Cerebellopontine angle tumors in young children, displaying cranial nerve deficits, and restricted diffusion on diffusion-weighted imaging: a new clinical triad for atypical teratoid/rhabdoid tumors.

Atypical teratoid/rhabdoid tumors (AT/RT) of the central nervous system (CNS) are rare, highly malignant neoplasms that carry a poor prognosis. Even with prompt diagnosis, gross total resection and early initiation of intensive adjuvant therapy, the majority of patients will succumb within 9-12 months of diagnosis. The CPA location in children harbors lesions along a wide spectrum varying from benign to highly malignant. Imaging features of lesions within the CPA that aid the diagnostic process will help to initiate early treatment in higher-grade lesions. We report three cases, in very young children, all with cranial nerve deficits, who displayed CPA lesions with restricted diffusion on diffusion-weighted imaging (DWI) with pathology confirming AT/RT. We propose that in young children with a CPA tumor diffusion-weighted imaging should be routinely evaluated to aid in prompt management. In addition, the diagnosis of AT/RT should be highly suggestive in infants presenting with cranial nerve findings as well as DWI restricted diffusion within the CPA.

Clinical and radiological determinants of transient symptoms associated with infarction (TSI).

BACKGROUND: The definition of transient ischemic attack was traditionally based on clinical features only. The wide use of magnetic resonance imaging (MRI) led to the definition of a new entity - transient symptoms associated with infarction (TSI). It is unclear why patients with similar radiological infarctions may have different clinical manifestation - ranging from complete symptoms resolution to major neurological sequelae. We sought to determine which factors differentiate acute diffuse weighted imaging (DWI) lesion presentation - stroke versus TSI. METHODS: 282 Participants, recruited for the Tel-Aviv Brain Acute Stroke Cohort study (TABASCO), were enrolled consecutively. Participants underwent extensive cognitive evaluation, wide laboratory tests and brain MRI scans evaluated for cerebral small vessel disease (SVD) biomarkers, according to the STRIVE protocol. Demographic and clinical characteristics were also examined. RESULTS: A total of 239 patients had stroke and 43 patients had TSI. TSI patients had smaller average lesion volume (0.77 cm3 versus 2.64 cm3, p = 0.002). Lesion location did not differentiate TSI and stroke. Stroke patients had elevated inflammatory markers, unrelated to lesion size (CRP 4.2 mg/L versus 1.7 mg/L, p = 0.011). TSI patients had better global cognitive score and MoCA score at admission and 24 months following the index event (p < 0.001). TSI patients also had better Berg balance score (p = 0.004). No significant association was found with MRI SVD markers. CONCLUSIONS: Lesion size, but not location, differentiates TSI and stroke, especially at a cutoff value of 10 cm3. Elevated inflammatory response was linked to worse course independently of lesion volume. Cognitive and high function tests are associated to the clinical phenotype of ischemic lesion and may be a marker of brain reserve and compensatory abilities. SVD markers do not differ between TSI and stroke patients and probably do not fully capture the extent of brain vascular pathology and reserve.

Inter- and intra-observer reproducibility of ADC measurements in esophageal carcinoma primary tumors.

The apparent diffuse coefficient (ADC) may correlate with the treatment response to chemotherapy/radiotherapy in solid tumors. Our aim was to determine the inter- and intra-observer reproducibility of ADC measurements in primary esophageal squamous cell carcinoma (ESCC). ADCs were blindly measured in 31 patients diagnosed with ESCC by two observers before treatment (pre-ADC) and after 5th fraction radiotherapy (intra-ADC) twice with a 2-week interval. The mean pre-ADC of primary tumors was 1.25±0.22 and 1.27±0.23 (in 10-3mm2/s) from observer A for measurements 1 and 2, respectively, and the intra-observer measurements were -0.02 bias vs. -0.13-0.09 limits of agreement. From observer B, the mean pre-ADC varied between 1.25±0.23 and 1.27±0.23 (in 10-3mm2/s) for measurements 1 and 2, respectively, and intra-observer measurements were -0.02 bias vs. -0.17∼0.16 limits of agreement. The mean pre-ADC of primary tumors was 1.26±0.24 (in 10-3mm2/s) from observers A and B, and inter-observer measurements were 0.01 bias vs. -0.09-0.09 limits of agreement, revealing a low inter-observer variance. Similar measurements of the intra-SD parameters showed that the pre- and intra-ADC of primary tumors differed significantly. Thus ADC measurements may have sufficient inter-observer and intra-observer reproducibility to measure primary tumor responses to treatment, and the ADCs before and during treatment differed.

Comparison of Diffuse Weighted Imaging and Fluid Attenuation Inversion Recovery Sequences of MRI in Brain Multiple Sclerosis Plaques Detection.

OBJECTIVE: Suitable magnetic resonance imaging (MRI) techniques from conventional to new devices can help physicians in diagnosis and follow up of Multiple Sclerosis (MS) patients. The aim of present research was to compare effectiveness of Fluid Attenuation Inversion Recovery (FLAIR) sequence of conventional MRI and Diffuse Weighted Imaging (DWI) sequence as a new technique in detection of brain MS plaques. MATERIALS & METHODS: In this analytic cross sectional study, sample size was assessed as 40 people to detect any significant difference between two sequences with a level of 0.05. DWI and FLAIR sequences of without contrast brain MRI of consecutive MS patients referred to MRI center of Shahid Sadoughi Hospital, Yazd, Iran from January to May 2012, were evaluated. RESULTS: Thirty-two females and 8 males with mean age of 35.20±9.80 yr (range = 11-66 yr) were evaluated and finally 340 plaques including 127(37.2%) in T2WI, 127(37.2%) in FLAIR, 63(18.5%) in DWI and 24(7.1%) in T1WI were detected. FLAIR sequence was more efficient than DWI in detection of brain MS plaques, oval, round, amorphous plaque shapes, frontal and occipital lobes, periventricular, intracapsular, corpus callosum, centrum semiovale, subcortical, basal ganglia plaques and diameter of detected MS plaques in DWI sequence was smaller than in FLAIR. CONCLUSION: Old lesion can be detected by conventional MRI and new techniques might be more useful in early inflammatory phase of MS and assessment of experimental treatments.

Restriction spectrum imaging improves MRI-based prostate cancer detection.

PURPOSE: To compare the diagnostic performance of restriction spectrum imaging (RSI), with that of conventional multi-parametric (MP) magnetic resonance imaging (MRI) for prostate cancer (PCa) detection in a blinded reader-based format. METHODS: Three readers independently evaluated 100 patients (67 with proven PCa) who underwent MP-MRI and RSI within 6 months of systematic biopsy (N = 67; 23 with targeting performed) or prostatectomy (N = 33). Imaging was performed at 3 Tesla using a phased-array coil. Readers used a five-point scale estimating the likelihood of PCa present in each prostate sextant. Evaluation was performed in two separate sessions, first using conventional MP-MRI alone then immediately with MP-MRI and RSI in the same session. Four weeks later, another scoring session used RSI and T2-weighted imaging (T2WI) without conventional diffusion-weighted or dynamic contrast-enhanced imaging. Reader interpretations were then compared to prostatectomy data or biopsy results. Receiver operating characteristic curves were performed, with area under the curve (AUC) used to compare across groups. RESULTS: MP-MRI with RSI achieved higher AUCs compared to MP-MRI alone for identifying high-grade (Gleason score greater than or equal to 4 + 3=7) PCa (0.78 vs. 0.70 at the sextant level; P < 0.001 and 0.85 vs. 0.79 at the hemigland level; P = 0.04). RSI and T2WI alone achieved AUCs similar to MP-MRI for high-grade PCa (0.71 vs. 0.70 at the sextant level). With hemigland analysis, high-grade disease results were similar when comparing RSI + T2WI with MP-MRI, although with greater AUCs compared to the sextant analysis (0.80 vs. 0.79). CONCLUSION: Including RSI with MP-MRI improves PCa detection compared to MP-MRI alone, and RSI with T2WI achieves similar PCa detection as MP-MRI.