Incidence, Presentation, and Natural History of Adrenal Hemorrhage: An Institutional Analysis

INTRODUCTION

Adrenal hemorrhage (AH) can occur due to multiple etiologies with variable radiographic appearance, often indistinguishable from underlying adrenal neoplasms. There is a lack of AH literature and evidence-based guidelines. Our study aimed to understand the prevalence and etiology of AH, follow-up, and incidence of underlying neoplasm.

METHODS

An institutional database was queried from January 2006 to October 2021 for patients with AH on imaging, excluding patients with known malignancies, adrenal masses, or prior adrenal surgery. Demographics, medical history, hematoma size, laterality, biochemical evaluation, intervention, and additional imaging were reviewed.

RESULTS

Of 490,301 imaging reports queried, 530 (0.11%) with AH met inclusion criteria. Most imaging (n = 485, 91.5%) was performed during trauma evaluation. Two patients underwent dedicated intervention at presentation. Interval imaging was performed in 114 (21.5%) patients at a median of 2.6 (interquartile range 0.99-13.4) mo, with resolution (n = 84, 73.7%) or decreased size of AH (n = 21, 18.4%) in most patients. Only 10 patients (1.9%) saw an outpatient provider in our system to address AH or evaluate for underlying mass, and 9 (1.7%) underwent biochemical screening. Thirteen patients (11% of 118 patients with any follow-up) had evidence of an adrenal mass, confirmed on serial imaging (n = 10) or adrenalectomy (n = 3). Scans performed for nontrauma indications were significantly more likely to have an underlying mass (n = 6/26 [23.1%]) than those performed for trauma evaluation (n = 7/92 [7.6%], P = 0.04).

CONCLUSIONS

AH is a rare finding associated with an increased rate of underlying adrenal mass, particularly when unrelated to trauma. Most AH resolves spontaneously without intervention. Follow-up imaging at 6 mo can help distinguish mass-associated AH from simple hemorrhage.

Performance of CT With Adrenal-Washout Protocol in Heterogeneous Adrenal Nodules: A Multiinstitutional Study

Background: Adrenal-protocol CT is commonly performed to distinguish adrenal adenomas from other adrenal tumors. However, the technique's utility among heterogeneous nodules is not well established, and the optimal method for placing ROIs in heterogeneous nodules is not clearly defined. Objective: To determine the diagnostic performance of adrenal-protocol CT to distinguish adenomas from non-adenomas among heterogeneous adrenal nodules, and to compare this performance among different methods for ROI placement. Methods: This retrospective study including 164 patients (mean age, 59.1 years; 61 men, 103 women) from seven institutions, with a total of 164 heterogeneous adrenal nodules evaluated by adrenal-protocol CT. All nodules had an available pathologic reference standard. A single investigator at each institution evaluated CT images. ROIs were placed on portal venous phase images using four ROI methods: standard ROI, single large ROI in nodule center; high ROI, single ROI on nodule's highest-attenuation area; low ROI, single ROI on nodule's lowest-attenuation; average ROI: mean of three ROIs on nodule's superior, middle, and inferior thirds using the approach for the standard ROI. ROIs were then placed in identical locations on unenhanced and delayed phases. Absolute washout was determined for all methods. Results: The nodules comprised 82 adenomas and 82 non-adenomas (36 pheochromocytomas, 20 metastases, 12 adrenocortical carcinomas, and 14 with other pathologies). Mean nodule size was 4.5±2.8 cm (range, 1.6-23.0 cm). Unenhanced CT attenuation of 10 HU or less exhibited sensitivity and specificity for adenoma of 22.0% and 96.3% for standard ROI, 11.0% and 98.8% for high ROI, 58.5% and 84.1% for low ROI, and 30.5% and 97.6% for average ROI methods. Adrenal-protocol CT overall (unenhanced attenuation of 10 HU or less, or absolute washout of 60% or greater) exhibited sensitivity and specificity for adenoma of 57.3% and 84.1% for standard ROI, 63.4% and 51.2% for high ROI, 68.3% and 62.2% for low ROI, and 59.8% and 85.4% for average ROI methods. Conclusion: Adrenal-protocol CT has poor diagnostic performance for distinguishing adenomas from non-adenomas among heterogeneous adrenal nodules, regardless of the method used for ROI placement. Clinical Impact: Adrenal-protocol CT has limited utility in the evaluation of heterogeneous adrenal nodules.

Interobserver agreement and prognostic value of image-based scoring systems in patients with primary sclerosing cholangitis

BACKGROUND

Primary sclerosing cholangitis (PSC) is a cholestatic liver disease that progresses to cirrhosis and liver failure. The Anali and Amsterdam scores are based upon imaging features on MRI and ERCP, respectively.

AIMS

We aimed to compare the interobserver variability and performances of these scores.

METHODS

Patients with PSC with at least 1 MRCP were included. Images were independently scored by 2 experts. Agreement and prognostic performance with a primary end point of hepatic decompensation was assessed.

RESULTS

Fifty-nine patients were included (67.8% male, 86.4% IBD). Interobserver agreement for the Anali and Amsterdam scores were moderate (k = 0.49; 95% CI 0.35-0.64 and k = 0.43; 95% CI 0.30-0.56, respectively). Among the Anali components, dysmorphy (caudate/right lobe ratio > 0.9) had fair agreement (k = 0.37; 95% CI 0.14-0.60) and portal hypertension (k = 0.64, 95% CI 0.32-0.89) and intrahepatic dilation (k = 0.70; 95% CI 0.53-0.87) had substantial agreement. The Amsterdam extrahepatic and intrahepatic scores had fair agreement (k = 0.38; 95% CI 0.23-0.52) and moderate agreement (k = 0.50; 95% CI 0.34-0.67), respectively. Anali score (HR 5.90, 95% CI 1.64-21.21), total bilirubin (HR = 3.23; 95% Cl 1.06-9.91), and age (HR = 1.05; 95% CI 1.00-1.11) were independent predictors of hepatic decompensation. Mayo risk score and Anali score had good discriminative ability with c-statistics of 0.78 (CI 0.59-0.96) and 0.76 (CI 0.56-0.91). Anali score remained an independent predictor after adjusting for Mayo risk score.

CONCLUSION

Anali score adds additional predictive value for hepatic decompensation in patients with PSC.

Adrenal Neoplasms: Lessons from Adrenal Multidisciplinary Tumor Boards

The radiologic diagnosis of adrenal disease can be challenging in settings of atypical presentations, mimics of benign and malignant adrenal masses, and rare adrenal anomalies. Misdiagnosis may lead to suboptimal management and adverse outcomes. Adrenal adenoma is the most common benign adrenal tumor that arises from the cortex, whereas adrenocortical carcinoma (ACC) is a rare malignant tumor of the cortex. Adrenal cyst and myelolipoma are other benign adrenal lesions and are characterized by their fluid and fat content, respectively. Pheochromocytoma is a rare neuroendocrine tumor of the adrenal medulla. Metastases to the adrenal glands are the most common malignant adrenal tumors. While many of these masses have classic imaging appearances, considerable overlap exists between benign and malignant lesions and can pose a diagnostic challenge. Atypical adrenal adenomas include those that are lipid poor; contain macroscopic fat, hemorrhage, and/or iron; are heterogeneous and/or large; and demonstrate growth. Heterogeneous adrenal adenomas may mimic ACC, metastasis, or pheochromocytoma, particularly when they are 4 cm or larger, whereas smaller versions of ACC, metastasis, and pheochromocytoma and those with washout greater than 60% may mimic adenoma. Because of its nonenhanced CT attenuation of less than or equal to 10 HU, a lipid-rich adrenal adenoma may be mimicked by a benign adrenal cyst, or it may be mimicked by a tumor with central cystic and/or necrotic change such as ACC, pheochromocytoma, or metastasis. Rare adrenal tumors such as hemangioma, ganglioneuroma, and oncocytoma also may mimic adrenal adenoma, ACC, metastasis, and pheochromocytoma. The authors describe cases of adrenal neoplasms that they have encountered in clinical practice and presented to adrenal multidisciplinary tumor boards. Key lessons to aid in diagnosis and further guide appropriate management are provided. © RSNA, 2023 Online supplemental material is available for this article. Quiz questions for this article are available through the Online Learning Center.

Imaging of Hepatobiliary Cancer

The liver and biliary tree are common sites of primary and secondary malignancies. MRI followed by CT is the mainstay for the imaging characterization of these malignancies with the dynamically acquired contrast enhanced phases being the most important for diagnosis. The liver imaging reporting and data system classification provides a useful framework for reporting lesions in patents with underlying cirrhosis or who are at high risk for developing hepatocellular carcinoma. Detection of metastases is improved with the use of liver specific MRI contrast agents and diffusion weighted sequences. Aside from hepatocellular carcinoma, which is often diagnosed noninvasively, other primary hepatobiliary tumors may require biopsy for definite diagnosis, especially when presenting with nonclassic imaging findings. In this review, we examine the imaging findings of common and less common hepatobiliary tumors.

A Multicenter Assessment of Interreader Reliability of LI-RADS Version 2018 for MRI and CT

Background Various limitations have impacted research evaluating reader agreement for Liver Imaging Reporting and Data System (LI-RADS). Purpose To assess reader agreement of LI-RADS in an international multicenter multireader setting using scrollable images. Materials and Methods This retrospective study used deidentified clinical multiphase CT and MRI and reports with at least one untreated observation from six institutions and three countries; only qualifying examinations were submitted. Examination dates were October 2017 to August 2018 at the coordinating center. One untreated observation per examination was randomly selected using observation identifiers, and its clinically assigned features were extracted from the report. The corresponding LI-RADS version 2018 category was computed as a rescored clinical read. Each examination was randomly assigned to two of 43 research readers who independently scored the observation. Agreement for an ordinal modified four-category LI-RADS scale (LR-1, definitely benign; LR-2, probably benign; LR-3, intermediate probability of malignancy; LR-4, probably hepatocellular carcinoma [HCC]; LR-5, definitely HCC; LR-M, probably malignant but not HCC specific; and LR-TIV, tumor in vein) was computed using intraclass correlation coefficients (ICCs). Agreement was also computed for dichotomized malignancy (LR-4, LR-5, LR-M, and LR-TIV), LR-5, and LR-M. Agreement was compared between research-versus-research reads and research-versus-clinical reads. Results The study population consisted of 484 patients (mean age, 62 years ± 10 [SD]; 156 women; 93 CT examinations, 391 MRI examinations). ICCs for ordinal LI-RADS, dichotomized malignancy, LR-5, and LR-M were 0.68 (95% CI: 0.61, 0.73), 0.63 (95% CI: 0.55, 0.70), 0.58 (95% CI: 0.50, 0.66), and 0.46 (95% CI: 0.31, 0.61) respectively. Research-versus-research reader agreement was higher than research-versus-clinical agreement for modified four-category LI-RADS (ICC, 0.68 vs 0.62, respectively; P = .03) and for dichotomized malignancy (ICC, 0.63 vs 0.53, respectively; P = .005), but not for LR-5 (P = .14) or LR-M (P = .94). Conclusion There was moderate agreement for LI-RADS version 2018 overall. For some comparisons, research-versus-research reader agreement was higher than research-versus-clinical reader agreement, indicating differences between the clinical and research environments that warrant further study. © RSNA, 2023 Supplemental material is available for this article. See also the editorials by Johnson and Galgano and Smith in this issue.

Sonographic Assessment of Acute Versus Chronic Cholecystitis: An Ultrasound Probability Stratification Model

OBJECTIVES

What sonographic variables are most predictive for acute cholecystitis? What variables differentiate acute and chronic cholecystitis?

METHODS

The surgical pathology database was reviewed to identify adult patients who underwent cholecystectomy for cholecystitis and had a preceding ultrasound of the right upper quadrant within 7 days. A total of 236 patients were included in the study. A comprehensive imaging review was performed to assess for gallstones, gallbladder wall thickening, gallbladder distension, pericholecystic fluid, gallstone mobility, the sonographic Murphy's sign, mural hyperemia, and the common hepatic artery peak systolic velocity.

RESULTS

Of 236 patients with a cholecystectomy, 119 had acute cholecystitis and 117 had chronic cholecystitis on surgical pathology. Statistical models were created for prediction. The simple model consists of three sonographic variables and has a sensitivity of 60% and specificity of 83% in predicting acute versus chronic cholecystitis. The most predictive variables for acute cholecystitis were elevated common hepatic artery peak systolic velocity, gallbladder distension, and gallbladder mural abnormalities. If a patient had all three of these findings on their preoperative ultrasound, the patient had a 96% chance of having acute cholecystitis. Two of these variables gave a 73-93% chance of having acute cholecystitis. One of the three variables gave a 40-76% chance of having acute cholecystitis. If the patient had 0 of 3 of the predictor variables, there was a 29% chance of having acute cholecystitis.

CONCLUSIONS

Gallbladder distension, gallbladder mural abnormalities, and elevated common hepatic artery peak systolic velocity are the most important sonographic variables in predicting acute versus chronic cholecystitis.

CT of hemorrhagic adrenal adenomas: radiologic-pathologic correlation

PURPOSE

To describe the appearance of chronically hemorrhagic adenomas on adrenal protocol CT and correlate imaging with pathologic findings.

METHODS

Retrospective case series of adult patients with resected adrenal adenomas showing internal hemorrhage at histology. Seven of nine patients underwent pre-operative adrenal protocol CT and 2/7 underwent unenhanced CT with portal venous phase CT. Two abdominal radiologists in consensus assessed the CT images for the presence of calcifications, macroscopic fat, cystic/necrotic appearance, and the presence, pattern, and percent nodule volume of areas < 10 HU on unenhanced CT. Absolute washout was calculated using a large ROI, and ROIs on the highest and lowest attenuating regions on the portal venous phase.

RESULTS

Mean adenoma length was 4.9 cm. All adenomas had areas measuring < 10 HU on unenhanced CT, ranging from < 20 to > 80% nodule volume. Calcifications were present in 4/9 adenomas and gross fat in 4/9 on CT. Of the seven cases with adrenal protocol CT, the absolute washout was < 60% in 5/7 using the large ROI, 5/7 using the low attenuation ROI, and 7/7 using the high attenuation ROI. At histology, all nine cases had microscopic evidence of hemorrhage, lipid rich adenoma cells, and fibrosclerosis. Myelolipomatous changes were identified in 4/9 cases, with the remaining five cases showing lipomatous metaplasia without a myeloid component.

CONCLUSION

Chronically hemorrhagic adrenal adenomas demonstrated variable areas < 10 HU on unenhanced CT corresponding to lipid rich adenoma cells. Absolute washout was most often < 60%, hypothesized to be due to fibrosclerosis within the adenomas.

Retained Morbidly Adherent Placenta Presenting as a Myometrial Mass in Patients With Vaginal Bleeding: A Case Series and Review of Current Literature

ABSTRACT

The differential diagnosis for a uterine mass and vaginal bleeding after abortion or delivery is broad and includes both benign and malignant causes. A rare etiology for this condition is retained morbidly adherent placenta. Few cases of retained morbidly adherent placenta presenting as a myometrial mass in the setting of vaginal bleeding have been described in the medical literature. In this case series and review of the current literature, we describe the ultrasound features of 3 retained morbidly adherent placentae, along with correlative magnetic resonance imaging findings.

Utility of combined gadoxetic acid and ferumoxytol-enhanced liver MRI for preoperative detection of colorectal cancer liver metastases: a pilot study

Background

Colorectal cancer (CRC) is the second-leading cause of cancer-related death worldwide and resection of CRC metastases confined to the liver is the treatment of choice when feasible. Ferumoxytol is an off-label contrast agent that opacifies vasculature and may be helpful in distinguishing metastases from small hemangiomas and blood vessels on gadoxetic acid-enhanced magnetic resonance imaging (MRI).

Purpose

To compare the diagnostic accuracy of MRI using a standard gadoxetic acid protocol and a combined gadoxetic acid/ferumoxytol protocol in patients with suspected colorectal hepatic metastases.

Material and Methods

In this institutional review board-approved, single-institution, retrospective study, eight patients underwent gadoxetic acid-enhanced liver MRI, supplemented with additional T1-weighted ferumoxytol enhanced sequences. Two radiologists in consensus identified all metastases using all available sequences, which served as the reference standard. Two different radiologists reviewed each exam twice, once using the standard protocol and once with additional ferumoxytol sequences. The detection rate was estimated as the predicted probability of a metastasis along with the 95% confidence interval (CI) using hierarchical logistic regression models.

Results

A total of 49 metastases were identified. The mean diameter was 10 mm, measured in greatest axial dimension (median=7 mm; range=2–70 mm). Readers 1 and 2 had detection rates of 69.6% (95% CI = 48.2–85.0) and 53.1% (95% CI = 35.2–70.3) for gadoxetic acid alone and 98.0% (95% CI = 86.3–99.7) and 83.5% (95% CI = 59.3–94.7) for combined protocol.

Conclusion

In this preliminary investigation, adding ferumoxytol-enhanced sequences to gadoxetic acid liver MRI protocol increased the detection rate of CRC hepatic metastases and may aid in preoperative decision making.

Management of Incidentally Detected Gallbladder Polyps: Society of Radiologists in Ultrasound Consensus Conference Recommendations

Gallbladder polyps (also known as polypoid lesions of the gallbladder) are a common incidental finding. The vast majority of gallbladder polyps smaller than 10 mm are not true neoplastic polyps but are benign cholesterol polyps with no inherent risk of malignancy. In addition, recent studies have shown that the overall risk of gallbladder cancer is not increased in patients with small gallbladder polyps, calling into question the rationale for frequent and prolonged follow-up of these common lesions. In 2021, a Society of Radiologists in Ultrasound, or SRU, consensus conference was convened to provide recommendations for the management of incidentally detected gallbladder polyps at US. See also the editorial by Sidhu and Rafailidis in this issue.

Ultrasound Screening for Transplant Renal Artery Stenosis Risk Stratification Using Standardized Criteria in Structured Reporting: A Validation Study

OBJECTIVES

To evaluate the effectiveness of templated ultrasound reports using transplant renal artery stenosis (TRAS) risk stratification (RS), particularly with regard to utilization of downstream angiographic studies and angiographic presence of TRAS.

METHODS

Ultrasounds with TRAS-RS templated reports from August 2017 to May 2020 were included. Studies were excluded if performed <28 days posttransplant and where TRAS was not clinically considered. A total of 530 ultrasounds met inclusion/exclusion criteria. TRAS-RS criteria were recorded (renal artery velocity ≥300 cm/s, spectral broadening in the renal artery, and intraparenchymal acceleration time ≥0.1 second). Depending on the number of criteria present, recipients were stratified into low (0/3), intermediate (1/3), high (2/3), and very high (3/3) risk for TRAS. Student's t-test was performed to identify whether the TRAS-RS category was associated with 1) performance of angiography to assess for TRAS and 2) angiographic presence of TRAS.

RESULTS

Of the 530 ultrasounds, 74 (14%) underwent angiography. Of these, 41 (55%) were positive for TRAS (overall positive rate, 8%). Number of ultrasounds, angiograms, and angiograms positive for TRAS, respectively, in each of the TRAS-RS categories for the 530 cases were: low probability: n = 370 (70% of all studied reports), 7 angiograms (2%), and 0 (0%) positive for TRAS; intermediate: n = 87 (16%), 24 angiograms (28%), and 8 (33%) positive; high: n = 46 (9%), 23 angiograms (50%), and 14 (61%) positive; and very high: n = 27 (5%), 20 angiograms (74%), and 19 (95%) positive. TRAS-RS score was associated with subsequent performance of angiography and positive rate for TRAS (P < .01).

CONCLUSION

Implementing a defined ultrasound screening tool with templated reporting for TRAS allowed for effective selection of those requiring an angiogram.

Survey Study on the Experience, Practice Patterns, and Preferences of the Fellows of the Society of Radiologists in Ultrasound for Evaluation and Management of Gallbladder Polyps Detected With Ultrasound

ABSTRACT

Gallbladder polyps (GPs) are a common incidental finding on ultrasound; however, important differences in recommended management exist among professional society guidelines.An electronic survey was sent to 189 fellows of the Society of Radiologists in Ultrasound. Main outcomes included preferences and current practice patterns for evaluation, management, and surveillance of GPs as well as personal lifetime experience with gallbladder sonography and GPs.A total of 64 subjects (34%) with experience in gallbladder sonography completed the study. The estimated combined total number of gallbladder scans seen by the responders was 3,071,880. None of fellows had ever seen a pedunculated GP <1 cm detected on ultrasound that was proven to be malignant at the time of detection or during subsequent follow-up. All of the fellows used size as a feature to stratify recommendations. The median size threshold currently used by Society of Radiologists in Ultrasound fellows for recommending ultrasound follow-up was 6 mm, and their preferred threshold was 7 mm. The median size threshold for recommending surgical consultation was 10 mm, and the preferred threshold was 10 mm. Wall thickening and shape were considered important factors by 76% and 67% of respondents, respectively.Society of Radiologists in Ultrasound fellows tend to provide recommendations most similar to the American College of Radiology and Canadian Association of Radiology guidelines for management of GPs. Many would prefer guidelines that result in fewer recommendations for follow-up and surgical consultation. Despite a substantial combined experience, this survey did not uncover any case of a small GP that was malignant.

Management of incidental adrenal nodules: a survey of abdominal radiologists conducted by the Society of Abdominal Radiology Disease-Focused Panel on Adrenal Neoplasms

Adrenal incidentalomas are common findings discovered at abdominal CT and MRI, yet the most appropriate management remains controversial and guidelines vary. The Society of Abdominal Radiology (SAR) Disease-Focused Panel on Adrenal Neoplasms sought to determine the practice patterns of abdominal radiologists regarding the interpretation and management of adrenal incidentalomas. An electronic survey consisting of eleven multiple choice questions about adrenal incidentalomas was developed and distributed to the email list of current and past SAR members. The response rate was 11.8% (423/3581) and most respondents were academic radiologists (80.6%). The 2017 American College of Radiology White Paper was the most used guideline, yet the management of indeterminate adrenal incidentalomas was highly variable with no single management option reaching a majority. Hormonal evaluation and endocrinology consultation was most often rarely or never recommended. The results of the survey indicate wide variability in the interpretation of imaging findings and management recommendations for incidental adrenal nodules among surveyed radiologists. Further standardization of adrenal incidentaloma guidelines and education of radiologists is needed.

Dynamic Positron Emission Tomography/Computed Tomography Imaging Correlate of Nonalcoholic Steatohepatitis

Nonalcoholic steatohepatitis (NASH) is a severe form of nonalcoholic fatty liver disease characterized by lobular inflammation and hepatocyte injury and is a key determinant of clinical outcome.¹ Liver biopsy remains the gold standard for diagnosis but is limited by risks of the procedure and interobserver variability. Although magnetic resonance imaging (MRI)-based technology may provide novel means to identify NASH,² there remains a significant need for other modalities to diagnose NASH noninvasively. Glucose transport, an integral tissue process altered in NASH,³ is measurable with ¹⁸F-fluorodeoxyglucose positron emission tomography (FDG PET). Because unenhanced computed tomography (CT) scan can detect hepatic steatosis quite reliably,⁴ and PET combines unenhanced CT for attenuation correction, we hypothesized that measurement of the combination of glucose transport by PET and steatosis by CT could yield a reliable radiologic correlate of NASH.

Non-Alcoholic Steatohepatitis Severity Associates with FGF21 Level and Kidney Glucose Uptake

Background: Nonalcoholic steatohepatitis (NASH) is a severe form of fatty liver disease that has been shown to be associated with chronic kidney disease (CKD). Mechanism for the association of NASH with CKD remains unclear. In this study, we examined the association between NASH severity and kidney glucose uptake and the liver-secreted signaling molecule fibroblast growth factor 21 (FGF21). Methods: Kinetic parameters for kidney glucose transport rate (K₁) and standardized uptake value (SUV) were determined using dynamic positron emission tomography after injection of ¹⁸F-fluorodeoxyglucose. Liver biopsies were scored for NASH activity (inflammation and ballooning), fibrosis, and steatosis FGF21 was measured from fasting serum samples. Patients were categorized by liver biopsy and multivariate analyses were performed to evaluate the associations. Results: Of 41 NASH patients 73% were females, 71% white, 51% with steatosis ≥2, 39% with NASH activity ≥4 and fibrosis ≥3. With severe NASH activity, kidney SUV significantly increased even when adjusted for underlying insulin-resistant (IR) state. Kidney K₁ decreased significantly in higher liver activity in unadjusted models but not when adjusted for IR. FGF21 decreased with severe liver activity in adjusted models (P < 0.05) and associated with kidney K1 but not SUV. Conclusion: Our pilot data indicate that kidney glucose metabolism associates with NASH activity and FGF21 levels, suggesting a potential mechanism to NASH-induced CKD. Clinical Trials.gov ID: NCT02754037.

Can abdominal CT features predict autonomous cortisol secretion in patients with adrenal nodules?

PURPOSE

To determine if CT features of adrenal nodules and of the remainder of the abdomen can predict autonomous cortisol secretion (ACH) in patients with adrenal nodules, and to identify a nodule size threshold below which ACH is unlikely.

METHODS

Retrospective review of adult patients with adrenal nodules who underwent CT of abdomen and 1-mg Dexamethasone suppression test within 1 year of each other. Patients were considered to have no ACH if serum cortisol was ≤ 1.8 µg/dL after the 1-mg dexamethasone suppression test and to have possible or definite autonomous cortisol secretion if serum cortisol was > 1.8 µg/dL. The following CT features were assessed: Adrenal nodule length, nodule width, unenhanced nodule attenuation, contralateral adrenal gland thickness, visceral and subcutaneous adipose tissue area, skeletal muscle area and density, and unenhanced liver attenuation.

RESULTS

29 patients had no autonomous cortisol secretion and 29 patients had possible or definite autonomous cortisol secretion. Nodule length and width were the only two variables that significantly differed between patients with nonfunctional nodules and those with possibly or definitely functional nodules. Using a threshold nodule length of 1.5 cm, the sensitivity and specificity for predicting possible or definite autonomous cortisol secretion was 93.1% and 37.9%, respectively.

CONCLUSION

Autonomous cortisol secretion in patients with adrenal nodules correlates with increasing nodule size. A nodule length threshold of 1.5 cm provides 93.1% sensitivity for predicting possible or definite ACH based on the 1-mg Dexamethasone suppression test.

Incidental Pancreatic Cysts on Cross-Sectional Imaging

Incidental pancreatic cysts are commonly encountered in radiology practice. Although some of these are benign, mucinous varieties have a potential to undergo malignant transformation. Characterization of some incidental pancreatic cysts based on imaging alone is limited, and given that some pancreatic cysts have a malignant potential, various societies have created guidelines for the management and follow-up of incidental pancreatic cysts. This article reviews the imaging findings and work-up of pancreatic cysts and gives an overview of the societal guidelines for the management and follow-up of incidental pancreatic cysts.

Incidental Adrenal Nodules

Incidentally detected adrenal nodules are common, and prevalence increases with patient age. Although most are benign, it is important for the radiologist to be able to accurately determine which nodules require further testing and which are safely left alone. The American College of Radiology incidental adrenal White Paper provides a structured algorithm based on expert consensus for management of incidental adrenal nodules. If further diagnostic testing is indicated, adrenal computed tomography is the most appropriate test in patients for nodules less than 4 cm. In addition to imaging, biochemical testing and endocrinology referral is warranted to exclude a functioning mass.

Accuracy of focal cystic appearance within adrenal nodules on contrast-enhanced CT to distinguish pheochromocytoma and malignant adrenal tumors from adenomas

PURPOSE

To determine the accuracy of cystic appearance within adrenal masses on contrast-enhanced CT in distinguishing pheochromocytomas and malignant adrenal tumors from adenomas.

METHODS

We performed a retrospective review of adult patients with pathologically proven adrenal tumors who underwent contrast-enhanced abdominal CT. There were 92 patients (mean age 64.7 years, 52 men) with 22 pheochromocytomas, 34 malignant masses, and 36 adenomas. Two abdominal radiologists independently reviewed CT images to determine the presence of cystic appearance within the adrenal masses, defined as focal regions of low attenuation within the tumor that subjectively had fluid density.

RESULTS

Cystic appearance was present in 12/22 (55%, 95% CI 32-76%) pheochromocytomas (mean size 5.3 cm), 15/34 (44%, 95% CI 27-62%) malignant masses (mean size 5.8 cm), and 2/36 (5.6%, 95% CI 0.7-9%) adenomas (mean size 3.2 cm). Sensitivity and specificity of cystic appearance for distinguishing pheochromocytoma or malignant masses from adenomas were 48.2% (95% CI 34.7-62.0%) and 94.4% (95% CI 81.3-99.3%), respectively. Cystic appearance was a significant predictor of tumor type (p = 0.015) even after controlling for tumor size. Reader agreement for cystic appearance was almost perfect with a kappa of 0.85.

CONCLUSION

Cystic appearance in adrenal tumors on contrast-enhanced CT has high specificity and low sensitivity for distinguishing pheochromocytoma and malignant adrenal masses from adenomas.

Right-sided scrotal varicocele and its association with malignancy: a multi-institutional study

PURPOSE

To determine the prevalence of isolated right-sided varicocele due to an obstructing malignancy in patients with no other evidence of malignancy.

METHODS

This retrospective, multi-institutional study included a text search for right-sided varicocele in consecutive reports of scrotal ultrasound studies performed between 4/22/1999 and 06/24/2018. Diagnosis was confirmed by a radiologist based on the following criteria: pampiniform plexus vein diameter of ≥ 2 mm, which has augmented flow or increases by ≥ 1 mm on Valsalva. Inclusion criteria for adequate follow-up were (1) abdominopelvic CT or MRI performed within 3 months prior to, or any time after, the ultrasound study; or (2) presence of clinical documentation more than 2 years after the ultrasound date. Exclusion criteria were existing cancer diagnosis in the abdomen or pelvis, epididymo-orchitis, intratesticular or intrascrotal mass, and prior scrotal surgery. Images of available CT or MRI studies were reviewed for presence of any explanation of right-sided varicocele.

RESULTS

210 patients with right-sided varicocele met inclusion and exclusion criteria. 118/210 had abdominopelvic CT or MRI in the assigned timeframe. Of these, no patients had malignancy that could account for right-sided varicoceles. Of the 92/210 patients without CT or MRI but with available clinical follow-up, none had a malignancy that could have caused an isolated right-sided varicocele. There was no underlying malignancy to explain the right-sided varicocele in any of the patients, 0/210, 95% CI [0.0-1.4%].

CONCLUSION

No associated malignancy was found in patients with isolated right-sided varicoceles to support additional imaging for malignancy screening.

Adherence to guidelines for hormonal evaluation in patients with incidentally detected adrenal nodules: effects of radiology report wording and standardized reporting

OBJECTIVE

To compare the rates of hormonal evaluation in patients who had CT reports describing adrenal incidentalomas with and without a specific recommendation for hormonal evaluation.

MATERIALS AND METHODS

We performed a retrospective review of adult outpatients without a history of cancer who had a CT report describing an incidental adrenal nodule. Radiology reports were reviewed to determine whether a standardized macro was used which gave specific recommendations for hormonal evaluation and endocrinology consultation. If no macro was used it was determined whether the report had a recommendation for hormonal evaluation and endocrinology consultation.

RESULTS

A standardized macro recommending hormonal evaluation and endocrinology referral was used in 45/129 (34.8%) reports that described an incidental adrenal nodule. A recommendation for hormonal evaluation was made in 5/84 (6.0%) reports without a macro. Hormonal evaluation was performed in 24/50 (48.0%) patients whose reports recommended it and in 11/79 (13.9%) patients whose reports did not (p < 0.0001). A recommendation for endocrinology referral was made in 2/84 (2.4%) reports without a macro. Patients were seen by endocrinology in 12/47 (25.5%) patients whose reports recommended an endocrinology referral evaluation and 5/82 (6.1%) patients whose reports did not (p < 0.0001). Hormonal evaluation was performed in 17/17 (100%) patients who were seen by endocrinology and 18/112 (16.1%) patients who were not (p < 0.0001). Eleven patients (8.5%) had an evaluation suggesting hyperfunctioning nodules (4 cortisol producing, 6 aldosterone producing, and 1 pheochromocytoma).

CONCLUSIONS

Utilizing standardized macros that make specific recommendations for hormonal evaluation in patients with adrenal incidentalomas leads to improved adherence to clinical guidelines.

Incidentally detected biliary ductal dilatation on contrast-enhanced CT: what is the incidence of occult obstructing malignancy?

PURPOSE

The purpose of this study was to determine the incidence of occult obstructing malignancy in the setting of asymptomatic biliary ductal dilatation incidentally detected and without identifiable cause on contrast-enhanced CT.

METHODS

A retrospective search identified patients with biliary ductal dilatation on contrast-enhanced CT from March 30, 2007 to November 1, 2017. Patients with biliary symptomatology or clinical concern for an obstructing process, an explanation for biliary ductal dilatation on index CT, intrahepatic without extrahepatic biliary ductal dilatation, concurrent pancreatic ductal dilatation, and inadequate follow-up were excluded. A reference standard of at least 1 year of imaging follow-up or 2 years of clinical follow-up was used to exclude occult obstructing malignancy.

RESULTS

156 patients were included; 120 patients met imaging follow-up criteria and 36 patients met clinical follow-up criteria. No cases of occult malignancy were identified as the source of biliary ductal dilatation (95% CI 0.0-1.9%). LFTs were available for 131 patients, of which 36 were elevated (27%). One case demonstrated a 1.2-cm ampullary adenoma on endoscopic retrograde cholangiopancreatography (occult on follow-up MRI, normal LFTs at the time of the index CT).

CONCLUSION

Asymptomatic biliary ductal dilatation incidentally detected and without identifiable cause on contrast-enhanced CT is likely benign in patients with normal LFTs, and further workup may not be warranted.

Structural and practical identifiability of dual-input kinetic modeling in dynamic PET of liver inflammation

Dynamic ¹⁸F-FDG PET with tracer kinetic modeling has the potential to noninvasively evaluate human liver inflammation using the FDG blood-to-tissue transport rate K ₁. Accurate kinetic modeling of dynamic liver PET data and K ₁ quantification requires the knowledge of dual-blood input function from the hepatic artery and portal vein. While the arterial input function can be derived from the aortic region on dynamic PET images, it is difficult to extract the portal vein input function accurately from PET images. The optimization-derived dual-input kinetic modeling approach has been proposed to overcome this problem by jointly estimating the portal vein input function and FDG tracer kinetics from time activity curve fitting. In this paper, we further characterize the model properties by analyzing the structural identifiability of the model parameters using the Laplace transform and practical identifiability using computer simulation based on fourteen patient datasets. The theoretical analysis has indicated that all the kinetic parameters of the dual-input kinetic model are structurally identifiable, though subject to local solutions. The computer simulation results have shown that FDG K ₁ can be estimated reliably in the whole-liver region of interest with reasonable bias, standard deviation, and high correlation between estimated and original values, indicating of practical identifiability of K ₁. The result has also demonstrated the correlation between K ₁ and histological liver inflammation scores is reliable. FDG K ₁ quantification by the optimization-derived dual-input kinetic model is promising for assessing liver inflammation.

Normal reference values for bladder wall thickness on CT in a healthy population

PURPOSE

To determine normal bladder wall thickness on CT in patients without bladder disease.

MATERIALS AND METHODS

Four hundred and nineteen patients presenting for trauma with normal CTs of the abdomen and pelvis were included in our retrospective study. Bladder wall thickness was assessed, and bladder volume was measured using both the ellipsoid formula and an automated technique. Patient age, gender, and body mass index were recorded. Linear regression models were created to account for bladder volume, age, gender, and body mass index, and the multiple correlation coefficient with bladder wall thickness was computed. Bladder volume and bladder wall thickness were log-transformed to achieve approximate normality and homogeneity of variance. Variables that did not contribute substantively to the model were excluded, and a parsimonious model was created and the multiple correlation coefficient was calculated. Expected bladder wall thickness was estimated for different bladder volumes, and 1.96 standard deviation above expected provided the upper limit of normal on the log scale.

RESULTS

Age, gender, and bladder volume were associated with bladder wall thickness (p = 0.049, 0.024, and < 0.001, respectively). The linear regression model had an R² of 0.52. Age and gender were negligible in contribution to the model, and a parsimonious model using only volume was created for both the ellipsoid and automated volumes (R² = 0.52 and 0.51, respectively).

CONCLUSION

Bladder wall thickness correlates with bladder wall volume. The study provides reference bladder wall thicknesses on CT utilizing both the ellipsoid formula and automated bladder volumes.

Dynamic PET of human liver inflammation: impact of kinetic modeling with optimization-derived dual-blood input function

The hallmark of nonalcoholic steatohepatitis is hepatocellular inflammation and injury in the setting of hepatic steatosis. Recent work has indicated that dynamic 18F-FDG PET with kinetic modeling has the potential to assess hepatic inflammation noninvasively, while static FDG-PET is less promising. Because the liver has dual blood supplies, kinetic modeling of dynamic liver PET data is challenging in human studies. This paper aims to identify the optimal dual-input kinetic modeling approach for dynamic FDG-PET of human liver inflammation. Fourteen patients with nonalcoholic fatty liver disease were included. Each patient underwent 1 h dynamic FDG-PET/CT scan and had liver biopsy within six weeks. Three models were tested for kinetic analysis: the traditional two-tissue compartmental model with an image-derived single-blood input function (SBIF), a model with population-based dual-blood input function (DBIF), and a new model with optimization-derived DBIF through a joint estimation framework. The three models were compared using Akaike information criterion (AIC), F test and histopathologic inflammation score. Results showed that the optimization-derived DBIF model improved liver time activity curve fitting and achieved lower AIC values and higher F values than the SBIF and population-based DBIF models in all patients. The optimization-derived model significantly increased FDG K1 estimates by 101% and 27% as compared with traditional SBIF and population-based DBIF. K1 by the optimization-derived model was significantly associated with histopathologic grades of liver inflammation while the other two models did not provide a statistical significance. In conclusion, modeling of DBIF is critical for dynamic liver FDG-PET kinetic analysis in human studies. The optimization-derived DBIF model is more appropriate than SBIF and population-based DBIF for dynamic FDG-PET of liver inflammation.

Abstract 3045: Pilot study of kernel-based dynamic (KBD) FDG-PET in patients with borderline resectable pancreatic cancer

Introduction: Patients (pts) with borderline resectable (BR) pancreatic cancer (PC) derive a clear survival benefit when margin-negative resection can be achieved after neoadjuvant treatment (tx). As such, reliable imaging is desperately needed to identify those patients with the best chance of surgical benefit. Current imaging with CT/MRI and standard 18F-fludeoxyglucose (FDG) PET lacks sensitivity and specificity to resolve residual tumor contact with the large blood vessels of the vascular groove. Dynamic PET with kernel-based image reconstruction developed by our group has potential to overcome limits of standard static PET by robust parametric imaging of radiotracer kinetics. KBD FDG-PET provides the FDG kinetic parameter K1 for tumor perfusion and Ki for tumor glucose utilization. A lower Ki/K1 ratio indicates a better perfused, less metabolically active tumor and is derived by our method without need for separate perfusion CT/MRI. Methods: Pts with PC staged as BR as defined by consensus guidelines were eligible. Pts were assessed by CA 19-9 and CT/MRI along with KBD FDG-PET both pre-tx and post-tx. KBD FDG PET was performed by IV bolus of 10 mCi of FDG followed by 60-min PET data acquisition. A 3-compartment model with 5 micro kinetic parameters K1, k2, k3, k4, and fv was used where K1 (mL/min/mL) denotes the rate constant of FDG transport from plasma to tissue, k2 (1/min) the transport rate from tissue to plasma, k3 (1/min) the rate of FDG conversion to FDG 6-phosphate, k4 (1/min) the rate of dephosphorylation, and fv the fractional blood volume. Ki was calculated from micro parameters by the formula K1*k3/(k2+k3). Parametric images of these kinetic parameters were obtained by voxel-wise implementation of kinetic modeling. Results: 4 pts were enrolled, 3 pts had pre- and post-tx KBD FDG-PET, and 2 pts were resected. In the 3 evaluable pts, an overall 62% decrease in tumor glucose utilization was observed (mean pre-tx Ki=.03, [range .013-.045]; mean post-tx Ki=.011 [range .004-.016]. Mean pre-tx K1=.37 (range .26-.50) and mean post-tx K1=.38 (range .31-.46). Delta Ki was -17%, -47%, and -91% and delta Ki/K1 was -9%, -28%, and -95% in pts 1, 2, 3 respectively. Pt 3 had the highest pre-tx Ki and the lowest pre-tx K1, but had a &gt;90% decrease in Ki and Ki/K1 post-tx, indicating a significant decrease in metabolic activity and concomitant increase in perfusion. Despite persistent superior mesenteric vein (SMV) abutment on standard post-tx imaging, margin-negative resection was achieved. In contrast, pt 1 had the lowest pre-tx Ki and highest pre-tx K1, but had a &lt;20% decrease in Ki and Ki/K1 post-tx. Like Pt 3, Pt 1 also had SMV contact on standard post-tx imaging, but in contrast, experienced margin-positive resection. Conclusions: KBD FDG-PET is a promising modification of standard static PET that provides useful kinetic parameters for evaluation of PC resectability.

Citation Format: John P. Schwerkoske, Guobao Wang, Kit W. Tam, Jasmine C. Huynh, Heather H. Hunt, Michael L. Rusnak, Cameron C. Foster, Michael T. Corwin, Karen E. Matsukuma, Dorina Gui, May T. Cho, Richard J. Bold, Ramsey D. Badawi, Edward J. Kim. Pilot study of kernel-based dynamic (KBD) FDG-PET in patients with borderline resectable pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3045.

Evidence Supporting LI-RADS Major Features for CT- and MR Imaging-based Diagnosis of Hepatocellular Carcinoma: A Systematic Review

The Liver Imaging Reporting and Data System (LI-RADS) standardizes the interpretation, reporting, and data collection for imaging examinations in patients at risk for hepatocellular carcinoma (HCC). It assigns category codes reflecting relative probability of HCC to imaging-detected liver observations based on major and ancillary imaging features. LI-RADS also includes imaging features suggesting malignancy other than HCC. Supported and endorsed by the American College of Radiology (ACR), the system has been developed by a committee of radiologists, hepatologists, pathologists, surgeons, lexicon experts, and ACR staff, with input from the American Association for the Study of Liver Diseases and the Organ Procurement Transplantation Network/United Network for Organ Sharing. Development of LI-RADS has been based on literature review, expert opinion, rounds of testing and iteration, and feedback from users. This article summarizes and assesses the quality of evidence supporting each LI-RADS major feature for diagnosis of HCC, as well as of the LI-RADS imaging features suggesting malignancy other than HCC. Based on the evidence, recommendations are provided for or against their continued inclusion in LI-RADS. ^© RSNA, 2017 Online supplemental material is available for this article.

The radiographically diagnosed adrenal myelolipoma: what do we really know?

PURPOSE

Adrenal myelolipomas are uncommon, benign tumors of the adrenal glands that are not routinely evaluated for autonomous hormone secretion or followed by repeat imaging, but may lead to retroperitoneal hemorrhage. Little is known about the natural history these tumors with the majority of previous publications being confined to case reports and small case series.

METHODS

We reviewed the computed tomography (CT) reports of 62,279 patients evaluated at a tertiary referral center between 2002 and 2015 for the presence of an adrenal myelolipoma >1 cm in size. We then reviewed the CT imaging and patient charts to determine tumor size, growth, evidence of retroperitoneal hemorrhage, and endocrine dysfunction.

RESULTS

We identified 150 (0.24%) patients with 155 radiographically diagnosed adrenal myelolipomas found on a CT scan during our study period. The median tumor size at discovery was 2.1 cm. Twelve (7.7%) tumors were >6 cm. Sixty-nine (46%) patients had a follow-up CT with a mean time interval between scans of 3.9 years. Eleven tumors (16%) grew over our follow-up period with a median growth rate of 0.16 cm/year. No patient developed a retroperitoneal hemorrhage. Twenty (13%) patients underwent an evaluation for endocrine dysfunction. Three patients had evidence of hypercortisolism and one patient had primary aldosteronism.

CONCLUSION

The majority of radiographically diagnosed adrenal myelolipomas found on abdominal CT imaging are small and slow growing. Retroperitoneal hemorrhage is uncommon, but the rate of associated endocrine dysfunction may be underestimated.

Rate and Reasons for Repeat CT Scanning in Transferred Trauma Patients

To describe the reasons and additional radiation for CT scans repeated after transfer to a trauma center. Retrospective study of patients transferred to a trauma center. Patients had repeat CT if a CTof the same region was repeated at the trauma center's emergency department. Indications for repeat CT scanning were abstracted. Radiation dosage was calculated in millisieverts. A total of 370 had CT scans and were transferred. Mean age was 39.1 ± 28.0 years. Seventy-four [20.0%, 95% confidence interval (CI) 16.0–24.4%] had 103 CTs repeated. Adults (64/254, 25.2%) were more likely than children (10/116, 8.6%) to undergo repeat CT (difference 16.6%, 95% CI 9.2–24.0%). Types of CTs repeated included: head 48 (47%), face 6 (6%), cervical spine/neck 21 (20%), thoracolumbar spine 4 (4%), chest 4 (4%), and abdominal/pelvic 20 (19%). Reasons for repeat CT were outside CT unavailable 31 (42%), insufficient image quality/additional details needed 15 (20%), disease progression 16 (22%), unknown 10 (14%), and consult request unknown reason 2 (3%). Median dose for the repeat CT scans was 4.19 mSv (interquartile range 1.98, 6.28) and was 4.79 mSv (interquartile range 2.47, 8.22) when the CTs were unavailable. Effective dose of the repeat scans was greater than 10 mSv in 13 (3.5%) patients. Patients transferred to a trauma center often undergo repeat CT. The most common reason for repeated imaging was failure to transport original CT scans with the patient or images that were unable to be viewed. Trauma centers should work with their catchment areas to establish systems that ensure transfer of all radiographic imaging.

Rate and Reasons for Repeat CT Scanning in Transferred Trauma Patients

To describe the reasons and additional radiation for CT scans repeated after transfer to a trauma center. Retrospective study of patients transferred to a trauma center. Patients had repeat CT if a CT of the same region was repeated at the trauma center's emergency department. Indications for repeat CT scanning were abstracted. Radiation dosage was calculated in millisieverts. A total of 370 had CT scans and were transferred. Mean age was 39.1 ± 28.0 years. Seventy-four [20.0%, 95% confidence interval (CI) 16.0-24.4%] had 103 CTs repeated. Adults (64/254, 25.2%) were more likely than children (10/116, 8.6%) to undergo repeat CT (difference 16.6%, 95% CI 9.2-24.0%). Types of CTs repeated included: head 48 (47%), face 6 (6%), cervical spine/neck 21 (20%), thoracolumbar spine 4 (4%), chest 4 (4%), and abdominal/pelvic 20 (19%). Reasons for repeat CT were outside CT unavailable 31 (42%), insufficient image quality/additional details needed 15 (20%), disease progression 16 (22%), unknown 10 (14%), and consult request unknown reason 2 (3%). Median dose for the repeat CT scans was 4.19 mSv (interquartile range 1.98, 6.28) and was 4.79 mSv (interquartile range 2.47, 8.22) when the CTs were unavailable. Effective dose of the repeat scans was greater than 10 mSv in 13 (3.5%) patients. Patients transferred to a trauma center often undergo repeat CT. The most common reason for repeated imaging was failure to transport original CT scans with the patient or images that were unable to be viewed. Trauma centers should work with their catchment areas to establish systems that ensure transfer of all radiographic imaging.

Evaluation of cystic duct patency: comparison of functional MR cholangiography with gadoxetate disodium and hepatobiliary scintigraphy in suspected acute cholecystitis

PURPOSE

This study aims to compare assessment of cystic duct patency between gadoxetate disodium MRI and hepatobiliary scintigraphy.

MATERIALS AND METHODS

We performed a prospective study of patients who underwent gadoxetate disodium MRI within 16 h of scintigraphy.

RESULTS

The gallbladder filled on MRI and scintigraphy in 8 patients, none with acute cholecystitis. The mean time to gallbladder filling was 14.6 and 18.9 min for MRI and scintigraphy, respectively. The gallbladder did not fill on both MRI and scintigraphy in 3 patients, all of whom had acute cholecystitis.

CONCLUSION

Evaluation of cystic duct patency using gadoxetate disodium MRI is comparable to hepatobiliary scintigraphy.

Practical dose reduction tips for abdominal interventional procedures using CT-guidance

Reducing the radiation dose should be an endeavor not only for diagnostic CT exams but also for interventional procedures using CT-guidance. Given that interventional procedures vary in scope and complexity, there is greater variability in radiation doses delivered during CT procedures. The goal in an interventional procedure is simply to advance the interventional instruments into the target lesions, and as such diagnostic level doses are not required and only narrow scan range scans need to be acquired. Adherence to the principles outlined in this article will allow such procedures to be performed with reduced radiation doses.

Sonography of Abdominal Pain in Children: Appendicitis and Its Common Mimics

Abdominal pain is very common in the pediatric population (<18 years of age). Sonography is a safe modality that can often differentiate the frequently encountered causes of abdominal pain in children. This pictorial essay will discuss the sonographic findings of acute appendicitis, including the imaging appearance of a perforated appendicitis. It will also present the sonographic features of the relatively common mimics of appendicitis, such as mesenteric adenitis/gastroenteritis, intussusception, Meckel diverticulum, and ovarian torsion.

Pelvic angioembolization in trauma - Indications and outcomes

INTRODUCTION

Pelvic stabilization with angioembolization (AE) is steadily supplanting operative management for the treatment of pelvic hemorrhage in trauma. We aimed to provide a brief review of the indications, effectiveness and complications associated with AE for pelvic injuries.

METHODS

We conducted a literature search using the terms "trauma," "angioembolization," and "pelvis" limited to studies published in the English language. Abstracts and full text were manually reviewed to identify suitable articles.

RESULTS

The current brief review is based on content from articles published in the last 10 years related to pelvic AE for retroperitoneal hemorrhage after trauma.

DISCUSSION

Pelvic injuries often require complex management because the high energy transfer causes concomitant injuries. Outcomes for hemodynamically unstable patients may be better with AE than with operative management.

CONCLUSION

Pelvic AE is the most effective intervention for management of hemorrhage associated with pelvic fracture in both hemodynamically stable and unstable patients. It can be used as the primary definitive intervention or in conjunction with operative management in the setting of concomitant intra-abdominal injury.

Arterial phase CT for the detection of splenic injuries in blunt trauma: would it improve clinical outcomes?

OBJECTIVE

To determine if the addition of an arterial phase abdominal computed tomography (CT) improves clinical outcomes in patients with blunt splenic injuries.

METHODS

Retrospective review of patients who underwent CT of the abdomen revealing splenic injuries. Clinical management in these patients was determined.

RESULTS

Fifty-one of three thousand five hundred twenty-five patients had splenic injuries. Twenty-five patients underwent nonsurgical management, and 3 failed. The theoretical additional arterial phase resulted in a 62% increase in mean effective dose compared to the portal venous phase alone.

CONCLUSIONS

Routine use of arterial phase CT in blunt trauma patients may not be warranted as there is minimal improvement in outcomes.

Graft arterial stenosis in kidney en bloc grafts from very small pediatric donors: incidence, timing, and role of ultrasound in screening

In previous studies with different donor selection criteria and noncontemporary surgical techniques, graft arterial stenosis (GAS) has been reported to occur more frequently in adult recipients of pediatric en bloc renal allografts (EBKT) as compared to single adult donor allografts. The purpose of our study was to evaluate the incidence of GAS within our EBKT recipient population and to evaluate clinical and imaging features of those cases with GAS. In a retrospective cohort study, we analyzed 182 EBKT performed at a single institution. We identified cases of suspected GAS based on clinical factors, lab results, and noninvasive imaging. Diagnosis of GAS was confirmed by digital subtraction angiography. Two EBKT recipients (1.1% of 182) had angiographically confirmed GAS at 2.5 and 4.5 months after transplant. In both cases, the stenoses were short segment within the proximal (perianastomotic) donor aorta, color Doppler ultrasound demonstrated peak systolic velocities of >400 cm/s, and poststenotic parvus tardus waveforms were present. Both patients underwent angioplasty and demonstrated postintervention improvement in renal function and blood pressure. Restenosis did not occur during follow up. In conclusion, recipients of EBKT have a low incidence of GAS, similar to the lowest reported for adult single allografts.

Angioembolization for solid organ injury: A brief review

INTRODUCTION

Non-operative management is the standard of care for blunt solid organ injuries in stable patients. Angioembolization is an important technique that improves success rates of non-operative management. We aimed to provide a brief review of the indications, effectiveness and complications associated with angioembolization for solid organ injuries.

METHODS

We conducted a literature search of the PubMed database using the terms "trauma", "angioembolization", and "solid organ embolization" limited to studies published in the English language. Abstracts and full text were manually reviewed to identify suitable articles.

RESULTS

The current brief review is based on content from the more recently published articles related to angioembolization for solid organ injuries after trauma.

DISCUSSION

Angioembolization is appropriate for hemodynamically stable patients with contrast extravasation on CT scan or high-grade injury to a solid organ. Non-operative management success rates have improved with the adoption of angioembolization. The complications associated with angioembolization are acceptable in the context of avoiding a laparotomy, and are often related to the severity of the injury.

CONCLUSION

Angioembolization is a natural extension of the move towards non-operative management for solid organ injuries. Randomized controlled trials are required to fully characterize the indications and efficacy of its use.

Sonographic appearance of a dermoid cyst (mature cystic teratoma) of the spleen

Splenic dermoids are rare, with few published case reports and no ultrasound images in the English literature. We report the case of a 57-year-old woman with that diagnosis and illustrate it with ultrasound, CT, and pathology images. We discuss the differential diagnosis of solid splenic lesions.

Multidetector CT of vascular compression syndromes in the abdomen and pelvis

Certain abdominopelvic vascular structures may be compressed by adjacent anatomic structures or may cause compression of adjacent hollow viscera. Such compressions may be asymptomatic; when symptomatic, however, they can lead to a variety of uncommon syndromes in the abdomen and pelvis, including median arcuate ligament syndrome, May-Thurner syndrome, nutcracker syndrome, superior mesenteric artery syndrome, ureteropelvic junction obstruction, ovarian vein syndrome, and other forms of ureteral compression. These syndromes, the pathogenesis of some of which remains controversial, can result in nonspecific symptoms of epigastric or flank pain, weight loss, nausea and vomiting, hematuria, or urinary tract infection. Direct venography or duplex ultrasonography can provide hemodynamic information in cases of vascular compression. However, multidetector computed tomography is particularly useful in that it allows a comprehensive single-study evaluation of the anatomy and resultant morphologic changes. Anatomic findings that can predispose to these syndromes may be encountered in patients who are undergoing imaging for unrelated reasons. However, the diagnosis of these syndromes should not be made on the basis of imaging findings alone. Severely symptomatic patients require treatment, which is generally surgical, although endovascular techniques are increasingly being used to treat venous compressions.