Predictors of Symptomatic Intracranial Hemorrhage after Endovascular Thrombectomy in Acute Ischemic Stroke Patients with Anterior Large Vessel Occlusion-Procedure Time and Reperfusion Quality Determine.

PURPOSE: We aimed to evaluate predictors of symptomatic intracranial hemorrhage (sICH) in acute ischemic stroke (AIS) patients following thrombectomy due to anterior large vessel occlusion (LVO). METHODS: Data on stroke patients from January 2018 to December 2020 in a tertiary care centre were retrospectively analysed. sICH was defined as intracranial hemorrhage associated with a deterioration of at least four points in the National Institutes of Health Stroke Scale (NIHSS) score or hemorrhage leading to death. A smoothed ridge regression model was run to analyse the impact of 15 variables on their association with sICH. RESULTS: Of the 174 patients (median age 77, 41.4% male), sICH was present in 18 patients. Short procedure time from groin puncture to reperfusion (per 10 min OR 1.24; 95% CI 1.071-1.435; p = 0.004) and complete reperfusion (TICI 3) (OR 0.035; 95% CI 0.003-0.378; p = 0.005) were significantly associated with a lower risk of sICH. On the contrary, successful reperfusion (TICI 3 and TICI 2b) was not associated with a lower risk of sICH (OR 0.508; 95% CI 0.131-1.975, p = 0.325). Neither the total time from symptom onset to reperfusion nor the intravenous thrombolysis was a predictor of sICH (per 10 min OR 1.0; 95% CI 0.998-1.001, p = 0.745) (OR 1.305; 95% CI 0.338-5.041, p = 0.697). CONCLUSION: Our findings addressed the paramount importance of short procedure time and complete reperfusion to minimize sICH risk. The total ischemic time from onset to reperfusion was not a predictor of sICH.

When Can an Emergency CTA Be Dispensed with for TIA Patients?

BACKGROUND: Transient ischemic attacks (TIAs) and minor strokes are often precursors of a major stroke. Therefore, diagnostic work-up of the TIA is essential to reduce the patient's risk of further ischemic events. PURPOSE: With the help of this retrospective study, we aim to determine for which TIA patients a CT angiography (CTA) is not immediately necessary in order to reduce radiation exposure and nephrotoxicity. MATERIAL AND METHODS: Clinical and imaging data from patients who presented as an emergency case with a suspected diagnosis of TIA at a teaching hospital between January 2016 and December 2021 were evaluated. The included 1526 patients were divided into two groups-group 1, with major pathologic vascular findings in the CTA, and group 2, with minor vascular pathologies. RESULTS: Out of 1821 patients with suspected TIA on admission, 1526 met the inclusion criteria. In total, 336 (22%) had major vascular pathologies on CTA, and 1190 (78%) were unremarkable. The majority of patients with major vascular pathologies were male and had a history of arterial hypertension, coronary heart disease, myocardial infarction, ischemic stroke, TIA, atherosclerotic peripheral vascular disease, smoking, antiplatelet medication, had a lower duration of TIA symptoms, and had lower ABCD2 scores. CONCLUSIONS: We were able to demonstrate a direct correlation between major CTA pathologies and a history of smoking, age, hyperlipidemia, history of peripheral arterial disease, and a history of stroke and TIA. We were able to prove that the ABCD2 score is even reciprocal to CTA pathology. This means that TIA patients without described risk factors do not immediately require a CTA and could be clarified in the course of treatment with ultrasound or MRI.

CT and DSA for evaluation of spontaneous intracerebral lobar bleedings.

Purpose: This study retrospectively examined the extent to which computed tomography angiography (CTA) and digital subtraction angiography (DSA) can help identify the cause of lobar intracerebral bleeding. Materials and methods: In the period from 2002 to 2020, data from patients who were >18 years at a university and an academic teaching hospital with lobar intracerebral bleeding were evaluated retrospectively. The CTA DSA data were reviewed separately by two neuroradiologists, and differences in opinion were resolved by consensus after discussion. A positive finding was defined as an underlying vascular etiology of lobar bleeding. Results: The data of 412 patients were retrospectively investigated. DSA detected a macrovascular cause of bleeding in 125/412 patients (33%). In total, sixty patients had AVMs (15%), 30 patients with aneurysms (7%), 12 patients with vasculitis (3%), and 23 patients with dural fistulas (6%). The sensitivity, specificity, positive and negative predictive values, and accuracy of CTA compared with DSA were 93, 97, 100, and 97%. There were false-negative CTA readings for two AVMs and one dural fistula. Conclusion: The DSA is still the gold standard diagnostic modality for detecting macrovascular causes of ICH; however, most patients with lobar ICH can be investigated first with CTA, and the cause of bleeding can be found. Our results showed higher sensitivity and specificity than those of other CTA studies.

Impact of dual-energy CT prior to radioembolization (RE).

BACKGROUND: Depiction of the exact arterial liver anatomy as well as identifying potential extrahepatic non-target vessels is crucial for a successful preparation of radioembolization (RE). PURPOSE: To compare the diagnostic impact of dual-energy computed tomography (DECT) to digital subtraction angiography prior to RE. MATERIAL AND METHODS: DECT was applied in 46 patients with hepatocellular carcinoma (HCC) prior to RE. Eighty kV DE as well as reconstructed 120 kV equivalent DE datasets were evaluated in comparison to correlating digital subtraction angiography (DSA) datasets. Two radiologists evaluated in consensus the delineation of liver arteries and extrahepatic non-target vessels utilizing a 4-point scale (4 = excellent delineation; 1 = non-diagnostic). In addition, the arterial vascularization of liver segment IV was evaluated and classified: signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR; liver arteries to adjacent liver tissue) were obtained via ROI analysis. RESULTS: Both imaging techniques (DECT, DSA) enabled high-quality assessment of all analyzed liver arteries. Out of the two CT datasets, 80 kVp-DE datasets offered superior delineation of the right gastric artery (3.5 ± 0.7 vs. 2.5 ± 0.5), the vascularization of segment IV (3.9 ± 0.2 vs. 3.3 ± 0.5) as well as potential extrahepatic non-target vessels (3.9 ± 0.1 vs. 3.3 ± 0.5). In accordance to the results of the qualitative analysis, 80 kVp-DE datasets also yielded higher SNR (34.84 vs. 29.31) and CNR (28.29 vs. 21.8) values in comparison to the 120 kVp datasets. CONCLUSION: Eighty kVp DECT enables a significantly better assessment of the arteries of the upper abdomen for therapy planning in comparison to correlating 120 kVp datasets. This may allow for identification of potential extrahepatic non-target vessels and assessment of target volume for therapy planning prior to DSA.

Evaluation of the PET component of simultaneous [(18)F]choline PET/MRI in prostate cancer: comparison with [(18)F]choline PET/CT.

PURPOSE: The aim of this study was to evaluate the positron emission tomography (PET) component of [(18)F]choline PET/MRI and compare it with the PET component of [(18)F]choline PET/CT in patients with histologically proven prostate cancer and suspected recurrent prostate cancer. METHODS: Thirty-six patients were examined with simultaneous [(18)F]choline PET/MRI following combined [(18)F]choline PET/CT. Fifty-eight PET-positive lesions in PET/CT and PET/MRI were evaluated by measuring the maximum and mean standardized uptake values (SUVmax and SUVmean) using volume of interest (VOI) analysis. A scoring system was applied to determine the quality of the PET images of both PET/CT and PET/MRI. Agreement between PET/CT and PET/MRI regarding SUVmax and SUVmean was tested using Pearson's product-moment correlation and Bland-Altman analysis. RESULTS: All PET-positive lesions that were visible on PET/CT were also detectable on PET/MRI. The quality of the PET images was comparable in both groups. Median SUVmax and SUVmean of all lesions were significantly lower in PET/MRI than in PET/CT (5.2 vs 6.1, p<0.05 and 2.0 vs 2.6, p<0.001, respectively). Pearson's product-moment correlation indicated highly significant correlations between SUVmax of PET/CT and PET/MRI (R=0.86, p<0.001) as well as between SUVmean of PET/CT and PET/MRI (R=0.81, p<0.001). Bland-Altman analysis revealed lower and upper limits of agreement of -2.77 to 3.64 between SUVmax of PET/CT vs PET/MRI and -1.12 to +2.23 between SUVmean of PET/CT vs PET/MRI. CONCLUSION: PET image quality of PET/MRI was comparable to that of PET/CT. A highly significant correlation between SUVmax and SUVmean was found. Both SUVmax and SUVmean were significantly lower in [(18)F]choline PET/MRI than in [(18)F]choline PET/CT. Differences of SUVmax and SUVmean might be caused by different techniques of attenuation correction. Furthermore, differences in biodistribution and biokinetics of [(18)F]choline between the subsequent examinations and in the respective organ systems have to be taken into account.