Application of Computed Tomography Perfusion Imaging-guided Mechanical Thrombectomy in Ischemic Stroke Patients with Large Vessel Occlusion beyond the Therapeutic Time Window.

INTRODUCTION: To explore the feasibility of applying computed tomography perfusion (CTP) imaging-guided mechanical thrombectomy in acute ischemic stroke patients with large vessel occlusion beyond the therapeutic time window. METHODS: The clinical data of acute cerebral infarction patients with large vessel occlusion who were beyond the therapeutic time window and admitted to Handan Central Hospital from January 2021 to March 2022 were retrospectively analyzed. All patients were assessed by the National Institutes of Health Stroke Scale (NIHSS) and were examined by one-stop CTP imaging. The preoperative onset time of the disease was more than 6 h. Fourteen patients underwent magnetic resonance imaging examination at the same time. Fifty-four patients were retrospectively divided into two groups based on the treatment methods: the mechanical thrombectomy group had 21 patients and the conservative treatment group had 33 patients. NIHSS scoring and computed tomography scan were performed before treatment, 6 h, 24 h, 7 days, and 30 days after treatment. RESULTS: The NIHSS scores of the patients with acute cerebral large vessel occlusion who underwent CTP imaging-guided mechanical thrombectomy at 6 h, 24 h, 7 days, and 30 days after treatment were compared with those of the conventional treatment group. The NIHSS score of the mechanical thrombectomy group was significantly better, and the difference was statistically significant (P < 0.05). In terms of the prognosis rate and expansion rate of infarct core volume, the patients of the mechanical thrombectomy group had a better prognosis, and the difference was statistically significant (P < 0.05). Artificial intelligence-assisted CTP diagnosis can facilitate the automatic evaluation of diseases and enable quick judgments that are independent of radiologists' evaluation, but it may pose a problem in the determination of infarct core volume (either being too high or too low). CONCLUSION: It is of great significance to apply CTP imaging in guiding the mechanical thrombectomy procedure in acute stroke patients with large vessel occlusion who are beyond the therapeutic time window.

Whole-Brain Volume CT Angiography can Effectively Detect Early Ischemic Cerebrovascular Diseases.

OBJECTIVE: To investigate the role of whole-brain volume computed tomography (CT) perfusion in assessing early ischemic cerebrovascular diseases. MATERIALS AND METHODS: Seventy-two patients with early ischemic cerebrovascular diseases who had undergone routine CT scan and 320-row volume CT whole-brain perfusion imaging within 8 h after admission were retrospectively enrolled in this one-center case-sectional study. The perfusion parameters of cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), time to peak (TTP), and dynamic CT angiogram (4D-CTA) were obtained and analyzed. RESULTS: Among 72 patients, 29 cases with 37 cerebral ischemic lesions were found in plain CT scan, whereas 51 cases with 76 lesions were found in whole-brain CT perfusion, with 30.6% more patients being detected. The CBF value was significantly lower in the abnormal than normal corresponding perfusion area in the healthy hemisphere (P<0.05), while the MTT and TTP values were significantly higher in the abnormal than the normal corresponding area (P<0.05). 4D-CTA image suggested that 59 cases had different degrees of stenosis or occlusion, including 11 mild, 18 moderate, 21 severe, and 9 occlusive cases. Four-D-CTA imaging could detect significantly (P<0.05) more patients with abnormal perfusion in severe cerebral vascular stenosis or occlusion than those with no, mild or moderate stenosis (93.33% vs. 16.67%) (P<0.05). The stenosis of intracranial and carotid arteries was positively correlated with MTT and TTP values (P<0.05). CONCLUSION: Whole-brain volume CT angiography can comprehensively display early cerebral ischemic lesions, cerebral blood perfusion status, and cerebral vascular stenosis, providing valuable information for early detection of ischemic cerebral diseases and appropriate treatment planning.

The Application of Computed Tomography Perfusion in the Alberta Stroke Program Early Computed Tomography Score for Endovascular Treatment of Acute Ischemic Stroke in the Anterior Circulation.

OBJECTIVE: The present study investigated the predictive value of each perfusion parameter of the Alberta Stroke Program Early Computed Tomography Score (ASPECTS) in CT perfusion (CTP) imaging for the prognosis of endovascular treatment at the time of admission in patients with acute ischemic stroke in the anterior circulation. PATIENTS AND METHODS: The imaging data of 62 patients with acute ischemic stroke in the anterior circulation with an onset time of 6 h or less were retrospectively analyzed. All patients underwent the one-stop whole-brain dynamic volume four-dimensional (4D) CT angiography (CTA)-CTP and cranial magnetic resonance imaging (MRI) within seven days after treatment. The patients were divided into better and worse prognosis groups according to their clinical symptoms, combined with an MRI-ASPECTS score of ≤ 6 within seven days after treatment. The observed perfusion parameters included cerebral blood flow (CBF)-ASPECTS, cerebral blood volume (CBV)-ASPECTS, mean transit time (MTT)-ASPECTS, and time to peak (TTP)-ASPECTS. The difference in ASPECTS scores involving the CTP parameter, as well as diagnostic power, was compared between the two groups of patients. RESULTS: All CTP-ASPECTS scores negatively correlated with clinical prognosis. The higher the CTP-ASPECTS scores preceding treatment in patients with ischemic stroke in the anterior circulation, the better the prognosis. There were statistically significant differences in the scores of CBF-ASPECTS and CBV-ASPECTS between the two groups (P < 0.05). Receiver operating curve (ROC) analysis showed that the parameter with the largest area under the curve (AUC) was the CBF-ASPECTS score (P = 0.003), with a sensitivity of 90.9%, a specificity of 59.1%, and an AUC of 0.806, which was the most valuable prognostic predictor. CONCLUSION: The CBF-ASPECTS score presented significant value as a primary indicator for predicting the outcome of endovascular treatment in patients with acute ischemic stroke in the anterior circulation, and it had good application prospects in clinical practice.

Intravoxel Incoherent Motion Magnetic Resonance Imaging with Integrated Slice-specific Shimming for old myocardial infarction: A Pilot Study.

Currently, little is known regarding the value of quantitative parameters derived from the intravoxel incoherent motion (IVIM) magnetic resonance imaging (MRI) with integrated slice-specific shimming (iShim) sequence in detecting old myocardial infarction and myocardial fibrosis. This study was to investigate the value of IVIM-MRI with iShim sequence in diagnosing old myocardial infarction and fibrosis. Thirty-five patients with both old myocardial infarction and myocardial fibrosis and 12 healthy volunteers were prospectively enrolled to undergo cardiac diffusion-weighted imaging (DWI) using seven b-values (0, 20, 60, 80, 120, 200 and 600 s/mm2). The iShim sequence was used for IVIM data acquisition, and the diffusion parameters, D, D* and f values for IVIM, and conventional apparent diffusion coefficient (ADC) were evaluated on the anterior, posterior and lateral walls of the ventricular septum using the short axis of the heart. Significant differences were found in the D, D* and f values between healthy subjects and patients with old myocardial infarction and myocardial fibrosis (P = 0.000), with the median value of the D and f significantly smaller in the myocardial infarction and fibrosis than in the normal control but the median value of D* significantly greater in the myocardial infarction and fibrosis than in the normal control. In the receiver operating curve analysis, the areas under the curve were 0.939, 0.988 and 0.959 for the D, D* and f values, respectively. The sensitivities and specificities were 84.6% and 94.4% for D, 88.9% and 84.6% for D* and 100% and 93.1% for the f values, respectively. In conclusion, the IVIM-derived parameters (D, D* and f) obtained using the iShim DWI technique showed high capacity in diagnosing old myocardial infarction and myocardial fibrosis by providing diffusion and perfusion information, which may have great importance in future clinical practice.

STROBE-A preliminary investigation of IVIM-DWI in cardiac imaging.

This study aims to explore the possibility to apply intravoxel incoherent motion-magnetic resonance imaging (IVIM-MRI) in cardiac imaging.Multi-b-value diffusion-weighted imaging (DWI) sequence scanning was performed on 12 healthy volunteers. A double exponential model was adopted, and the b-value sequence was 0, 20, 60, 80, 120, 200, and 600 second/mm. The D-value, D*-value, and f-value of the anterior posterior and lateral walls of the ventricular septum were respectively measured on the short axis section of the heart, the parameters of the myocardium in different blood supply areas in each segment were recorded, and the measured data of these different segments were compared using analysis of variance.Among these 12 healthy volunteers, the D-value, D*-value, and f-value of these 72 segments were not exactly equal, the D-values of the myocardium in the 5th and 11th segment were lower than those in the 2nd, 3rd, 8th, and 9th segments, and the pairwise differences were statistically significant (P < .001). Furthermore, the difference in D-value between the 5th and 11th segments was not statistically significant (P = 1.000). The D*-value and f-value of the myocardium in the 5th and 11th segment were higher than those in the 2nd, 3rd, 8th, and 9th segments, and the pairwise differences were statistically significant (P < .001). Furthermore, the differences in D*-value and f-value between the 5th and 11th segments was not statistically significant (P = .214, .787).The intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) technique can quantitatively reflect the diffusion and blood perfusion status of the myocardium.

Diagnostic significance of diffusion-weighted MRI in patients with cervical cancer: a meta-analysis.

The aim of this meta-analysis is to demonstrate whether diffusion-weighted magnetic resonance imaging (DWI) could assist in the precise diagnosis of cervical cancer or not. Both English and Chinese electronic databases were searched for potential relevant studies followed by a comprehensive literature search without any language restriction. Two reviewers independently assessed the methodological quality of the included trials. Standardized mean difference (SMD) and its corresponding 95 % confidence interval (95 % CI) were calculated in this meta-analysis. We chose Version 12.0 STATA statistical software to analyze our statistical data. Thirteen eligible cohort studies were selected for statistical analysis, including 645 tumor tissues and 504 normal tissues. Combined SMD of apparent diffusion coefficient (ADC) suggested that the ADC value in cervical cancer tissues was significantly lower than that of normal tissue (SMD = 2.80, 95 % CI = 2.64 ~ 2.96, P < 0.001). Subgroup analysis stratified by ethnicity indicated a higher ADC value in the normal tissues compared to the cancer tissues in both the Asian and Caucasian subgroups (Asians: SMD = 2.83, 95 % CI = 2.64 ~ 3.02, P < 0.001; Caucasians: SMD = 2.73, 95 % CI = 2.45 ~ 3.01, P < 0.001, respectively). The results from the subgroup analysis by MRI machine type revealed a statistically significant difference in ADC value between normal cervical tissue and tumor tissues among all of the six MRI machine type subgroups (all P < 0.05). The main finding from our meta-analysis revealed that increased signal intensity on DWI and decreased signal on ADC seem to be useful in the diagnosis of cervical cancer. DWI could therefore be an important imaging tool in potentially identifying patients with cervical cancer.