Comparison of Ultra-High-Resolution and Normal-Resolution CT-Angiography for Intracranial Aneurysm Detection in Patients with Subarachnoid Hemorrhage.

RATIONALE AND OBJECTIVES: Ruptured intracranial aneurysms (IAs) are the leading cause for atraumatic subarachnoid hemorrhage. In case of aneurysm rupture, patients may face life-threatening complications and require aneurysm occlusion. Detection of the aneurysm in computed tomography (CT) imaging is therefore essential for patient outcome. This study provides an evaluation of the diagnostic accuracy of Ultra-High-Resolution Computed Tomography Angiography (UHR-CTA) and Normal-Resolution Computed Tomography Angiography (NR-CTA) concerning IA detection and characterization. MATERIALS AND METHODS: Consecutive patients with atraumatic subarachnoid hemorrhage who received Digital Subtraction Angiography (DSA) and either UHR-CTA or NR-CTA were retrospectively included. Three readers evaluated CT-Angiography regarding image quality, diagnostic confidence and presence of IAs. Sensitivity and specificity were calculated on patient-level and segment-level with reference standard DSA-imaging. CTA patient radiation exposure (effective dose) was compared. RESULTS: One hundred and eight patients were identified (mean age = 57.8 ±â€¯14.1 years, 65 women). UHR-CTA revealed significantly higher image quality and diagnostic confidence (P < 0.001) for all readers and significantly lower effective dose (P < 0.001). Readers correctly classified ≥55/56 patients on UHR-CTA and ≥44/52 patients on NR-CTA. We noted significantly higher patient-level sensitivity for UHR-CTA compared to NR-CTA for all three readers (reader 1: 41/41 [100%] vs. 28/34 [82%], reader 2: 41/41 [100%] vs. 30/34 [88%], reader 3: 41/41 [100%] vs. 30/34 [88%], P ≤ 0.04). Segment-level analysis also revealed significantly higher sensitivity for UHR-CTA compared to NR-CTA for all three readers (reader 1: 47/49 [96%] vs. 34/45 [76%], reader 2: 47/49 [96%] vs. 37/45 [82%], reader 3: 48/49 [98%] vs. 37/45 [82%], P ≤ 0.04). Specificity was comparable for both techniques. CONCLUSION: We found Ultra-High-Resolution CT-Angiography to provide higher sensitivity than Normal-Resolution CT-Angiography for the detection of intracranial aneurysms in patients with aneurysmal subarachnoid hemorrhage while improving image quality and reducing patient radiation exposure.

Brain connectivity networks underlying resting heart rate variability in acute ischemic stroke.

Acute strokes can affect heart rate variability (HRV), the mechanisms how are not well understood. We included 42 acute stroke patients (2-7 days after ischemic stroke, mean age 66 years, 16 women). For analysis of HRV, 20 matched controls (mean age 60.7, 10 women) were recruited. HRV was assessed at rest, in a supine position and individual breathing rhythmus for 5 min. The coefficient of variation (VC), the root mean square of successive differences (RMSSD), the powers of low (LF, 0.04-0.14 Hz) and high (HF, 0.15-0.50 Hz) frequency bands were extracted. HRV parameters were z-transformed related to age- and sex-matched normal subjects. Z-values < -1 indicate reduced HRV. Acute stroke lesions were marked on diffusion-weighted images employing MRIcroN and co-registered to a T1-weighted structural volume-dataset. Using independent component analysis (ICA), stroke lesions were related to HRV. Subsequently, we used the ICA-derived lesion pattern as a seed and estimated the connectivity between these brain regions and seven common functional networks, which were obtained from 50 age-matched healthy subjects (mean age 68.9, 27 women). Especially, LF and VC were frequently reduced in patients. ICA revealed one covarying lesion pattern for LF and one similar for VC, predominantly affecting the right hemisphere. Activity in brain areas corresponding to these lesions mainly impact on limbic (r = 0.55 ± 0.08) and salience ventral attention networks (0.61 ± 0.10) in the group with reduced LF power (z-score < -1), but on control and default mode networks in the group with physiological LF power (z-score > -1). No different connectivity could be found for the respective VC groups. Our results suggest that HRV alteration after acute stroke might be due to affecting resting-state brain networks.

A Rapid Late Enhancement MRI Protocol Improves Differentiation between Brain Tumor Recurrence and Treatment-Related Contrast Enhancement of Brain Parenchyma.

PURPOSE: Differentiation between tumor recurrence and treatment-related contrast enhancement in MRI can be difficult. Late enhancement MRI up to 75 min after contrast agent application has been shown to improve differentiation between tumor recurrence and treatment-related changes. We investigated the diagnostic performance of late enhancement using a rapid MRI protocol optimized for clinical workflow. METHODS: Twenty-three patients with 28 lesions suspected for glioma recurrence underwent MRI including T1-MPRAGE-series acquired 2 and 20 min after contrast agent administration. Early contrast series were subtracted from late contrast series using motion correction. Contrast enhancing lesions were retrospectively and independently evaluated by two readers blinded to the patients' later clinical course and histology with or without the use of late enhancement series. Sensitivity, specificity, NPV, and PPV were calculated for both readers by comparing results of MRI with histological samples. RESULTS: Using standard MR sequences, sensitivity, specificity, PPV, and NPV were 0.84, 0, 0.875, and 0 (reader 1) and 0.92, 0, 0.885, and 0 (reader 2), respectively. Early late enhancement increased sensitivity, specificity, PPV, and NPV to 1 for each value and for both readers. Inter-reader reliability increased from 0.632 (standard MRI sequences) to 1.0 (with early late enhancement). CONCLUSION: The described rapid late enhancement MRI protocol improves MRI-based discrimination between tumor tissue and treatment-related changes of the brain parenchyma.

Beyond Glioma: The Utility of Radiomic Analysis for Non-Glial Intracranial Tumors.

The field of radiomics is rapidly expanding and gaining a valuable role in neuro-oncology. The possibilities related to the use of radiomic analysis, such as distinguishing types of malignancies, predicting tumor grade, determining the presence of particular molecular markers, consistency, therapy response, and prognosis, can considerably influence decision-making in medicine in the near future. Even though the main focus of radiomic analyses has been on glial CNS tumors, studies on other intracranial tumors have shown encouraging results. Therefore, as the main focus of this review, we performed an analysis of publications on PubMed and Web of Science databases, focusing on radiomics in CNS metastases, lymphoma, meningioma, medulloblastoma, and pituitary tumors.

Structured Reporting of Acute Ischemic Stroke - Consensus-Based Reporting Templates for Non-Contrast Cranial Computed Tomography, CT Angiography, and CT Perfusion. / Strukturierte Befundung beim ischämischen Schlaganfall: Konsensbasierte Befundvorlagen für die native Computertomografie, CT-Angiografie und CT-Perfusion des Neurokraniums.

PURPOSE: Structured reporting is an essential step in establishing standardized quality standards in diagnostic radiology. The German Society of Radiology and the German Society of Neuroradiology aim to provide templates for the structured reporting of different radiological examinations. METHOD: The Information Technology working group of the German Society of Radiology developed structured templates for the radiological reporting of different indications in consensus with specialist support by experts. RESULTS: We present a template for the structured reporting of examinations of patients with acute ischemic stroke by non-contrast computed tomography, CT angiography, and CT perfusion. This template is provided on the website www.befundung.drg.de for free use. CONCLUSION: Implementation of the structured template may increase quality and provide a minimum standard for radiological reports in patients with acute ischemic stroke. KEY POINTS: · The German Society of Radiology and the German Society of Neuroradiology are providing support for the development of structured templates in German.. · We present a template for the structured reporting of examinations of patients with acute ischemic stroke by non-contrast computed tomography, CT angiography, and CT perfusion. This template is provided on the website www.befundung.drg.de for free use.. · Implementation of the structured template may increase quality and provide a minimum standard for radiological reports in patients with acute ischemic stroke.. CITATION FORMAT: · Brendle C, Bender B, Selo N et al. Structured Reporting of Acute Ischemic Stroke - Consensus-Based Reporting Templates for Non-Contrast Cranial Computed Tomography, CT Angiography, and CT Perfusion. Fortschr Röntgenstr 2021; 193: 1315 - 1317.

Acetic acid compared with i-scan imaging for detecting Barrett's esophagus: a randomized, comparative trial.

BACKGROUND: Traditional surveillance in patients with Barrett's esophagus (BE) has relied on random biopsies. Targeted biopsies that use advanced imaging modalities may significantly improve detection of specialized columnar epithelium (SCE). OBJECTIVE: We compared the efficacy of targeted biopsies that used i-scan or acetic acid to random biopsies in the detection of SCE. DESIGN: Patients with visible columnar lined epithelium or known BE were randomized at a 1:1 ratio to undergo acetic acid application or i-scan with targeted biopsies. SETTING: Targeted biopsies were performed based on surface architecture according to the Guelrud classification followed by 4-quadrant biopsies. PATIENTS: A total of 95 patients were randomized. INTERVENTION: A total of 46 patients underwent acetic acid staining, and 49 underwent i-scan imaging. Random biopsies were performed in 86 patients. MAIN OUTCOME MEASUREMENTS: The primary outcome was the yield of SCE as confirmed by histologic assessment. RESULTS: The diagnostic yield for SCE was significantly higher with targeted biopsies than with random biopsies in both groups combined (63% vs 24%; P = .0001). The yield of targeted biopsies was significantly greater with both i-scan (66% vs 21%; P = .009) and acetic acid (57% vs 26%; P = .012) technologies and did not differ between these groups. The accuracy for predicting SCE was 96% (k = .92) for i-scan and 86% (k = .70) for acetic acid analysis. LIMITATIONS: No dysplastic lesions were found. CONCLUSION: The i-scan or acetic acid-guided biopsies have a significantly higher diagnostic yield for identifying SCE, with significantly fewer biopsies, as compared with a protocol of random biopsies. Acetic acid and i-scan showed comparable results diagnosing SCE in our study. ( CLINICAL TRIAL REGISTRATION NUMBER: NCT01442506.).