Faculty Bibliography

PURPOSE/OBJECTIVE:To retrospectively evaluate the utility of biphasic multi-detector computed tomography (MDCT) with arterial and portal venous phases for the detection of suspected acute mesenteric ischemia (AMI) in emergency department (ED) patients compared to limited surgical confirmation. METHODS:A research ethics board (REB)-approved retrospective review of all consecutive adult patients who underwent an emergency biphasic 64-MDCT examination of the abdomen and pelvis due to clinical suspicion for AMI over a 5-year period at a single tertiary-care institution was performed. Patients who underwent biphasic 64-MDCT scans performed for any clinical concern other than suspected acute mesenteric ischemia were excluded. Specifically, reported vascular and bowel findings were used to establish occlusive arterial, venous, and non-occlusive MDCT findings of AMI. Correlation was made with surgical findings in operatively managed patients and with serum lactate values preceding imaging assessment. Diagnostic yield and positive predictive value calculations were performed. RESULTS:Two hundred and twenty-five patients underwent MDCT for suspected occlusive AMI between 10 Jan 2011 and 31Jul 2016. Of these, 200 patients were negative for AMI and 25 patients (mean age 73.5 years; age range 48 to 94 years; 13 men and 12 women) had MDCT findings positive for bowel ischemia (yield of 11.1%). On MDCT, 18/25 (72%) had an occlusive arterial etiology for AMI, 2/25 (8%) had an occlusive venous etiology, and 5/25 (20%) had non-occlusive AMI. Twenty of 25 (80%) patients with positive MDCT findings of AMI also had an elevated serum lactate level, including 14/18 (77.8%) patients with arterial occlusive AMI on MDCT, 2/2 (100%) with venous-occlusive AMI on MDCT, and 4/5 (80%) with non-occlusive AMI on MDCT. Correlation with surgical findings led to a positive predictive value (PPV) of biphasic MDCT for surgically proven all-cause occlusive ischemia of 92.9%. Further substratification revealed PPVs of arterial and venous-occlusive ischemia of 85.7% and 7.1%, respectively. Of the 225 patients MDCT-positive for AMI, 213 had pre-imaging serum lactate assessments. Of 188 patients MDCT-negative for AMI, 85 patients had elevated serum lactate (45.2%). Twenty of the 25 patients with positive MDCT findings of AMI (80%) also had an elevated serum lactate level, including 14/18 (77.8%) patients with arterial occlusive AMI on MDCT, 2/2 (100%) with venous-occlusive AMI on MDCT, and 4/5 (80%) with non-occlusive AMI on MDCT. CONCLUSION/CONCLUSIONS:Emergent biphasic MDCT demonstrated low but non-trivial yield (11.1%) for the depiction of suspected acute mesenteric ischemia but was particularly low for occlusive venous AMI (0.9%). The relationship between serum lactate elevation and positive MDCT findings of AMI in our study conforms to prior work and cautiously suggests value in routine serum lactate assessment preceding imaging for patient prioritization.

There has been a substantial increase in the utilization of imaging, particularly of multi-detector computed tomography (MDCT), for the evaluation of patients with suspected urolithiasis over the past 2 decades. While the diagnostic accuracy of computed tomography (CT) for urolithiasis is excellent, it has also resulted in substantial medical expenditures and increased ionizing radiation exposure. This is especially concerning in patients with known nephrolithiasis and in younger patients. This pictorial review will focus on recent trends and controversies in imaging of patients with suspected urolithiasis, including the current roles of ultrasound (US), MDCT, and magnetic resonance imaging, the estimated radiation dose from MDCT and dose reduction strategies, as well as imaging of suspected renal colic in pregnant patients. The current epidemiological, clinical, and practice management literature will be appraised.

Congenital cardiac anomalies are a common finding during prenatal anatomical survey ultrasound examination. Cardiac anomalies are a major cause of prenatal and neonatal mortality and morbidity. If the anomaly is not lethal, most would require surgical correction. Therefore, early recognition of these abnormalities is essential for parental counseling and delivery planning, as well as analysis of neonatal treatment options. Although prenatal ultrasound plays an important role in identification of such anomalies, diagnosis and interpretation of imaging findings require familiarity and knowledge of the common imaging features. In this article, we provide a comprehensive review of ultrasound appearance of common fetal cardiac anomalies.

PURPOSE/OBJECTIVE:To determine the yield of non-contrast multi-detector computed tomography (MDCT) of the abdomen and pelvis in diagnosing ureteral calculi as well as other alternative acute conditions in male vs in female adult patients presenting to the emergency department with new onset of symptoms. METHODS:Our institutional review board approved a retrospective review of the official reports of the non-contrast MDCT examinations of the abdomen and pelvis performed on adults (18 years and older) presenting to our emergency department with a suspected ureteral calculus from October 1, 2011 to October 30, 2013. Patients with recently documented ureteral calculi, known urinary tract infection, malignancy, and trauma were excluded from the study. From a total of 1097 non-contrast MDCT examinations of the abdomen and pelvis over the 2-year period, 400 randomly selected examinations were reviewed (approximately one-third of all the examinations). We compared the prevalence of ureteral calculi between the male and female population. P values and confidence intervals were determined using software Stata 14. Other acute intra-abdominal and intra-pelvic findings amenable to prompt medical care were also documented and analyzed separately. RESULTS:The mean patient age was 55.2 years, with a range of 19-90 years. This included 170 female (mean age 56.8 years) and 230 male patients (mean age 54.2 years). Ureteral calculi were detected in 170 (42.5%) of the patients [111 males (48%) and 59 females (34.7%)] with a prevalence which was statistically significantly higher in the male patients compared to in the female patients (P < 0.01, confidence level of 95% and CI of 13.2-13.4). An alternative diagnosis was made based on the MDCT findings in 49 patient cases (12.25 %), including 26 females (15.29%) and 23 males (10.00%). There was no statistically significant difference in alternative acute findings in male compared to in female patients (P > 0.05). This was with the exception of acute pyelonephritis, which was statistically significantly higher in the female patients (P < 0.01). CONCLUSION/CONCLUSIONS:The likelihood of making the diagnosis of a ureteral calculus on non-contrast MDCT of the abdomen and pelvis was statistically significantly higher in male patients compared with female patients presenting to our emergency department. However, there was no statistically significant difference in the alternative diagnoses, with the exception of pyelonephritis, which was more common in women.

PURPOSE/OBJECTIVE:While pelvic congestion syndrome and chronic pelvic pain are relatively common in women, no large- or medium-sized studies have been conducted to our knowledge to evaluate the frequency and severity of ovarian vein dilatation (OVD) on computed tomography (CT). The purpose of our study was therefore to analyze a large number of consecutive abdominal and pelvic CT scans in adult women to determine OVD frequency and severity. METHODS:An IRB-approved, single-institution retrospective analysis of 1042 consecutive abdominal and pelvic CT scans in women ages 25-65 was performed. Scans were evaluated for the presence and severity of OVD and association with "nutcracker anatomy." A gradation scheme was developed based on quartile analysis. RESULTS:143 of the CT scans had OVD (13.7%). Of the positive scans, 96 were bilateral, 29 were left-side only, 18 were right-side only, and 18 had nutcracker-type compression of the left renal vein (14.4% of scans with left or bilateral OVD). In positive scans, the mean and median left OVD were 7.5 and 7 mm, respectively, and right-side were 7.2 and 7 mm, respectively. Based on quartile analysis, OVD grading was mild (< 6 mm), moderate (6-8 mm), or severe (> 8 mm), with moderate including the middle 50% of patients. CONCLUSIONS:OVD was found on 13.7% of 1042 consecutive female abdominal and pelvic CT scans, with "nutcracker anatomy" present in 14.4% of the scans with left OVD. Moderate dilatation was defined as an OVD of 6-8 mm at the iliac crests.

Obesity is a growing problem around the world, and radiology departments frequently encounter difficulties related to large patient size. Diagnosis and management of suspected venous thromboembolism, in particular deep venous thrombosis (DVT) and pulmonary embolism (PE), are challenging even in some lean patients, and can become even more complicated in the setting of obesity. Many obstacles must be overcome to obtain imaging examinations in obese patients with suspected PE and/or DVT, and to ensure that these examinations are of sufficient quality to diagnose or exclude thromboembolic disease, or to establish an alternative diagnosis. Equipment limitations and technical issues both need to be acknowledged and addressed. Table weight limits and scanner sizes that readily accommodate obese and even morbidly obese patients are not in place at many clinical sites. There are also issues with image quality, which can be substantially compromised. We discuss current understanding of the effects of patient size on imaging in general and, more specifically, on the imaging modalities used for the diagnosis and treatment of DVT and PE. Emphasis will be placed on the technical parameters and protocol nuances, including contrast dosing, which are necessary to refine and optimize images for the diagnosis of DVT and PE in obese patients, while remaining cognizant of radiation exposure. More research is necessary to develop consistent high-level evidence regarding protocols to guide radiologists, and to help them effectively utilize emerging technology.

Although a broad spectrum of entities can induce acute pathologic changes in the small bowel, there are relatively few imaging features that are characteristic of a specific diagnosis on the basis of CT findings. Specific clinical information, including time course and onset of disease, patient risk factors, and any recent pharmacologic or radiation therapy, is often instrumental in refining the differential diagnosis. A wide spectrum of disorders is reviewed in this article; however, given the breadth of disorders associated with the small bowel, neoplastic and infectious conditions affecting the small bowel that can manifest acutely are not specifically discussed. Vascular diseases that can affect the small bowel regionally or diffusely, including thromboembolic and hypoperfusion phenomena, as well as a spectrum of vasculitides, are reviewed. Iatrogenic causes of small bowel disorders are discussed, including angiotensin-converting enzyme inhibitor-induced angioedema, and chemotherapy- and radiation therapy-associated patterns of disease. Autoimmune and hereditary conditions that can affect the small bowel, including systemic lupus erythematosus and genetic C1 esterase inhibitor deficiency, respectively, are reviewed. ^©RSNA, 2018.

OBJECTIVE:Common fetal anomalies of the kidneys and urinary tract encompass a complex spectrum of abnormalities that can be detected prenatally by ultrasound. Common fetal anomalies of the kidneys and urinary tract can affect amniotic fluid volume production with the development of oligohydramnios or anhydramnios, resulting in fetal pulmonary hypoplasia and, potentially, abnormal development of other fetal structures. CONCLUSION/CONCLUSIONS:We provide an overview of common fetal anomalies of the kidneys and urinary tract with an emphasis on sonographic patterns as well as pathologic and postnatal correlation, along with brief recommendations for postnatal management. Of note, we render an updated classification of fetal abnormalities of the kidneys and urinary tract based on the presence or absence of associated urinary tract dilation. In addition, we review the 2014 classification of urinary tract dilation based on the Linthicum multidisciplinary consensus panel.