VAI TRÒ CỦA CỘNG HƯỞNG TỪ ĐÀN HỒI 3 TESLA TRONG ĐÁNH GIÁ ĐỘ XƠ HÓA GAN

Mục tiêu: Khảo sát độ xơ hóa gan trên cộng hưởng từ đàn hồi (CHTĐH) và mối liên quan giữa CHTĐH với mô bệnh học trong đánh giá độ xơ hóa gan ở bệnh nhân viêm gan mạn.Phương pháp: Nghiên cứu hồi cứu, mô tả, khảo sát CHTĐH gan trước sinh thiết ở 20 bệnh nhân viêm gan mạn tại bệnh viện Chợ Rẫy từ tháng 11/2019 đến tháng 5/2021. Kết quả: Tuổi trung bình trong nghiên cứu là 51,4 tuổi. Có 100% bệnh nhân là nữ. Độ cứng gan trung bình (đơn vị kilopascal = kPa) trong nhóm nghiên cứu tương ứng với mỗi nhóm theo phân độ Metavir lần lượt là 3,1 ± 0,2 (F1, n = 8), 3,6 ± 0,1 (F2, n = 11) và 5,3 (F3, n = 1). Không có trường hợp nào có độ cứng gan F4. Hệ số tương quan Spearman là 0,63 (p=0,003) cho thấy có sự tương quan thuận, mạnh giữa độ cứng gan trên CHTĐH với mức độ xơ hóa gan theo Metavir trên mô bệnh học. Dựa vào đường cong ROC, với điểm cắt là 3,7 kPa có thể dự đoán xơ hóa gan có ý nghĩa (≥ F2) với độ nhạy 58%, độ đặc hiệu 100%. Chúng tôi chưa tìm được giá trị kPa trong dự đoán xơ hóa gan ≥ F3 và F4.Kết luận: CHTĐH là một kỹ thuật mới, an toàn, không xâm lấn, có thể thay thế sinh thiết để đánh giá giai đoạn xơ hóa gan.

Stability of Liver Radiomics across Different 3D ROI Sizes—An MRI In Vivo Study

We aimed to evaluate the stability of radiomic features in the liver of healthy individuals across different three-dimensional regions of interest (3D ROI) sizes in T1-weighted (T1w) and T2-weighted (T2w) images from different MR scanners. We retrospectively included 66 examinations of patients without known diseases or pathological imaging findings acquired on three MRI scanners (3 Tesla I: 25 patients, 3 Tesla II: 19 patients, 1.5 Tesla: 22 patients). 3D ROIs of different diameters (10, 20, 30 mm) were drawn on T1w GRE and T2w TSE images into the liver parenchyma (segment V–VIII). We extracted 93 radiomic features from the different ROIs and tested features for significant differences with the Mann–Whitney-U (MWU)-test. The MWU-test revealed significant differences for most second- and higher-order features, indicating a systematic difference dependent on the ROI size. The features mean, median, root mean squared (RMS), 10th percentile, and 90th percentile were not significantly different. We also assessed feature robustness to ROI size variation with overall concordance correlation coefficients (OCCCs). OCCCs across the different ROI-sizes for mean, median, and RMS were excellent (>0.90) in both sequences on all three scanners. These features, therefore, seem robust to ROI-size variation and suitable for radiomic studies of liver MRI.

Evaluation of the Relationship Between the Internal Acoustic Canal Anatomy and Loops of the Anterior Inferior Cerebellar Artery Using 3-Tesla Magnetic Resonance Imaging

Background: Anatomical variations in vascular structures are frequently encountered. In the cerebellopontine region, anatomical variations, especially variations in the anterior inferior cerebellar artery (AICA) in relation to cranial nerves passing through the internal acoustic canal (IAC), are common. Magnetic resonance imaging (MRI) provides detailed information for the evaluation of the cerebellopontine region and the IAC anatomy. Objectives: This study aimed to examine the relationship between the IAC anatomy and AICA loop variations and to investigate the frequency of anatomical variations and its correlation with demographic variables. Patients and Methods: In this study, 253 patients (age > 18 years), who underwent 3-Tesla MRI of the temporal bone between July 2019 and December 2019, were retrospectively evaluated. The exclusion criteria were images of poor diagnostic quality due to technical or patient-related reasons and the presence of a localized tumor that could disrupt the IAC. Four patients were excluded from the study because they had tumors related to IAC. The AICA variations were categorized according to the Chavda classification. The IAC size, canal diameter, canal length, and meatus width were measured, and the canals were characterized as cylindrical, funnel-shaped, and bud-shaped. Results: A total of 249 patients were included in this study. The Chavda type I vascular loop was the most common type on both sides. The mean size measurements of IACs were significantly higher in the group of vascular loops compared to the group without vascular loops. The presence of a vascular loop was significantly more common in funnel- and bud-shaped IACs compared to cylindrical IAC. Also, there was a negative correlation between the patient’s age and all IAC dimensions. Conclusion: The results of the present study showed that the AICA loop variations were closely related to the size and shape of the IAC.

Rescue Intracranial Stenting in acute Ischemic Stroke v1

Background In acute ischemic stroke (AIS) caused by intracranial large vessel occlusion, rescue intracranial stenting (RIS) has been recently a treatment option to achieve recanalization in patients with the failure of mechanical thrombectomy (MT). Nevertheless, there are few studies supporting this beneficial treatment in two cerebral circulations. We aimed to analyze whether the use of RIS would improve prognosis “non-poor” of patients at 3 months. Methods and Findings This was a interventional, single-arm study in patients with AIS who were treated with rescue stenting at Can Tho S.I.S hospital. Inclusion criteria consisted of: evidence of intracranial large vessel occlusion, absence of intracranial hemorrhage and severe stenosis or reocclusion after MT. Tandem lesion, loss to follow-up after discharge and a severe or fatal combined illness before AIS were excluded. The primary outcome was the “non-poor” outcome rate at 3 months and postprocedural symptomatic intracerebral hemorrhage (sICH). The study is registered with ClinicalTrials.gov, NCT04986774.Between August 2019 and May 2021, 85 eligible patients were comprised of 82 (96.5%) successful recanalization and 4 (4.7%) sICH. “Non-poor” outcome comprising of good (mRS 0 - ≤ 2) and fair (mRS 3). “Non-poor” outcome at 3 months occurred 47 (55.3%), in which there were 35 (41.2%) good outcome. DAPT was associated with new infarcts (RR = 0.1; 95%CI 0.01 - 0.7, NNT = 2) and sICH (RR = 0.1; 95%CI 0.01 - 0.9; NNT = 2). MRI 3 Tesla evaluated diagnostic occlusive lesions with sensitivity (Se) = 98.5%, positive Likelihood Ratio (LR+) = 3.5. The pc-ASPECTS < 6 points was associated with poor outcome (RR = 2.1, 95% CI 1.2- 3.7). Many predictors from demographic, history, time onset, dysphagia, imaging of MRI 3 Tesla, preprocedure, procedure and postprocedure were demonstrated the influence on poor outcome after RIS significantly (all RR > 1, all p < 0.05). The main limitations of the study was conducted in a single center, these results from clinical symptoms to imaging of MRI 3 Tesla could not only be influenced by selection bias but also not generalize to other countries in Asia. Conclusions The RISIS trial suggests that RIS could be an important alternative and additional treatment afterfailureMT despite low proportion of postprocedural sICH. Trial registration Clinicaltrials.gov, Identifier:NCT04986774.

An Anatomic Study of the Sural Nerve Using 3-Tesla MRI: A Comparison to Cadaveric Data With Surgical Applications

Background: The sural nerve (SN) is a sensory cutaneous nerve that is at risk of iatrogenic injury during surgery at the lateral ankle. Prior anatomic studies of the SN are limited primarily to cadaveric studies with small sample sizes. Our study analyzed a large cohort of magnetic resonance images (MRIs) of the ankle to obtain a more generalizable, in vivo sample of distal SN course. Methods: A total of 204 3-tesla MRI studies of the ankle were analyzed. Three reviewers measured the distance from the SN to various landmarks including the distal tip of the lateral malleolus (DTLM) and the lateral border of the Achilles tendon (LBA). Results: Mean vertical distance from SN to DTLM was 2.2 cm (range, 0.9-3.6 cm). Mean horizontal distance from SN to DTLM and to LBA at the level of DTLM was 1.7 cm (range, 0.8-3.0 cm) and 1.9 cm (range, 1.0-2.9 cm), respectively. Mean horizontal distance from SN to LBA at the level of superior Achilles tendon insertion onto the calcaneus (SAI) was 2.6 cm (range, 1.4-3.7 cm), and mean horizontal distance from SN to LBA at 5 cm above SAI was 0.9 cm (range, 0.4-1.8 cm). Conclusion: The variation in SN course observed in our study allowed us to propose “safe zones” for several surgical approaches including the extensile lateral approach to the calcaneus (ELAC), the sinus tarsi approach (STA), the direct lateral approach to the lateral malleolus (DLA), and the posterolateral approach to the ankle (PLA), which we hope will minimize iatrogenic injury to the SN. Level of Evidence: Level IV, case series.

Analysis of deep grey nuclei susceptibility in early childhood: a quantitative susceptibility mapping and R2* study at 3 Tesla

Purpose Aging is the most significant determinant for brain iron accumulation in the deep grey matter. Data on brain iron evolution during brain maturation in early childhood are limited. The purpose of this study was to investigate age-related iron deposition in the deep grey matter in children using quantitative susceptibility (QSM) and R2* mapping. Methods We evaluated brain MRI scans of 74 children (age 6–154 months, mean 40 months). A multi-echo gradient-echo sequence obtained at 3 Tesla was used for the QSM and R2* calculation. Susceptibility of the pallidum, head of caudate nucleus, and putamen was correlated with age and compared between sexes. Results Susceptibility changes in all three nuclei correlated with age (correlation coefficients for QSM/R2*: globus pallidus 0.955/0.882, caudate nucleus 0.76/0.65, and putamen 0.643/0.611). During the first 2 years, the R2* values increased more rapidly than the QSM values, indicating a combined effect of iron deposition and myelination, followed by a likely dominating effect of iron deposition. There was no significant gender difference. Conclusion QSM and R2* can monitor myelin maturation processes and iron accumulation in the deep grey nuclei of the brain in early life and may be a promising tool for the detection of deviations of this normal process. Susceptibility in the deep nuclei is almost similar early after birth and increases more quickly in the pallidum. The combined use of QSM and R2* analysis is beneficial.