T2-weighted Dixon MRI of the spine: A feasibility study of quantitative vertebral bone marrow analysis

PurposeTo compare the measurements of fat fraction (FF) and in-phase vs. opposed-phase ratio between two-dimensional T2-weighted (T2W) spin-echo (SE) Dixon and three-dimensional (3D) T1-weighted (T1W) volume interpolated breath-hold examination (VIBE) Dixon sequences in malignant vertebral lesions and normal vertebral bone marrow.Materials and methodsThirty patients with focal vertebral malignancies (20 men, mean age, 67.3 ± 9.4 [SD] years; age range: 41–84 years) and 30 patients without malignant spinal disease (11 men, mean age, 70.1 ± 12.9 [SD]; age range: 53–93 years) were retrospectively included. Each patient underwent spine MRI at 1.5 Tesla including T2W SE and T1W VIBE 2-point Dixon sequences. Two readers independently performed 3D-volume of interest (VOI) and region of interest (ROI)-based FF and IO-ratio measurements of malignant lesions and normal vertebrae. Student t-test, Pearson correlation (r) test and two-way mixed model intraclass correlation coefficients (ICC) were used to compare measurements.ResultsT2W SE and T1W VIBE mean FF and IO-ratio were significantly smaller in malignancy compared to normal marrow, but there were significant differences of paired measurement mean values between T2W SE and T1W VIBE Dixon parameters in malignant lesions T2W SE VOI FF = 9%, T2W SE ROI FF = 7%, T2W SE IO-ratio = 4% vs. T1W VIBE VOI FF = 11%, T1W VIBE ROI FF = 9%, T1W VIBE IO-ratio = ?2%, and in normal vertebrae T2W SE VOI FF = 74%, T2W SE ROI FF = 77%, T2W SE IO-ratio = 51% vs. T1W VIBE VOI FF = 67%, T1W VIBE ROI FF = 73%, T1W VIBE IO-ratio = 58% (each P comparing the paired T2W TSE and T1W VIBE parameter, respectively < 0.001). There was excellent positive correlation between T2 W SE and T1 W VIBE-FF (r ≥ 0.99) and VOI and ROI FF measurements for each sequence (r ≥ 0.99). Inter-reader agreement was excellent for all measurements (ICC ≥ 0.94 for all).ConclusionCalculation of T2W SE Dixon derived FF is feasible and gave valid results that help discriminate between malignant vertebral lesions and normal vertebral bone marrow.     

Diagnostic performance of ultra-low dose versus standard dose CT for non-traumatic abdominal emergencies

PurposeThe 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 methodsAll 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 125 mAs for STD and 55 mAs for ULD. Diagnostic performance was retrospectively evaluated on ULD and STD CTs using clinical follow-up as a reference diagnosis.ResultsA 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).ConclusionIn 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.     

Bladder endometriosis: Preoperative MRI analysis with assessment of extension to ureteral orifices

PurposeThe purpose of this study was to retrospectively evaluate the performance of magnetic resonance imaging (MRI) in locating endometriosis implants within the bladder wall with assessment of ureteral orifice extension using surgical findings as standard of reference.Materials and methodsMRI examinations of 39 consecutive women (mean age: 31.2 ± 5.5 [SD] years; age range: 22–42 years) operated in 3 university hospitals for bladder endometriosis over a 6-year period were reviewed by 2 independent readers. Interobserver agreement was assessed using Kappa tests. Results of consensus reading were used to calculate sensitivity, specificity and accuracy of MRI for the diagnosis, location and extent of endometriosis implants using surgical findings as the standard of reference.ResultsMean bladder repletion volume was 134 ± 110 [SD] mL (range: 21–479 mL). The mean largest endometriosis implant diameter was 30 ± 7 [SD] mm (range: 19–41 mm). On MR images, 34/39 (87%) endometriosis implants were present in the two anterior thirds of the dome (k = 0.45), 31/39 (79%) extended or were present in the posterior third pouch (k = 0.92) and 25/39 (64%) extended into the bladder base (k = 0.84) with sensitivities of 100% (31/31; 95% confidence interval [CI]: 89–100%), 100% (30/30; 95% CI: 88–100%) and 90% (19/21; 95% CI: 69–98%), respectively, specificities of 83% (5/6, 95% CI: 36–100), 88% (7/8, 95% CI: 47–100%), 87% (13/15; 95% CI: 52–96), respectively and accuracies of 97% (36/37, 95% CI: 86–100%), 97% (37/38; 95% CI: 86–100%), and 89% (32/36; 95% CI: 74–97%), respectively. In 9 (9/25; 36%) patients with bladder base involvement, a zero distance was reported between endometriosis implants and ureteral orifices, all but one presenting with low-to-moderate bladder volumes. In the two patients who needed ureteral resection-reimplantation, ureteral dilation was associated with a zero distance. External adenomyosis was reported in 26/39 (66%) patients (k = 0.94).ConclusionA dedicated preoperative MRI work-up for bladder endometriosis helps accurately depict and locate endometriosis implants. Adequate bladder filling is needed to improve appropriate estimate of the distance between endometriosis implants and ureteral orifices to better predict requirement of ureteral resection-reimplantation.     

Awake spinal anesthesia facilitates spine surgery in poor surgical candidates: A case series

BackgroundAnnually, hundreds of thousands of patients undergo surgery for degenerative spine disease (DSD). This represents only a fraction of patients that present for surgical consideration. Procedures are often avoided due to comorbidities that make patients poor candidates for general anesthesia (GA) and its associated risks. With increasing interest in awake surgery under spinal anesthesia (SA), the authors have observed that SA may facilitate spine surgery in patients with relative contraindications to GA. With this in mind, the authors set out to summarize the outcomes of a series of highly comorbid patients who received surgery under SA.MethodsCase logs of a single surgeon were reviewed, and patients undergoing spine surgery under SA were identified. Within this group, patients were identified with relative contraindications to GA, such as advanced age and medical comorbidities. For these patients, for whom surgery was facilitated by SA, the medical records were consulted to report demographic information and patient outcomes.ResultsTen highly comorbid patients were identified who received lumbar spine surgery for DSD under SA. Comorbidities included octogenarian status, obesity, and chronic health conditions such as heart disease. The cohort had a mean age of 75.5 and a mean American Society of Anesthesiologists Physical Status (ASA-PS) score of 3.1. The patients were predicted to have a 2.74-fold increase of serious complications compared to the average patient. There were no adverse events.ConclusionFor patients with symptomatic, refractory DSD and relative contraindications to GA, SA may facilitate safe surgical intervention with excellent outcomes.     

Threshold for lateral meniscal body extrusion on MRI in middle-aged and elderly patients with symptomatic knee osteoarthritis

PurposeTo determine the MRI-based threshold of lateral meniscal body extrusion (LMBE) that are associated with meniscal damage, cartilage damage and radiological knee osteoarthritis (OA).Materials and methodsA total of 142 patients (59 men and 83 women) with a mean age of 57.2 ± 7.9 (SD) years (range: 41–77 years) with symptomatic knee OA were included. Radiological assessment was performed using the Kellgren-Lawrence scoring system. Meniscus and cartilage damage were assessed using the whole-organ magnetic resonance imaging score. Meniscal extrusion was quantified on coronal sections of intermediate-weighted MRI sequences. Differences between medial and lateral compartments in meniscal extrusion and incidence of tibiofemoral OA-related structural changes were assessed using Wilcoxon signed rank test and Bowker test. Receiver operating characteristic curves and Youden index were used for determining thresholds for meniscal extrusion.ResultsA total of 142 knees were assessed. Meniscal body extrusion distances between medial and lateral compartments were significantly different in the entire sample, and in subjects with and without radiological knee OA (P < 0.05 for all). The incidence of structural changes between medial and lateral compartments were significantly different (P = 0.003 for meniscal damage; P = 0.001 for femoral cartilage damage). Three mm and 2 mm were determined to be the optimal thresholds for medial and lateral meniscal body extrusion, respectively.ConclusionMedial and lateral meniscal body extrusion were associated with the incidence of OA-related knee structural changes in symptomatic patients with knee OA. A threshold of 2 mm for LMBE with respect to meniscal damage, cartilage damage and radiological knee OA was determined.     

Synthetic MRI is not yet ready for morphologic and functional assessment of patellar cartilage at 1.5 Tesla

PurposeThe purpose of this study was to compare morphologic assessment and relaxometry of patellar hyaline cartilage between conventional sequences (fast spin-echo [FSE] T2-weighted fat-saturated and T2-mapping) and synthetic T2 short-TI inversion recovery (STIR) and T2 maps at 1.5 T magnetic resonance imaging (MRI).MethodThe MRI examinations of the knee obtained at 1.5 T in 49 consecutive patients were retrospectively studied. There were 21 men and 28 women with a mean age of 45 ± 17.7 (SD) years (range: 18–88 years). Conventional and synthetic acquisitions were performed, including T2-weighted fat-saturated and T2-mapping sequences. Two radiologists independently compared patellar cartilage T2-relaxation time on conventional T2-mapping and synthetic T2-mapping images. A third radiologist evaluated the patellar cartilage morphology on conventional and synthetic T2-weighted images. The presence of artifacts was also assessed. Interobserver agreement for quantitative variables was assessed using intraclass correlation coefficient (ICC).ResultsIn vitro, conventional and synthetic T2 maps yielded similar mean T2 values 58.5 ± 2.3 (SD) ms and 58.8 ± 2.6 (SD) ms, respectively (P = 0.414) and 6% lower than the expected experimental values (P = 0.038). Synthetic images allowed for a 15% reduction in examination time compared to conventional images. On conventional sequences, patellar chondropathy was identified in 35 patients (35/49; 71%) with a mean chondropathy grade of 4.8 ± 4.8 (SD). On synthetic images, 28 patients (28/49; 57%) were diagnosed with patellar chondropathy, with a significant 14% difference (P = 0.009) and lower chondropathy scores (3.7 ± 4.9 [SD]) compared to conventional images. Motion artifacts were more frequently observed on synthetic images (18%) than on conventional ones (6%). The interobserver agreement was excellent for both conventional and synthetic T2 maps (ICC > 0.83). Mean cartilage T2 values were significantly greater on synthetic images (36.2 ± 3.8 [SD] ms; range: 29-46 ms) relative to conventional T2 maps (31.8 ± 4.1 [SD] ms; range: 26-49 ms) (P < 0.0001).ConclusionDespite a decrease in examination duration, synthetic images convey lower diagnostic performance for chondropathy, greater prevalence of motion artifacts, and an overestimation of T2 values compared to conventional MRI sequences.     

Differentiating between active and latent tuberculosis with chest computed tomography

PurposeThe purpose of this study was to evaluate the capabilities of chest computed tomography (CT) in distinguishing between active and latent tuberculosis in patients positive for interferon-gamma release assay (IGRA) testing, and to compare the performance of CT with that of quantitative IGRA testing in a low incidence setting.Materials and methodsPatients with latent or active tuberculosis define by an IGRA positive test were retrospectively recruited. Sensitivity, specificity and accuracy were determined for CT variables and quantitative IGRA results. Final diagnosis of active tuberculosis was based on clinical data and microbiological culture. Univariable and multivariable analyses were performed using logistic regression model to identify CT variables associated with the diagnosis of active tuberculosis.ResultsA total of 92 patients with positive IGRA results who underwent CT examination were included. There were 54 men and 38 women with a mean age of 53.5 ± 18 (SD) years (range: 40–68 years). Of them, 22 patients (24%) had positive Mycobacterium tuberculosis culture and 70 (76%) had latent tuberculosis. Among CT variables, consolidation had the greatest sensitivity (77%; 95%CI: 60–95%) and “tree-in-bud” the greatest specificity (97%; 95% CI: 93–100%) for the diagnosis of active tuberculosis. At univariable analysis “tree-in-bud”, splenic calcification and non-calcified lung nodules were the significant variables independently associated with active tuberculosis. At multivariable analysis, the adjusted odds ratio of “tree-in-bud” was 42.91 (95% CI: 5.62–327.42). Using an optimal threshold of 51 spots, quantitative IGRA yielded 64% sensitivity (95% CI: 44–84%) and 61% specificity (95% CI: 50–73%) for the diagnosis of active tuberculosis.ConclusionsIn a low incidence setting, chest CT, especially when “tree-in-bud” pattern is present, is superior to quantitative IGRA testing to identify patients with active tuberculosis among those with positive IGRA testing.     

Diffusion-weighted MRI and PET/CT reproducibility in epithelial ovarian cancers during neoadjuvant chemotherapy

PurposeTo investigate the reproducibility of diffusion-weighted (DW) MRI and ¹⁸F-Fluorodeoxyglucose (¹⁸F-FDG)-Positron emission tomography/CT (PET/CT) in monitoring response to neoadjuvant chemotherapy in epithelial ovarian cancer.Materials and methodsTen women (median age, 67 years; range: 41.8–77.3 years) with stage IIIC-IV epithelial ovarian cancers were included in this prospective trial (NCT02792959) between 2014 and 2016. All underwent initial laparoscopic staging, four cycles of carboplatine-paclitaxel-based chemotherapy and interval debulking surgery. PET/CT and DW-MRI were performed at baseline (C0), after one cycle (C1) and before surgery (C4). Two nuclear physicians and two radiologists assessed five anatomic sites for the presence of ≥ 1 lesion. Target lesions in each site were defined and their apparent diffusion coefficient (ADC), maximal standardized uptake value (SUV-max), SUV-mean, SUL-peak, metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were monitored (i.e., 10 patients × 5 sites × 3 time-points). Their relative early and late changes were calculated. Intra/inter-observer reproducibilities of qualitative and quantitative analysis were estimated with Kappa and intra-class correlation coefficients (ICCs).ResultsFor both modalities, inter- and intra-observer agreement percentages were excellent for initial staging but declined later for DW-MRI, leading to lower Kappa values for inter- and intra-observer variability (0.949 and 1 at C0, vs. 0.633 and 0.643 at C4, respectively) while Kappa values remained > 0.8 for PET/CT. Inter- and intra-observer ICCs were > 0.75 for SUV-max, SUL-peak, SUV-mean and their change regardless the time-point. ADC showed lower ICCs (range: 0.013–0.811). ANOVA found significant influences of the evaluation time, the measurement used (ADC, SUV-max, SUV-mean, SUV-max, SUL-peak, MTV or TLG) and their interaction on ICC values (P = 0.0023, P< 0.0001 and P =0.0028, respectively).ConclusionWhile both modalities demonstrated high reproducibility at baseline, only SUV-max, SUL-peak, SUV-mean and their changes maintained high reproducibility during chemotherapy.     

An updated model of hydrocephalus in sheep to evaluate the performance of a device for ambulatory wireless monitoring of cerebral pressure through shunts

BackgroundCerebrospinal fluid (CSF) diversion by shunts is the most common surgical treatment for hydrocephalus. Though effective, shunts are associated with risk of dysfunction leading to multiple surgical revisions, affecting patient quality-of-life and incurring high healthcare costs. There is a need for ambulatory monitoring systems for life-long assessment of shunt status. The present study aimed to develop a preclinical model assessing the feasibility of our wireless device for continuous monitoring of cerebral pressure in shunts.MethodsWe first adapted a previous hydrocephalus model in sheep, which used an intracisternal kaolin injection. Seven animals were used to establish the model, and 1 sheep with naturally dilated ventricles was used as control. Hydrocephalus was confirmed by clinical examination and brain imaging before inserting the ventriculoperitoneal shunts and the monitoring device allowing continuous measurement of the pressure through the shunt for a few days in 3 sheep. An external ventricular drain was used as gold standard.ResultsOur results showed that a reduction in kaolin dose associated to postoperative management was crucial to reduce morbidity and mortality rates in the model. Ventriculomegaly was confirmed by imaging 4 days after injection of 75 mg kaolin into the cisterna magna. For the implanted sheep, recordings revealed high sensitivity of our sensor in detecting fluctuations in cerebral pressure compared to conventional measurements.ConclusionsThis proof-of-concept study highlights the potential of this preclinical model for testing new shunt devices.     

CT and MRI characteristics of ovarian mature teratoma in patients with anti-N-methyl-D-aspartate receptor encephalitis

PurposeThe purpose of this study was to determine the computed tomography (CT) and magnetic resonance imaging (MRI) characteristics of ovarian mature teratoma in patients with anti-N-methyl-d-aspartate receptor encephalitis (NMDAR-E).Materials and MethodsA total of 125 women (mean age, 40.9 ± 17.8 [SD] years; age range: 12–85 years) with 146 histopathologically or radiologically proven ovarian mature teratomas who underwent preoperative CT and MRI examinations were retrospectively included. Eight patients with 11 teratomas had NMDAR-E, whereas 117 patients with 135 teratomas did not have NMDAR-E. CT and MRI examinations were retrospectively reviewed and teratomas in patients with NMDAR-E were compared to those in patients without NMDAR-E. Comparisons were performed using Mann-Whitney U test or Fisher exact test.ResultsIn patients with NMDAR-E, maximum diameter of teratomas (26.1 ± 9.3 [SD] mm), prevalence of teeth/calcification (36%) and rate of occupation by fat components (26%) were lower than those in patients without NMDAR-E (67.0 ± 37.6 [SD] mm [P < 0.01]; 75% [P < 0.05]; and 65%[P < 0.01], respectively). More than 75% of space was occupied by fat components in 76/135 teratomas (56%) in patients without NMDAR-E, whereas this was not observed in any teratoma in patients without NMDAR-E.ConclusionBy comparison with teratomas in patients without NMDAR-E, teratomas in patients with NMDAR-E are smaller, have few teeth/calcification, and the amount of space occupied by fat components is smaller.     

Focal splenic lesions: Imaging spectrum of diseases on CT,MRI and PET/CT

The spleen can be affected by a variety of diseases. Some of them are readily identified as variations of normal or benign diseases on imaging. However, for a substantial number of focal splenic abnormalities, the diagnosis can be difficult so that histopathologic analysis may be required for a definite diagnosis. In this review, the typical splenic abnormalities that can be diagnosed with imaging with a high degree of confidence are illustrated. The complementary role of computed tomography (CT), magnetic resonance imaging and positron emission tomography/CT that helps make a diagnostic approach is discussed. Finally, current applications and future trends of radiomics and artificial intelligence for the diagnosis of splenic diseases are addressed.     

Artificial intelligence to predict clinical disability in patients with multiple sclerosis using FLAIR MRI

PurposeThe purpose of this study was to create an algorithm that combines multiple machine-learning techniques to predict the expanded disability status scale (EDSS) score of patients with multiple sclerosis at two years solely based on age, sex and fluid attenuated inversion recovery (FLAIR) MRI data.Materials and methodsOur algorithm combined several complementary predictors: a pure deep learning predictor based on a convolutional neural network (CNN) that learns from the images, as well as classical machine-learning predictors based on random forest regressors and manifold learning trained using the location of lesion load with respect to white matter tracts. The aggregation of the predictors was done through a weighted average taking into account prediction errors for different EDSS ranges. The training dataset consisted of 971 multiple sclerosis patients from the “Observatoire français de la sclérose en plaques” (OFSEP) cohort with initial FLAIR MRI and corresponding EDSS score at two years. A test dataset (475 subjects) was provided without an EDSS score. Ten percent of the training dataset was used for validation.ResultsOur algorithm predicted EDSS score in patients with multiple sclerosis and achieved a MSE = 2.2 with the validation dataset and a MSE = 3 (mean EDSS error = 1.7) with the test dataset.ConclusionOur method predicts two-year clinical disability in patients with multiple sclerosis with a mean EDSS score error of 1.7, using FLAIR sequence and basic patient demographics. This supports the use of our model to predict EDSS score progression. These promising results should be further validated on an external validation cohort.     

Medial meniscal ossicles: Associated knee MRI findings in a multicenter case-control study

PurposeThe purpose of this study was to assess and compare the prevalence of meniscal, ligament and cartilage lesions on knee MRI in a series of age- and sex-matched patients with and without medial meniscal ossicle.Materials and methodsForty-two knee MRI examinations obtained in 42 patients (36 men, 6 women; mean age, 42.5 ± 22.2 [SD] years; range: 19–65 years) on which a medial meniscal ossicle was present were compared to 42 knee MRI examinations obtained in 42 age- and sex-matched patients (36 men, 6 women; mean age, 41.8 ± 20.6 [SD] years; range: 19–65 years) on which no medial meniscal ossicles were present. Two radiologists (R1, R2) blinded to the presence of meniscal ossicle by reading only the fat-saturated intermediate-weighted MR images separately assessed the presence of meniscal, ligament and cartilage lesions on these 84 knee MRI examinations. Prevalence of meniscal and ligament lesions and degree of cartilage degradation at MRI were compared between knees with and those without medial meniscal ossicle.ResultsIn knees with medial meniscal ossicle, R1 and R2 detected 33 (79%) and 38 (90%) medial meniscal lesions, respectively that involved the posterior root (n = 25/32 for R1/R2), the posterior horn (n = 19/14 for R1/R2) or the body (n = 8/10 for R1/R2). The prevalence of posterior root tear (60% [25/42]/76% [32/42] for R1/R2) and that of anterior cruciate ligament (ACL) lesions (48% [20/42]/57% [24/42] for R1/R2) as well as the medial cartilage degradation score (3.35 ± 0.87 [SD] for R1 and 3.92 ± 0.78 [SD] for R2) were significantly greater in knees with than in knees without medial meniscal ossicle (root lesions: P < 0.01 for both readers; ACL lesions and medial cartilage score: P < 0.01 for both readers).ConclusionOn MRI examination, knees with a medial meniscal ossicle demonstrate a greater frequency of medial posterior root tear and of ACL lesions and a greater degree of medial femoro-tibial cartilage degradation by comparison with knees without medial ossicle.     

Instability of the extensor digitorum tendons in Jaccoud arthropathy assessed by semi-dynamic MRI of the metacarpophalangeal joints

PurposeThe purpose of this study was to test the hypothesis that Jaccoud arthropathy (JA) in patients with systemic lupus erythematosus (SLE) is associated with instability of the extensor digitorum (ED) tendons during flexion of the metacarpophalangeal (MCP) joints by comparing the position of the ED tendons between SLE patients with JA and control subjects on hand MRI obtained with flexed and extended MCP joints.Materials and methodsThirty-two hands of SLE patients with JA (13 women and 3 men; mean age, 50.0 ± 12.2 [SD] years; age range: 26–68 years) and 24 hands of sex- and age-matched control subjects (20 women and 4 men; mean age, 50.1 ± 13.0 [SD] years; age range: 24–68 years) were included in the study. Axial spin echo T1-weighted MRI images of the second to fifth MCP joints in flexion and in extension were obtained. Two radiologists (R1 and R2) separately measured the amplitude and assessed the direction of the displacement of the ED tendons with respect to the midline at the level of each MCP joint. Statistical analysis included two-way ANOVA with random effects to assess differences in amplitude and Fisher–Freeman–Halton exact test to assess differences in direction with P-values < 0.0083 and < 0.0063 considered as statistically significant respectively.ResultsAmplitude of the displacement of the ED tendons was statistically significantly greater in SLE patients with JA than in control subjects in flexion for both readers (median 58°, 95% confidence interval [CI]: 50°–65° vs. 20°, 95% CI: 16°–24°; P < 0.0001 for R1 and 54°, 95% CI: 47°–61° vs. 25°, 95% CI: 22°–28°; P < 0.0001 for R2) and in extension for one reader (17°, 95% CI: 15°–20° vs. 14°, 95% CI: 11°–16°; P = 0.0048 for R1 and 20°, 95% CI: 15°–25° vs. 16°, 95% CI: 12°–18°; P = 0.0292 for R2). Ulnar deviation of the ED tendons was statistically significantly more frequent in SLE patients with JA than in control subjects in flexion and in extension for both readers (P < 0.0001).ConclusionJA is associated with instability of the ED tendons in patients with SLE best depicted when MCP joints are flexed.     

Intravoxel incoherent motion MRI for the initial characterization of non-fatty non-vascular soft tissue tumors

PurposeTo compare the capabilities of intravoxel incoherent motion (IVIM) to those of monoexponential diffusion-weighted imaging for differentiating benign from malignant non-vascular, non-fatty soft tissue tumors (NVSFSTT).Material and methodsA total of 64 patients with 64 histologically confirmed soft-tissue tumors were retrospectively included. There were 23 men and 41 women with a mean age of 52 ± 17 (SD) (range: 18–92 years). IVIM parameters, including molecular diffusion restriction coefficient (ADC_true), perfusion fraction, and tissue perfusion related coefficient were compared to mean monoexponential ADC (ADC_std) values. Two readers calculated all parameters, which were compared to histopathological findings that were used as standard of reference.ResultsThe overall performance of ADC_true and ADC_std was similar for the benign-malignant differentiation of NFNVSTT with accuracies ranging from 73% to 75% for both readers (P = 0.3). Interobserver reproducibility was considered excellent for both ADC_std and all IVIM parameters (ICC = 0.81–0.96). When myxoid tumors were excluded from morphological analysis, an increase in sensitivity of 16–21% of ADC_true was observed, with no changes in specificity values. The use of perfusion related IVIM parameters in association with ADC_true did not improve tumor characterization.ConclusionThe use of IVIM parameters does not improve the characterization of NVNFSTT by comparison with conventional monoexponential ADC calculation.     

MRI associated factors of clinical efficacy of embolization in patients with pelvic venous insufficiency

PurposeThe purpose of this study was to identify anatomical findings at magnetic resonance imaging (MRI) associated with successful percutaneous embolization in women with pelvic venous insufficiency (PVI).Material and methodsBetween 2008 and 2018, 168 consecutive women (mean age, 39 ± 9 [SD] years; range: 21–69 years) who underwent percutaneous embolization for PVI confirmed by MRI and phlebography were included. Clinical efficacy of embolization was evaluated by patients’ opinion or visual analogue scale. Associated factors of success of embolization were searched by comparing MRI findings in women with successful embolization with those in women with failed embolization using univariate analyses.ResultsThe mean follow-up was 36 ± 29 (SD) months (range: 12–138 months). Clinical efficacy of embolization was obtained in 126/168 women (75%), complete symptom improvement in 33/168 women (20%) and significant partial improvement in 92/168 women (55%). No symptom improvement and symptoms exacerbation were observed in 17/168 (10%) and 2/168 (1%) women, respectively. At univariate analysis, right ovarian vein diameter ≤ 7 mm and vulvar varicosities were associated with successful embolization (P = 0.04 and P = 0.01, respectively) and left ovarian vein diameter ≤ 7 mm was associated with a complete improvement of symptoms (P = 0.03). At multivariate analysis, a small right ovarian vein diameter was the single MRI variable associated with clinical efficacy of embolization (P = 0.04).ConclusionSmall ovarian vein diameters on MRI are associated with best clinical efficacy of percutaneous embolization in PVI. Right ovarian vein diameter > 7 mm should warrant further phlebography to exclude venous insufficiency.     

Three artificial intelligence data challenges based on CT and MRI

PurposeThe second edition of the artificial intelligence (AI) data challenge was organized by the French Society of Radiology with the aim to: (i), work on relevant public health issues; (ii), build large, multicentre, high quality databases; and (iii), include three-dimensional (3D) information and prognostic questions.Materials and methodsRelevant clinical questions were proposed by French subspecialty colleges of radiology. Their feasibility was assessed by experts in the field of AI. A dedicated platform was set up for inclusion centers to safely upload their anonymized examinations in compliance with general data protection regulation. The quality of the database was checked by experts weekly with annotations performed by radiologists. Multidisciplinary teams competed between September 11^th and October 13^th 2019.ResultsThree questions were selected using different imaging and evaluation modalities, including: pulmonary nodule detection and classification from 3D computed tomography (CT), prediction of expanded disability status scale in multiple sclerosis using 3D magnetic resonance imaging (MRI) and segmentation of muscular surface for sarcopenia estimation from two-dimensional CT. A total of 4347 examinations were gathered of which only 6% were excluded. Three independent databases from 24 individual centers were created. A total of 143 participants were split into 20 multidisciplinary teams.ConclusionThree data challenges with over 1200 general data protection regulation compliant CT or MRI examinations each were organized. Future challenges should be made with more complex situations combining histopathological or genetic information to resemble real life situations faced by radiologists in routine practice.     

Impact of dose reduction and the use of an advanced model-based iterative reconstruction algorithm on spectral performance of a dual-source CT system: A task-based image quality assessment

PurposeTo assess the impact of dose reduction and the use of an advanced modeled iterative reconstruction algorithm (ADMIRE) on image quality in low-energy monochromatic images from a dual-source dual energy computed tomography CT (DSCT) platform.Materials and methodsAcquisitions on an image-quality phantom were performed using DSCT equipment with 100/Sn150 kVp for four dose levels (CTDI_vol: 20/11/8/5mGy). Raw data were reconstructed for six energy levels (40/50/60/70/80/100 keV) using filtered back projection and two levels of ADMIRE (A3/A5). Noise power spectrum (NPS) and task-based transfer function (TTF) were calculated on virtual monoenergetic images (VMIs). Detectability index (d′) was computed to model the detection task of two enhanced iodine lesions as function of keV.ResultsNoise-magnitude was significantly reduced between 40 to 70 keV by ?56 ± 0% (SD) (range: ?56%–?55%) with FBP; ?56 ± 0% (SD) (?56%–?56%) with A3; and ?57 ± 1% (SD) (range: ?57%–?56%) with A5. The average spatial frequency of the NPS peaked at 70 keV and decreased as ADMIRE level increased. TTF values at 50% were greatest at 40 keV and shifted towards lower frequencies as the keV increased. The detectability of both lesions increased with increasing dose level and ADMIRE level. For the simulated lesion with iodine at 2 mg/mL, d’ values peaked at 70 keV for all reconstruction types, except for A3 at 20 mGy and A5 at 11 and 20 mGy, where d’ peaked at 60 keV. For the other simulated lesion, d’ values were highest at 40 keV and decreased beyond.ConclusionAt low keV on VMIs, this study confirms that iterative reconstruction reduces the noise magnitude, improves the spatial resolution and increases the detectability of enhanced iodine lesions.     

Automated brain MRI metrics in the EPIRMEX cohort of preterm newborns: Correlation with the neurodevelopmental outcome at 2 years

PurposeThe purpose of this study was to identify in the EPIRMEX cohort the correlations between MRI brain metrics, including diffuse excessive high signal intensities (DEHSI) obtained with an automated quantitative method and neurodevelopmental outcomes at 2 years.Materials and methodsA total of 390 very preterm infants (gestational age at birth ≤ 32 weeks) who underwent brain MRI at term equivalent age at 1.5T (n = 338) or 3T (n = 52) were prospectively included. Using a validated algorithm, automated metrics of the main brain surfaces (cortical and deep gray matter, white matter, cerebrospinal fluid) and DEHSI with three thresholds were obtained. Linear adjust regressions were performed to assess the correlation between brain metrics with the ages and stages questionnaire (ASQ) score at 2 years.ResultsBasal ganglia and thalami, cortex and white matter surfaces positively and significantly correlated with the global ASQ score. For all ASQ sub-domains, basal ganglia and thalami surfaces significantly correlated with the scores. DEHSI was present in 289 premature newborns (74%) without any correlation with the ASQ score. Metrics of DEHSI were greater at 3T than at 1.5T.ConclusionBrain MRI metrics obtained in our multicentric cohort correlate with the neurodevelopmental outcome at 2 years of age. The quantitative detection of DEHSI is not predictive of adverse outcomes. Our automated algorithm might easily provide useful predictive information in daily practice.