Imaging of Small-Bowel Neuroendocrine Neoplasms: AJR Expert Panel Narrative Review.

Neuroendocrine neoplasms (NENs) of the small bowel are typically slow-growing lesions that remain asymptomatic until reaching an advanced stage. Imaging modalities for lesion detection, staging, and follow-up in patients with known or suspected NEN include CT enterography, MR enterography, and PET/CT using a somatostatin receptor analog. FDG PET/CT may have a role in the evaluation of poorly differentiated NENs. Liver MRI, ideally with a hepatocyte-specific contrast agent, should be used in the evaluation of hepatic metastases. Imaging informs decisions regarding both surgical approaches and systematic therapy (specifically, peptide receptor radionuclide therapy). This AJR Expert Panel Narrative Review describes the multimodality imaging features of small-bowel NENs; explores the optimal imaging modalities for their diagnosis, staging, and follow-up; and discusses how imaging may be used to guide therapy.

Small Bowel Neoplasms: A Pictorial Review.

Small bowel tumors are rare and account for approximately 3% of all gastrointestinal tumors in the United States. The incidence of small bowel neoplasms is rising-in particular, there is a rising incidence of small bowel carcinoid tumors. This may in part be due to small bowel lesion identification in an increasing number of cross-sectional imaging studies performed for other indications as well as increased use of advanced imaging techniques to assess specifically for small bowel disease. Diagnosis is a challenge owing to nonspecific clinical manifestation, rare occurrence, and low index of clinical suspicion. Yet, various small bowel neoplasms have characteristic imaging features at CT and MRI when optimal distention of the small bowel is achieved, correlating well with features seen in gross specimens. Understanding the imaging features of small bowel neoplasms is important to improve the radiologist's ability to diagnose and characterize small bowel neoplasms. Most small bowel tumors are clinically silent for long periods, and nearly half of the benign tumors are found incidentally during surgery or at cross-sectional imaging performed for other reasons. The authors review the imaging features of common benign and malignant small bowel neoplasms to aid the radiologist in diagnosis of small bowel tumors. ©RSNA, 2020.

Bladder volume correction factors measured with 3D ultrasound and BladderScan.

INTRODUCTION: The aim of this study was to investigate conventional 3D ultrasound and portable BladderScan volume measurements and implement correction factors to ensure accurate volume metrics. MATERIALS AND METHODS: Healthy participants without urinary urgency were recruited for a prospective hydration study in which three consecutive voids were analyzed for two separate visits. Just before and after voiding, 3D ultrasound and BladderScan volumes were measured. Estimated voided volumes were calculated as the volume immediately prior to void minus any post void residual and were compared to actual voided volumes measured using a graduated container. Percent errors were calculated, and an algebraic method was implemented to create correction factors for 3D ultrasound and BladderScan. RESULTS: Sixteen individuals completed the study, and six voids were recorded for each participant. A total of 96 volume measurements ranging from 0 mL to 1050 mL with an average of 394 +/- 26 mL were analyzed. Both 3D ultrasound and BladderScan significantly underestimated voided volumes with averages of 296 +/- 22 and 362 +/- 27, respectively. Average percent error for the 3D ultrasound group was 30.1% (pre-correction) and 20.7% (post-correction) (p < 0.01) and 22.4% (pre-correction) and 21.8% (post-correction) for the BladderScan group (p = 0.20). The voided volume correction factors for 3D ultrasound and BladderScan were 1.30 and 1.06, respectively. CONCLUSION: BladderScan and 3D ultrasound typically underestimate voided volumes. Correction factors enabled more accurate measurements of voided volumes for both 3D ultrasound and BladderScan. Accurate volume measurements will be valuable for the development of non-invasive urodynamics techniques.

A Spectrum of Entities That May Mimic Abdominopelvic Abscesses Requiring Image-guided Drainage.

A variety of entities may mimic drainable abscesses. This can lead to misdiagnosis of these entities, unnecessary percutaneous placement of a pigtail drainage catheter, other complications, and delay in appropriate treatment of the patient. Types of entities that may mimic drainable abscesses include neoplasms (lymphoma, gallbladder cancer, gastrointestinal stromal tumor, ovarian cancer, mesenteric fibromatosis, ruptured mature cystic teratoma, recurrent malignancy in a surgical bed), ischemia/infarction (liquefactive infarction of the spleen, infarcted splenule), diverticula (calyceal, Meckel, and giant colonic diverticula), and congenital variants (obstructed duplicated collecting system). Postoperative changes, including expected anatomy after urinary diversion or Roux-en-Y gastric bypass and small bowel resection, may also pose a diagnostic challenge. Nonpyogenic infections (Mycobacterium tuberculosis, Mycobacterium avium complex, echinococcal cysts) and inflammatory conditions such as xanthogranulomatous pyelonephritis and gossypiboma could also be misinterpreted as drainable fluid collections. Appropriate recognition of these entities is essential for optimal patient care. This article exposes radiologists to a variety of entities for which percutaneous drainage may be requested, but is not indicated, and highlights important imaging findings associated with these entities to facilitate greater diagnostic accuracy and treatment in their practice. ©RSNA, 2018.

Consensus Statement of Society of Abdominal Radiology Disease-Focused Panel on Barium Esophagography in Gastroesophageal Reflux Disease.

OBJECTIVE: The Society of Abdominal Radiology established a panel to prepare a consensus statement on the role of barium esophagography in gastroesophageal reflux disease (GERD), as well as recommended techniques for performing the fluoroscopic examination and the gamut of findings associated with this condition. CONCLUSION: Because it is an inexpensive, noninvasive, and widely available study that requires no sedation, barium esophagography may be performed as the initial test for GERD or in conjunction with other tests such as endoscopy.

Follow the Stream: Imaging of Urinary Diversions.

Urinary diversion is a surgical technique to redirect the stream of urine, most often after cystectomy. Cystectomy may be performed both for benign and for malignant conditions. Bladder cancer is the most common indication for cystectomy, and most patients who undergo radical cystectomy and urinary diversion have muscle-invasive or high-risk non-muscle-invasive bladder cancer. There are two major surgical approaches for urinary diversions performed after radical cystectomy: continent and incontinent diversions. For incontinent urinary diversions, a cutaneous ostomy is used for continuous urine drainage (eg, ileal conduit). With a continent diversion procedure, the patient may void through the native urethra or self-catheterize through a surgically created stoma. The goals of imaging after urinary diversion are to assess postoperative anatomy, detect postoperative complications, evaluate for residual or recurrent tumor and metastatic disease, and monitor for upper tract distention and/or deterioration. Multiple imaging modalities and techniques may be used to evaluate urinary diversions, including computed tomographic and magnetic resonance urography, intravenous pyelography, ultrasonography, pouchography, loopography, and nephrostomy studies. Knowledge of the expected postoperative appearance after urinary diversions and potential postoperative complications is crucial because many complications may be clinically silent. Radiologists must be able to recognize the expected postoperative appearance as well as complications to facilitate appropriate diagnosis and treatment of patients after cystectomy and urinary diversion. (©)RSNA, 2016.

Dysphagia secondary to anterior cervical fusion: radiologic evaluation and findings in 74 patients.

OBJECTIVE: The objective of our study was to assess the frequency, cause, and time course of dysphagia after anterior cervical fusion (ACF). MATERIALS AND METHODS: A review of the surgical database revealed that 1789 patients underwent ACF procedures during the 8-year study period. A radiologic database review indicated that 80 of the 1789 patients underwent radiologic evaluation for the assessment of dysphagia after ACF. Three patients were excluded from the study because they had a history of dysphagia before ACF, and three additional patients were excluded because they had more recently undergone Nissen fundoplication, intubation, and radiation therapy, respectively. Modified barium swallow (MBS) studies and esophagrams of the 74 remaining patients were collected and analyzed to determine the cause of dysphagia and time course of dysphagia onset after surgery. RESULTS: Dysphagia was evaluated radiologically in 74 of the 1789 ACF patients (4.1%) using video MBS studies (n=66) and esophagography (n=26). Patients underwent radiologic evaluation from 1 to 1150 days after surgery (mean, 120 days after surgery); 76% of the patients presented more than 2 weeks after surgery. The location of the ACF in the study group was the upper, mid, and lower cervical spine in 5.4% (n=4), 55.4% (n=41), and 39.2% (n=29) of patients, respectively. Soft-tissue swelling with displacement of the pharynx or esophagus was identified in 91% of patients (n=67). More serious complications of ACF that resulted in dysphagia included surgical hardware displacement or bone graft displacement (n=18), esophageal perforation (n=3), and a retropharyngeal abscess (n=3). Pharyngeal functional abnormalities were detected in 50 patients, with penetration, aspiration, or both seen in 32. CONCLUSION: Dysphagia is an underrecognized but significant complication of ACF. After ACF, 4.1% of patients presented for radiologic evaluation of dysphagia. Although ACF procedures are most frequently performed in the lower cervical spine, dysphagia is a more common clinical problem after ACF in the mid cervical spine. Radiologic examinations should be specifically tailored to evaluate ACF patients.

Dysphagia revisited: common and unusual causes.

Dysphagia is a common clinical problem whose prevalence is increasing with the aging population in the United States. The term dysphagia is commonly used to describe subjective awareness of swallowing difficulty during the passage of a bolus from the mouth to the stomach or the perception of obstruction during swallowing. Dysphagia may be further classified as oropharyngeal or substernal, depending on the location of this sensation. It can be due to benign or malignant structural lesions, esophageal motility abnormalities, oropharyngeal dysfunction (including aspiration), neuromuscular disorders, or postsurgical changes and is also associated with gastroesophageal reflux disease. Pathologic conditions of the oral cavity, pharynx, esophagus, and proximal stomach can manifest with dysphagia. Imaging remains the preferred method for evaluating patients with dysphagia, and dysphagia is an increasingly encountered indication for radiologic evaluation. Fluoroscopic studies, including the modified barium swallow and esophagography in particular, are often used in the assessment of patients with dysphagia, and the techniques used for these studies should be tailored to the patient's needs. Fluoroscopic studies can be used to evaluate the esophagus for structural abnormalities (eg, webs, diverticula, strictures, masses) and to assess function (eg, the swallowing mechanism and esophageal motility). Knowledge of the imaging spectrum of disease entities that may cause dysphagia and thorough radiologic assessment with a tailored approach may help avoid misdiagnosis.

Imaging of bariatric surgery: normal anatomy and postoperative complications.

Obesity is a disease that has reached epidemic proportions in the United States and around the world. During the past 2 decades, bariatric surgery has become an increasingly popular form of treatment for morbid obesity. The most common bariatric procedures performed include laparoscopic Roux-en-Y gastric bypass, laparoscopic adjustable gastric banding, and laparoscopic sleeve gastrectomy. Fluoroscopic upper gastrointestinal examinations and abdominal computed tomography (CT) are the major imaging tests used to evaluate patients after these various forms of bariatric surgery. The purpose of this article is to present the surgical anatomy and normal imaging findings and postoperative complications for these bariatric procedures at fluoroscopic examinations and CT. Complications after Roux-en-Y gastric bypass include anastomotic leaks and strictures, marginal ulcers, jejunal ischemia, small bowel obstruction, internal hernias, intussusception, and recurrent weight gain. Complications after laparoscopic adjustable gastric banding include stomal stenosis, malpositioned bands, pouch dilation, band slippage, perforation, gastric volvulus, intraluminal band erosion, and port- and band-related problems. Finally, complications after sleeve gastrectomy include postoperative leaks and strictures, gastric dilation, and gastroesophageal reflux. The imaging features of these various complications of bariatric surgery are discussed and illustrated.

Imaging obese patients: problems and solutions.

Obesity is an epidemic in the United States and Western World with an associated increasing impact on radiology departments. The increased prevalence of obesity in conjunction with the growing use and success of bariatric surgery results in an influx of obese patients into the health system in need of hospital services and care. Imaging services in particular are in demand in this patient population. Obese patients place special needs upon facilities and imaging equipment and also create technical challenges. This manuscript will address problems and potential solutions for imaging obese patients, specifically with regards to the modalities of radiography, fluoroscopy, computed tomography, and magnetic resonance imaging.

Is cystoscopy indicated for incidentally identified bladder wall thickening?

INTRODUCTION: The purpose of this study was to evaluate the yield of cystoscopy in detecting bladder malignancy following incidentally identified bladder wall thickening observed on computed tomography (CT) scans. METHODS AND MATERIALS: Data from 3000 consecutive patients who underwent diagnostic cystoscopy at a single institution from 2006-2009 were collected retrospectively. All prior CT scan reports were reviewed, and patients whose sole indication for cystoscopy was incidentally detected bladder wall thickening were identified. Patients were categorized as diffuse thickening, focal thickening, or focal bladder mass based on the radiologist's report. Collected data included patient age, gender, race, smoking history, history of hematuria, medications for benign prostate hypertrophy or overactive bladder as well as cystoscopy results, pathology results, and follow up. RESULTS: Twenty-two patients (0.7% of cystoscopies) underwent cystoscopy for incidentally identified bladder wall thickening including 11 (50%) with focal bladder wall thickening, 8 (36.4%) with diffuse bladder wall thickening, and 3 (13.6%) with focal bladder mass lesions. Five patients (22.7%) had suspicious lesions on cystoscopy requiring endoscopic surgery with biopsy. Two patients with focal bladder mass lesions were found to have low grade, superficial bladder cancer (66.7% of patients with focal bladder mass lesions and 9.1% of all patients with incidental bladder wall thickening). No patients with diffuse or focal bladder wall thickening had malignancy. CONCLUSIONS: Incidental findings of diffuse and focal bladder wall thickening on CT scan were found to have a low yield for the detection of urinary tract malignancy. Incidentally detected focal bladder mass lesions are more likely to have malignant pathology.

ACR Appropriateness Criteria® Right Upper Quadrant Pain: 2022 Update.

Acute right upper quadrant pain is one of the most common presenting symptoms in hospital emergency departments, as well as outpatient settings. Although gallstone-related acute cholecystitis is a leading consideration in diagnosis, a myriad of extrabiliary sources including hepatic, pancreatic, gastroduodenal, and musculoskeletal should also be considered. This document focuses on the diagnostic accuracy of imaging studies performed specifically to evaluate acute right upper quadrant pain, with biliary etiologies including acute cholecystitis and its complications being the most common. An additional consideration of extrabiliary sources such as acute pancreatitis, peptic ulcer disease, ascending cholangitis, liver abscess, hepatitis, and painful liver neoplasms remain a diagnostic consideration in the right clinical setting. The use of radiographs, ultrasound, nuclear medicine, CT, and MRI for these indications are discussed. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

ACR Appropriateness Criteria® Abnormal Liver Function Tests.

Liver function tests are commonly obtained in symptomatic and asymptomatic patients. Various overlapping lab patterns can be seen due to derangement of hepatocytes and bile ducts function. Imaging tests are pursued to identify underlying etiology and guide management based on the lab results. Liver function tests may reveal mild, moderate, or severe hepatocellular predominance and can be seen in alcoholic and nonalcoholic liver disease, acute hepatitis, and acute liver injury due to other causes. Cholestatic pattern with elevated alkaline phosphatase with or without elevated γ-glutamyl transpeptidase can be seen with various causes of obstructive biliopathy. Acute or subacute cholestasis with conjugated or unconjugated hyperbilirubinemia can be seen due to prehepatic, intrahepatic, or posthepatic causes. We discuss the initial and complementary imaging modalities to be used in clinical scenarios presenting with abnormal liver function tests. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

ACR Appropriateness Criteria® Left Lower Quadrant Pain: 2023 Update.

The differential diagnosis for left lower quadrant pain is wide and conditions range from the benign and self-limited to life-threatening surgical emergencies. Along with patient history, physical examination, and laboratory tests, imaging is often critical to limit the differential diagnosis and identify life-threatening abnormalities. This document will discuss the guidelines for the appropriate use of imaging in the initial workup for patients who present with left lower quadrant pain, patients with suspected diverticulitis, and patients with suspected complications from diverticulitis. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Imaging following bariatric procedures: Roux-en-Y gastric bypass, gastric sleeve, and biliopancreatic diversion.

Morbid obesity remains as a common and increasing health problem. Due to limited long-term success with nonsurgical weight loss measures for morbid obesity, bariatric surgery is being performed more and more often in both academic and private practice settings and has proven to be an effective treatment option with sustained weight loss, decreased morbidity, reversal of comorbidities, and prolonged life expectancies [Am J Clin Nutr 55:615S-619S, 1992; Brolin, Nutrition 12:403-404, 1996; Fisher and Schauer, Am J Surg 184:9S-16S 2002]. The Roux-en-Y gastric bypass, biliopancreatic diversion, and gastric sleeve will be discussed in terms of their expected imaging appearance and potential complications.

ACR Appropriateness Criteria® Hernia.

Abdominopelvic hernias are common clinical entities composed of a wide variety of congenital, traumatic, and iatrogenic etiologies. Any weakness in the body wall may result in hernia of cavity contents with concomitant risks of morbidity and mortality. Presentations may be specific, palpable body wall mass/bulge, or vague, nonspecific pain through bowel obstruction. This document focuses on initial imaging of the adult population with signs of symptoms prompting suspicion of abdominopelvic hernia. Imaging of the abdomen and pelvis to evaluate defects is essential for prompt diagnosis and treatment. Often CT and ultrasound are the first-line modalities to quickly evaluate the abdomen and pelvis, providing for accurate diagnoses and management of patients. MRI protocols may be useful as first-line imaging studies, especially in patients with orthopedic instrumentation. Although often performed, abdominal radiographs and fluorographic procedures may provide indirect evidence of hernias but are usually not indicated for initial diagnosis of hernia. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer-reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances in which peer-reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

ACR Appropriateness Criteria® Staging of Colorectal Cancer: 2021 Update.

Preoperative imaging of rectal carcinoma involves accurate assessment of the primary tumor as well as distant metastatic disease. Preoperative imaging of nonrectal colon cancer is most beneficial in identifying distant metastases, regardless of primary T or N stage. Surgical treatment remains the definitive treatment for colon cancer, while organ-sparing approach may be considered in some rectal cancer patients based on imaging obtained before and after neoadjuvant treatment. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

ACR Appropriateness Criteria® Right Lower Quadrant Pain: 2022 Update.

This document focuses on imaging in the adult and pregnant populations with right lower quadrant (RLQ) abdominal pain, including patients with fever and leukocytosis. Appendicitis remains the most common surgical pathology responsible for RLQ abdominal pain in the United States. Other causes of RLQ pain include right colonic diverticulitis, ureteral stone, and infectious enterocolitis. Appropriate imaging in the diagnosis of appendicitis has resulted in decreased negative appendectomy rate from as high as 25% to approximately 1% to 3%. Contrast-enhanced CT remains the primary and most appropriate imaging modality to evaluate this patient population. MRI is approaching CT in sensitivity and specificity as this technology becomes more widely available and utilization increases. Unenhanced MRI and ultrasound remain the diagnostic procedures of choice in the pregnant patient. MRI and ultrasound continue to perform best in the hands of the experts. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer-reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances in which peer-reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Aggressive bladder carcinoma in an HIV-positive man with tetraplegia and neurogenic bladder.

BACKGROUND/OBJECTIVE: Patients with neurogenic bladder secondary to spinal cord injury who are managed long term with an indwelling catheter are known to be at increased risk for transitional cell carcinoma of the bladder. Immunosuppression is a known risk factor for malignancies that often are more aggresSive than those seen in normal populations. METHOD: Case report and discussion of management recommendations. RESULTS: We summarize the case of a 44-year-old HIV-positive C5-C6 incomplete tetraplegic male (date of injury 1980), who was diagnosed with transitional cell carcinoma of the bladder and succumbed to disease within 6 months of diagnosis. The patient was a non-smoker who was never managed with an indwelling catheter. There has been no such case reported in the literature. CONCLUSIONS: HIV infection in the presence of a neurogenic bladder may carry an increased risk of aggressive bladder malignancy. More studies are warranted to determine whether routine annual screening with cystoscopy in all patients with HIV and neurogenic bladder is indicated.

Liver injury diagnosed on computed tomography after use of an automated cardiopulmonary resuscitation device.

We report a case of an 89-year-old female with active extravasation and hemoperitoneum from a liver laceration demonstrated on multidetector computed tomography (CT), attributed to the use of an automated mechanical cardiopulmonary resuscitation (CPR) device. Although iatrogenic internal injuries related to manual CPR and CPR devices have previously been reported [1, 2], there has been no reported CT evidence of liver injury related to automated CPR devices to the authors' knowledge. Imaging findings of complications related to the use of automated CPR devices are important to recognize and also help explain the possible mechanisms of injury. Liver injuries with active bleeding following CPR may have devastating consequences related to hemodynamic instability and may have an increased incidence when CPR is performed using an automated chest compression device.