in staging CT of neuroendocrine tumor patients using standard filtered back projection and adaptive statistical iterative reconstruction. Eur J Radiol 2015; 84:1601-1607. [DOI: 10.1016/j.ejrad.2015.04.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Revised: 04/12/2015] [Accepted: 04/20/2015] [Indexed: 10/23/2022]
|
12
|
Khawaja RDA, Singh S, Blake M, Harisinghani M, Choy G, Karosmangulu A, Padole A, Do S, Brown K, Thompson R, Morton T, Raihani N, Koehler T, Kalra MK. Ultra-low dose abdominal MDCT: using a knowledge-based Iterative Model Reconstruction technique for substantial dose reduction in a prospective clinical study. Eur J Radiol 2014; 84:2-10. [PMID: 25458225 DOI: 10.1016/j.ejrad.2014.09.022] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Revised: 09/08/2014] [Accepted: 09/29/2014] [Indexed: 01/21/2023]
Abstract
PURPOSE To assess lesion detection and image quality parameters of a knowledge-based Iterative Model Reconstruction (IMR) in reduced dose (RD) abdominal CT examinations. MATERIALS AND METHODS This IRB-approved prospective study included 82 abdominal CT examinations performed for 41 consecutive patients (mean age, 62 ± 12 years; F:M 28:13) who underwent a RD CT (SSDE, 1.5 mGy ± 0.4 [∼ 0.9 mSv] at 120 kV with 17-20 mAs/slice) immediately after their standard dose (SD) CT exam (10 mGy ± 3 [∼ 6 mSv] at 120 kV with automatic exposure control) on 256 MDCT (iCT, Philips Healthcare). SD data were reconstructed using filtered back projection (FBP). RD data were reconstructed with FBP and IMR. Four radiologists used a five-point scale (1=image quality better than SD CT to 5=image quality unacceptable) to assess both subjective image quality and artifacts. Lesions were first detected on RD FBP images. RD IMR and RD FBP images were then compared side-by-side to SD-FBP images in an independent, randomized and blinded fashion. Friedman's test and intraclass correlation coefficient were used for data analysis. Objective measurements included image noise and attenuation as well as noise spectral density (NSD) curves to assess the noise in frequency domain were obtained. In addition, a low-contrast phantom study was performed. RESULTS All true lesions (ranging from 32 to 55) on SD FBP images were detected on RD IMR images across all patients. RD FBP images were unacceptable for subjective image quality. Subjective ratings showed acceptable image quality for IMR for organ margins, soft-tissue structures, and retroperitoneal lymphadenopathy, compared to RD FBP in patients with a BMI ≤ 25 kg/m(2) (median-range, 2-3). Irrespective of patient BMI, subjective ratings for hepatic/renal cysts, stones and colonic diverticula were significantly better with RD IMR images (P<0.01). Objective image noise for RD FBP was 57-66% higher, and for RD IMR was 8-56% lower than that for SD-FBP (P<0.01). NSD showed significantly lower noise in the frequency domain with IMR in all patients compared to FBP. CONCLUSION IMR considerably improved both objective and subjective image quality parameters of RD abdominal CT images compared to FBP in patients with BMI less than or equal to 25 kg/m(2).
Collapse
Affiliation(s)
| | - Sarabjeet Singh
- MGH Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Michael Blake
- MGH Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Mukesh Harisinghani
- MGH Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Garry Choy
- MGH Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Ali Karosmangulu
- MGH Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Atul Padole
- MGH Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Synho Do
- MGH Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Kevin Brown
- CT Research and Advanced Development, Philips Healthcare, Cleveland, OH, USA
| | - Richard Thompson
- CT Research and Advanced Development, Philips Healthcare, Cleveland, OH, USA
| | - Thomas Morton
- CT Research and Advanced Development, Philips Healthcare, Cleveland, OH, USA
| | - Nilgoun Raihani
- CT Research and Advanced Development, Philips Healthcare, Cleveland, OH, USA
| | - Thomas Koehler
- Philips Technologie GmbH, Innovative Technologies, Hamburg, Germany
| | - Mannudeep K Kalra
- MGH Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| |
Collapse
|