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Yap LPP, Sani FM, Chung E, Gowdh NFM, Ng WL, Wong JHD. Customised weight-based volume contrast media protocol for multiphase abdominal computed tomography. Singapore Med J 2024:00077293-990000000-00085. [PMID: 38305361 DOI: 10.4103/singaporemedj.smj-2021-461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 10/19/2022] [Indexed: 02/03/2024]
Abstract
INTRODUCTION Multiphase computed tomography (CT) using fixed volume contrast media may lead to high radiation exposure and toxicity in patients with low body weight. We evaluated a customised weight-based protocol for multiphase CT in terms of radiation exposure, image quality and cost savings. METHODS A total of 224 patients were recruited. An optimised CT protocol was applied using 100 kV and 1 mL/kg of contrast media dosing. The image quality and radiation dose exposure of this CT protocol were compared to those of a standard 120 kV, 80 mL fixed volume protocol. The radiation dose information and CT Hounsfield units were recorded. The signal-to-noise ratio, contrast-to-noise ratio (CNR) and figure of merit (FOM) were used as comparison metrics. The images were assessed for contrast opacification and visual quality by two radiologists. The renal function, contrast media volume and cost were also evaluated. RESULTS The median effective dose was lowered by 16% in the optimised protocol, while the arterial phase images achieved significantly higher CNR and FOM. The radiologists' evaluation showed more than 97% absolute agreement with no significant differences in image quality. No significant differences were found in the pre- and post-CT estimated glomerular filtration rate. However, contrast media usage was significantly reduced by 1,680 mL, with an overall cost savings of USD 421 in the optimised protocol. CONCLUSION The optimised weight-based protocol is cost-efficient and lowers radiation dose while maintaining overall contrast enhancement and image quality.
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Affiliation(s)
- Lilian Poh Poh Yap
- Department of Biomedical Imaging, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
- Department of Biomedical Imaging, Universiti Malaya Medical Centre, Lembah Pantai, Kuala Lumpur, Malaysia
| | - Fadhli Mohamed Sani
- Department of Biomedical Imaging, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
- Department of Biomedical Imaging, Universiti Malaya Medical Centre, Lembah Pantai, Kuala Lumpur, Malaysia
| | - Eric Chung
- Department of Biomedical Imaging, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
- Department of Biomedical Imaging, Universiti Malaya Medical Centre, Lembah Pantai, Kuala Lumpur, Malaysia
| | - Nadia Fareeda Muhammad Gowdh
- Department of Biomedical Imaging, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
- Department of Biomedical Imaging, Universiti Malaya Medical Centre, Lembah Pantai, Kuala Lumpur, Malaysia
| | - Wei Lin Ng
- Department of Biomedical Imaging, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
- Department of Biomedical Imaging, Universiti Malaya Medical Centre, Lembah Pantai, Kuala Lumpur, Malaysia
| | - Jeannie Hsiu Ding Wong
- Department of Biomedical Imaging, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
- Department of Biomedical Imaging, Universiti Malaya Medical Centre, Lembah Pantai, Kuala Lumpur, Malaysia
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Greffier J, Barbotteau Y, Gardavaud F. iQMetrix-CT: New software for task-based image quality assessment of phantom CT images. Diagn Interv Imaging 2022; 103:555-562. [DOI: 10.1016/j.diii.2022.05.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 05/27/2022] [Indexed: 01/09/2023]
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Frandon J, Akessoul P, Hamard A, Bezandry E, Loffroy R, Addala T, Bertrand MM, Beregi JP, Greffier J. Comparison of acquisition and iterative reconstruction parameters in abdominal computed tomography-guided procedures: a phantom study. Quant Imaging Med Surg 2022; 12:281-291. [PMID: 34993078 DOI: 10.21037/qims-21-328] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 06/21/2021] [Indexed: 11/06/2022]
Abstract
BACKGROUND Many computed tomography (CT) navigation systems have been developed to help radiologists improve the accuracy and safety of the procedure. We evaluated the accuracy of one CT computer-assisted guided procedure with different reduction dose protocols. METHODS A total of 128 punctures were randomly made by two operators on two different anthropomorphic phantoms. The tube voltage was fixed to 100 kVp. Tube currents (mAs) were defined to obtain 4 dose levels: 180 mAs (D1.00), 90 mAs (D0.50), 45 mAs (D0.25) and 15 mAs (D0.10) with respective volume CT dose index (CTDIvol) of 7.02, 3.52, 1.75 and 0.59 mGy. The raw data were reconstructed using level 2 of advanced model-based iterative reconstruction (ADMIRE) (A2) for D1.00, A3 for D0.50, A4 for D0.25 and A5 for D0.10. Two 12-mm targets per phantom were selected. The mean Euclidean distance (EuD) between the tip of the needle and the isocenter of the target was measured for each puncture. The different measures were compared by paired Student's t-tests. RESULTS The mean EuD was 7.0±3.1 mm for the 128 punctures performed. Regardless of which phantom was considered, no significant difference in accuracy occurred between the 4 dose levels, which were 7.1±3.5 mm for D1.00; 7.1±3.1 mm for D0.50; 7.2±3.0 mm for D0.25 and 6.6±2.6 mm for D0.10. CONCLUSIONS Abdominal CT-guided procedures, using computer-assisted navigation and iterative reconstruction algorithms, allow precise punctures on anthropomorphic phantoms with a dose reduction of -92% compared to a standard protocol.
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Affiliation(s)
- Julien Frandon
- Department of Medical Imaging, Nîmes University Hospital, University of Montpellier, Medical Imaging Group Nîmes, EA 2992, Nîmes, France
| | - Philippe Akessoul
- Department of Medical Imaging, Nîmes University Hospital, University of Montpellier, Medical Imaging Group Nîmes, EA 2992, Nîmes, France
| | - Aymeric Hamard
- Department of Medical Imaging, Nîmes University Hospital, University of Montpellier, Medical Imaging Group Nîmes, EA 2992, Nîmes, France
| | - Edinaud Bezandry
- Department of Medical Imaging, Nîmes University Hospital, University of Montpellier, Medical Imaging Group Nîmes, EA 2992, Nîmes, France
| | - Romaric Loffroy
- Department of Vascular and Interventional Radiology, Image-Guided Therapy Center, ImViA Laboratory-EA 7535, François-Mitterrand University Hospital, Dijon, France
| | - Takieddine Addala
- Department of Medical Imaging, Nîmes University Hospital, University of Montpellier, Medical Imaging Group Nîmes, EA 2992, Nîmes, France
| | - Martin M Bertrand
- Digestive Surgery Department, Nîmes University Hospital, Nîmes, France
| | - Jean-Paul Beregi
- Department of Medical Imaging, Nîmes University Hospital, University of Montpellier, Medical Imaging Group Nîmes, EA 2992, Nîmes, France
| | - Joël Greffier
- Department of Medical Imaging, Nîmes University Hospital, University of Montpellier, Medical Imaging Group Nîmes, EA 2992, Nîmes, France
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Greffier J, Frandon J, Si-Mohamed S, Dabli D, Hamard A, Belaouni A, Akessoul P, Besse F, Guiu B, Beregi JP. Comparison of two deep learning image reconstruction algorithms in chest CT images: A task-based image quality assessment on phantom data. Diagn Interv Imaging 2021; 103:21-30. [PMID: 34493475 DOI: 10.1016/j.diii.2021.08.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 08/02/2021] [Accepted: 08/04/2021] [Indexed: 12/22/2022]
Abstract
PURPOSE The purpose of this study was to compare the effect of two deep learning image reconstruction (DLR) algorithms in chest computed tomography (CT) with different clinical indications. MATERIAL AND METHODS Acquisitions on image quality and anthropomorphic phantoms were performed at six dose levels (CTDIvol: 10/7.5/5/2.5/1/0.5mGy) on two CT scanners equipped with two different DLR algorithms (TrueFidelityTM and AiCE). Raw data were reconstructed using the filtered back-projection (FBP) and the lowest/intermediate/highest DLR levels (L-DLR/M-DLR/H-DLR) of each algorithm. Noise power spectrum, task-based transfer function (TTF) and detectability index (d') were computed: d' modelled detection of a soft tissue mediastinal nodule, ground-glass opacity, or high-contrast pulmonary lesion. Subjective image quality of anthropomorphic phantom images was analyzed by two radiologists. RESULTS For the L-DLR/M-DLR levels, the noise magnitude was lower with TrueFidelityTM than with AiCE from 2.5 to 10 mGy. For H-DLR, noise magnitude was lower with AiCE . For L-DLR and M-DLR, the average NPS spatial frequency (fav) values were greater for AiCE except for 0.5 mGy. For H-DLR levels, fav was greater for TrueFidelityTM than for AiCE. TTF50% values were greater with AiCE for the air insert, and lower than TrueFidelityTM for the polyethylene insert. From 2.5 to10 mGy, d' was greater for AiCE than for TrueFidelityTM for H-DLR for all lesions, but similar for L-DLR and M-DLR. Image quality was rated clinically appropriate for all levels of both algorithms, for dose from 2.5 to 10 mGy, except for L-DLR of AiCE. CONCLUSION DLR algorithms reduce the image-noise and improve lesion detectability. Their operations and properties impacted both noise-texture and spatial resolution.
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Affiliation(s)
- Joël Greffier
- Department of Medical Imaging, CHU Nimes, Univ Montpellier, Medical Imaging Group Nimes, EA 2992, 30029 Nîmes, France.
| | - Julien Frandon
- Department of Medical Imaging, CHU Nimes, Univ Montpellier, Medical Imaging Group Nimes, EA 2992, 30029 Nîmes, France
| | - Salim Si-Mohamed
- Department of Radiology, Hospices Civils de Lyon, 69500 Lyon, France
| | - Djamel Dabli
- Department of Medical Imaging, CHU Nimes, Univ Montpellier, Medical Imaging Group Nimes, EA 2992, 30029 Nîmes, France
| | - Aymeric Hamard
- Department of Medical Imaging, CHU Nimes, Univ Montpellier, Medical Imaging Group Nimes, EA 2992, 30029 Nîmes, France
| | - Asmaa Belaouni
- Department of Medical Imaging, CHU Nimes, Univ Montpellier, Medical Imaging Group Nimes, EA 2992, 30029 Nîmes, France
| | - Philippe Akessoul
- Department of Medical Imaging, CHU Nimes, Univ Montpellier, Medical Imaging Group Nimes, EA 2992, 30029 Nîmes, France
| | - Francis Besse
- Department of Radiology Centre Cardiologique Nord, 93200 Saint Denis, France
| | - Boris Guiu
- Department of Radiology Saint-Eloi University Hospital, 34295 Montpellier, France
| | - Jean-Paul Beregi
- Department of Medical Imaging, CHU Nimes, Univ Montpellier, Medical Imaging Group Nimes, EA 2992, 30029 Nîmes, France
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Comparison of image quality between spectral photon-counting CT and dual-layer CT for the evaluation of lung nodules: a phantom study. Eur Radiol 2021; 32:524-532. [PMID: 34185147 DOI: 10.1007/s00330-021-08103-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 04/30/2021] [Accepted: 05/26/2021] [Indexed: 12/13/2022]
Abstract
OBJECTIVES To evaluate the image quality (IQ) of a spectral photon-counting CT (SPCCT) using filtered back projection (FBP) and hybrid iterative reconstruction (IR) algorithms (iDose4), in comparison with a dual-layer CT (DLCT) system, and to choose the best image quality according to the IR level for SPCCT. METHODS Two phantoms were scanned using a standard lung protocol (120 kVp, 40 mAs) with SPCCT and DLCT systems. Raw data were reconstructed using FBP and 9 iDose4 levels (i1/i2/i3/i4/i5/i6/i7/i9/i11) for SPCCT and 7 for DLCT (i1/i2/i3/i4/i5/i6/i7). Noise power spectrum and task-based transfer function (TTF) were computed. Detectability index (d') was computed for detection of 4 mm ground-glass nodule (GGN) and solid nodule. Two chest radiologists performed an IQ evaluation (noise/nodule sharpness/nodule conspicuity/overall IQ) in consensus, and chose the best image for SPCCT. RESULTS Noise magnitude was -47% ± 2% lower on average with SPCCT than with DLCT for iDose4 range from i1 to i6. Average NPS spatial frequencies increased for SPCCT in comparison with DLCT. TTF also increased, except for the air insert with FBP, and i1/i2/i3. Higher detectability was found for SPCCT for both GGN and solid nodules. IQ for both types of nodule was rated consistently higher with SPCCT than with DLCT for the same iDose4 level. For SPCCT and both nodules, the scores for noise and conspicuity improved with increasing iDose4 level. iDose4 level 6 provided the best subjective IQ for both types of nodule. CONCLUSIONS Higher IQ for GGN and solid nodules was demonstrated with SPCCT compared with DLCT with better detectability using iDose4. KEY POINTS Using spectral photon-counting CT compared with dual-layer CT, noise magnitude was reduced with improvements in spatial resolution and detectability of ground-glass nodules and solid lung nodules. As the iDose4 level increased, noise magnitude was reduced and detectability of ground-glass and solid lung nodules was better for both CT systems. For spectral photon-counting CT imaging, two chest radiologists determined iDose4 level 6 as the best image quality for detecting ground-glass nodules and solid lung nodules.
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Sato T, Yoshimura N, Horii Y, Yamazaki M, Sato K, Kumagai K, Ishikawa H. Low Tube Voltage Computed Tomography Venography for Patients With Deep Vein Thrombosis of the Lower Extremities - A Comparison With Venous Ultrasonography. Circ J 2021; 85:369-376. [PMID: 33441495 DOI: 10.1253/circj.cj-20-0416] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Low tube voltage computed tomography venography (CTV) can be expected to increase imaging contrast and decrease radiation exposure by using iterative reconstruction (IR). This study evaluated the diagnostic ability of low tube voltage CTV with IR for deep vein thrombosis (DVT), compared to ultrasonography (US).Methods and Results:Two experienced radiologists retrospectively reevaluated the CTV data of 55 of 318 consecutive patients suspected of having DVT or pulmonary embolism between December 2015 and April 2017. The 55 patients had undergone both low tube voltage CTV and US (within 1 day before or after CTV). The lower extremity veins were divided into 10 segments. The DVT forms were categorized into 3 types: complete, concentric, and eccentric. We analyzed the 534 overall segments (16 segments excluded in US) measured using both CTV and US. The sensitivity-specificity was overall 73.3-90.0%, for femoropopliteal, it was 90.0-93.2%, and for the calf, it was 71.1-87.2%. The diagnostic accuracy between the 'eccentric only' and 'others' groups focusing on DVT forms was compared, and significant differences were revealed, especially in the muscular vein. CONCLUSIONS The DVT diagnostic ability above the knee was comparable between low tube voltage CTV with IR and conventional CTV, and the radiation dose was reduced. It was suggested that eccentric DVT measured by CTV tend to be a false-positive, especially in the calf muscular vein.
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Affiliation(s)
- Tatsuhiko Sato
- Department of Radiology and Radiation Oncology, Niigata University Graduate School of Medical and Dental Sciences
| | - Norihiko Yoshimura
- Department of Radiology and Radiation Oncology, Niigata University Graduate School of Medical and Dental Sciences
| | - Yosuke Horii
- Department of Radiology and Radiation Oncology, Niigata University Graduate School of Medical and Dental Sciences
| | - Motohiko Yamazaki
- Department of Radiology and Radiation Oncology, Niigata University Graduate School of Medical and Dental Sciences
| | - Ken Sato
- Department of Radiology and Radiation Oncology, Niigata University Graduate School of Medical and Dental Sciences
| | - Kazuki Kumagai
- Department of Radiology and Radiation Oncology, Niigata University Graduate School of Medical and Dental Sciences
| | - Hiroyuki Ishikawa
- Department of Radiology and Radiation Oncology, Niigata University Graduate School of Medical and Dental Sciences
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Nicolan B, Greffier J, Dabli D, de Forges H, Arcis E, Al Zouabi N, Larbi A, Beregi JP, Frandon J. Diagnostic performance of ultra-low dose versus standard dose CT for non-traumatic abdominal emergencies. Diagn Interv Imaging 2021; 102:379-387. [PMID: 33714689 DOI: 10.1016/j.diii.2021.02.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 02/09/2021] [Accepted: 02/18/2021] [Indexed: 12/29/2022]
Abstract
PURPOSE The purpose of this study was to compare the diagnostic performance of ultra-low dose (ULD) to that of standard (STD) computed tomography (CT) for the diagnosis of non-traumatic abdominal emergencies using clinical follow-up as reference standard. MATERIALS AND METHODS All consecutive patients requiring emergency abdomen-pelvic CT examination from March 2017 to September 2017 were prospectively included. ULD and STD CTs were acquired after intravenous administration iodinated contrast medium (portal phase). CT acquisitions were performed at 125mAs for STD and 55mAs for ULD. Diagnostic performance was retrospectively evaluated on ULD and STD CTs using clinical follow-up as a reference diagnosis. RESULTS A total of 308 CT examinations from 308 patients (145 men; mean age 59.1±20.7 (SD) years; age range: 18-96 years) were included; among which 241/308 (78.2%) showed abnormal findings. The effective dose was significantly lower with the ULD protocol (1.55±1.03 [SD] mSv) than with the STD (3.67±2.56 [SD] mSv) (P<0.001). Sensitivity was significantly lower for the ULD protocol (85.5% [95%CI: 80.4-89.4]) than for the STD (93.4% [95%CI: 89.4-95.9], P<0.001) whereas specificities were similar (94.0% [95%CI: 85.1-98.0] vs. 95.5% [95%CI: 87.0-98.9], respectively). ULD sensitivity was equivalent to STD for bowel obstruction and colitis/diverticulitis (96.4% [95%CI: 87.0-99.6] and 86.5% [95%CI: 74.3-93.5] for ULD vs. 96.4% [95%CI: 87.0-99.6] and 88.5% [95%CI: 76.5-94.9] for STD, respectively) but lower for appendicitis, pyelonephritis, abscesses and renal colic (75.0% [95%CI: 57.6-86.9]; 77.3% [95%CI: 56.0-90.1]; 90.5% [95%CI: 69.6-98.4] and 85% [95%CI: 62.9-95.4] for ULD vs. 93.8% [95%CI: 78.6-99.2]; 95.5% [95%CI: 76.2-100.0]; 100.0% [95%CI: 81.4-100.0] and 100.0% [95%CI: 80.6-100.0] for STD, respectively). Sensitivities were significantly different between the two protocols only for appendicitis (P=0.041). CONCLUSION In an emergency context, for patients with non-traumatic abdominal emergencies, ULD-CT showed inferior diagnostic performance compared to STD-CT for most abdominal conditions except for bowel obstruction and colitis/diverticulitis detection.
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Affiliation(s)
- Basien Nicolan
- Department of Medical Imaging, Nîmes University Hospital, University of Montpellier, Medical Imaging Group Nîmes, EA 2415, 30000 Nîmes, France
| | - Joël Greffier
- Department of Medical Imaging, Nîmes University Hospital, University of Montpellier, Medical Imaging Group Nîmes, EA 2415, 30000 Nîmes, France
| | - Djamel Dabli
- Department of Medical Imaging, Nîmes University Hospital, University of Montpellier, Medical Imaging Group Nîmes, EA 2415, 30000 Nîmes, France
| | - Hélène de Forges
- Department of Medical Imaging, Nîmes University Hospital, University of Montpellier, Medical Imaging Group Nîmes, EA 2415, 30000 Nîmes, France
| | - Elise Arcis
- Department of Medical Imaging, Nîmes University Hospital, University of Montpellier, Medical Imaging Group Nîmes, EA 2415, 30000 Nîmes, France
| | - Nadir Al Zouabi
- Department of Medical Imaging, Nîmes University Hospital, University of Montpellier, Medical Imaging Group Nîmes, EA 2415, 30000 Nîmes, France
| | - Ahmed Larbi
- ISERIS imagerie médicale, 34000 Montpellier, France
| | - Jean-Paul Beregi
- Department of Medical Imaging, Nîmes University Hospital, University of Montpellier, Medical Imaging Group Nîmes, EA 2415, 30000 Nîmes, France
| | - Julien Frandon
- Department of Medical Imaging, Nîmes University Hospital, University of Montpellier, Medical Imaging Group Nîmes, EA 2415, 30000 Nîmes, France.
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Hamard A, Greffier J, Bastide S, Larbi A, Addala T, Sadate A, Beregi JP, Frandon J. Ultra-low-dose CT versus radiographs for minor spine and pelvis trauma: a Bayesian analysis of accuracy. Eur Radiol 2020; 31:2621-2633. [PMID: 33034747 DOI: 10.1007/s00330-020-07304-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2020] [Revised: 08/08/2020] [Accepted: 09/16/2020] [Indexed: 01/23/2023]
Abstract
OBJECTIVES To compare diagnosis performance and effective dose of ultra-low-dose CT (ULD CT) versus radiographs in suspected spinal or pelvic ring or hip fracture for minor trauma. METHODS ULD CT, in addition to radiography, was prospectively performed in consecutive patients admitted to the emergency department for minor traumas, during working hours over 2 months. Presence of a recent fracture was assessed by two blind radiologists independently. Sensitivities and specificities were estimated using the best valuable comparator (BVC) as a reference and using a latent class model in Bayesian inference (BLCM). Dosimetric indicators were recorded and effective doses (E) were calculated using conversion coefficient. RESULTS Eighty areas were analyzed in 69 patients, including 22 dorsal spine, 28 lumbar spine, and 30 pelvic ring/hip. Thirty-six fractures (45%) were observed. Applying the BVC method, depending on location, ULD CT sensitivity was 80 to 100% for reader 1 and 85 to 100% for reader 2, whereas radiographic sensitivity was 60 to 85% for reader 1 and 50 to 92% for reader 2. With BLCM approach for reader 2, ULD CT sensitivity for all locations/dorsal spine/lumbar spine and pelvic ring-hip was 87.1/75.9/84.2/76.9% respectively. Corresponding radiograph sensitivity was 73.8, 54.8, 80.4, and 68.7%. Effective doses of ULD CT were similar to radiographs for dorsal and hip locations whereas for lumbar spine, ULD CT effective dose was 1.83 ± 0.59 mSv compared with 0.96 ± 0.59 mSv (p < 0.001). CONCLUSION Sensitivity for fracture detection was higher for ULD CT compared with radiographs with an effective dose comparable to radiographs. KEY POINTS • Ultra-low-dose spine and pelvis CT demonstrates better fracture detection when compared with radiographs. • The effective dose of ultra-low-dose spine and pelvis CT scan and radiographs is comparable. • Replacement of radiographs by ULD CT in daily practice for trauma patients is an option to consider and should be evaluated by a randomized trial.
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Affiliation(s)
- Aymeric Hamard
- Medical Imaging Group, CHU Nimes, Univ Montpellier, Montpellier, France.
| | - Joel Greffier
- Medical Imaging Group, CHU Nimes, Univ Montpellier, Montpellier, France
| | - Sophie Bastide
- Department of Biostatistics, Epidemiology, Public Health and Innovation in Methodology (BESPIM), CHU Nimes, Univ Montpellier, Montpellier, France
| | - Ahmed Larbi
- Medical Imaging Group, CHU Nimes, Univ Montpellier, Montpellier, France
| | - Takieddine Addala
- Medical Imaging Group, CHU Nimes, Univ Montpellier, Montpellier, France
| | - Alexandre Sadate
- Medical Imaging Group, CHU Nimes, Univ Montpellier, Montpellier, France
| | - Jean-Paul Beregi
- Medical Imaging Group, CHU Nimes, Univ Montpellier, Montpellier, France
| | - Julien Frandon
- Medical Imaging Group, CHU Nimes, Univ Montpellier, Montpellier, France
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CT dose optimization for the detection of pulmonary arteriovenous malformation (PAVM): A phantom study. Diagn Interv Imaging 2020; 101:289-297. [DOI: 10.1016/j.diii.2019.12.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Accepted: 12/14/2019] [Indexed: 12/31/2022]
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Image Quality Measured From Ultra-Low Dose Chest Computed Tomography Examination Protocols Using 6 Different Iterative Reconstructions From 4 Vendors, a Phantom Study. J Comput Assist Tomogr 2020; 44:95-101. [DOI: 10.1097/rct.0000000000000947] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Kataria B, Althén JN, Smedby Ö, Persson A, Sökjer H, Sandborg M. Assessment of image quality in abdominal CT: potential dose reduction with model-based iterative reconstruction. Eur Radiol 2018; 28:2464-2473. [PMID: 29368163 PMCID: PMC5938296 DOI: 10.1007/s00330-017-5113-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 08/23/2017] [Accepted: 09/29/2017] [Indexed: 01/20/2023]
Abstract
PURPOSE To estimate potential dose reduction in abdominal CT by visually comparing images reconstructed with filtered back projection (FBP) and strengths of 3 and 5 of a specific MBIR. MATERIAL AND METHODS A dual-source scanner was used to obtain three data sets each for 50 recruited patients with 30, 70 and 100% tube loads (mean CTDIvol 1.9, 3.4 and 6.2 mGy). Six image criteria were assessed independently by five radiologists. Potential dose reduction was estimated with Visual Grading Regression (VGR). RESULTS Comparing 30 and 70% tube load, improved image quality was observed as a significant strong effect of log tube load and reconstruction method with potential dose reduction relative to FBP of 22-47% for MBIR strength 3 (p < 0.001). For MBIR strength 5 no dose reduction was possible for image criteria 1 (liver parenchyma), but dose reduction between 34 and 74% was achieved for other criteria. Interobserver reliability showed agreement of 71-76% (κw 0.201-0.286) and intra-observer reliability of 82-96% (κw 0.525-0.783). CONCLUSION MBIR showed improved image quality compared to FBP with positive correlation between MBIR strength and increasing potential dose reduction for all but one image criterion. KEY POINTS • MBIR's main advantage is its de-noising properties, which facilitates dose reduction. • MBIR allows for potential dose reduction in relation to FBP. • Visual Grading Regression (VGR) produces direct numerical estimates of potential dose reduction. • MBIR strengths 3 and 5 dose reductions were 22-34 and 34-74%. • MBIR strength 5 demonstrates inferior performance for liver parenchyma.
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Affiliation(s)
- Bharti Kataria
- Department of Radiology, Department of Medical and Health Sciences, Center for Medical Image Science and Visualization (CMIV), Linköping University, S-581 85, Linköping, Sweden.
| | - Jonas Nilsson Althén
- Department of Medical Physics, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
| | - Örjan Smedby
- School of Technology and Health (STH), KTH Royal Institute, Stockholm, Sweden
| | - Anders Persson
- Department of Radiology, Department of Medical and Health Sciences, Center for Medical Image Science and Visualization (CMIV), Linköping University, S-581 85, Linköping, Sweden
| | - Hannibal Sökjer
- Department of Medical and Health Sciences, Linköping University, S-581 83, Linköping, Sweden
| | - Michael Sandborg
- Department of Medical Physics, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
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Larbi A, Orliac C, Frandon J, Pereira F, Ruyer A, Goupil J, Macri F, Beregi J, Greffier J. Detection and characterization of focal liver lesions with ultra-low dose computed tomography in neoplastic patients. Diagn Interv Imaging 2018; 99:311-320. [DOI: 10.1016/j.diii.2017.11.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2017] [Revised: 08/20/2017] [Accepted: 11/16/2017] [Indexed: 12/12/2022]
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Shen RF, Yan ZH, Wang J. Effect of automatic exposure technique combined with iterative reconstruction on radiation dose of liver computed tomography. Shijie Huaren Xiaohua Zazhi 2017; 25:3155-3160. [DOI: 10.11569/wcjd.v25.i35.3155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM To observe the effect of automatic exposure technique combined with iterative reconstruction on radiation dose of liver computed tomography (CT).
METHODS From July 2016 to July 2017, 69 patients who underwent liver enhanced CT examinations were randomly divided into control group, group A, and group B (23 cases in each group), in which reconstruction was performed using filtered back projection, automatic exposure technique, and automatic exposure technique combined with iterative reconstruction (strength 3), respectively. The CT values of different parts in CT images, subjective evaluation, objective evaluation, and radiation dose were comparatively analyzed in the three groups.
RESULTS There was no significant difference in the CT values of the liver, portal vein, and paraspinal muscles in the three groups (P > 0.05). The subjective evaluation indexes (such as visibility, pixel performance, and overall diagnostic confidence) of CT images in groups A and B were significantly higher than those of the control group (P < 0.05), and the scores of group B were significantly higher than those of group A (P < 0.05). The noise intensity of groups A and B was significantly lower than that of the control group, while the signal to noise ratio and contrast to noise ratio were significantly higher than those in the control group, with group B performing significantly better than group A (P < 0.05). The radiation doses in groups A and B were 8.57 mSv ± 0.86 mSv and 6.92 mSv ± 0.51 mSv, respectively, which were significantly lower than that in the control group.
CONCLUSION In liver CT examination, using automatic exposure technology combined with iterative reconstruction technology can significantly improve the image quality and reduce radiation dose effectively.
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Affiliation(s)
- Ren-Fu Shen
- Department of Radiology, Mingzhou Hospital of Ningbo, Ningbo 315000, Zhejiang Province, China
| | - Zhong-Hao Yan
- Department of Radiology, Mingzhou Hospital of Ningbo, Ningbo 315000, Zhejiang Province, China
| | - Jin Wang
- Department of Radiology, Mingzhou Hospital of Ningbo, Ningbo 315000, Zhejiang Province, China
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Si-Mohamed S, Greffier J, Bobbia X, Larbi A, Delicque J, Khasanova E, Beregi JP, Macri F. Diagnostic performance of a low dose triple rule-out CT angiography using SAFIRE in emergency department. Diagn Interv Imaging 2017; 98:881-891. [DOI: 10.1016/j.diii.2017.09.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 08/07/2017] [Accepted: 09/07/2017] [Indexed: 12/13/2022]
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Greffier J, Larbi A, Macri F, Beregi JP, Pereira F. EFFECT OF PATIENT SIZE, ANATOMICAL LOCATION AND MODULATION STRENGTH ON DOSE DELIVERED AND IMAGE-QUALITY ON CT EXAMINATION. RADIATION PROTECTION DOSIMETRY 2017; 177:373-381. [PMID: 28453660 DOI: 10.1093/rpd/ncx055] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2017] [Accepted: 04/06/2017] [Indexed: 06/07/2023]
Abstract
To study the effect of patient size, anatomical location and modulation strength (MS) on image-quality and delivered dose of CT scans acquired with automatic-exposure-control system (AEC). Four anthropomorphic phantoms (three paediatric and one thin adult) were studied, and normal and obese adults were simulated by placing bolus plates around the adult phantom. Thorax and abdomen-pelvis CT were performed using an AEC system equipped with five possible MS. Modulated tube current (mAsmod) was compared to Reference mAs and image-noise was assessed. Effective-mAs were lower than Reference-mAs for all but the obese phantom. However, reversal points were estimated for an effective diameter of 27.8 cm in thorax and 26.9 cm in abdomen-pelvis scans, beyond which the patterns of MS were inversed. mAsmod were dependent on attenuation differences among distinct anatomical location. Finally, dose delivered was associated to the mAsmod and patient's size, with both affecting image-quality.
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Affiliation(s)
- Joël Greffier
- Department of Radiology, Nîmes University Hospital, Nîmes, France
| | - Ahmed Larbi
- Department of Radiology, Nîmes University Hospital, Nîmes, France
| | - Francesco Macri
- Department of Radiology, Nîmes University Hospital, Nîmes, France
| | - Jean-Paul Beregi
- Department of Radiology, Nîmes University Hospital, Nîmes, France
| | - Fabricio Pereira
- Department of Radiology, Nîmes University Hospital, Nîmes, France
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Kang H, Park JG, Park SK, Kim BS, Lee KN, Oh KS. Performance of Half-dose Chest Computed Tomography in Lung Malignancy Using an Iterative Reconstruction Technique. KOSIN MEDICAL JOURNAL 2017. [DOI: 10.7180/kmj.2017.32.1.47] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Objectives The purpose of this study was to evaluate the performance of half-dose chest CT using an iterative reconstruction technique in patients with lung malignancies. Methods The Dual-source CT scans were obtained and half-dose datasets were reconstructed with 5 different strengths in 38 adults with lung malignancies. Two radiologists graded subjective image quality; noise, contrast and sharpness at the central/peripheral lung, mediastinum and chest wall of the reconstructed half-dose images, compared with those of standard-dose images, using a three-point scale. A lesion assessment; lesion conspicuity and diagnostic confidence, was also performed. The quantitative image noises; contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) were measured and compared with those of standard-dose images. Results The subjective image noise in the half-dose images was less than that of the standard-dose images. The contrast in strengths 2 to 5 was superior, the sharpness of the lung parenchyma in strengths 3 to 5 was inferior, and the CNR/SNR in all strengths were higher than those of standard-dose images ( P < 0.05). The improvement of subjective image noise and contrast, the decrease in sharpness, were correlated with strength level ( P < 0.05). The lesion conspicuity in half-dose images of strengths 4 and 5 was decreased. The diagnostic confidence of the half-dose images of all strengths was comparable to that of the standard-dose images ( P < 0.05). Conclusions Half-dose chest CT images using an iterative reconstruction technique show decreased image noise, increased contrast, and diagnostic confidence comparable to standard-dose images. Images reconstructed with strength 2 and 3 appear to be the optimal choice in clinical practice.
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Greffier J, Pereira FR, Viala P, Macri F, Beregi JP, Larbi A. Interventional spine procedures under CT guidance: How to reduce patient radiation dose without compromising the successful outcome of the procedure? Phys Med 2017; 35:88-96. [DOI: 10.1016/j.ejmp.2017.02.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 02/15/2017] [Accepted: 02/16/2017] [Indexed: 11/26/2022] Open
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Bommart S, Berthet J, Durand G, Pujol J, Mathieu C, Marty-Ané C, Kovacsik H. Imaging of postoperative complications following surgery for lung cancer. Diagn Interv Imaging 2017; 98:11-20. [DOI: 10.1016/j.diii.2015.06.022] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2014] [Revised: 06/16/2015] [Accepted: 06/18/2015] [Indexed: 12/17/2022]
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Ouaddah A, Boughaci D. Harmony search algorithm for image reconstruction from projections. Appl Soft Comput 2016. [DOI: 10.1016/j.asoc.2016.02.031] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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20
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Macri F, Greffier J, Pereira F, Rosa AC, Khasanova E, Claret PG, Larbi A, Gualdi G, Beregi JP. Value of ultra-low-dose chest CT with iterative reconstruction for selected emergency room patients with acute dyspnea. Eur J Radiol 2016; 85:1637-44. [DOI: 10.1016/j.ejrad.2016.06.024] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 06/13/2016] [Accepted: 06/30/2016] [Indexed: 12/18/2022]
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21
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Ultra-low-dose chest CT with iterative reconstruction does not alter anatomical image quality. Diagn Interv Imaging 2016; 97:1131-1140. [PMID: 27451261 DOI: 10.1016/j.diii.2016.06.009] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 06/20/2016] [Accepted: 06/27/2016] [Indexed: 12/16/2022]
Abstract
PURPOSE To evaluate the effect of dose reduction with iterative reconstruction (IR) on image quality of chest CT scan. MATERIALS AND METHODS Eighteen human cadavers had chest CT with one reference CT protocol (RP-CT; 120kVp/200mAs) and two protocols with dose reduction: low-dose-CT (LD-CT; 120kVp/40mAs) and ultra-low-dose CT (ULD-CT; 120kVp/10mAs). Data were reconstructed with filter-back-projection (FBP) for RP-CT and with FBP and IR (sinogram affirmed iterative reconstruction [SAFIRE®]) algorithm for LD-CT and ULD-CT. Volume CT dose index (CTDIvol) were recorded. The signal-to-noise (SNR), contrast-to-noise (CNR) ratios of LD-CT and ULD-CT and quantitative parameters were compared to RP-CT. Two radiologists reviewed the CT examinations assessed independently the quality of anatomical structures and expressed a confidence level using a 2-point scale (50% and 95%). RESULTS CTDIvol was 2.69 mGy for LD-CT (-80%; P<0.01) and 0.67 mGy for ULD-CT (-95%; P<0.01) as compared to 13.42 mGy for RP-CT. SNR and CNR were significantly decreased (P<0.01) for LD-CT and ULD-CT, but IR improved these values satisfactorily. No significant differences were observed for quantitative measurements. Radiologists rated excellent/good the RP-CT and LD-CT images, whereas good/fair the ULD-CT images. Confidence level for subjective anatomical analysis was 95% for all protocols. CONCLUSIONS Dose reduction with a dose lower than 1 mGy, used in conjunction with IR allows performing chest CT examinations that provide a high quality of anatomical structures.
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Greffier J, Pereira F, Macri F, Beregi JP, Larbi A. CT dose reduction using Automatic Exposure Control and iterative reconstruction: A chest paediatric phantoms study. Phys Med 2016; 32:582-9. [DOI: 10.1016/j.ejmp.2016.03.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 02/23/2016] [Accepted: 03/16/2016] [Indexed: 10/22/2022] Open
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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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Dose reduction with iterative reconstruction in multi-detector CT: What is the impact on deformation of circular structures in phantom study? Diagn Interv Imaging 2016; 97:187-96. [DOI: 10.1016/j.diii.2015.06.019] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Revised: 06/12/2015] [Accepted: 06/15/2015] [Indexed: 11/21/2022]
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Cassagnes L, Pérignon R, Amokrane F, Petermann A, Bécaud T, Saint-Lebes B, Chabrot P, Rousseau H, Boyer L. Aortic stent-grafts: Endoleak surveillance. Diagn Interv Imaging 2016; 97:19-27. [DOI: 10.1016/j.diii.2014.12.014] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 11/28/2014] [Accepted: 12/01/2014] [Indexed: 11/28/2022]
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Ohana M, Labani A, Jeung M, Ghannudi S, Gaertner S, Roy C. Iterative reconstruction in single source dual-energy CT pulmonary angiography: Is it sufficient to achieve a radiation dose as low as state-of-the-art single-energy CTPA? Eur J Radiol 2015. [DOI: 10.1016/j.ejrad.2015.07.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Nguyen NTA, Charron G, Blais D, Roberge D. Turn down the noise—a blinded evaluation of iterative image reconstruction in radiation therapy computed tomography simulation. Pract Radiat Oncol 2015; 5:e393-400. [DOI: 10.1016/j.prro.2014.12.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Revised: 11/23/2014] [Accepted: 12/29/2014] [Indexed: 11/27/2022]
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MDCT of interatrial septum. Diagn Interv Imaging 2015; 96:891-9. [PMID: 25981979 DOI: 10.1016/j.diii.2015.02.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 01/26/2015] [Accepted: 02/03/2015] [Indexed: 11/23/2022]
Abstract
ECG-gated cardiac multidetector row computed tomography (MDCT) allows precise analysis of the interatrial septum (IAS). This pictorial review provides a detailed description of the normal anatomy, variants and abnormalities of the IAS such as patent foramen ovale, congenital abnormalities such as atrial septal defects as well as tumors and tumoral-like processes that develop on the IAS.
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Malgras B, Lo Dico R, Pautrat K, Dohan A, Boudiaf M, Pocard M, Soyer P. Gastrointestinal stenting: Current status and imaging features. Diagn Interv Imaging 2015; 96:593-606. [PMID: 25953525 DOI: 10.1016/j.diii.2015.04.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 04/02/2015] [Indexed: 12/13/2022]
Abstract
The use of stents in the gastrointestinal tract has been subjected to major changes. Initially, the use of stents was restricted to malignant strictures in patients with metastatic disease. But thanks to reduction of the morbidity and mortality rates, they are now used with curative intention and in patients with benign diseases after careful selection. However, for patients presenting with colon obstruction due to an advanced colon carcinoma, the mortality and morbidity are still high. The purpose of this review is to provide an overview of indications, techniques and further developments of the stents in the gastrointestinal tract and to highlight the predominant role of multidetector row computed tomography (MDCT) in the detection of potential complications.
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Affiliation(s)
- B Malgras
- Department of Surgical Oncology, hôpital Lariboisière, AP-HP, 2, rue Ambroise-Paré, 75475 Paris cedex 10, France.
| | - R Lo Dico
- Department of Surgical Oncology, hôpital Lariboisière, AP-HP, 2, rue Ambroise-Paré, 75475 Paris cedex 10, France
| | - K Pautrat
- Department of Surgical Oncology, hôpital Lariboisière, AP-HP, 2, rue Ambroise-Paré, 75475 Paris cedex 10, France
| | - A Dohan
- Department of Abdominal and Interventional Imaging, hôpital Lariboisière, AP-HP, 2, rue Ambroise-Paré, 75475 Paris cedex 10, France; Sorbonne Paris Cité, université Diderot - Paris 7, 10, avenue de Verdun, 75010 Paris, France; UMR Inserm 965, hôpital Lariboisière, 2, rue Ambroise-Paré, 75010 Paris, France
| | - M Boudiaf
- Department of Abdominal and Interventional Imaging, hôpital Lariboisière, AP-HP, 2, rue Ambroise-Paré, 75475 Paris cedex 10, France
| | - M Pocard
- Department of Surgical Oncology, hôpital Lariboisière, AP-HP, 2, rue Ambroise-Paré, 75475 Paris cedex 10, France; Sorbonne Paris Cité, université Diderot - Paris 7, 10, avenue de Verdun, 75010 Paris, France; UMR Inserm 965, hôpital Lariboisière, 2, rue Ambroise-Paré, 75010 Paris, France
| | - P Soyer
- Department of Abdominal and Interventional Imaging, hôpital Lariboisière, AP-HP, 2, rue Ambroise-Paré, 75475 Paris cedex 10, France; Sorbonne Paris Cité, université Diderot - Paris 7, 10, avenue de Verdun, 75010 Paris, France; UMR Inserm 965, hôpital Lariboisière, 2, rue Ambroise-Paré, 75010 Paris, France
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Blum A, Gervaise A, Teixeira P. Iterative reconstruction: Why, how and when? Diagn Interv Imaging 2015; 96:421-2. [DOI: 10.1016/j.diii.2015.04.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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31
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CT pulmonary angiogram with 60% dose reduction: Influence of iterative reconstructions on image quality. Diagn Interv Imaging 2015; 96:487-93. [DOI: 10.1016/j.diii.2014.08.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Revised: 08/26/2014] [Accepted: 08/27/2014] [Indexed: 11/18/2022]
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Dose reduction with iterative reconstruction: Optimization of CT protocols in clinical practice. Diagn Interv Imaging 2015; 96:477-86. [PMID: 25797211 DOI: 10.1016/j.diii.2015.02.007] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 02/16/2015] [Accepted: 02/17/2015] [Indexed: 01/29/2023]
Abstract
OBJECTIVES To create an adaptable and global approach for optimizing MDCT protocols by evaluating the influence of acquisition parameters and Iterative Reconstruction (IR) on dose reduction and image quality. MATERIALS AND METHODS MDCT acquisitions were performed on quality image phantom by varying kVp, mAs, and pitch for the same collimation. The raw data were reconstructed by FBP and Sinogram Affirmed Iterative Reconstruction (SAFIRE) with different reconstruction kernel and thickness. A total of 4032 combinations of parameters were obtained. Indices of quality image (image noise, NCT, CNR, SNR, NPS and MTF) were analyzed. We developed a software in order to facilitate the optimization between dose reduction and image quality. Its outcomes were verified on an adult anthropomorphic phantom. RESULTS Dose reduction resulted in the increase of image noise and the decrease of SNR and CNR. The use of IR improved these indices for the same dose without affecting NCT and MTF. The image validation was performed by the anthropomorphic phantom. The software proposed combinations of parameters to reduce doses while keeping indices of the image quality adequate. We observed a CTDIvol reduction between -44% and -83% as compared to the French diagnostic reference levels (DRL) for different anatomical localization. CONCLUSION The software developed in this study may help radiologists in selecting adequate combinations of parameters that allows to obtain an appropriate image with dose reduction.
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Burckel LA, Defez D, Chaillot P, Douek P, Boussel L. Use of an automatic recording system for CT doses: Evaluation of the impact of iterative reconstruction on radiation exposure in clinical practice. Diagn Interv Imaging 2015; 96:265-72. [DOI: 10.1016/j.diii.2014.11.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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