MRI assessment of rectal cancer response to neoadjuvant therapy: a multireader study.

OBJECTIVES: A watch and wait strategy with the goal of organ preservation is an emerging treatment paradigm for rectal cancer following neoadjuvant treatment. However, the selection of appropriate patients remains a challenge. Most previous efforts to measure the accuracy of MRI in assessing rectal cancer response used a small number of radiologists and did not report variability among them. METHODS: Twelve radiologists from 8 institutions assessed baseline and restaging MRI scans of 39 patients. The participating radiologists were asked to assess MRI features and to categorize the overall response as complete or incomplete. The reference standard was pathological complete response or a sustained clinical response for > 2 years. RESULTS: We measured the accuracy and described the interobserver variability of interpretation of rectal cancer response between radiologists at different medical centers. Overall accuracy was 64%, with a sensitivity of 65% for detecting complete response and specificity of 63% for detecting residual tumor. Interpretation of the overall response was more accurate than the interpretation of any individual feature. Variability of interpretation was dependent on the patient and imaging feature investigated. In general, variability and accuracy were inversely correlated. CONCLUSIONS: MRI-based evaluation of response at restaging is insufficiently accurate and has substantial variability of interpretation. Although some patients' response to neoadjuvant treatment on MRI may be easily recognizable, as seen by high accuracy and low variability, that is not the case for most patients. KEY POINTS: • The overall accuracy of MRI-based response assessment is low and radiologists differed in their interpretation of key imaging features. • Some patients' scans were interpreted with high accuracy and low variability, suggesting that these patients' pattern of response is easier to interpret. • The most accurate assessments were those of the overall response, which took into consideration both T2W and DWI sequences and the assessment of both the primary tumor and the lymph nodes.

Emergent postpartum pelvic sonography.

This article describes the variable appearance of the normal postpartum uterus and reviews complications which can occur in the postpartum period, with particular emphasis on the sonographic findings. Postpartum complications are a common presentation to the emergency department. The majority of these patients present with secondary postpartum hemorrhage. Additional symptoms of pain or clinical findings of pyrexia and leukocytosis confound the clinical scenario and necessitate further evaluation with imaging. Ultrasonography is the mainstay in the initial imaging evaluation of the postpartum patient, with occasional progression to CT, MR, or angiography. We sought to provide a brief review of the literature, with pictorial review of key imaging findings, with a focus on ultrasonography. We provide a pictorial and brief literature review, with case examples from our institution, of key postpartum complications. Ultrasonography is an important component of evaluation in postpartum patients, particularly those with hemorrhage or other complication.

Body MRI Subspecialty Reinterpretations at a Tertiary Care Center: Discrepancy Rates and Error Types.

OBJECTIVE. Radiology departments in tertiary care centers are frequently asked to perform secondary interpretations of imaging studies, particularly when a patient is transferred from a community hospital. Discrepancy rates in radiology vary widely, with low rates reported for preliminary resident reports that are overread by attending radiologists (2-6%) and higher rates (up to 56%) for secondary interpretations. Abdominal and pelvic imaging and cross-sectional imaging have the highest discrepancy rates. The purpose of our study was to determine the discrepancy rate and the most common reasons for discrepancies between abdominal and pelvic MRI reports obtained from outside institutions and secondary interpretations of these reports by a fellowship-trained radiologist at a tertiary care center. MATERIALS AND METHODS. We retrospectively identified 395 secondary MRI reports from January 2015 to December 2018 that were labeled as body MRI examinations at a tertiary care center. Thirty-eight cases were excluded for various reasons, including incorrect categorization or lack of outside report. We reviewed the outside reports, compared them with the secondary interpretations, and categorized the cases as discrepancy or no discrepancy. The discrepancies were subdivided into the most likely reason for the error using previously published categories; these categories were also divided into perceptive and cognitive errors. RESULTS. Of the 357 included cases, 246 (68.9%) had at least one discrepancy. The most common reason for error was faulty reasoning (34.3%), which is a cognitive error characterized by misidentifying an abnormality. Satisfaction of search, which is a perceptive error, was the most common reason for second discrepancies (15.0%). CONCLUSION. Secondary interpretations of body MR images at a tertiary care center identify a high rate of discrepancies, with cognitive error types predominating.

Spleno-parametrial ectopic varices: an unusual porto-systemic shunt in portal hypertension.

BACKGROUND: Cirrhotic liver disease commonly is complicated by portal hypertension, and the resultant porto-systemic shunts are an important cause of morbidity and mortality in cirrhotic patients. Identification of these shunts and their management is an important part of the medical care provided to this population. CASE: We present the case of a patient with nonalcoholic steatohepatitis or nonalcoholic fatty liver disease and resultant portal hypertension who developed an unusual porto-systemic shunt, which at first was thought to represent a highly vascular gynecologic mass. The splanchnic blood was shunted through a recanalized vein interconnecting the splenic vein with the parametrial venous plexus. CONCLUSION: Unrecognized portal hypertension and resultant porto-systemic shunts may mask themselves as vascular masses and result in catastrophic surgical outcomes if not fully characterized preoperatively.