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Aim  Neurocutaneous melanocytosis is a rare neurocutaneous syndrome defined by the presence of large and/or multiple congenital cutaneous nevi and melanocytic deposits in the central nervous system. We sought to define the spectrum of central nervous system abnormalities in children with neurocutaneous melanocytosis. Method  We retrospectively reviewed cases of neurocutaneous melanocytosis referred to the pediatric neuro‐oncology service at our center from 2003 to 2010. Results  Of 14 patients (11 males, 3 females) identified, eight were living. Median age of survivors was 31 months (range 12mo–6y 10mo) while median age of death was 81 months (19mo–28y). Of the six patients who died, all had diffuse leptomeningeal melanocytic deposits and four had leptomeningeal melanoma. All patients had neuroimaging: six had findings suggestive of diffuse leptomeningeal melanocytosis; seven had multifocal melanocytic deposits; and one patient had normal neuroimaging but focal seizures. Spinal abnormalities were common: three patients had extensive dorsal spinal arachnoid cysts and one had a benign cervical spindle cell tumor. Seven patients had epilepsy. Three patients had profound developmental delay; the other 11 patients had no or mild delay. Interpretation  Children with neurocutaneous melanocytosis exhibit a wide range of intracranial and intraspinal abnormalities and variable clinical outcomes.

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Rationale and Objectives Delayed cerebral ischemia (DCI) is a devastating condition that occurs secondary to aneurysmal subarachnoid hemorrhage (A-SAH). The purpose is to compare CT perfusion (CTP) and digital subtraction angiography (DSA) for determining DCI in A-SAH. Materials and Methods A retrospective study of A-SAH patients admitted at our institution between December 2004 and December 2008 was performed. CTP and DSA were obtained at days 6–8 following aneurysm rupture. Both qualitative and quantitative analyses of CT perfusion deficits were performed. DSA was categorized as presence or absence of vasospasm. The reference standard for determining DCI was based on clinical deterioration or infarction on CT or MRI. The test characteristics of CTP and DSA were calculated and their graphs of conditional probabilities were constructed using Bayesian analysis. Results Fifty-seven patients were included; 79%(45/57) had DCI. Seventy percent(40/57) had CTP perfusion deficits; 80%(36/45) of the DCI and 33%(4/12) of no DCI patients. Sixty-three percent(36/57) had DSA demonstrating vasospasm; 73%(33/45) of the DCI and 25%(3/12) of no DCI patients. Quantitative analysis of the CTP data revealed a significant difference in cerebral blood flow values for the DCI (29.4 mL/100gm/min) and no DCI groups (40.5 mL/100gm/min, p=0.0213). The sensitivity, specificity, positive and negative predictive values for CTP were 0.80(95% CI 0.68–0.92), 0.67(95% CI 0.40–0.93), 0.90(95% CI 0.82–0.96), 0.47(95% CI 0.27–0.62) and for DSA were 0.73(95% CI 0.60–0.86), 0.75(95% CI 0.50–0.99), 0.92(95% CI 0.82–0.98) and 0.43(95% CI 0.26–0.53), respectively. Conclusion CTP and DSA have similar test characteristics and Bayesian analysis for determining DCI in A-SAH patients.

In patients with cancer undergoing routine ECHO, the cardiothoracic ratio at routine CT scans was highly correlated with that at CXR. Preliminary estimates in this small study indicate a low likelihood of LVH when the CTR is less than 0.49.

From the surprisingly limited evidence available in the literature, it must be concluded that all non-calcified echogenic renal lesions detected with ultrasound need a CT to rule out an RCC.

Purpose To assess the association between clear-cell carcinoma pathology grade at nephrectomy and magnetic resonance imaging (MRI) tumor enhancement. Materials and Methods The Institutional Review Board approved this retrospective study and waived the informed consent requirement. In all, 32 patients underwent multiphase contrast-enhanced MRI prior to nephrectomy. MRI tumor enhancement was measured using two approaches: 1) the most enhancing portion of the tumor on a single slice and 2) volumetric analysis of enhancement in the entire tumor. Associations between pathological grade, tumor size, and enhancement were evaluated using the Kruskal–Wallis test and generalized logistic regression models. Results No significant association between pathology grade and enhancement was found when measurements were made on a single slice. When measured in the entire tumor, significant associations were found between higher pathology grades and lower mean, median, top 10%, top 25%, and top 50% tumor enhancement (P < 0.001–0.002). On multivariate analysis the association between grade and enhancement remained significant (P = 0.041–0.043), but tumor size did not make an additional contribution beyond tumor enhancement alone in differentiating between tumor grades. Conclusion There is significant association between tumor grade and enhancement, but only when measured in the entire tumor and not on the most enhancing portion on a single slice.

BACKGROUND AND PURPOSE There is a desire within many institutions to reduce the radiation dose in CTP examinations. The purpose of this study was to simulate dose reduction through the addition of noise in brain CT perfusion examinations and to determine the subsequent effects on quality and quantitative interpretation. MATERIALS AND METHODS A total of 22 consecutive reference CTP scans were identified from an institutional review board–approved prospective clinical trial, all performed at 80 keV and 190 mAs. Lower-dose scans at 188, 177, 167, 127, and 44 mAs were generated through the addition of spatially correlated noise to the reference scans. A standard software package was used to generate CBF, CBV, and MTT maps. Six blinded radiologists determined quality scores of simulated scans on a Likert scale. Quantitative differences were calculated. RESULTS For qualitative analysis, the correlation coefficients for CBF (−0.34; P < .0001), CBV (−0.35; P < .0001), and MTT (−0.44; P < .0001) were statistically significant. Interobserver agreements in quality for the simulated 188-, 177-, 167-, 127-, and 44-mAs scans for CBF were 0.95, 0.98, 0.98, 0.95, and 0.52, respectively. Interobserver agreements in quality for the simulated CBV were 1, 1, 1, 1, and 0.83, respectively. For MTT, the interobserver agreements were 0.83, 0.86, 0.88, 0.74, and 0.05, respectively. For quantitative analysis, only the lowest simulated dose of 44 mAs showed statistically significant differences from the reference scan values for CBF (−1.8; P = .04), CBV (0.07; P < .0001), and MTT (0.46; P < .0001). CONCLUSIONS From a reference CTP study performed at 80 keV and 190 mAs, this simulation study demonstrates the potential of a 33% reduction in tube current and dose while maintaining image quality and quantitative interpretations. This work can be used to inform future studies by using true, nonsimulated scans.