A sign on CT that predicts a hazardous ureteral anomaly

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In a prior case series, we noted a sign on CT associated with inguinoscrotal herniation of the ureter.

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In this study, we analyzed all CT urograms performed at our institution over 1 year.

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Deviation of the ureter from the psoas muscle at L4 by >1 cm should raise suspicion for a distal ureteral anomaly.

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Morbid obesity and congenital anomalies may result in a similar imaging appearance.

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Awareness of this anomaly can have significant operative implications.

Introduction

An aberrant course of the distal ureter can pose a risk of ureteral injury during surgery for inguinal hernia repair and other groin operations. In a recent case series of inguinoscrotal hernation of the ureter, we found that each affected ureter was markedly anterior to the psoas muscle at its mid-point on abdominal CT. We hypothesized that this abnormality in the abdominal course of the ureter would predict the potentially hazardous aberrant course of the distal ureter.

Presentation of cases

We reviewed all evaluable CT urograms performed at St. Louis University Hospital from June 2012 to July 2013 and measured the ureteral course at several anatomically fixed points.

Discussion

93% (50/54) of ureters deviated by less than 1 cm from the psoas muscle in their mid-course (at the level of the L4 vertebra). Reasons for anterior deviation of the ureter in this study included morbid obesity with prominent retroperitoneal fat, congenital renal abnormality, and post-traumatic renal/retroperitoneal hematoma. We determined that the optimal level on abdominal CT to detect the displaced ureter was the mid-body of the L4 vertebra.

Conclusion

Anterior deviation of the ureter in its mid-course appears to predict inguinoscrotal herniation of the ureter. This finding is a sensitive predictor and should raise concern for this anomaly in the appropriate clinical setting. It is not entirely specific as morbid obesity and congenital anomalies may result in a similar imaging appearance. We believe that this association has not been reported previously. Awareness of this anomaly can have significant operative implications.

Diffusion-weighted MRI hyperintensity patterns differentiate CJD from other rapid dementias

BACKGROUND

Diffusion-weighted imaging (DWI) and fluid-attenuated inversion recovery (FLAIR) MRI have high sensitivity and specificity for Creutzfeldt-Jakob disease (CJD). No studies, however, have demonstrated how MRI can distinguish CJD from nonprion causes of rapidly progressive dementia (npRPD). We sought to determine the diagnostic accuracy of MRI for CJD compared to a cohort of npRPD subjects.

METHODS

Two neuroradiologists blinded to diagnosis assessed DWI and FLAIR images in 90 patients with npRPD (n = 29) or prion disease (sporadic CJD [sCJD], n = 48, or genetic prion disease [familial CJD, n = 6, and Gerstmann-Sträussler-Scheinker, n = 7]). Thirty-one gray matter regions per hemisphere were assessed for abnormal hyperintensities. The likelihood of CJD was assessed using our previously published criteria.

RESULTS

Gray matter hyperintensities (DWI > FLAIR) were found in all sCJD cases, with certain regions preferentially involved, but never only in limbic regions, and rarely in the precentral gyrus. In all sCJD cases with basal ganglia or thalamic DWI hyperintensities, there was associated restricted diffusion (apparent diffusion coefficient [ADC] map). This restricted diffusion, however, was not seen in any npRPD cases, in whom isolated limbic hyperintensities (FLAIR > DWI) were common. One reader's sensitivity and specificity for sCJD was 94% and 100%, respectively, the other's was 92% and 72%. After consensus review, the readers' combined MRI sensitivity and specificity for sCJD was 96% and 93%, respectively. Familial CJD had overlapping MRI features with sCJD.

CONCLUSIONS

The pattern of FLAIR/DWI hyperintensity and restricted diffusion can differentiate sCJD from other RPDs with a high sensitivity and specificity. MRI with DWI and ADC should be included in sCJD diagnostic criteria. New sCJD MRI criteria are proposed.

How surgeon age affects post-treatment surveillance strategies for melanoma patients

The intensity of post-treatment melanoma patient follow-up varies widely among physicians. We investigated whether physician age accounts for the observed variation in surveillance intensity among plastic surgeons. A custom-designed questionnaire was mailed to USA and non-USA surgeons, all of whom were members of the American Society of Plastic and Reconstructive Surgeons. Subjects were asked how they use 14 specific follow-up modalities during years 1-5 and 10 following primary treatment for patients with cutaneous melanoma. Repeated-measures analysis of variance was used to compare practice patterns by TNM stage, year post-surgery, and age. Of the 3,032 questionnaires mailed, 1,142 (38%) were returned. Of those returned, 395 (35%) were evaluable. Non-evaluability was usually due to lack of melanoma patient follow-up in surgeons' practices. Follow-up strategies for most of the 14 modalities were highly correlated across TNM stages and years post-surgery, as expected. The pattern of testing varied significantly by surgeon age for 3 modalities (complete blood count, liver function tests, and chest X-ray), but the variation was quite small. We concluded that the post-treatment surveillance practice patterns of ASPRS members caring for patients with cutaneous melanoma vary only marginally with physician age. Continuing medical education could account for this observation.

Effect of initial tumor stage on patient follow-up after potentially curative surgery for cutaneous melanoma

The optimal follow-up strategy after completion of therapy for melanoma is not known. We evaluated the effect of TNM stage on the self-reported surveillance strategies employed by practicing plastic surgeons caring for otherwise healthy patients subjected to potentially curative treatment for cutaneous melanoma. Hypothetical patient profiles and a detailed questionnaire based on these profiles were mailed to a random sample (N=3,032) of the 4,320 members of the American Society of Plastic and Reconstructive Surgeons. The effect of TNM stage on the surveillance strategies chosen was analyzed by repeated-measures ANOVA. There were 1,142 responses to the 3,032 surveys; 395 were evaluable. Plastic surgeons often do not provide postoperative follow-up themselves; this was the most frequent reason for non-evaluability. Surveillance of patients after resection of melanoma relies most heavily on office visits, chest X-ray, CBC, and liver function tests. All other surveillance modalities are used infrequently. Most respondents modify their surveillance practices slightly according to the patient's initial TNM stage. Most commonly used modalities are employed significantly more frequently with increasing TNM stage. This effect persists through ten years of follow-up, but the differences across stages are tiny. We conclude that most plastic surgeons performing surveillance after potentially curative surgery in otherwise healthy patients with melanoma use similar follow-up strategies for patients of all TNM stages. These data permit the rational design of a controlled clinical trial of high-intensity vs. low-intensity follow-up.

Current practice of patient follow-up after potentially curative resection of cutaneous melanoma

Follow-up care for patients who have undergone potentially curative resection of cutaneous melanoma varies widely among physicians, and the underlying rationale has not been assessed. To quantify current practice patterns and to discern motivation, a custom-designed questionnaire was mailed to U.S. and non-U.S. surgeons, all of whom were members of the American Society of Plastic and Reconstructive Surgeons (ASPRS). Surveys were mailed to 3,032 ASPRS members, chosen randomly from a total of 4,320 members. Of the 1,142 questionnaires that were returned, 395 were evaluable. Nonevaluability was usually due to lack of melanoma patients receiving follow-up in the surgeons' practices. Surveillance of patients after resection of melanoma relies most heavily on office visit, chest x-ray, complete blood count, and liver function tests. There was surprisingly little influence of elective node dissection on follow-up practices. Imaging tests such as computed tomography, magnetic resonance imaging, and position emission tomography scan were rarely employed. Surveillance is motivated by many factors, particularly early detection of recurrence of the index melanoma and second primary melanomas. This survey provides information regarding current follow-up strategies recommended by ASPRS surgeons after potentially curative resection of cutaneous melanoma. There is considerable variation in surveillance intensity and in motivation among practitioners, thus representing a lack of consensus.