Prophylactic Use of Biologic Mesh in Ileal Conduit (PUBMIC): A Randomized Clinical Trial.

PURPOSE: We assessed the effect of prophylactic biologic mesh on parastomal hernia (PSH) development in patients undergoing cystectomy and ileal conduit (IC). MATERIALS AND METHODS: This phase 3, randomized, controlled trial (NCT02439060) included 146 patients who underwent cystectomy and IC at the University of Southern California between 2015 and 2021. Follow-ups were physical exam and CT every 4 to 6 months up to 2 years. Patients were randomized 1:1 to receive FlexHD prophylactic biological mesh using sublay intraperitoneal technique vs standard IC. The primary end point was time to radiological PSH, and secondary outcomes included clinical PSH with/without surgical intervention and mesh-related complications. RESULTS: The 2 arms were similar in terms of baseline clinical features. All surgeries and mesh placements were performed without any intraoperative complications. Median operative time was 31 minutes longer in patients who received mesh, yet with no statistically significant difference (363 vs 332 minutes, P = .16). With a median follow-up of 24 months, radiological and clinical PSHs were detected in 37 (18 mesh recipients vs 19 controls) and 16 (8 subjects in both arms) patients, with a median time to radiological and clinical PSH of 8.3 and 15.5 months, respectively. No definite mesh-related adverse events were reported. Five patients (3 in the mesh and 2 in the control arm) required surgical PSH repair. Radiological PSH-free survival rates in the mesh and control groups were 74% vs 75% at 1 year and 69% vs 62% at 2 years. CONCLUSIONS: Implementation of biologic mesh at the time of IC construction is safe without significant protective effects within 2 years following surgery.

Sarcopenia and body fat change as risk factors for radiologic incisional hernia following robotic nephrectomy.

OBJECTIVE: To assess the effect of body muscle and fat metrics on the development of radiologic incisional hernia (IH) following robotic nephrectomy. MATERIALS AND METHODS: We retrospectively reviewed the records of patients who underwent robotic nephrectomy for kidney tumors between 2011 and 2017. All pre- and postoperative CTs were re-reviewed by experienced radiologists for detection of radiologic IH and calculation of the following metrics using Synapse 3D software: cross-sectional psoas muscle mass at the level of L3 and L4 as well as subcutaneous and visceral fat areas. Sarcopenia was defined as psoas muscle index below the lowest quartile. Cox proportional hazard model was constructed to examine the association between muscle and fat metrics and the risk of developing radiologic IH. RESULTS: A total of 236 patients with a median (IQR) age of 64 (54-70) years were included in this study. In a median (IQR) follow-up of 23 (14-38) months, 62 (26%) patients developed radiologic IH. On Cox proportional hazard model, we were unable to detect an association between sarcopenia and risk of IH development. In terms of subcutaneous fat change from pre-op, both lower and higher values were associated with IH development (HR (95% CI) 2.1 (1.2-3.4), p = 0.01 and 2.4 (1.4-4.1), p < 0.01 for < Q1 and ≥ Q3, respectively). Similar trend was found for visceral fat area changes from pre-op with a HR of 2.8 for < Q1 and 1.8 for ≥ Q3. CONCLUSION: Both excessive body fat gain and loss are associated with development of radiologic IH in patients undergoing robotic nephrectomy.

Predicting Perceived Reporting Complexity of Abdominopelvic Computed Tomography With Deep Learning.

OBJECTIVE: The purpose of this pilot study was to examine human and automated estimates of reporting complexity for computed tomography (CT) studies of the abdomen and pelvis. METHODS: A total of 1019 CT studies were reviewed and categorized into 3 complexity categories by 3 abdominal radiologists, and the majority classification was used as ground truth. Studies were randomized into a training set of 498 studies and a test set of 521 studies. A 2-stage neural network model was trained on the training set; the first-stage image-level classifier produces image embeddings that are used in the second-stage sequential model to provide a study-level prediction. RESULTS: All 3 human reviewers agreed on ratings for 470 of the 1019 studies (46%); at least 2 of the 3 reviewers agreed on ratings for 1010 studies (99%). After training, the neural network model predicted complexity labels that agreed with the radiologist consensus rating on 55% of the studies; 90% of the incorrect predicted categories were errors where the predicted category differed from the consensus rating by one level of complexity. CONCLUSIONS: There is moderate interrater agreement in radiologist-perceived reporting complexity for CT studies of the abdomen and pelvis. Automated prediction of reporting complexity in radiology studies may be a useful adjunct to radiology practice analytics.

The assessment of sarcopenia using psoas muscle thickness per height is not predictive of post-operative complications in IBD.

BACKGROUND: Sarcopenia is associated with postoperative complications in inflammatory bowel disease. It has most commonly been defined using the skeletal muscle index, computed after analysis of cross-sectional muscle area at L3. Psoas muscle thickness normalized to height (PMTH), which is easier to derive, is a potential surrogate of SMI and sarcopenia in patients with cirrhosis and chronic pancreatitis. We investigate whether sarcopenia defined by PMTH has utility in predicting post-operative outcomes in patients with inflammatory bowel disease. METHODS: We performed a retrospective study of adults undergoing IBD-related surgery from 2009 to 2019 at two hospitals. Sarcopenia was defined by sex-specific PMTH at the umbilicus on cross-sectional imaging using a 50th percentile median cutoff. Predictive models were created using variables (BMI, age, sex, smoking status, albumin, INR, platelets, hemoglobin, hypertension, diabetes, CAD, medications) that may be associated with complications (mortality, reoperation, readmission, transfusions, ICU admission, infection, DVT/PE), and sarcopenia for comparison. RESULTS: 85 patients with IBD were included. Lower albumin level (OR = 0.52, p = 0.039) and biologic use (OR = 5.92, p = 0.006) were associated with postoperative complications. There was no significant difference using PMTH compared to a model incorporating hypoalbuminemia and biologic use in predicting complications. Sarcopenia on univariate analysis was associated with a lower 30 day rate of reoperation (p = 0.04). CONCLUSIONS: A low status of PMTH was not associated with increased postoperative complications, however hypoalbuminemia and biologic use were. PMTH as a surrogate for sarcopenia requires further study, ideally with prospective studies comparing PMTH with accepted radiographic surrogates for sarcopenia, to determine its role in clinical decision making.

Tricuspid Annular Diameter Measurement on Routine Chest CT Can Detect Significant Tricuspid Regurgitation.

OBJECTIVE. The objective of this study was to determine if moderate to severe tricuspid regurgitation (TR) can be predicted on routine non-ECG-gated CT images of the chest with contrast agent. MATERIALS AND METHODS. Non-ECG-gated CT images of the chest in 674 people who had undergone echocardiography within 24 hours of CT were retrospectively reviewed. CT images were reviewed, and measurements of the tricuspid annular diameter were recorded. Echocardiogram reports were independently reviewed, and the presence and severity of TR was recorded. TR was graded in a multiparametric approach using a combination of qualitative, quantitative, and objective measures. TR grades of either "moderate" or "severe" were considered significant, and grades reported as "no regurgitation," "trace," "trivial," or "mild" were considered insignificant. RESULTS. The overall prevalence of significant (moderate or severe) TR was 15.0% (10.7% prevalence in men and 19.8% in women). Using ≥ 41 mm as a cut point on CT, the prediction accuracy reached an AUC of 0.92 (95% CI, 0.89-0.96). Specificity was 96.5% (95% CI, 95.0-97.9%), sensitivity was 75.7% (95% CI, 67.6-83.8%), positive predictive value was 80.2%, and negative predictive value was 95.5%. CONCLUSION. Using a cut point of ≥ 41 mm, measurement of the tricuspid valve annulus on routine CT of the chest can predict moderate to severe TR with a specificity of 96.5% and sensitivity of 75.7%. Measurements below threshold had a 95.5% negative predictive value. Tricuspid annular diameter can be measured on routine contrast-enhanced CT images of the chest, and, when above threshold, further evaluation with echocardiography should be recommended.

Refining Convolutional Neural Network Detection of Small-Bowel Obstruction in Conventional Radiography.

OBJECTIVE: The purpose of this study was to evaluate improvement of convolutional neural network detection of high-grade small-bowel obstruction on conventional radiographs with increased training set size. MATERIALS AND METHODS: A set of 2210 abdominal radiographs from one institution (image set 1) had been previously classified into obstructive and nonobstructive categories by consensus judgments of three abdominal radiologists. The images were used to fine-tune an initial convolutional neural network classifier (stage 1). An additional set of 13,935 clinical images from the same institution was reduced to 5558 radiographs (image set 2) primarily by retaining only images classified positive for bowel obstruction by the initial classifier. These images were classified into obstructive and nonobstructive categories by an abdominal radiologist. The combined 7768 radiographs were used to train additional classifiers (stage 2 training). The best classifiers from stage 1 and stage 2 training were evaluated on a held-out test set of 1453 abdominal radiographs from image set 1. RESULTS: The ROC AUC for the neural network trained on image set 1 was 0.803; after stage 2, the ROC AUC of the best model was 0.971. By use of an operating point based on maximizing the validation set Youden J index, the stage 2-trained model had a test set sensitivity of 91.4% and specificity of 91.9%. Classification performance increased with training set size, reaching a plateau with over 200 positive training examples. CONCLUSION: Accuracy of detection of high-grade small-bowel obstruction with a convolutional neural network improves significantly with the number of positive training radiographs.

Novel kidney segmentation system to describe tumour location for nephron-sparing surgery.

PURPOSE: To propose a novel system based on segmental renal anatomy for objectively reporting location of clinical T1 masses for nephron-sparing surgery. METHODS: The kidney was subdivided into 12 standard segments, based on the computed tomography images. In 103 patients (105 cT1 tumours), three blinded radiologists (A, B, and C) prospectively reported segmental tumour location, size, and tumour-feeding arteries. Baseline, peri-operative, and post-operative data of 98 patients who underwent partial nephrectomy (PN) were prospectively collected, and the correlation between segmental tumour location and peri-operative data was evaluated. Kappa statistics were used to measure the inter-observer agreements. RESULTS: Tumour location could be assigned to the defined renal segment in all cases. Median tumour size was 2.8 cm (range 0.6-5.8). Inter-observer concordance was as follows: A versus B 0.82 (95% CI 0.74-0.90); A versus C 0.89 (95% CI 0.83-0.95); and B versus C 0.84 (95% CI 0.76-0.92). First, second, third, and fourth segments were involved by the tumour in 23, 39, 17, and 21% of cases, respectively. Number of segments involved by the tumour correlated with tumour size (p = 0.007), number of tumour-feeding arteries (p = 0.001), estimated blood loss during PN (p = 0.03), and trended towards higher post-operative complication rate (p = 0.07). Tumour-feeding arteries were identifiable in 80 patients (76%). CONCLUSIONS: Kidney segmentation (KS) system is an objective and reproducible radiologic method of universally reporting tumour location according to 12 renal segments. By adding descriptive information on tumour characteristics in candidates for nephron-sparing surgery, this novel KS system could serve as an adjunct to current nephrometry systems.

Growing teratoma syndrome: clinical and radiographic characteristics.

OBJECTIVES: To present an overview of our surgical experience in the management of growing teratoma syndrome. METHODS: A retrospective analysis of all patients undergoing post-chemotherapy retroperitoneal lymphadenectomy between November 2005 and February 2012 revealed 15 patients who met the criteria for growing teratoma syndrome. Their clinical data, imaging characteristics, and surgical and oncological outcomes were reviewed. RESULTS: The median age at diagnosis was 23 years. Primary testis tumors included non-seminomatous germ cell tumor in 12 of 15 patients, seminoma in two of 15 patients and hemorrhagic mass in one patient. Mature teratoma was present in just six (40%) of the orchiectomy specimens. All patients received preoperative chemotherapy. On imaging, the median size of the largest retroperitoneal mass was 7 cm (range 3.9-24.5 cm). The median rate of linear growth was 0.5 cm/month (range 0.03-2.9), and the increase in volume was 9.2 cm(3) /month. All tumors were found to have cystic and necrotic components. Median operative time was 6.2 h (range 4.2-15.2 h). Estimated blood loss was 600 mL (range 100-7000 mL), and median length of stay was 5 days (range 3-19 days). Four patients required resection of non-retroperitoneal growing teratoma masses after post-chemotherapy retroperitoneal lymphadenectomy to achieve tumor-free status. There were two minor (Clavien I-II) and two major postoperative complications (Clavien ≥III). All patients are alive and disease free with a median duration of follow-up of 8 months (range 1-64 months). CONCLUSIONS: Growing teratoma syndrome tumors vary in their growth rate, but they all appear to have cystic features with necrosis elements on radiographic evaluation. Aggressive surgical excision is associated with excellent outcomes.

Highlights from the scientific and educational abstracts presented at the ASER 2012 Annual Scientific Meeting and Postgraduate Course.

The American Society of Emergency Radiology 2012 Annual Scientific Meeting and Post-Graduate Course encompassed a wide range of topics: traumatic and non-traumatic emergencies, radiation dose management, technical innovations and advancements, emergency preparedness, mass casualties, and teleradiology. This article highlights the scientific and educational abstracts presented at the meeting.

Natural History of Radiologic Incisional Hernia Following Robotic Nephrectomy.

Objective: To evaluate the incidence and natural history of radiologic incisional hernia (IH) in patients who underwent robotic partial or radical nephrectomy. Materials and Methods: We retrospectively reviewed the records of patients who underwent robotic partial or radical nephrectomy for kidney tumor in our institution between January 2011 and April 2017. All pre- and postoperative imagings were re-reviewed for detection of IH per Tonouchi classification. Patients who developed hernia were followed up and classified into stable or progressive group. Clinical findings and radiologic features of these patients are reported. Results: A total of 247 patients (169 partial and 78 radical nephrectomies) were included in the study. The incidence of radiologic IH was 27.53%, graded as early-onset (35.3%), late-onset (51.5%), and bowel/fat containing (13.2%). Median time to radiologic IH was 1.7 years. During the follow-up of 68 patients who developed hernia, 33 (48.5%) had progressive and 8 (11.7%) developed clinical hernia. Median time to progression was 1.5 years. On multivariable analysis, adjuvant therapy was an independent predictor for radiologic hernia development (HR 3.23). Pathologic T stage ≥2 and history of open abdominal surgery were also significantly associated with hernia progression (HR 3.93 and 3.47, respectively). Conclusions: Radiologic IH after robotic partial or radical nephrectomy is common. Progression rate is as high as 50% with median time to progression of 1.5 years. Adjuvant therapy is an independent predictor for IH development, whereas higher stage and history of open abdominal surgery are associated with IH progression.

Detection of high-grade small bowel obstruction on conventional radiography with convolutional neural networks.

The purpose of this pilot study is to determine whether a deep convolutional neural network can be trained with limited image data to detect high-grade small bowel obstruction patterns on supine abdominal radiographs. Grayscale images from 3663 clinical supine abdominal radiographs were categorized into obstructive and non-obstructive categories independently by three abdominal radiologists, and the majority classification was used as ground truth; 74 images were found to be consistent with small bowel obstruction. Images were rescaled and randomized, with 2210 images constituting the training set (39 with small bowel obstruction) and 1453 images constituting the test set (35 with small bowel obstruction). Weight parameters for the final classification layer of the Inception v3 convolutional neural network, previously trained on the 2014 Large Scale Visual Recognition Challenge dataset, were retrained on the training set. After training, the neural network achieved an AUC of 0.84 on the test set (95% CI 0.78-0.89). At the maximum Youden index (sensitivity + specificity-1), the sensitivity of the system for small bowel obstruction is 83.8%, with a specificity of 68.1%. The results demonstrate that transfer learning with convolutional neural networks, even with limited training data, may be used to train a detector for high-grade small bowel obstruction gas patterns on supine radiographs.

Living donor liver transplantation: post-operative imaging follow-up of right lobe liver donors.

PURPOSE: To identify long-term post-operative imaging findings resulting from right lobe liver donation. METHODS: This retrospective imaging review consisted of 42 adults (20 males, 22 females, mean age 36.6 years, range 18.7-55.9 years) who underwent right lobe liver donation with pre- and post-operative imaging between 1999 and 2006. The mean follow-up period was 30.2 months (range 12.3-69.6 months). Follow-up imaging evaluation included assessment of the biliary tree, particularly isolated bile ducts draining to and terminating at the cut surface (orphan ducts). Three-dimensional volumetry of the liver remnant was also assessed. RESULTS: After liver donation, 29/42 (69%) participants demonstrated orphan ducts on follow-up imaging (95% confidence interval 52.9% to 82.4%). In those patients with orphan ducts, the main draining ducts were normal in 70% and dilated in 69%. Nearly all right lobe liver donors with orphan ducts had no clinical symptoms on follow-up (28/29); the only liver donor with clinical symptoms on follow-up was subsequently diagnosed with primary biliary cirrhosis. Mean regenerated liver volume was approximately 93%, with mean pre-operative total liver volume of 1552 ml (median 1504 ml, range 1040-2520 ml) and mean post-operative total liver volume of 1446 ml (median 1455 ml, range 964-2090 ml). CONCLUSIONS: Orphan ducts are changes that may be seen after liver donation. The presence of these findings in the absence of clinical symptoms or abnormal hepatic chemistries does not require further work-up and should not be considered pathologic.

Abdominal radiograph pearls and pitfalls for the emergency department radiologist: a pictorial review.

Abdominal plain films are often the first imaging examination performed on a patient with abdominal pain in the emergency department. Radiograph findings can help guide clinical management and the need for advanced imaging. A pictorial review of a range of abdominal radiograph findings is presented, including bowel gas patterns, abdominal organ evaluation, pathologic gas, calcifications, implanted devices, and foreign bodies.

Maternal reactions to two-dimensional compared to three-dimensional foetal ultrasonography.

Our objective was to quantitatively compare maternal reactions to viewing a three-dimensional (3D) ultrasound image of the foetal face to a traditional two-dimensional (2D) sonographic image. One hundred and twelve pregnant women were asked to evaluate their excitement, relief, amazement and satisfaction reactions to 2D and 3D ultrasound images of their foetus' face. A weighted kappa Cochran-Armitage trend test, Fisher exact test and generalised estimating equations were used to analyse the data obtained. 3D imaging was found to result in significantly more favourable reactions than 2D imaging of the foetal face. 3D imaging was significantly better than 2D in regard to the clearness of the image, feeling closer to the baby, experiencing amazement and recognising specific facial features. We hypothesised that 3D images might evoke more feelings of fear than 2D, but our analysis found there were no significant differences in this regard. 3D ultrasonography of the foetal face is well received by patients. It has been shown in this study to elicit stronger and more positive maternal reactions regarding excitement, amazement and satisfaction than experienced with 2D ultrasound.