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Ultra-low dose computed tomography (ULD-CT) was shown to be a good alternative to digital radiographs in various locations. This study aimed to assess the diagnostic sensitivity and specificity of ULD-CT versus digital radiographs in patients consulting for extremity traumas in emergency room.Digital radiography and ULD-CT scan were performed in patients consulting at the emergency department (February-August 2018) for extremity traumas. Fracture detection was evaluated retrospectively by two blinded independent radiologists. Sensitivity and specificity were evaluated using best value comparator (BVC) and a Bayesian latent class model (LCM) approaches and clinical follow-up. Image quality, quality diagnostic and diagnostic confidence level were evaluated (Likert scale). The effective dose received was calculated.Seventy-six consecutive patients (41 men, mean age: 35.2±13.2 years), with 31 wrists/hands and 45 ankles/feet traumas were managed by emergency physicians. According to clinical data, radiography had 3 false positive and 10 false negative examinations, and ULD-CT, 2 of each. Radiography and ULD-CT specificities were similar; sensitivities were lower for radiography, with BVC and Bayesian. With Bayesian, ULD-CT and radiography sensitivities were 90% (95% CI: 87-93%) and 76% (95% CI: 71-81%, P0.0001) and specificities 96% (95% CI: 93-98%) and 93% (95% CI: 87-97%, P=0.84). The inter-observer agreement was higher for ULD-CT for all subjective indexes. The effective dose for ULD-CT and radiography was 0.84±0.14 and 0.58±0.27 µSv (P=0.002) for hand/wrist, and 1.50±0.32 and 1.44±0.78 µSv (P=NS) for foot/ankle.With an effective dose level close to radiography, ULD-CT showed better detection of extremities fractures in the emergency room and may allow treatment adaptation. Further studies need to be performed to assess impact of such examination in everyday practice.ClinicalTrials.gov Identifier: NCT04832490.

To compare the organ-dose and effective-dose (E) delivered to the patient during percutaneous vertebroplasty (PVP) of one thoracic or lumbar vertebra performed under CT guidance or using a fixed C-arm.Consecutive adult patients undergoing PVP of one vertebra under CT-guidance, with optimized protocol and training of physicians, or using a fixed C-arm were retrospectively included from January 2016 to June 2017. Organ-doses were computed on 16 organs using CT Expo 2.4 software for the CT procedures and PCXMC 2.0 for the fixed C-arm procedures. E was also computed with both software. Dosimetric values per anatomic locations for all procedures were compared using the paired Mann-Whitney-Wilcoxon test.In total, 73 patients were analysed (27 men and 46 women, mean age 78 ± 10 years) among whom 35 (48%) underwent PVP under CT guidance and 38 (52%) PVP using a fixed C-arm. The median E was 11.31 [6.54; 15.82] mSv for all PVPs performed under CT guidance and 5.58 [3.33; 8.71] mSv for fixed C-arm and the differences was significant (p0.001). For lumbar PVP, the organ doses of stomach, liver and colon were significantly higher with CT-scan than with the fixed C-arm: 97% (p=0.02); 21% (p=0.099) and 375% (p=0.002), respectively. For thoracic PVP, the lung organ dose was significantly higher with CT-scan than with the fixed C-arm (127%; p0.001) and the oesophagus organ doses were not significantly different (p = 0.626).This study showed that the E and the organ dose on directly exposed organs were both higher for PVP performed under CT-guidance than with the fixed C-arm.

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.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.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) (P0.001). 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], P0.001) 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).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.

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. 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. 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). Sensitivity for fracture detection was higher for ULD CT compared with radiographs with an effective dose comparable to radiographs. • 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.

To determine the margins of non-inferiority of the sensitivity of CT and the sample size needed to test the non-inferiority of CT in comparison with MRI. During a 2-year period, elderly patients with suspected radiographically occult post-traumatic bone injuries were investigated by CT and MRI in two institutions. Four radiologists analyzed separately the CT and MRI examinations to detect post-traumatic femoral injuries. Their sensitivities at CT (SeCT) and MRI (SeMRI) were calculated with the reference being a best valuable comparator (consensus reading of the MRI and clinical follow-up). ROC analysis followed by an exact test (Newcombe’s approach) was performed to assess the 95% confidence interval (CI) for the difference SeCT–SeMRI for each reader. A sample size calculation was performed based on our observed results by using a one-sided McNemar’s test. Twenty-nine out of 102 study participants had a post-traumatic femoral injury. SeCT ranged between 83 and 93% and SeMRI ranged between 97 and 100%. The 95% CIs for (SeCT–SeMRI) were [− 5.3%, + 0.8%], (pR1 = 0.1250), [− 4.5%; + 1.2%] (pR2 = 0.2188), [− 3.4%; + 1.1%] (pR3 = 0.2500) to [− 3.8%; + 1.6%] (pR4 = 0.3750) according to readers, with a lowest limit for 95% CIs superior to a non-inferiority margin of (− 6%) for all readers. A population of 440 patients should be analyzed to test the non-inferiority of CT in comparison with MRI. CT and MRI are sensitive for the detection of radiographically occult femoral fractures in elderly patients after low-energy trauma. The choice between both these modalities is a compromise between the most available and the most sensitive technique. • The sensitivity of four separate readers to detect radiographically occult post-traumatic femoral injuries in elderly patients after low-energy trauma ranged between 83 and 93% at CT and between 97 and 100% at MRI according to a best valuable comparator including MRI and clinical follow-up. • CT is a valuable alternative method to MRI for the detection of post-traumatic femoral injuries in elderlies after low-energy trauma if a 6% loss in sensitivity can be accepted in comparison with MRI. • The choice between CT and MRI is a compromise between the most available and the most sensitive technique.

To determine the best compromise between low radiation dose and suitable image quality for the detection of lytic and sclerotic bone lesions of the lumbar spine and pelvis. A phantom was scanned using the routine protocol (STD, 13 mGy) and six decreasing dose levels. Raw data were reconstructed using level 3 of iterative reconstruction (IR3) with 1-mm slice thickness for the STD protocol and highest IR levels with 3-mm slice thickness for the others. CTDIvol was used for radiation dose assessment. Quantitative criteria (noise power spectrum [NPS], task-based transfer function [TTF], and the detectability index [d′]), as well as qualitative analysis, were used to compare protocols. NPS and TTF were computed using specific software (imQuest). d′ was computed for two imaging tasks: lytic and sclerotic bone lesions. A subjective analysis was performed to validate the image quality obtained on the anthropomorphic phantom with the different dose values. Similar d′ values were found for CTDIvol from 3 to 4 mGy with IR4 and from 1 to 2 mGy for IR5 compared with d′ values using the STD protocol. Image quality was validated subjectively for IR4 but rejected for IR5 (image smoothing). Finally, for the same d′, the dose was reduced by 74% compared with the STD protocol, with the CTDIvol being 3.4 mGy for the lumbar spine and for the pelvis. A dose level as low as 3.4 mGy, in association with high levels of IR, provides suitable image quality for the detection of lytic and sclerotic bone lesions of the lumbar spine and pelvis. • A CTDI vol of 3.4 mGy, in association with high iterative reconstruction level, provides suitable image quality for the detection of lytic and sclerotic bone lesions, both at objective and subjective analysis. • Compared with the standard protocol, radiation dose can be reduced up to 74% for the lumbar spine and pelvis. • A task-based image quality assessment using the detectability index represents an objective method for the assessment of image quality and bridges the gap between complex physical metrics and subjective image analysis.

International audience; Study objective:To evaluate the diagnostic performance of chest ultralow-dose computed tomography (CT) compared with chestradiograph for minor blunt thoracic trauma.Methods:One hundred sixty patients with minor blunt thoracic trauma were evaluatedfirst by chest radiograph and subsequentlywith a double-acquisition nonenhanced chest CT protocol: reference CT and ultralow-dose CT with iterative reconstruction. Twostudy radiologists independently assessed injuries with a structured report and subjective image quality and calculated certaintyof diagnostic confidence level.Results:Ultralow-dose CT had a sensitivity and specificity of 100% compared with reference CT in the detection of injuries (187lesions) in 104 patients. Chest radiograph detected abnormalities in 82 patients (79% of the population), with lower sensitivityand specificity compared with ultralow-dose CT (P

International audience; Purpose: To compare the evaluation of malignant focal liver lesions (FLLs) using a semi-automated RECIST tool with a standard and an ultra-low dose (ULD) computed tomography (CT) protocol.Materials and methods: Thirty-four patients with malignant FLLs underwent two abdominal-pelvic CT examinations one using a standard protocol and one using an ULD protocol. There were 23 men and 11 women with a mean age 64.3±14.4 (SD) years (range: 22-91 years). Dosimetric indicators were recorded, and effective dose was calculated for both examinations. Mean malignant FLL attenuation, image noise and contrast-to-noise-ratio (CNR) were compared. The largest malignant FLL per patient was evaluated using the semi-automated RECIST tool to determine longest axis length, longest orthogonal axis length, volume and World Health Organisation area.Results: Dosimetric values were significantly reduced by -56% with ULD compared to standard protocol. No differences in mean malignant FLL attenuation values were found between the two protocols. Image noise was significantly increased for all locations (P

Background Strategic drug therapy for rheumatoid arthritis (RA) patients with prolonged remission is not well defined. According to recent guidelines, tapering biological Disease-Modifying Anti-Rheumatic Drugs (bDMARDs) may be considered. We aimed to evaluate the effectiveness of long-term maintenance of tocilizumab (TCZ) treatment after the progressive tapering of infusions. Methods We conducted an exploratory, prospective, single-center, open-label study, on RA patients with sustained remission of at least 3 months and treated with TCZ infusions every 4 weeks. The initial re-treatment interval was extended to 6 weeks for the first 3 months. Thereafter, the spacing between infusions was determined by the clinician. Successful long-term maintenance following the tapering of TCZ infusions was defined by patients still treated after two years by TCZ with a minimum dosing interval of 5 weeks. Results Thirteen patients were enrolled in the study. Eight out of thirteen were still treated by TCZ after two years. Successful long-term maintenance was possible in six patients, with four patients maintaining a re-treatment interval of 8-weeks or more. We observed 5 patients with TCZ withdrawal: one showing adverse drug reaction (neutropenia) and four with secondary failure. Patients achieving successful long-term maintenance with TCZ were significantly younger than those with secondary failure (p p Conclusions A progressive tapering of TCZ infusions may be possible for many patients. However, larger studies, including more patients, are needed to confirm this therapeutic option. Trial registration NCT02909998. Date of registration: October 2008.

International audience; Purpose: To compare the noise-magnitude and noise-texture obtained using strong kernel across two generations of iterative reconstruction (IR) algorithms proposed by three manufacturers.Materials and methods: Five computed tomography (CT) systems equipped with two generations of IR algorithm (hybrid/statistical IR [H/SIR] or full/partial model-based IR [MBIR]) were compared. Acquisitions on Catphan 600 phantom were performed at 120kV and three dose levels (CTDIvol: 3, 7 and 12mGy). Raw data were reconstructed using standard "bone" kernel for filtered back projection and one iterative level of two generations of IR algorithms. Contrast-to-noise ratio (CNR) was computed using three regions of interest placed semi-automatically: two placed in the low-density polyethylene and Teflon inserts and another placed on the solid water. Noise power spectrum (NPS) was computed to assess the NPS-peak and noise-texture.Results: CNR was significantly greater in MBIR compared to H/SIR algorithms for all CT systems (P

OBJECTIVES: Our objective was to determine disagreement rates in radiological reports provided by using a double-reading protocol in a national teleradiology company. METHODS: From January 2015 to July 2016, 134169 radiological exams from 36 French centers, benefited outsourced interpretations by certified radiologists, in both regular and after-hours activities. Of these, 2040 CT and MR-scans (1.5%) were subjected to a second opinion by other radiologists in the field of their anatomical specialty (cerebral, thoracic, abdominal-pelvic, and osteoarticular). A five-point agreement scale graded from 0 to 4 was assigned for each exam. Disagreements were considered as minor if no clinical consequence for patient (scores 1 and 2) and major if potential clinical consequence (score 3 and 4). Independent radiologists performed a retrospective analysis and a stratified statistical analysis. RESULTS: Double reading was performed on CT-scans (n = 934/2040, 45.8%) and MR-scans (n = 1106/2040, 54.2%) performed in regular (80.1%) and after-hours activities (19.9%). Disagreement scores occurred in 437 exams (21.4%), including major disagreements in 59 (2.9%). Among these, 48/754 were assigned by the thoracic second reader (6.4%), 6/70 by the abdominal-pelvic second reader (8.6%), 3/901 by the osteoarticular second reader (0.3%), and 2/315 by the cerebral second reader (0.6%), with statistical significant difference. No additional disagreement rate was observed in regular and after-hours activities (P = 0.63). CONCLUSIONS: Double-reading of outsourced CT and MRI interpretations yielded 21.4% disagreement rate, with potential clinical consequence for patient in 2,9% of the cases. These results are in accordance with those previously reported and suggests that quality assurance of outsourced interpretations is needed.

International audience; Objective To assess diagnostic reference levels (DRLs) in surgery for the most frequent procedures as required by the European Directive 2013/59/Euratom. Methods A survey was conducted in six centers. Eight orthopedic, urology and gastrointestinal surgical procedures were analyzed. Kerma area product (KAP) and fluoroscopy time (FT) were recorded for 50 patients (except for elbow 30 patients) per procedure and per center from September 2016 to September 2017. DRLs were calculated as the 3rd quartiles of the distributions. For shoulder surgery, DRLs were defined according to the complexity of the procedure. For hand/wrist and foot/ankle surgery, DRLs were defined according to the technology (conventional C-arm vs. mini-C-arm). Results Results of 1870 procedures were retrieved. DRLs were calculated for the two dosimetric indicators and the eight procedures. DRLs were 2130 mGy.cm2 and 1.4 min for proximal femoral intramedullary nail, 1185 mGy.cm2 and 0.9 min for laparoscopic cholecystectomy and 2195 mGy.cm2 and 1.0 min for double-J (pigtail) ureteral catheter insertion. For shoulder surgery, KAP and FT were significantly higher (p andlt; 0.05) for intramedullary procedures compared to extramedullary procedures. For hand/wrist and foot/ankle surgery, the KAPs were significantly higher (p andlt; 0.05) with conventional C-arm compared to mini-C-arm, but FTs were not significantly different (p not significant). Conclusion This study reports DRLs in surgery based on a multicentric survey. Key Points • Delivered dose in surgery depends on procedure, practice and patient. • Diagnostic reference levels (DRLs) are proposed for eight surgical procedures. • DRLs are useful to benchmark practices and optimize protocols. © 2018, European Society of Radiology.

International audience; PURPOSE: To assess the value of the routine use of radiochromic films in abdominopelvic embolization procedures to improve patient follow-up. METHODS: A total of 55~patients who underwent transcatheter abdominopelvic embolization were prospectively included. Six types of procedures were evaluated including hepatic chemoembolization (HCE), gonadal veins embolization (GVE), uterine elective embolization (UEE), uterine urgent embolization (UUE), abdominal elective embolization (AEE), and abdominal urgent embolization (AUE). Dosimetric indicators (DIs) such as air-kerma (AK) and kerma-area-product (KAP) were collected and peak skin dose (PSD) was measured with radiochromic films. Correlations between PSD and DIs were searched for. RESULTS: The mean (\textpmstandard deviation [SD]) PSD for the various procedures were: 1033\textpm502~mGy for HCE; 476\textpm271~mGy for GVE; 460\textpm171 mGy for UEE; 531\textpm263~mGy for UUE; 708\textpm896~mGy for AEE; 683\textpm392~mGy for AUE. Strong correlations were observed between PSD and DIs (r=0.974 for AK and r=0.925 for KAP). PSD was\textgreater2Gy in one procedure and all procedures (7/132) procedures resulted in AK\textgreater2Gy, mostly for HCE and AEE. CONCLUSION: Dosimetry using radiochromic film is only appropriate for HCE, AEE and AUE, whereas dose-mapping systems present a more suitable solution for all embolizations including those with AK that occasionally exceed 2Gy.

To compare the diagnostic accuracy of DWI and STIR sequences in Whole body (WB) MRI of SpA patients. Twenty consecutive patients with confirmed active SpA and 20 controls were investigated with identical WB MRI protocols, including DWI and STIR images. Two observers recorded 'lesions' (high signal intensity foci on STIR and high b-value DWI) in 17 anatomical areas, making a 17-point 'area score' and a 40-point 'lesion score'. ROC performance, inter-observer agreement, correlation with clinical parameters and spine and sacro-iliac joints (SIJ) MRI scores were assessed. SpA patients had significantly higher lesion scores on DWI than on STIR (p

International audience; Objective: To assess the interactive Skin Dose Map® tool (SDMTool) integrated to the radiation dose management system (RDMS) DoseWatch® with Gafchromic® films for implementation in routine practice.Methods: A retrospective dose estimation software SDMTool was used to calculate Peak Skin Dose (PSD) and display the patient skin dose distribution. PSD was calculated with a triangle mesh of 0.055 cm2 resolution on ICRP 110 male anthropomorphic phantom and with a square ROI of 1 cm2 on flat phantom. The tool uses Radiation Dose Structured Reports (RDSR) data to model exposure events and calculate the PSD per event. The PSD and the skin dose distribution estimated with SDMTool were evaluated in comparison with Gafchromic® films positioned under the PMMA phantom (20 cm) for 13 configurations. Measurements were performed on a Philips system. Statistical analysis were carried out to compare PSDFilm and PSDSDM.Results: Average differences between PSDFilm and PSDSDM were 6% ± 6% (range from -3% to 22%) for flat phantom and 5% ± 7% (range from -3% to 25%) for ICRP phantom. Concordance was good between the measured PSDFilm and the estimated PSDSDM with Lin's coefficient estimation and 95% Confidence Interval of 0.979 [0.875; 0.984] for flat phantom and 0.977 [0.877; 0.985] for ICRP phantom. Dose map representations are concordant for 11 of the 13 tests on PMMA phantom. Disparities arose from the limitations of the RSDR format: table displacement during fluoroscopy events and the use of wedge filter.Conclusion: The results found in this experimental evaluation show that the SDMTool is a suitable alternative to Gafchromic® film to calculate PSD.

To compare the diagnostic accuracy of whole-body T1, short tau inversion recovery (STIR), high b-value diffusion-weighted imaging (DWI), and sequence combinations to detect bone involvement in prostate cancer (PCa) and multiple myeloma (MM) patients. We included 50 consecutive patients with PCa at high risk for metastasis and 47 consecutive patients with a histologically confirmed diagnosis of MM who received whole-body MRI at two institutions from January to December 2015. Coronal T1, STIR, and reconstructed coronal high b-values DWI were obtained for all patients. Two musculoskeletal radiologists read individual sequences, pairs of sequences (T1-DWI, T1-STIR, and STIR-DWI), and all combined (T1-STIR-DWI) to detect bone involvement. Receiver operating characteristic curve analysis was used to assess diagnostic performance according to a “best valuable comparator” combining baseline and 6-month imaging and clinical and biological data. Interobserver agreement was calculated. Interobserver agreement for individual and combined MRI sequences was very good in the PCa group and ranged from good to very good in the MM group (0.76–1.00). In PCa patients, T1-DWI, T1-STIR, and T1-STIR-DWI showed the highest performance (sensitivity = 100% [95% CI = 90.5–100%], specificity = 100% [75.3–100%]). In MM patients, the highest performance was achieved by T1-STIR-DWI (sensitivity = 100% [88.4–100%], specificity = 94.1% [71.3–100%]). T1-STIR-DWI significantly outperformed all sequences (p

Purpose The purpose of this study was to evaluate a cooperation program in order to compare incidence of complications after peripherally inserted central catheter (PICC) placement between radiologists and technicians. Materials and methods PICC placement technique was standardized with ultrasound-guided puncture and fluoroscopic guidance. Numbers of PICC delegated to technicians, and PICC placement difficulties, were prospectively recorded for the whole study population whereas complications such as PICC infection, deep venous thrombosis and catheter occlusion were prospectively recorded until PICC removal for a subgroup of patients included during one month. Results A total of 722 patients had PICC placement. There were 382 men and 340 women with a mean age of 66.8 ± 15.8 (SD) years (range: 18–94 years); of these, 442/722 patients (61.22%) were included in the cooperation program with 433/722 patients (59.97%) who effectively had PICC placement by technicians and 289/722 (40.03%) by radiologists. Technicians needed radiologists’ help for 23/442 patients (5.20%) including 6 failed PICC placement subsequently performed by radiologists. Twenty complications (20/77; 26%) were recorded in the subgroup of 77 patients studied for complications. No differences in complications rate were found between the 33 patients who underwent PICC placement by radiologists (6/33; 18%) and the 44 patients who underwent PICC placement by technicians (14/44; 32%) (P = 0.296). Complications included 8 PICC-related infections (8/77; 10.4%), 3 deep venous thromboses (3/77; 3.9%) and 9 catheter occlusions (9/77; 11.7%). Conclusion PICC placement led by technicians is feasible and safe without statistical difference in terms of complications compared to PICC placement made by radiologists.

International audience; Purpose: To compare the noise-magnitude and noise-texture across two generations of iterative reconstruction (IR) algorithms proposed by three manufacturers according to the dose level. Materials and methods: Five computed tomography (CT) systems equipped with two generations of IR algorithms (hybrid/statistical IR [H/SIR] or full/partial model-based IR [MBIR]) were compared. Acquisitions on Catphan 600 phantom were performed at 120kV and three dose levels (3-, 7- and 12-mGy). Raw data were reconstructed using standard "soft tissue" kernel for filtered back projection and one iterative level of two generations of IR algorithms. Contrast to-noise-ratio (CNR) was computed using three regions of interest: two of them placed in the low-density polyethylene (LDPE) and Teflon® inserts and another placed on the solid water. Noise power spectrum (NPS) was computed to assess the noise-magnitude (NPS peak) and noise-texture (NPS spatial frequency). Results: CNR increased significantly in MBIR compared to H/SIR algorithms for General-Electric (GE) Healthcare (45%±12 [SD]) and Philips Healthcare systems (62%±11 [SD]) (P

International audience; Purpose To compare metallic artifact reduction (MAR) algorithms proposed by four vendors according to the delivered dose and iterative level using a phantom study. Methods Four CT systems (Revolution GSI®, Ingenuity Elite®, Somatom Edge®, and Aquilion Prime®) equipped with MAR algorithms (Smart MAR®, O-MAR®, iMAR®, and SEMAR®) were compared. Acquisitions were performed with CIRS model 062M Phantom containing a titanium rod core insert using 120 kV and two dose levels (3 and 7 mGy). Images were reconstructed with and without MAR algorithms using standard “soft tissue” kernel for filtered back projection (FBP) and intermediary iterative level. Artifact propagation was assessed by counting the number of pixels containing a HU outside a defined threshold interval (> 100HU and < −80 HU). Artifact correction was evaluated by computing the differences between images with and without MAR. Results Accuracy of NCT values increased significantly using MAR algorithms, IR, and high dose levels (P < 0.001). Image noise reduced −31 ± 15 (SD) % (range: −50%;−14%) with Smart-MAR®, −28 ± 3 (SD) % (range −31%; −25%) with O-MAR®, −32 ± 7 (SD) % (range: −40%; −24%) with iMARCN®, −52 ± 8 (SD) % (range: −60%; −42%) with iMARTH® and −29 ± 6 (SD) % (range: −37%; −23%) with SEMAR®. The number of pixels outside the threshold interval was also reduced using MAR algorithms. Each MAR algorithm corrected in distinct patterns, with satisfactory artifact correction for all MAR algorithms. Conclusion This study demonstrates that artifact correction using MAR algorithms differs according to the main manufacturers, although corrections are satisfactory for all systems. Corrections also improved by using IR and increasing the dose level.

The benefit of an intradiscal injection of corticosteroids for low back pain with active discopathy is not totally resolved.The objective of this study was to estimate the clinical efficacy of an intradiscal injection of glucocorticoids versus lidocaine in patients with low back pain and active discopathy (Modic 1 changes).A prospective, single-blind, randomized controlled study was conducted in 2 tertiary care centers with spine units. We enrolled 50 patients (mean age 50 years; 46% women) with lumbar active discopathy on MRI and failure of medical treatment for more than 6 weeks. Participants were randomly assigned to receive an intradiscal injection of glucocorticoids [50mg prednisolone acetate (GC group), n=24] or lidocaine [40mg (L group), n=26] by senior radiologists. Outcome measures were low back pain in the previous 8 days (10-point visual analog scale), Dallas Pain Questionnaire, Oswestry Disability Index, analgesic treatment and work status at 1, 3 and 6 months as well as pain at 1, 2 and 3 weeks. The primary outcome was change in pain between baseline and 1 month.Data for 39 patients (78%; 17 in the GC group, 22 in the L group) were analyzed for the primary outcome. Pain intensity was significantly reduced at 1 month in the GC versus L group [mean (SD) -2.7 (2.3) and +0.1 (2.0), P0.001] but not at 3 and 6 months. At 1 and 3 months, the groups significantly differed in daily activities of the Dallas Pain Questionnaire in favour of the GC group. The groups did not differ in consumption of analgesics or professional condition at any time. No serious intervention-related adverse events occurred. Study limitations included patients lost to the study because of injection-related technical issues in the L5/S1 disc and short time of follow-up.As compared with intradiscal injection of lidocaine, intradiscal injection of prednisolone acetate for low back pain with active discopathy may reduce pain intensity at 1 month but not at 3 and 6 months.

Resume Contexte Des etudes recentes ont montre que l’IRM etait performante dans l’evaluation des differentes composantes de la pubalgie du sportif (PS). Cependant, et a notre connaissance, aucune etude n’a evalue la correlation systematique entre une description precise des lesions tendineuses ou parietales en IRM, les constatations chirurgicales et l’analyse histologique. De fait, nous avons realise une etude cas-temoin afin de determiner si l’IRM pouvait evaluer precisement une tendinopathie du long adducteur (LA), les lesions parietales, en comparaison a la chirurgie ainsi qu’a l’analyse histologique. Hypothese Dans la PS, l’IRM peut differencier une etiologie symphysaire, musculotendineuse ou d’origine parietale inguinale. Materiel et methodes Dix-huit patients furent consecutivement inclus dans notre etude entre novembre 2011 et avril 2013 pour PS. Pour constituer un groupe temoin, nous avons egalement inclus 18 sujets masculins. Toutes les IRM ont ete lues en consensus par 2 radiologues osteo-articulaires a la recherche de symphysite pubienne et pour evaluation musculotendineuse ainsi que parietale abdominale, puis comparees a la chirurgie et a l’analyse histologique. Resultats Concernant la symphysite pubienne, nous avons mis en evidence 4 œdemes medullaires en miroir (14 %), 2 fentes secondaires (7 %) et 2 lesions du ligament pubien superieur (7 %). Pour les lesions du LA, nous avons essentiellement rencontre 13 œdemes medullaires asymetriques (46 %), 15 hyperemies (54 %). Et en ce qui concerne la paroi abdominale, le calibre de l’orifice inguinal profond dans le groupe symptomatique et dans le groupe temoin etait respectivement 27,3 ± 6,4 mm et 23,8 ± 6,3 mm. La correlation entre l’evaluation IRM, et chirurgie/histologie etait faible : 20 % pour le tendon LA et 9 % pour la paroi abdominale. Si nous avions choisi le critere de jugement « atteint contre non atteint », cette correlation aurait ete plus forte : 100 % pour le tendon LA et 73 % pour la paroi abdominale. Conclusion L’evaluation IRM de la pubalgie chronique du sportif concerne preferentiellement la tendinopathie du LA et la dehiscence de l’orifice inguinal profond avec une correlation importante au couple chirurgie/histologie., si l’on considere uniquement l’item « atteint contre non atteint », et malgre une faible correlation si l’on essaye de classifier precisement ces lesions. Niveau de preuves III. Etude cas-temoin.

Resume Les luxations carpiennes et carpometacarpiennes representent un groupe heterogene de pathologies resultant d’un traumatisme a haute energie. La luxation peri-lunaire est la plus courante et la plus connue des luxations carpiennes, se presentant generalement apres un traumatisme en hyper-extension. D’autres formes plus rares ont des mecanismes traumatiques differents. Les luxations carpometacarpiennes (LCMC) sont rares et peuvent affecter une ou plusieurs articulations du carpe. En l’absence de traitement, ces lesions sont une cause d’instabilite du poignet. L’objectif de ce manuscrit est d’aborder une approche radiologique systematique dans l’evaluation du poignet traumatique et d’illustrer deux cas aigus et rares de LCMC.

International audience; Posttraumatic carpal and carpometacarpal dislocations represent a heterogeneous group of disorders resulting from high-energy wrist trauma. Perilunate injury is the most common and best-known manifestation of carpal dislocation, typically occurring after hyperextension trauma. Other forms are very rare and have different causative mechanisms. Carpometacarpal (CMC) dislocations are also uncommon and may affect isolated or multiple CMC joints. These lesions are prone to wrist instability if not treated promptly. The aim of this article is to provide a systematic radiologic approach to the evaluation of wrist injury and to present two acute cases of rare CMC dislocations.

Resume Les tumeurs et pseudotumeurs du genou sont des pathologies frequentes. La synoviale ayant une place importante dans le genou, les tumeurs et pseudotumeurs d’origine synoviale sont donc tres frequentes. L’IRM joue un role primordial dans le bilan et la caracterisation de ces lesions. La demarche diagnostique doit etre systematisee. Il faut tout d’abord localiser la lesion dans le genou, puis la rattacher a une structure anatomique ; enfin le contexte clinique, epidemiologique (âge du patient, argument de frequence, signes associes) et la caracterisation en IRM permettent de mieux preciser le diagnostic.

Resume L’articulation du genou est une des regions anatomiques les plus explorees en imagerie. La decouverte d’une anomalie osseuse, en rapport ou non avec la symptomatologie ayant motive l’examen, est extremement frequente. L’objectif de ce travail est de presenter une revue iconographique des pathologies osseuses les plus frequentes du genou. Rappelons d’emblee que l’IRM doit toujours etre interpretee en ayant la connaissance de la clinique, de la biologie et des cliches standard.

Resume La graisse n’est pas un simple tissu de comblement. En plus de son role de reserve energique et de son implication dans des mecanismes hormonaux, elle possede dans certaines zones du corps des proprietes mecaniques sous-estimees. Ainsi, au niveau du genou, la graisse anterieure, qui presente une anatomie plus complexe qu’il n’y parait, doit resister a d’importantes forces de cisaillement et de compression. Lorsque ces contraintes mecaniques depassent les limites physiologiques, on observera des lesions specifiques peu connues. La graisse superficielle est ainsi un site de dissection « aigue » appele decollement de Morel-Lavallee, ou subit un clivage plus complexe, moins franc en cas de cisaillement chronique, aboutissant a la formation d’une « neo-bursite » ou « hygroma ». La graisse anterieure profonde se decompose en 3 « matelas » principaux intracapsulaires mais extrasynoviaux : le corps adipeux infrapatellaire (CAiP) ou graisse de Hoffa, le matelas suprapatellaire et enfin le matelas prefemoral ou supratrochleen. Le CAiP de Hoffa joue un role mecanique important en servant « d’amortisseur » et de « guide » au tendon patellaire et meme a la patella lors des mouvements de flexion-extension. Lorsque les contraintes repetees sur cette structure anatomique deviennent trop importantes, elle reagit dans un premier temps par une reaction inflammatoire et une augmentation de volume, puis peut secondairement se « metaplasier » en tissu fibreux, voire en cartilage ou en os. De facon plus rare, les deux autres matelas graisseux profonds (suprapatellaire et supratrochleen) peuvent egalement, suite a des contraintes repetees, subir le meme type de remaniement inflammatoire et evoluer vers une metaplasie en un tissu plus « dur », avec comme corollaire une douleur anterieure et une limitation fonctionnelle.

International audience; Tumors and tumor-like lesions of the knee are common conditions. Because the synovial membrane covers a large part of the knee, tumors and tumor-like lesions of the knee are mostly synovial. Magnetic resonance imaging (MRI) plays a major role in the assessment and characterization of these lesions. However, the diagnostic approach of these lesions must be performed systematically. First, the lesion must be precisely located, and then the anatomical structure involved must be determined. Finally, clinical background that includes the age of the patient, frequency of the disease and, if any, associated signs as well as MRI characteristics must be analyzed. In this review, we describe the anatomy of the knee and its compartments and provide a description of the main tumors and tumor-like lesions of the knee. We present a diagnostic approach based on the location within the knee of the lesions and the anatomical structures involved.

OBJECTIVES To determine the proportion of prostate cancer (PCa) patients with oligometastatic disease (≤3 synchronous lesions) using whole body magnetic resonance imaging with diffusion-weighted imaging (WB-MRI/DWI). To determine the proportion of patients with nodal disease confined within currently accepted target areas for extended lymph node dissection (eLND) and pelvic external beam radiation therapy (EBRT). SUBJECTS AND METHODS Two radiologists reviewed WB-MRI/DWI studies in 96 consecutive newly diagnosed metastatic PCa patients; 46 patients with newly diagnosed castration naive PCa (mHNPC) and 50 patients with first appearance of metastasis during monitoring for non-metastatic castration resistant PCa (M0 to mCRPC). The distribution of metastatic deposits was assessed and the proportions of patients with oligometastatic disease and with LN metastases located within eLND and EBRT targets were determined. RESULTS Twenty-eight percent of mHNPC and 50% of mCPRC entered the metastatic disease with ≤3 sites. Bone metastases (BM) were identified in 68.8% patients; 71.7% of mHNPC and 66% mCRPC patients. Most commonly involved areas were iliac bones and lumbar spine. Enlarged lymph nodes (LN) were detected in 68.7% of patients; 69.6% of mHNPC and 68.0% of mCRPC. Most commonly involved areas were para-aortic, inter-aortico-cava, and external iliac areas. BM and LN were detected concomitantly in 41% of mHNPC and 34% of mCRPC. Visceral metastases were detected in 6.7%. Metastatic disease was confined to LN located within the accepted boundaries of eLND or pelvic EBRT target areas in only ≤25% and ≤30% of patients, respectively. CONCLUSIONS Non-invasive mapping of metastatic landing sites in PCa using WB-MRI/DWI shows that 28% of the mHNPC patients, and 52% of the mCRPC can be classified as oligometastatic, thus challenging the concept of metastatic targeted therapy. More than two thirds of metastatic patients have LN located outside the usually recommended targets of eLND and pelvic EBRT. Prophylactic or salvage treatments of these sole areas in patients with high-risk prostate cancer may not prevent the emergence of subsequent metastases. Prostate © 2016 Wiley Periodicals, Inc.

International audience; PURPOSE:To evaluate the impact of Automatic Exposure Control (AEC) on radiation dose and image quality in paediatric chest scans (MDCT), with or without iterative reconstruction (IR).METHODS:Three anthropomorphic phantoms representing children aged one, five and 10-year-old were explored using AEC system (CARE Dose 4D) with five modulation strength options. For each phantom, six acquisitions were carried out: one with fixed mAs (without AEC) and five each with different modulation strength. Raw data were reconstructed with Filtered Back Projection (FBP) and with two distinct levels of IR using soft and strong kernels. Dose reduction and image quality indices (Noise, SNR, CNR) were measured in lung and soft tissues. Noise Power Spectrum (NPS) was evaluated with a Catphan 600 phantom.RESULTS:The use of AEC produced a significant dose reduction (p

Resume L’IRM en imagerie musculosquelettique est, de nos jours, un outil indispensable pour la prise en charge diagnostique, le « staging » et le suivi des patients. La diffusion (DWI) fait partie des sequences fonctionnelles qui informent sur le degre de cellularite des lesions. Grâce a la mesure du coefficient apparent de diffusion (ADC), elle renseigne sur les mouvements des molecules d’eau extracellulaires extravasculaires. Malgre une litterature profuse dans differents domaines, de nombreuses etudes different et apportent des conclusions contradictoires sur l’utilisation et la pertinence de cette sequence. Dans notre experience, ses capacites de detection en pathologie oncologique en font une technique validee dans le bilan d’extension (local, regional et a distance) de certains cancers solides. En termes de caracterisation tissulaire, elle ne peut pour l’instant constituer, selon nous, qu’une aide diagnostique mais toujours en comparaison avec le signal de la lesion sur les sequences conventionnelles, surtout en cas de pathologie oncologique. Concernant le suivi sous traitement des pathologies cancereuses ou rhumatismales, l’evolution de l’ADC pourrait representer un argument supplementaire de reponse au traitement plus fiable que pour la caracterisation initiale d’une lesion, car toujours a interpreter en fonction de l’ADC initial de la lesion et de la connaissance des therapeutiques du patient.

Resume La fasciite a eosinophiles est une entite rare decrite pour la premiere fois par Shulman en 1974 et localisee preferentiellement aux portions distales des membres. L’IRM est l’examen d’imagerie de choix aussi bien pour le diagnostic que pour le suivi de cette affection. La forme classique typique en IRM se caracterise par une atteinte exclusive des fascias, mais il peut exister de facon moins frequente des anomalies de signal des tissus musculaires et de la graisse hypodermique adjacents aux fascias. Les diagnostics differentiels du syndrome de Shulman en IRM sont nombreux et varies parmi les affections des tissus mous superficiels et profonds.

Objectives To evaluate the distortion of circular structures induced by the increased image noise related to dose reduction and to assess the effect of iterative reconstruction (IR). Methods MDCT acquisitions were performed with 120 kVp for 200/100/60/40/20 mAs with 100%/50%/30%/20%/10% of dose. Raw data were reconstructed by filtered back projection (FBP) and with two IR strengths. Image quality indices referred to water and acrylic were measured on a quality image phantom. Areas, perimeters, circularity were measured on the circular inserts of 4.8, 7.9 and 11.1 mm on a morphological phantom. Results Dose reduction resulted in increased image noise and in decreased signal to noise ratio and contrast to noise ratio. IR improved these indices for the same dose without affecting the signal (number CT) and spatial resolution (modulation transfer function). The values of area, perimeter and circularity were altered compared to the actual value and the inserts were visually deformed with the dose reduction. IR improved these three parameters. Image quality indices, areas, perimeters and circularity of inserts were similar between the acquisition at 100% of the dose in FBP, 50% in strength-3 and 30% in strength-5 with different curves of noise power spectrum. Conclusion IR associated to 70% of dose reduction modifies the images smooth (NPS) but maintains adequate image quality indices without causing distortions of circular structures.

Stress maneuvers inspired by arthroscopic techniques have been previously studied for MRA of shoulder, hip, knee and wrist. Axial traction in MRA of the wrist is advantageous to study intrinsic ligaments and cartilage, but seems useless to assess tendons or nerves disorders. Based on our experience and a well-chosen iconography, we would like to emphasize the contribution of axial traction in MRA of wrist disorders.

Whole-body coverage using MRI was developed almost 2 decades ago. The first applications focused on the investigation of the skeleton to detect neoplastic disease, mainly metastases from solid cancers, and involvement by multiple myeloma and lymphoma. But the extensive coverage of the whole musculoskeletal system, combined with the exquisite sensitivity of MRI to tissue alteration in relation to different pathologic conditions, mainly inflammation, has led to the identification of a growing number of indications outside oncology. Seronegative rheumatisms, systemic sclerosis, inflammatory diseases involving muscles or fascias, and multifocal osseous, vascular, or neurologic diseases represent currently validated or emerging indications of whole-body MRI (WB-MRI). We first illustrate the most valuable indications of WB-MRI in seronegative rheumatisms that include providing significant diagnostic information in patients with negative or ambiguous MRI of the sacroiliac joints and the lumbar spine, assessing disease activity in advanced (ankylosed) central disease, and evaluating the peripherally dominant forms of spondyloarthropathy. Then we review the increasing indications of WB-MRI in other rheumatologic and nonneoplastic disorders, underline the clinical needs, and illustrate the role of WB-MRI in the positive diagnosis and evaluation of disease burden, therapeutic decisions, and treatment monitoring.

Purpose To assess the distribution of bone lesions in patients with prostate cancer (PCa) and those with multiple myeloma (MM) using whole-body magnetic resonance imaging (MRI); and to assess the added value of four anatomical regions located outside the thoraco-lumbo-pelvic area to detect the presence of bone lesions in a patient-based perspective. Materials and methods Fifty patients (50 men; mean age, 67 ± 10 [SD] years; range, 59–87 years) with PCa and forty-seven patients (27 women, 20 men; mean age, 62.5 ± 9 [SD] years; range, 47–90 years) with MM were included. Three radiologists assessed bone involvement in seven anatomical areas reading all MRI sequences. Results In patients with PCa, there was a cranio-caudal increasing prevalence of metastases (22% [11/50] in the humeri and cervical spine to 60% [30/50] in the pelvis). When the thoraco-lumbo-pelvic region was not involved, the prevalence of involvement of the cervical spine, proximal humeri, ribs, or proximal femurs was 0% in patients with PCa and ≥ 4% (except for the cervical spine, 0%) in those with MM. Conclusion In patients with PCa, there is a cranio-caudal positive increment in the prevalences of metastases and covering the thoraco-lumbo-pelvic area is sufficient to determine the metastatic status of a patient with PCa. In patients with MM, there is added value of screening all regions, except the cervical spine, to detect additional lesions.

The original version of this article, published on 01 August 2018, unfortunately contained two mistakes.

MRI is a very attractive approach for tumour detection and oncological staging with its absence of ionizing radiation, high soft tissue contrast and spatial resolution. Less than 10 years ago the use of Whole Body MRI (WB-MRI) protocols was uncommon due to many limitations, such as the forbidding acquisition times and limited availability. This decade has marked substantial progress in WB-MRI protocols. This very promising technique is rapidly arising from the research world and is becoming a commonly used examination for tumour detection due to recent technological developments and validation of WB-MRI by multiple studies and consensus papers. As a result, WB-MRI is progressively proposed by radiologists as an efficient examination for an expanding range of indications. As the spectrum of its uses becomes wider, radiologists will soon be confronted with the challenges of this technique and be urged to be trained in order to accurately read and report these examinations. The aim of this review is to summarize the validated indications of WB-MRI and present an overview of its most recent advances. This paper will briefly discuss how this examination is performed and which are the recommended sequences along with the future perspectives in the field.

International audience; PURPOSE: The purpose of this study was to evaluate and compare the diagnostic accuracy of ultra-low dose (ULD) computed tomography (CT) with that of standard dose (STD) CT in the detection and characterization of focal liver lesions in neoplastic patients. MATERIALS AND METHODS: A total of 177 neoplastic patients who underwent two abdominopelvic CT examinations (one with STD and one with ULD protocol) for suspected focal liver lesions were included. There were 103 men and 74 women with a mean age of 64.6\textpm14.4 (SD) (range: 19-93 years). Raw data images were reconstructed with iterative reconstruction. Dose length product (DLP) and effective dose for both protocols were compared. Images were independently evaluated by two radiologists for image-quality, diagnostic quality, and confidence level. RESULTS: DLP for STD and ULD were respectively 215.4\textpm92.0 (SD) mGy\textperiodcenteredcm (range: 76-599mGy\textperiodcenteredcm) and 90.7\textpm37.2 (SD) mGy\textperiodcenteredcm (range: 32-254mGy\textperiodcenteredcm). Effective dose for STD and ULD CT were 3.2\textpm1.4 (SD) mSv (range: 1.1-9.0mSv) and 1.4\textpm0.6 (SD) mSv (range: 0.5 to 3.8mSv). A significant 58% dose reduction was found between the two protocols (P\textless0.05). Noise, signal-to-noise ratio and contrast-to-noise ratio were higher with the ULD protocol compared to the STD protocol. No differences in subjective image quality were found between the two protocols. STD CT revealed focal liver lesions in 80 patients and ULD CT in 70 patients (P\textless0.05). ULD protocol resulted in a sensitivity of 83.8% and a specificity of 96.9% for the diagnosis of focal liver lesions although it was not able to characterize them properly (Se 62.5%). CONCLUSION: STD CT helps detect and characterize focal liver lesions. ULD CT offers good performance to detect focal liver lesions but with lower performances for lesion characterization.

Purpose To determine the frequency and causes for limitations in the radiographic evaluation of surgically treated long bone fractures. Materials and methods Six readers separately scored 140 sets of antero-posterior (AP) and lateral radiographs of surgically treated long bone fractures, using a radiographic union score (RUS). We determined the rate of assessability of the fracture edges at each of the four cortical segments (n = 560) seen tangentially on the two radiographs and the causes for non-assessability. The rate of feasibility of the RUS (more than two fracture edges assessable per fracture) was determined and compared according to different parameters. Results Fracture edges were visible in 71% to 81% of the 560 cortical segments. Metal hardware superimposition was the most frequent cause for non-assessability (79–95%). RUS values could be calculated in 58% to 75% of fractures. Scoring was statistically significantly less frequently calculable in plated (31–56%) than in nailed fractures (90–97%), in distal (47–61%) than in proximal (78–89%) bones and in upper (27–49%) than in lower (76–91%) limb bones (P ≤ 0.01). Conclusions The type of stabilization hardware is the main limiting factor in the radiographic assessment of surgically treated long bone fractures. Scoring was feasible in only 31% to 56% of plated fractures.

International audience; 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.

International audience; OBJECTIVES: To compare the diagnostic performance of "triple rule out" CT angiography (TRO-CTA) at 100kVp using sinogram affirmed iterative reconstruction (SAFIRE) with TRO-CTA at 120kVp using filtered back projection (FBP) in patients with acute chest pain. METHODS: Consecutive non-prepared patients from a single radiological emergency department, referred for acute chest pain evaluation with TRO-CTA, were randomly assigned to two different TRO-CTA protocols. Fifty patients (66% men; mean age, 66.6\textpm19.0 [SD] years [range: 24-97years]) had TRO-CTA at 120kVp with FBP and 97 patients (67% men; mean age, 62.8\textpm17.9 [SD] years [range: 24-93years]) had TRO-CTA at 100kVp with SAFIRE. Two radiologists reviewed the TRO-CTA images for pathologic findings and degree of diagnostic confidence. Image noise, vessel attenuation value, signal-to-noise and contrast-to-noise ratios in five main thoracic arteries were measured for objective and subjective analysis. RESULTS: A total of 147 patients (98 men, 49 women; mean age, 64.7\textpm18.4 [SD] [range, 24-97years) were included with good diagnostic confidence and equivalent pathological findings between the two TRO-CTA protocols. Objective and subjective analysis were identical between protocols and radiologists, except for vessel attenuation in the ascending aorta (P=0.02) and image noise in the pulmonary trunk (P=0.04). The effective radiation dose decreased significantly by 34% in the low dose TRO-CTA using SAFIRE protocol (5.7\textpm2.7 vs 8.6\textpm6.1mSv; P=4.7\texttimes10-6). CONCLUSIONS: Low dose TRO-CTA protocol using SAFIRE allows a high confidence diagnostic level with the benefit of a 34% radiation dose decrease compared with a standard TRO-CTA protocol using FBP.

Objective Evaluate the diagnostic value of cone beam computed tomography (CBCT) for scaphoid and wrist fractures that are missed on standard radiographs. Materials and methods Between September 2014 and October 2015, we prospectively enrolled 49 patients with a clinically suspected scaphoid fracture following an acute injury but had normal radiographs. Each patients underwent radiographs, CBCT and (magnetic resonance imaging) MRI within 7 days of the initial injury event. Both exam were evaluated independently by two radiologists. Results For scaphoid cortical fractures CBCT sensitivity is 100% (95% CI: 75%–100%), specificity 97% (95% CI: 83%–100%). CBCT diagnosed all 24 corticals wrist fractures, corresponding to a sensitivity of 100% (95% CI: 83%–100%), specificity of 95% (95% CI: 75%–100%). Kappa agreement rate between the two radiologists was K = 0.95 (95% CI: 0.85–1) for scaphoid fractures and K = 0.87 (95% CI: 0.73–1) for wrist fractures. Conclusions CBCT is superior to radiographs for diagnosing occult cortical fractures. Because of its low radiation dose, we believe that CBCT can be used in current practice as a replacement or supplement to radiographs to detect these fractures and optimize the cost-effectiveness ratio by limiting the number of needless immobilizations.

International audience; PURPOSE: The aim of the study was to evaluate the assessability of the suprascapular nerve (SSN) by ultrasonography in cadavers and healthy volunteers. MATERIALS AND METHODS: With ultrasonography guidance, needles were placed at origin of the SSN of four cadavers and evaluated by dissection. Two blinded radiologists performed 60 ultrasonography scans in 30 healthy volunteers to study the entire SSN at five anatomical landmarks. RESULTS: Dissection revealed that the needles were correctly located at the nerve's origin. There were no significant differences between the two radiologists' measurements of nerve size and depth. The interobserver correlation for the description of the nerve at the five predefined anatomical landmarks was very good (ICC=0.7-1). CONCLUSION: Five anatomical landmarks were used to analyze the SSN with ultrasonography. Its supraclavicular portion was easier to describe than its scapular portion; a segment of the SSN was not visible between these two portions.

Resume L’etude des ligamentoplasties, en particulier du ligament croise anterieur (LCA), est une indication frequente dans la pratique quotidienne de l’imagerie du genou. La connaissance de l’aspect normal, de l’evolution attendue dans le temps, et des potentielles complications de ces plasties est indispensable. L’IRM est la methode d’imagerie de choix. Cet article illustre les principales complications specifiques de cette intervention, qui sont le positionnement suboptimal des tunnels d’insertion, le conflit entre le greffon et les reliefs osseux, la rupture (partielle ou complete) de la plastie par friction ou traumatisme, l’arthrofibrose et en particulier le syndrome « du cyclope », la fragmentation ou migration du materiel de fixation, la reaction granulomateuse sur biomateriel.

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.