CT-based diagnostic algorithm to identify bowel and/or mesenteric injury in patients with blunt abdominal trauma.

OBJECTIVES: To develop a CT-based algorithm and evaluate its performance for the diagnosis of blunt bowel and/or mesenteric injury (BBMI) in patients with blunt abdominal trauma. METHODS: This retrospective study included a training cohort of 79 patients (29 with BBMI and 50 patients with blunt abdominal trauma without BBMI) and a validation cohort of 37 patients (13 patients with BBMI and 24 patients with blunt abdominal trauma without BBMI). CT examinations were blindly analyzed by two independent radiologists. For each CT sign, the kappa value, sensitivity, specificity, and accuracy were calculated. A diagnostic algorithm was built using a recursive partitioning model on the training cohort, and its performances were assessed on the validation cohort. RESULTS: CT signs with kappa value > 0.6 were extraluminal gas, hemoperitoneum, no or moderate bowel wall enhancement, and solid organ injury. CT signs yielding best accuracies in the training cohort were extraluminal gas (98%; 95% CI: 91-100), bowel wall defect (97%; 95% CI: 91-100), irregularity of mesenteric vessels (97%; 95% CI: 90-99), and mesenteric vessel extravasation (97%; 95% CI: 90-99). Using a recursive partitioning model, a decision tree algorithm including extraluminal gas and no/moderate bowel wall enhancement was built, achieving 86% sensitivity (95% CI: 74-99) and 96% specificity (95% CI: 91-100) in the training cohort and 92% sensitivity (95% CI: 78-97) and 88% specificity (95% CI: 74-100) in the validation cohort for the diagnosis of BBMI. CONCLUSIONS: An effective diagnostic algorithm was built to identify BBMI in patients with blunt abdominal trauma using only extraluminal gas and no/moderate bowel wall enhancement on CT examination. KEY POINTS: • A CT diagnostic algorithm that included extraluminal gas and no/moderate bowel wall enhancement was built for the diagnosis of surgical blunt bowel and/or mesenteric injury. • A decision tree combining only two reproducible CT signs has high diagnostic performance for the diagnosis of surgical blunt bowel and/or mesenteric injury.

Skeletal muscle loss during chemotherapy and its association with survival and systemic treatment toxicity in metastatic colorectal cancer: An AGEO prospective multicenter study.

PURPOSE: We showed in a previous study that the PG-SGA score is associated with survival and chemotherapy-related toxicities in metastatic colorectal cancer (mCRC) patients. The objective was to evaluate the association between pretherapeutic sarcopenia and variation in skeletal muscle index (SMI) during treatment with these outcomes in the same population. METHODS: This prospective, multicenter, observational study enrolled non-pretreated mCRC patients. SMI was measured on routine CT scan at day 0 (D0) and day 60 (D60). Nutritional factors were collected at D0. Progression-free survival (PFS) and overall survival (OS) were calculated from treatment start. RESULTS: 149 patients were included from 7/2013 to 11/2016. Pretherapeutic sarcopenia was not significantly associated with survival or chemotherapy-related toxicities. The decrease in SMI > 14% was significantly associated with shorter PFS (6 vs 9 mo; HR 1.8, 95% CI 1.1-3.1, p = 0.02) and OS (8.5 vs 26 mo; HR 2.6, 95% CI 1.4-4.8, p = 0.002), independently of hypoalbuminemia and malnutrition defined by PG-SGA. Patients with a SMI decrease > 14% had a higher rate of grade ≥ 2 clinical toxicities (40% vs 22%, OR 3.0, 95% CI 1.2-7.7, p = 0.02), but the difference was not statistically significant in multivariable analysis. CONCLUSION: To our knowledge, this is the first study to assess prospectively the association of skeletal muscle loss with survival and treatment toxicities in non-pretreated patients with mCRC. Pretherapeutic sarcopenia was not associated with poor outcomes, but the loss of skeletal muscle mass within 60 days from treatment start was highly prognostic, independently of other prognostic and nutritional factors.

Diagnostic Algorithm to Differentiate Benign Atypical Leiomyomas from Malignant Uterine Sarcomas with Diffusion-weighted MRI.

Background Improving the differentiation of uterine sarcomas from atypical leiomyomas remains a clinical challenge and is needed to avoid inappropriate surgery. Purpose To develop a diagnostic algorithm including diffusion-weighted MRI criteria to differentiate malignant uterine sarcomas from benign atypical leiomyomas. Materials and Methods This case-control retrospective study identified women with an atypical uterine mass at MRI between January 2000 and April 2017, with surgery or MRI follow-up after 1 year or longer. A diagnostic algorithm including T2-weighted MRI and diffusion-weighted imaging (DWI) signal and apparent diffusion coefficient (ADC) values was developed to predict for sarcoma. The training set consisted of 51 sarcomas and 105 leiomyomas. Two external validation sets were used to evaluate interreader reproducibility (16 sarcomas; 26 leiomyomas) and impact of reader experience (29 sarcomas; 30 leiomyomas). Wilson confidence intervals (CIs) were calculated for sensitivity and specificity. Results Evaluated were 156 women (median age, 50 years; interquartile range, 44-63 years). Predictive MRI criteria for malignancy were enlarged lymph nodes or peritoneal implants, high DWI signal greater than that in endometrium, and ADC less than or equal to 0.905 × 10-3 mm2/sec. Conversely, a global or focal area of low T2 signal intensity and a low or an intermediate DWI signal less than that in endometrium or lymph nodes allowed readers to confidently diagnose as benign a uterine mass demonstrating one or more of these signs (P < .001) in 100% cases in all three data sets. The sensitivities and specificities of the algorithm for diagnosis of malignancy were 98% (50 of 51 masses; 95% CI: 90%, 100%) and 94% (99 of 105 masses; 95% CI: 88%, 98%) in the training set; 88% (14 of 16 masses; 95% CI: 64%, 97%) and 100% (26 of 26 masses; 95% CI: 87%, 100%) in the validation set; and 83% (24 of 29 masses; 95% CI: 65%, 92%) and 97% (29 of 30 masses; 95% CI: 83%, 99%) for the less experienced reader, respectively. Conclusion A diagnostic algorithm with predictive features including lymphadenopathy, high diffusion-weighted imaging signal with reference to endometrium, and low apparent diffusion coefficient enabled differentiation of malignant sarcomas from atypical leiomyomas, and it may assist inexperienced readers. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Méndez in this issue.

Usefulness of Magnetic Resonance Imaging in the Diagnosis of Juxtaglomerular Cell Tumors: A Report of 10 Cases and Review of the Literature.

Juxtaglomerular cell tumors (JCTs), a rare but potentially curable cause of hypertension, are difficult to diagnose because they may be missed or misidentified as a cyst by computed tomography (CT). Their magnetic resonance imaging (MRI) pattern has not been well described. We report the clinical, biological, and radiologic features of 10 patients with JCTs. Eight were women, and median age was 24.5 years. All had severe hypokalemic hypertension related to marked secondary hyperaldosteronism. Median plasma renin and aldosterone concentrations were 392 (minimum-maximum [min-max], 70.5-4,800) mIU/L and 1,490 (min-max, 671-2,492) pmol/L, respectively. Plasma prorenin concentration was 835.5 (min-max, 133-6,546) mIU/L. Median tumor size was 17.5mm. On CT, JCTs were spontaneously isodense, with little enhancement after contrast media injection. On MRI, JCTs were iso- (7/10) or hypointense (3/10) on T1-weighted images (WIs). On T2-WIs, JCTs were hypointense (2/10), isointense (4/10), or heterogeneously hyperintense (4/10). A thin peripheral "pseudo-capsule" (hypointense on T2-WIs) was observed in 6 of 10 cases. Contrast enhancement was low, slightly heterogeneous, and delayed. On diffusion-WIs, tumors were hyperintense with a restricted apparent diffusion coefficient. When hypertension with secondary hyperaldosteronism remains unexplained after CT, MRI of the kidney should be considered, especially for young women.

Prediction of Everolimus Toxicity and Prognostic Value of Skeletal Muscle Index in Patients With Metastatic Renal Cell Carcinoma.

BACKGROUND: The objective of the study was to assess the prognostic role of skeletal muscle index (SMI) in metastatic renal cell carcinoma (mRCC) patients treated with everolimus, and its effect of on everolimus-induced toxicity. PATIENTS AND METHODS: Consecutive mRCC patients treated with everolimus between February 2007 and November 2014 underwent computed tomography scans at a single center performed by the same radiologist. SMI was assessed before everolimus treatment using the L3 cross-sectional area. Overall survival (OS) was analyzed according to SMI value. Results were adjusted using the International Metastatic Database Consortium (IMDC) prognostic group, body mass index (BMI), and/or number of previous tyrosine kinase inhibitor lines (NPL). RESULTS: One hundred twenty-four mRCC patients (mean age, 60.21 years) were treated with everolimus as second- or third-line (82.3%) or > third-line (17.7%) therapy. Most patients (87.9%) had clear cell carcinoma. IMDC prognostic group was "favorable" (32.3%), "intermediate" (50%), or "poor" (17.7%). Median SMI was 40.75. OS was longer in patients from the highest versus lowest SMI tercile: 21.9 versus 10 months (P = .002). Continuous SMI at baseline was not significantly associated with OS after adjustment for IMDC prognostic group, BMI, or NPL but the highest versus lowest SMI tercile was an independent prognostic factor in multivariate analysis (P = .025). There was no difference in everolimus toxicity between SMI tercile groups. CONCLUSION: SMI was an independent prognostic factor for mRCC patients treated with everolimus. Whether this provides additional prognostic value to IMDC criteria needs to be confirmed in a larger cohort. SMI does not seem to be predictive of everolimus-induced toxicity.

Intravoxel Incoherent Motion Diffusion-weighted Imaging of Multiple Myeloma Lesions: Correlation with Whole-Body Dynamic Contrast Agent-enhanced MR Imaging.

PURPOSE: To correlate intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) parameters with the enhancement patterns of bone marrow and focal lesion obtained on whole-body (WB) dynamic contrast agent-enhanced (DCE) magnetic resonance (MR) images in patients with stage-III multiple myeloma (MM) before and after systemic therapy. MATERIALS AND METHODS: Twenty-seven patients with MM were retrospectively included in this institutional review board-approved study. Requirement for written informed consent was waived. All patients underwent WB DCE MR imaging before treatment and 18 patients underwent repeat MR imaging 3 months after treatment. A transverse IVIM DWI sequence with 10 b values (0, 10, 20, 30, 50, 80, 100, 200, 400, and 800 sec/mm(2)) was acquired within bone marrow and focal lesions. The IVIM parameters (perfusion fraction [f], molecular diffusion coefficient [D], and perfusion-related D [D*]) and apparent diffusion coefficient (ADC) were extracted for both focal lesions and bone marrow and correlated with focal lesions and maximal bone marrow enhancement (BMEmax) (Spearman correlation coefficient) at baseline and at follow-up (Wilcoxon signed-rank test). RESULTS: D and ADC values positively correlated with BMEmax (r = 0.7, P < .001; and r = 0.455, P = .0435, respectively). Patients with increased BMEmax showed significantly increased ADC and D within bone marrow versus patients who did not have increased BMEmax (ADC, 0.67 × 10(-3) mm(2)/sec vs 0.54 × 10(-3) mm(2)/sec, P = .03; D, 0.58 × 10(-3) mm(2)/sec vs 0.42 × 10(-3) mm(2)/sec, P < .001). Within focal lesions, f was the maximum in lesions that showed enhancement followed by washout. After treatment in good responders, the significant decrease in maximal enhancement value of focal lesions (baseline vs after treatment, 213.9% ± 78.7 [standard deviation] vs 131% ± 53.6, respectively; P < .001) was accompanied by a significant decrease in f (baseline vs after treatment, 11% ± 3.8 vs 5.8% ± 4.7, respectively; P < .001). CONCLUSION: Diffuse bone marrow involvement is associated with increased D. Hypervascular focal lesions with high maximal enhancement value of focal lesions also show high f value. Likewise, the decreased maximal enhancement value of focal lesions after treatment is accompanied by decreased f.

Measurement of placental perfusion by dynamic contrast-enhanced MRI at 4.7 T.

PURPOSE: The purposes of this study were to develop quantitative dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) at 4.7 T for perfusion measurement and to evaluate the ability of this technique to distinguish between low and normal levels of placental perfusion in a controlled rat model. MATERIALS AND METHODS: This study was approved by the animal care committee. Poor placental perfusion in the left uterine horn was achieved by ligation of the left uterine vascular pedicle on the 17th embryonic day in 12 pregnant rats. High-temporal resolution DCE-MRI (<1 second) was performed on the 19th embryonic day. Single-compartment analysis was used to calculate placental blood flow (F), volume fraction (Vb), and time delay (Dt) for each placenta and its 2 layers in both uterine horns. Mixed regression analysis was used to compare parameters between the ligated and nonligated horn and between placental layers. RESULTS: We examined 53 placentas: 11 on the ligated side and 42 on the control side. On the control side, the mean (SD) values were 115 (72) mL/min per 100 mL for F, 38.6% (11.7%) for Vb, and 5.5 (5.3) seconds for Dt. Placental blood flow was significantly lower on the ligated side (66 [30] mL/min per 100 mL; P = 0.001).Placental blood flow and Vb were significantly higher, whereas Dt was significantly lower in the inner layer than in the outer layer in both horns (P=0.0001). CONCLUSIONS: Quantitative analyses of perfusion are feasible with DCE-MRI at 4.7 T.Dynamic contrast-enhanced magnetic resonance imaging can differentiate between low and normal levels of placental perfusion in a rat model. Dynamic contrast-enhanced magnetic resonance imaging at 4.7 T is a promising preclinical tool for quantifying and monitoring microvascularization.