Predictive value of joint fluid volume on advanced pre-procedure imaging related to success of arthrocentesis and presence of septic arthritis.

PURPOSE: Septic arthritis is a dangerous medical condition requiring prompt diagnosis, often via arthrocentesis. A "dry tap" occurs when no fluid is aspirated. We hypothesized that the absence of a joint effusion on pre-procedure advanced imaging would reliably predict a dry tap and exclude septic arthritis. METHODS: A cohort of 217 arthrocentesis cases of large joints (hips, shoulders, knees) from our institution, with pre-procedure advanced imaging (CT, MR, US) of the same joint performed within the previous 48 h, was analyzed. Exclusion criteria included non-native joints or inadequate imaging of the affected joint. These cases underwent blinded review by 4 radiologists who measured the deepest pocket of joint fluid on the pre-procedure imaging. Wilcoxon rank-sum test was performed comparing joint fluid pocket size to outcomes of successful aspiration and final diagnosis. RESULTS: A smaller average joint pocket fluid size was present on advanced imaging in both dry taps compared with successful arthrocenteses (p < .0001), and in uninfected joints compared with septic joints (p = .0001). However, the overlap of values was too great to allow for a perfectly predictive cutoff. 29% (5/17) of patients with no visible joint fluid on pre-aspiration imaging underwent successful arthrocentesis, one case representing septic arthritis. CONCLUSION: Volume of joint fluid on advanced pre-arthrocentesis imaging cannot reliably predict subsequent dry tap nor exclude septic arthritis.

Hepatic Mucinous Cystic Neoplasm Versus Simple Biliary Cyst: Assessment of Distinguishing Imaging Features Using CT and MRI.

OBJECTIVE. The purpose of our study was to identify the imaging features that differentiate a hepatic mucinous cystic neoplasm (MCN) from a simple biliary cyst. MATERIALS AND METHODS. Surgically resected hepatic MCNs and simple biliary cysts over a 20-year period (October 29, 1997-January 23, 2018) with preoperative CT, MRI, or both were retrospectively identified. Included cases underwent histopathologic confirmation of diagnosis based on the 2010 World Health Organization criteria and blinded imaging review. Various imaging features, including cyst shape and septal enhancement, were assessed for performance. For septate cysts, the relationship of the septation to the cyst wall-that is, arising from the wall without an indentation versus arising from an external macrolobulation-was recorded. Statistical analysis was performed for the imaging features with the chi-square test. RESULTS. The study group comprised 22 hepatic MCNs and 56 simple biliary cysts. A unilocular hepatic cystic lesion was highly predictive of a simple biliary cyst (positive predictive value = 95.2%). The imaging feature of septations arising only from macro-lobulations was 100% specific for a simple biliary cyst on CT (p = 0.001). The presence of septations arising from the cyst wall without indentation was 100% sensitive for hepatic MCN but was only 56.3% specific on CT. Septal enhancement reached 100% sensitivity for hepatic MCN on MRI (p = 0.018). CONCLUSION. The presence of septations, relationship of the septations to the cyst wall, and septal enhancement were sensitive imaging features in the detection of hepatic MCN. The imaging feature of septations arising only from macrolobulations in the cyst wall was specific for simple biliary cysts on CT and helped differentiate simple biliary cysts from hepatic MCNs.

Evaluation of Soft-Tissue Hematomas With Real-Time, Contrast-Enhanced Ultrasound: A Pilot Study With Preliminary Findings.

ABSTRACT: In this study, we investigated the feasibility of using contrast-enhanced ultrasound (CEUS) to detect active hemorrhage in patients presenting with soft-tissue hematomas. Adult patients with clinically suspected, actively bleeding hematomas were prospectively enrolled. Contrast-enhanced ultrasound was used to assess for contrast extravasation. Ultrasound results were compared with those of multidetector computed tomographic (MDCT) imaging, operative findings, and clinical course. Sixteen patients (9 women, 7 men; mean age, 69 [SD, 13] years) were enrolled. Thirteen patients underwent MDCT imaging during their initial visit, and for 11, CEUS and computed tomography (CT) findings were concordant. The remaining patients had a negative CEUS study that was consistent with their clinical course. In 8 patients, CT imaging showed active extravasation (6 arterial, 1 indeterminate, 1 slow venous). Contrast-enhanced ultrasound and CT findings were concordant for all cases of arterial bleeding. For 1 patient, CEUS provided superior diagnostic information by identifying a pseudoaneurysm. The 2 discrepant patient cases had a ≥3-hour delay between CT and CEUS, and in 1 patient, CEUS was limited by body habitus. The second patient had no active bleeding identified in the operating room. Compared with CT, CEUS had a sensitivity and specificity of 75% and 100%, respectively, and positive and negative predictive values were 100% and 71%, respectively. Diagnostic accuracy was 85% in this limited study. Contrast-enhanced ultrasound is a promising alternative to MDCT in select patients and may sometimes provide superior clinical information. Limiting factors are large hematoma size, unfavorable anatomic location, and body habitus.

Mucinous cystic neoplasms of the liver with biliary prolapse.

OBJECTIVES: To describe the prevalence, clinical and radiological findings of biliary prolapse in pathologically proven mucinous cystic neoplasm of the liver (MCN-L). METHODS: Thirty-four patients, all female with median age 50 years (range, 14-82), with histologically confirmed MCN-L were enrolled. Median tumor size was 9 cm (range, 2-21 cm). Fifty-seven examinations (17 ultrasound, 25 CT, and 15 MR) among 34 MCN-Ls were reviewed. Two radiologists retrospectively assessed images for tumor location, size and other morphological features of the tumor, presence of biliary prolapse and upstream bile duct dilatation. Ultrasound, CT, and MR were assessed separately. Clinical features were evaluated. Clinical and radiological characteristics of MCN-L with and without biliary prolapse were compared. RESULTS: 15% (5/34) of MCN-Ls showed biliary prolapse confirmed at pathology. None of MCN-Ls were associated with invasive carcinoma. Patients with biliary prolapse were significantly younger than those without (median 27 years [22-56] vs. median 51 years [14-82], p = 0.03). MCN-Ls with biliary prolapse were significantly smaller than those without (median 6.4 cm [2.2-7.5] vs. median 9.6 cm [3.1-21], p = 0.01). The upstream bile duct was dilated more frequently in MCN-Ls with biliary prolapse (100% vs. 38%, p = 0.02). Jaundice was significantly more common in MCN-Ls with biliary prolapse (80 vs 3%, p = 0.0005). Other clinical or radiological features were not significantly different between two groups. CONCLUSIONS: Biliary prolapse was found in 15% of MCN-Ls. MCN-Ls with biliary prolapse were significantly smaller and were more commonly associated with upstream bile duct dilation and jaundice than those without biliary prolapse.

When Benign Behaves Badly: Atypical Hemangiomas on Contrast-Enhanced Ultrasonography.

ABSTRACT: Hemangioma is the most common benign liver tumor and is frequently encountered as an incidental finding on imaging. The classic enhancement pattern of hemangioma is diagnostic on contrast-enhanced ultrasound (CEUS), and it follows the same pattern of enhancement on computed tomography and magnetic resonance imaging. However, there is a subset of hemangiomas that demonstrate atypical enhancement patterns on CEUS. The ability to recognize the different enhancement patterns and discern when additional imaging or biopsy may be necessary is essential to accurately interpret an atypical hemangioma on CEUS. This article reviews various enhancement patterns of hemangioma on CEUS to avoid pitfalls in characterization of focal liver lesions on CEUS.

Radiology of Intra-Aortic Balloon Pump Catheters.

Radiographs play an important role in ascertaining appropriate placement of the intra-aortic balloon pump catheter. This imaging essay highlights correct and incorrect positioning of these catheters, with emphasis on the variability of radiopaque markers used with different catheter models and on axillary versus femoral catheter placement routes. Keywords: Conventional Radiography, CT, Percutaneous, Cardiac, Vascular, Aorta, Anatomy, Cardiac Assist Devices, Catheters © RSNA, 2022.

Multi-Center Follow-up Study to Develop a Classification System Which Differentiates Mucinous Cystic Neoplasm of the Liver and Benign Hepatic Cyst Using Machine Learning.

RATIONALE AND OBJECTIVES: To date, no clinically useful classification system has been developed for reliably differentiating mucinous cystic neoplasm (MCN) from a benign hepatic cyst (BHC) in the liver. The objective was to use machine learning and a multi-center study design to develop and assess the performance of a novel classification system for predicting whether a hepatic cystic lesion represents MCN or BHC. MATERIALS AND METHODS: A multi-center cohort study identified 154 surgically resected hepatic cystic lesions in 154 subjects which were pathologic confirmed as MCN (43) or BHC (111). Readers at each institution recorded seven pre-determined imaging features previously identified as potential differentiating features from prior publications. The contribution of each of these features to differentiating MCN from BHC was assessed by machine learning to develop an optimal classification system. RESULTS: Although several of the assessed imaging features demonstrated statistical significance, only 3 imaging features were found by machine learning to significantly contribute to a potential classification system: (1) solid enhancing nodule (2) all septations arising from an external macro-lobulation (3) whether the lesion was solitary or one of multiple cystic liver lesions. The optimal classification system had only four categories and correctly identified 144/154 lesion (93.5%). CONCLUSION: This multi-center follow-up study was able to use machine learning to develop a highly accurate classification system for differentiation of hepatic MCN from BHC, which could be readily applied to clinical practice.

Culture media composition influences patient-derived organoid ability to predict therapeutic responses in gastrointestinal cancers.

BACKGROUNDA patient-derived organoid (PDO) platform may serve as a promising tool for translational cancer research. In this study, we evaluated PDO's ability to predict clinical response to gastrointestinal (GI) cancers.METHODSWe generated PDOs from primary and metastatic lesions of patients with GI cancers, including pancreatic ductal adenocarcinoma, colorectal adenocarcinoma, and cholangiocarcinoma. We compared PDO response with the observed clinical response for donor patients to the same treatments.RESULTSWe report an approximately 80% concordance rate between PDO and donor tumor response. Importantly, we found a profound influence of culture media on PDO phenotype, where we showed a significant difference in response to standard-of-care chemotherapies, distinct morphologies, and transcriptomes between media within the same PDO cultures.CONCLUSIONWhile we demonstrate a high concordance rate between donor tumor and PDO, these studies also showed the important role of culture media when using PDOs to inform treatment selection and predict response across a spectrum of GI cancers.TRIAL REGISTRATIONNot applicable.FUNDINGThe Joan F. & Richard A. Abdoo Family Fund in Colorectal Cancer Research, GI Cancer program of the Mayo Clinic Cancer Center, Mayo Clinic SPORE in Pancreatic Cancer, Center of Individualized Medicine (Mayo Clinic), Department of Laboratory Medicine and Pathology (Mayo Clinic), Incyte Pharmaceuticals and Mayo Clinic Hepatobiliary SPORE, University of Minnesota-Mayo Clinic Partnership, and the Early Therapeutic program (Department of Oncology, Mayo Clinic).

Detection of distal ureteral stones in pregnancy using transvaginal ultrasound.

AIMS: To determine the performance of transvaginal ultrasound for the visualization of distal ureteral stones in pregnant patients with renal colic and to evaluate the diagnostic value of secondary findings suggestive of obstructing ureteral stone disease. METHODS: We retrospectively identified 129 pregnant patients with a total of 142 encounters with both abdominal and transvaginal ultrasound. Ultrasound images for each patient were reviewed recording the presence of stone with location, hydronephrosis, resistive indices (RI), and status of the ureteral jets. Patients were subcategorized into two groups based on the visualization of distal ureteral stone. RESULTS: The transvaginal technique identified 94% (N = 16/17) of sonographically detected stones in the distal ureter/urethra, while the transabdominal technique identified 29% (N = 5/17). The combined imaging for initial assessment of renal colic in pregnancy demonstrated a sensitivity of 89%, specificity 100%, and negative predictive value (NPV) of 98%. The frequency of hydronephrosis was statistically greater in the visualized stone group (94% vs 51%). Mean RI was identical in both groups however the delta RI was significantly elevated in those patients with distal ureteral stones with a mean delta RI value of 0.05. The rate of absence of ureteral jets was not statistically significant. CONCLUSION: The present data would suggest a utility of transvaginal ultrasound for the evaluation of the pregnant patient with 94% of distal stones being detected transvaginal versus 29% transabdominally. Additionally, there was significantly increased hydronephrosis and elevated RIs in patients with distal ureteral stones.

Incidence of major hemorrhage after aggressive image-guided liver mass biopsy in the era of individualized medicine.

PURPOSE: To analyze a large volume of image-guided liver mass biopsies to assess for an increased incidence of major hemorrhage after aggressive liver mass sampling, and to determine if coaxial technique reduces major hemorrhage rate. METHODS: Patients who underwent image-guided liver mass biopsy over a 15-year period (December 7, 2001-September 22, 2016) were retrospectively identified. An aggressive biopsy was defined as a biopsy event in which ≥ 4 core needle passes were performed. Association of major hemorrhage after aggressive liver mass biopsy and other potential risk factors of interest were assessed using logistic regression analysis. For the subset of aggressive biopsies, Fisher's exact test was used to compare the incidence of major hemorrhage using coaxial versus noncoaxial techniques. RESULTS: Aggressive biopsies constituted 11.6% of biopsy events (N =579/5011). The incidence of major hemorrhage with <4 passes was 0.4% (N =18/4432) and with ≥4 passes 1.2% (N =6/579). In univariable models, aggressive biopsy was significantly associated with major hemorrhage (OR 3.0, 95% CI 1.16-6.92, p =0.025). After adjusting for gender and platelet count, the association was not significant at the p =0.05 level (OR 2.58, 95% CI 0.927-6.24, p =0.067). The rate of major hemorrhage in the coaxial biopsy technique group was 1.4% (N =3/209) compared to 1.1% (N =4/370) in the noncoaxial biopsy technique group, which was not a significant difference (p =0.707). CONCLUSIONS: Although aggressive image-guided liver mass biopsies had an increased incidence of major hemorrhage, the overall risk of bleeding remained low. The benefit of such biopsies will almost certainly outweigh the risk in most patients.

Incidence and Risk Factors for Adverse Events Related to Image-Guided Liver Biopsy.

OBJECTIVE: To determine the incidence of major adverse events related to a large volume of image-guided liver biopsies performed at our institution over a 12-year period and to identify risk factors for major bleeding events. PATIENTS AND METHODS: A retrospective analysis of an internally maintained biopsy registry was performed. The analysis revealed that 6613 image-guided liver biopsies were performed in 5987 adult patients between December 7, 2001, and December 31, 2013. Liver biopsies were performed using real-time ultrasound guidance and a spring-loaded biopsy device, with rare exceptions. Adverse events considered major and included in this study were hematoma, infection, pneumothorax, hemothorax, and death. Using data from the biopsy registry, we evaluated statistically significant risk factors (P<.05) for hematoma related to image-guided liver biopsy, including coagulation status, biopsy technique, and medications. RESULTS: A total of 49 acute and delayed major adverse events (0.7%) occurred after 6613 liver biopsy events. The incidence of hematoma requiring transfusion and/or angiographic intervention was 0.5% (34 of 6613). The incidence of infection was 0.1% (8 of 6613), and that of hemothorax was 0.06% (4 of 6613). No patient (0%) incurred a pneumothorax after biopsy. Three patients (0.05%) died within 30 days of liver biopsy, 1 being directly related to biopsy. Thirty-eight of 46 major adverse events (83%) presented acutely (within 24 hours). More than 2 biopsy passes, platelets 50,000/µL or less, and female sex were statistically significant risk factors for postbiopsy hemorrhage. CONCLUSION: Image-guided liver biopsy performed by subspecialized interventionalists at a tertiary medical center is safe when the platelet count is greater than 50,000/µL. With appreciation of specific risk factors, safety outcomes of this procedure can be optimized in both general and specialized centers.