Review of appendicitis: routine, complicated, and mimics.

Appendicitis is one of the most common sources of abdominal pain in the emergency setting and is generally considered a straightforward diagnosis. However, atypical appearances, non-visualization, and inconclusive features can make these cases more complicated. The objectives of this article are to review the differential diagnoses for right lower quadrant pain, discuss the imaging characteristics of simple appendicitis on computed tomography (CT), and provide guidance for equivocal cases, complicated appendicitis, and appendicitis mimics. This review will also discuss the identification and management of neoplasms of the appendix.

Incidence of pulmonary embolism in COVID-19 infection in the ED: ancestral, Delta, Omicron variants and vaccines.

PURPOSE: This retrospective review examines the incidence of pulmonary embolism (PE) during computed tomography pulmonary angiography (CTPA) exams performed in the emergency room setting of a tertiary care center over dominant periods of the ancestral, Delta, and Omicron variants of COVID-19. MATERIALS/METHODS: Demographic information, patient comorbidities and risk factors, vaccination status, and COVID-19 infection status were collected from patient's charts. Incidence of PE in COVID positive patients was compared between variant waves. Subgroup analysis of vaccination effect was performed. RESULTS: CTPA was ordered in 18.3% of COVID-19 positive patients during the ancestral variant period, 18.3% during the Delta period and 17.3% during the Omicron wave. PE was seen in 15.0% of the ancestral COVID-19 variant cohort, 10.6% in the Delta COVID cohort and 9.23% of the Omicron cohort, reflecting a 41% and 60% increased risk of PE with ancestral variants compared to Delta and Omicron periods respectively. The study however was underpowered and the difference in rate of PE did not reach statistically significance (p = 0.43 and p = 0.22). Unvaccinated patients had an 2.75-fold increased risk of COVID-associated PE during the Delta and Omicron periods (p = .02) compared to vaccinated or recovered patients. CONCLUSION: Vaccination reduces the risk of COVID-19 associated PE. Patients infected with the Delta and Omicron COVID-19 variants may have a lower incidence of pulmonary embolism, though a larger or multi-institution study is needed to prove definitively.

An Unusual Presentation of Breast Implant Rupture.

ABSTRACT: A 99mTc-methylene diphosphate (MDP) bone scintigraphy scan was performed to follow up metastatic breast cancer. A circular region of radiotracer uptake in the location of the patient's left breast implant was seen. Review of the same-day chest CT and the prior CT showed that the patient's breast implant had ruptured in the interim. The 99mTc-MDP uptake in the capsule of the breast implant was attributed to rupture, likely secondary to inflammation. This is an example of an unusual presentation of breast implant rupture discovered on a 99mTc-MDP bone scintigraphy scan.

Revisiting racial disparities in ED CT utilization during the Affordable Care Act era: 2009-2018 data from the NHAMCS.

OBJECTIVE: To examine the trends in CT utilization in the emergency department (ED) for different racial and ethnic groups, factors that may affect utilization, and the effects of increased insurance coverage since passage of the Affordable Care Act in 2010. MATERIALS AND METHODS: Data from the National Hospital Ambulatory Medical Care Survey (NHAMCS) for the years 2009-2018 were used for the analysis. The NHAMCS is a cross-sectional survey which has random and systematical samples of more than 200,000 visits to over 250 hospital EDs in the USA. Patient demographic characteristics, source of payment/insurance, clinical presentation, and disposition from the ED were recorded. Descriptive statistics and multivariate logistic regression were performed. RESULTS: Between 2009 and 2018, the rate of uninsured patients in the ED decreased from 18.1% to as low as 9.9%, but this was not associated with a decrease in the disparity in CT utilization between non-Hispanic Black and non-Hispanic White patients. CT use rate increased 38% over the study period. Factors strongly associated with CT utilization include age, source of payment, triage category, disposition from the ED, and residence. After controlling for these factors, non-Hispanic White patients were 21% more likely to undergo CT than non-Hispanic Black patients, though no disparity was seen for Hispanic or Asian/other groups. CONCLUSION: Despite increased insurance coverage over the sample period, racial disparities between non-Hispanic Black and non-Hispanic White patients persist in CT utilization, though no disparity was seen for Hispanic or Asian/other patients. The source of this disparity remains unclear and is likely multifactorial.

Beyond hernias: a multimodality review of abdominal wall pathology.

The diagnosis of abdominal wall pathology is often obvious on clinical physical examination; however, multimodality imaging often yields incidental, and occasionally important, findings aiding in assessing the overall clinical picture. While various hernias are common, there are numerous other causes of abdominal wall pathology. Knowledge of these entities is crucial to avoid misinterpretation and assure proper radiological judgment.

Measurement of pancreatic cystic lesions on magnetic resonance imaging: efficacy of standards in reducing inter-observer variability.

PURPOSE: The purpose of this study is to assess inter-observer variability in the measurement of pancreatic cystic lesions with MRI and to determine the impact of measurement standards. MATERIALS AND METHODS: In this IRB-approved, HIPAA-compliant study with waiver of informed consent, 144 MRI examinations, containing pancreatic cystic lesions measuring between 5 and 35 mm, were reviewed independently by two radiology attendings and two abdominal imaging fellows. Measurements were repeated by the same reviewers 12 weeks later after the introduction of measurement standards. Results were analyzed using within-subject standard deviation, intraclass correlation coefficient, and kappa. RESULTS: Prior to standardization, the within-subject standard deviation, showing measurement variability in each cyst, was 4.0 mm, which was reduced to 3.3 mm after introduction of measurement standards (p < 0.01). Overall inter-observer agreement, kappa, improved from 0.59 to 0.65 (p = 0.04). The frequency of all four reviewers agreeing on size category increased from 51% to 60%. The intraclass correlation coefficient increased from 0.81 to 0.86. CONCLUSIONS: There is significant and frequent inter-observer variability in the measurement of pancreatic cystic lesions with MRI which could affect clinical management. Implementation of measurement standards reduces measurement variability and aids in preventing erroneous reporting of growth and potentially unwarranted changes in management.

Non-oncologic applications of diffusion-weighted imaging (DWI) in the genitourinary system.

Diffusion-weighted imaging (DWI) has become an increasingly used tool in abdominal and pelvic magnetic resonance imaging (MRI), primarily in the oncologic setting. DWI sequences are being added to routine MRI protocols at many institutions, and as its use has spread, more non-oncologic applications have been explored. The purpose of this article is to provide a review of DWI applications in inflammatory, infectious, autoimmune-mediated, and ischemic processes affecting the genitourinary system.

Case report: corpus cavernosum thrombosis occurring during a long-range aviation mission initially diagnosed as lymphoma.

A 23-year-old active duty United States Air Force air crew male presented to the flight medicine clinic in Germany after experiencing sudden onset penile pain while flying as part of a long-range operational mission. He was admitted to the German hospital and empirically treated for infection with antibiotics, which did not improve his symptoms. Initial magnetic resonance imaging of the pelvis with and without intravenous contrast was reported to be concerning for lymphoma, which prompted transport to a regional medical center in the United States. Further evaluation and review of the pelvic magnetic resonance imaging established a diagnosis of corpus cavernosum thrombosis. Conservative management with 3 months of standard anticoagulation therapy was effective in resolving the patient's symptoms. Corpus cavernosum thrombosis is a rare condition which appears to be associated with prolonged air travel that can easily be misdiagnosed as a much more serious condition; however, once accurate diagnosis is made, it is easily managed and treated.

Nononcologic applications of diffusion-weighted imaging in the gastrointestinal system.

OBJECTIVE: The purpose of this article is to review infectious, inflammatory, and auto-immune-mediated processes in the gastrointestinal system where diffusion-weighted imaging can be helpful as well as pitfalls associated with its use. CONCLUSION: Diffusion-weighted imaging has become an important and widely used tool in abdominal and pelvic MRI, but it has been used primarily for oncologic applications. As more body MRI protocols are routinely including diffusion-weighted imaging, this sequence can be useful in evaluating an increasing number of nononcologic processes.

A case of hyperfunctioning pancreatic mixed adenoneuroendocrine carcinoma (MANEC) arising from ectopic pancreatic tissue in the liver.

We report the case of a hyperfunctioning mixed adenoneuroendocrine carcinoma (MANEC) arising from ectopic pancreatic tissue in the liver. To our knowledge, the imaging appearance of a MANEC in the liver has never been reported. Literature on MANEC and its imaging features, including its appearance on the MR hepatobiliary phase and differential considerations, are reviewed and discussed.

Multidetector computerized tomography urography as the primary imaging modality for detecting urinary tract neoplasms in patients with asymptomatic hematuria.

PURPOSE: We determined whether multidetector computerized tomography urography is sensitive and specific for detecting urinary tract neoplasms when used as the primary imaging modality for evaluating patients with hematuria. MATERIALS AND METHODS: A retrospective review was performed of the radiological, urological and pathological records of 468 patients without a history of urinary neoplasms who presented with hematuria. All patients underwent multidetector computerized tomography urography and complete urological evaluation, including cystoscopy. Laboratory urinalysis and cytology were done in 350 and 318 of the 468 patients, respectively. Multivariate logistic regression analysis was performed using the variables multidetector computerized tomography urography diagnosis, worst urine cytology, number of red blood cells per high power field, gross hematuria, age and gender to predict urinary tract neoplasm. RESULTS: A total of 50 urinary neoplasms were diagnosed in 468 patients. Multidetector computerized tomography urography detected 32 of 50 neoplasms for a sensitivity of 64%, specificity of 98%, positive predictive value of 76% and negative predictive value of 96%. There were 10 false-positive and 18 false-negative multidetector computerized tomography urography studies. Multivariate logistic regression showed that abnormal multidetector computerized tomography urography findings, ie neoplasm (p <0.0001), and suspicious or positive urine cytology (p = 0.0009) were significant. Patients with an abnormal multidetector computerized tomography urography diagnosis and suspicious or positive urine cytology had 44 and 47 times greater odds, respectively, of having urinary neoplasms compared to the odds in those with normal examinations. CONCLUSIONS: Multidetector computerized tomography urography is relatively sensitive and highly specific for detecting urinary neoplasms. It may serve as the primary imaging modality to evaluate patients with hematuria. Multidetector computerized tomography urography does not eliminate the role of cystoscopy in the evaluation of hematuria.

Opacification of the genitourinary collecting system during MDCT urography with enhanced CT digital radiography: nonsaline versus saline bolus.

OBJECTIVE: The purpose of this study was to determine whether a saline bolus during CT urography improves urinary collecting system opacification and whether the addition of enhanced CT digital radiography (CTDR) improves urinary collecting system visualization with or without a saline bolus. MATERIALS AND METHODS: One hundred eight CT urography and enhanced CTDR examinations were reviewed. Fifty-four patients were given a saline bolus during CT urography, and 54 patients underwent CT urography without a saline bolus. Urinary collecting system opacification was evaluated by group (saline vs nonsaline), imaging technique (CT urography alone vs CT urography plus enhanced CTDR), number of enhanced CTDR images, and site of nonopacified urinary segments. Using a multivariate logistic regression model, we determined significance of variables and odds of complete opacification. RESULTS: In the saline group, 248 nonopacified sites were identified on CT urography alone and 95 sites with CT urography plus enhanced CTDR. In the nonsaline group, 185 nonopacified sites were identified on CT urography alone and 59 sites with CT urography plus enhanced CTDR. Combining both groups, 433 nonopacified sites were identified with CT urography alone and 154 sites with CT urography plus enhanced CTDR. Multivariate logistic regression showed significance for group (p = 0.010), imaging method (p < 0.0001), number of enhanced CTDR images (p = 0.048), and site of segment opacification (p < 0.0001). The renal pelvis shows the greatest odds and the distal ureter the lowest odds for complete opacification by group or imaging method. CONCLUSION: The addition of a saline bolus offers no improvement, whereas the addition of enhanced CTDR offers significant improvement in collecting system opacification during CT urography.