Reproducibility of rCBV in glioblastomas using T2*-weighted perfusion MRI: an evaluation of sampling, normalization, and experience.

PURPOSE: The reproducibility of relative cerebral blood volume (rCBV) measurements among readers with different levels of experience is a concern. This study aimed to investigate the inter-reader reproducibility of rCBV measurement of glioblastomas using the hotspot method in dynamic susceptibility contrast perfusion magnetic resonance imaging (DSC-MRI) with various strategies. METHODS: In this institutional review board-approved single-center study, 30 patients with glioblastoma were retrospectively evaluated with DSC-MRI at a 3.0 Tesla scanner. Three groups of reviewers, including neuroradiologists, general radiologists, and radiology residents, calculated the rCBV based on the number of regions of interest (ROIs) and reference areas. For statistical analysis of feature reproducibility, the intraclass correlation coefficient (ICC) and Bland-Altman plots were used. Analyses were made among individuals, reader groups, reader-group pooling, and a population that contained all of them. RESULTS: For individuals, the highest inter-reader reproducibility was observed between neuroradiologists [ICC: 0.527; 95% confidence interval (CI): 0.21-0.74] and between residents (ICC: 0.513; 95% CI: 0.20-0.73). There was poor reproducibility in the analyses of individuals with different levels of experience (ICC range: 0.296-0.335) and in reader-wise and group-wise pooling (ICC range: 0.296-0.335 and 0.397-0.427, respectively). However, an increase in ICC values was observed when five ROIs were used. In an analysis of all strategies, the ICC for the centrum semiovale was significantly higher than that for contralateral white matter (P < 0.001). CONCLUSION: The inter-reader reproducibility of rCBV measurement was poor to moderate regardless of whether it was calculated by neuroradiologists, general radiologists, or residents, which may indicate the need for automated methods. Choosing five ROIs and using the centrum semiovale as a reference area may increase reliability for all users.

Presentation characteristics and clinical outcome of patients with giant cell arteritis followed by a single center.

BACKGROUND: Giant cell arteritis (GCA) is a large vessel vasculitis that may cause significant morbidity in the elderly population. We aimed to evaluate presentation characteristics, treatment, and outcome in a cohort of patients with GCA diagnosed and followed in a single center. METHODS: A retrospective chart review revealed 84 (41 M/43 F) registered patients diagnosed with GCA between 1990 and 2020. Clinical features at presentation and follow-up, radiographical imaging, temporal artery biopsy (TAB), and laboratory findings were retrieved from digital medical records or hard-copy patient files. Of these, 33 patients' follow-up period was less than 12 months; hence, relapses and treatment outcomes were examined in the remaining 51 (60.5%) patients. RESULTS: A total of 84 patients were included in the cohort. The mean age at diagnosis was 68.4 ± 7.9 years (range: 49-85). At presentation, 60 (71.4%) patients had headache, 22 (26.2%) had symptoms compatible with polymyalgia rheumatica (PMR), and 23 (27.4%) had visual loss. Three (3.6%) patients had solid organ malignancies while two had hematologic malignancies (2.4%) before GCA diagnosis. TAB was obtained in 63 (75%) patients, in 47 of whom (74.6%) the pathological findings were consistent with GCA. A PET/ CT scan has been performed before glucocorticoids (GCs) initiation in 43 (51.2%) patients and of these, 37 (86.0%) revealed uptake consistent with large vessel involvement. The median follow-up time of the 51 patients was 3.7 (IQR: 1.8-6.8) years. GCs were started promptly after the diagnosis. During the follow-up period, 28 (54.9%) patients experienced a relapse. Thirty-nine (78%) patients were under GC treatment, with a mean dosage of 4.8 ± 2.8 g/day at the final visit. At the final visit, 20.3% (17:84) had died whereas 9.8% (5:51) had permanent vision loss. DISCUSSION: Treatment of GCA is challenging. GCA causes serious morbidities and increased mortality. PET/CT is highly effective in detecting large vessel vasculitis in GCA and could perhaps replace TAB in the future.