Comparison between postcontrast thin-slice T1-weighted 2D spin echo and 3D T1-weighted SPACE sequences in the detection of brain metastases at 1.5 and 3 T.

OBJECTIVES: Accurate detection of metastatic brain lesions (MBL) is critical due to advances in radiosurgery. We compared the results of three readers in detecting MBL using T1-weighted 2D spin echo (SE) and sampling perfection with application-optimized contrasts using different flip angle evolution (SPACE) sequences with whole-brain coverage at both 1.5 T and 3 T. METHODS: Fifty-six patients evaluated for MBL were included and underwent a standard protocol (1.5 T, n = 37; 3 T, n = 19), including postcontrast T1-weighted SE and SPACE. The rating was performed by three raters in two sessions > six weeks apart. The true number of MBL was determined using all available imaging including follow-up. Intraclass correlations for intra-rater and inter-rater agreement were calculated. Signal intensity ratios (SIR; enhancing lesion, white matter) were determined on a subset of 46 MBL > 4 mm. A paired t-test was used to evaluate postcontrast sequence order and SIR. Reader accuracy was evaluated by the coefficient of determination. RESULTS: A total of 135 MBL were identified (mean/subject 2.41, SD 6.4). The intra-rater agreement was excellent for all 3 raters (ICC = 0.97-0.992), as was the inter-rater agreement (ICC = 0.995 SE, 0.99 SPACE). Subjective qualitative ratings were lower for SE images; however, signal intensity ratios were higher in SE sequences. Accuracy was high in all readers for both SE (R2 0.95-0.96) and SPACE (R2 0.91-0.96) sequences. CONCLUSIONS: Although SE sequences are superior to gradient echo sequences in the detection of small MBL, they have long acquisition times and frequent artifacts. We show that T1-weighted SPACE is not inferior to standard thin-slice SE sequences in the detection of MBL at both imaging fields. CRITICAL RELEVANCE STATEMENT: Our results show the suitability of 3D T1-weighted turbo spin echo (TSE) sequences (SPACE, CUBE, VISTA) in the detection of brain metastases at both 1.5 T and 3 T. KEY POINTS: • Accurate detection of brain metastases is critical due to advances in radiosurgery. • T1-weighted SE sequences are superior to gradient echo in detecting small metastases. • T1-weighted 3D-TSE sequences may achieve high resolution and relative insensitivity to artifacts. • T1-weighted 3D-TSE sequences have been recommended in imaging brain metastases at 3 T. • We found T1-weighted 3D-TSE equivalent to thin-slice SE at 1.5 T and 3 T.

Comparison of Prostate Imaging Reporting and Data System (PI-RADS) version 1 and version 2 and combination with apparent diffusion coefficient as a predictor of biopsy outcome.

PURPOSE: The main aim of the study was to compare the diagnostic performance of Prostate Imaging Reporting and Data System (PI-RADS) versions 1 and 2 for detection of prostate carcinoma (PCa) and clinically significant prostate carcinoma (CSPCa). The second aim was to evaluate the potential benefit of adding the apparent diffusion coefficient (ADC) and prostate specific antigen (PSA) density to the standard evaluation protocol. METHODS: A total of 167 consecutive patients with elevated PSA underwent magnetic resonance imaging. The images were evaluated prospectively using both versions of the PI-RADS and the results compared with 12-core template biopsy and magnetic resonance/transrectal ultrasound fusion biopsy. Receiver-operating characteristic (ROC) curves were compared for each scoring system using DeLong\'s test. The area under the curve (AUC) was calculated for ADC and PSA density for lesions scored 4. RESULTS: PI-RADS V2 had high discriminative ability for PCa prediction with an AUC of 0.824 (95% CI 0.763 to 0.885), compared to an AUC of 0.724 (95% CI 0.654 to 0.794) for PI-RADS V1 (p = 0.0335). ADC demonstrated a higher discriminative ability with an AUC of 0.702 (95% CI 0.548 to 0.856) in CSPCa prediction. Using the obtained ADC threshold of 828x10^-6 mm^2/s improved specificity to 86.73% with a sensitivity of 60.38%. CONCLUSION: PI-RADS version 2 exhibited significantly higher discriminative ability for PCa and CSPCa detection compared to PI-RADS version 1. Using the ADC can improve the tumor predictability of PI-RADS version 2 in lesions scored 4.

Latent Schizencephaly With Psychotic Phenotype or Schizophrenia With Schizencephaly? A Case Report and Review of the Literature.

OBJECTIVES: Although schizencephaly belongs to the class of neurodevelopmental disorders, which are a well-known predisposing factor for psychosis, there is a lack of relevant studies and diagnostic guidelines on this relationship. METHOD: A case report of first-episode psychosis with persistent negative symptoms associated with schizencephaly is described and compared with 7 other cases found in the literature. RESULTS: We found perinatal pathology, cognitive deficit, and EEG abnormality in a patient with atypical initial symptoms of psychosis such as olfactory hallucinations. Abnormal EEG findings (left frontal spikes and frontal intermittent rhythmic delta activity) called for magnetic resonance imaging, which revealed left parieto-occipital closed-lip schizencephaly. The patient exhibited a partial response to low-dose amisulpride treatment. CONCLUSION: We conclude that schizencephaly in our patient was at first asymptomatic and later developed into clinically manifest schizophrenia-like disorder. Both magnetic resonance imaging and EEG were essential tools for establishing this diagnosis.

The aging effect on prostate metabolite concentrations measured by 1H MR spectroscopy.

OBJECTIVE: The effects of aging, magnetic field and the voxel localization on measured concentrations of citrate (Cit), creatine (Cr), cholines (Cho) and polyamines (PA) in a healthy prostate were evaluated. MATERIALS AND METHODS: 36 examinations at both 1.5T and 3T imagers of 52 healthy subjects aged 19-71 years were performed with PRESS 3D-CSI sequences (TE = 120 and 145 ms). Concentrations in laboratory units and their ratios to citrate were calculated using the LCModel technique. Absolute concentrations were also obtained after the application of correction coefficients. Statistical analysis was performed using a robust linear mixed effects model. RESULTS: Significant effects of aging, the magnetic field strength and the voxel position in central (CZ) or peripheral (PZ) zones on all measured metabolites were found. The concentrations (mmol/kg wet tissue) including prediction intervals in a range of 20-70 years were found: Cit: 7.9-17.2; Cho: 1.4-1.7; Cr: 2.8-2.5; PA (as spermine): 0.6-2.1 at 3T in CZ. In PZ, the concentrations were higher by about 10 % as compared to CZ. CONCLUSION: Increasing citrate and spermine concentrations with age are significant and correlate well with a recently described increase of zinc in the prostate. These findings should be considered in decision-making if the values obtained from a subject are in the range of control values.