Seung Chai Jung

Vessel Wall Imaging of the Intracranial and Cervical Carotid Arteries

Vessel wall imaging can depict the morphologies of atherosclerotic plaques, arterial walls, and surrounding structures in the intracranial and cervical carotid arteries beyond the simple luminal changes that can be observed with traditional luminal evaluation. Differentiating vulnerable from stable plaques and characterizing atherosclerotic plaques are vital parts of the early diagnosis, prevention, and treatment of stroke and the neurological adverse effects of atherosclerosis. Various techniques for vessel wall imaging have been developed and introduced to differentiate and analyze atherosclerotic plaques in the cervical carotid artery. High-resolution magnetic resonance imaging (HR-MRI) is the most important and popular vessel wall imaging technique for directly evaluating the vascular wall and intracranial artery disease. Intracranial artery atherosclerosis, dissection, moyamoya disease, vasculitis, and reversible cerebral vasoconstriction syndrome can also be diagnosed and differentiated by using HR-MRI. Here, we review the radiologic features of intracranial artery disease and cervical carotid artery atherosclerosis on HR-MRI and various other vessel wall imaging techniques (e.g., ultrasound, computed tomography, magnetic resonance, and positron emission tomography-computed tomography).

Metabolomic analysis of percutaneous fine-needle aspiration specimens of thyroid nodules: Potential application for the preoperative diagnosis of thyroid cancer.

Thyroid nodules are a very common problem. Since malignant thyroid nodules should be treated surgically, preoperative diagnosis of thyroid cancer is very crucial. Cytopathologic analysis of percutaneous fine-needle aspiration (FNA) specimens is the current gold standard for diagnosing thyroid nodules. However, this method has led to high rates of inconclusive results. Metabolomics has emerged as a useful tool in medical fields and shown great potential in diagnosing various cancers. Here, we evaluated the potential of nuclear magnetic resonance (NMR) analysis of percutaneous FNA specimens for preoperative diagnosis of thyroid cancer. We analyzed metabolome of FNA samples of papillary thyroid carcinoma (n = 35) and benign follicular nodule (n = 69) using a proton NMR spectrometer. The metabolomic profiles showed a considerable discrimination between benign and malignant nodules. Receiver operating characteristic (ROC) curve analysis indicated that seven metabolites could serve as discriminators (area under ROC curve value, 0.64–0.85). These findings demonstrated that NMR analysis of percutaneous FNA specimens of thyroid nodules can be potentially useful in the accurate and rapid preoperative diagnosis of thyroid cancer.

Endovascular Treatment of Intracranial Aneurysms in Patients With Autosomal Dominant Polycystic Kidney Disease.

BACKGROUND Little is known about the outcome of endovascular treatment for intracranial aneurysms in patients with autosomal dominant polycystic kidney disease (ADPKD). OBJECTIVE To present clinical outcomes in terms of safety, effectiveness, and renal functions to assess contrast-induced nephropathy in endovascular coil embolization for intracranial aneurysms in ADPKD patients. METHODS Nineteen ADPKD patients (female:male, 15:4; mean age, 49.8 years; range, 20-67 years) had 26 aneurysms (mean size, 5.86 mm; range, 2.5-11.6 mm) and underwent 22 endovascular treatment sessions from 2001 to 2013. Four patients presented with ruptured aneurysms. Periprocedural complications, clinical outcomes with modified Rankin Scale scores, laboratory findings, and chronic kidney disease (CKD) stage before and after treatment were documented. Acute renal impairment was defined as serum creatinine (Cr) elevation by ≥ 0.5 mg/dL or 25% relative to baseline. RESULTS Symptomatic periprocedural complications developed after 1 endovascular procedure (1 of 22, 4.5%), and good clinical outcomes (modified Rankin Scale scores, 0-1) were achieved in 90% of patients (17 of 19). Overall, acute renal impairment occurred in 9.1% of treatment sessions (2 of 22). Acute renal impairment developed in 25% of high-risk patients (baseline Cr > 2.0 mg/dL) and 33.3% of baseline CKD stage 5 sessions but in none of the low-risk patients (baseline Cr ≤ 2.0 mg/dL) and in no CKD stage 1 to 4 sessions. CONCLUSION With appropriate management, coil embolization may be safe and effective for intracranial aneurysms in ADPKD. There is a concern about contrast-induced nephropathy in patients with CKD stage 5 or high serum Cr level (>2.0 mg/dL).

Simultaneous Endovascular Treatment of Ruptured Cerebral Aneurysms and Vasospasm

Objective The management of patients with ruptured cerebral aneurysms and severe vasospasm is subject to considerable controversy. We intended to describe herein an endovascular technique for the simultaneous treatment of aneurysms and vasospasm. Materials and Methods A series of 11 patients undergoing simultaneous endovascular treatment of ruptured aneurysms and vasospasm were reviewed. After placement of a guiding catheter within the proximal internal carotid artery for coil embolization, an infusion line of nimodipine was wired to one hub, and of a microcatheter was advanced through another hub (to select and deliver detachable coils). Nimodipine was then infused continuously during the coil embolization. Results This technique was applied to 11 ruptured aneurysms accompanied by vasospasm (anterior communicating artery, 6 patients; internal carotid artery, 2 patients; posterior communicating and middle cerebral arteries, 1 patient each). Aneurysmal occlusion by coils and nimodipine-induced angioplasty were simultaneously achieved, resulting in excellent outcomes for all patients, and there were no procedure-related complications. Eight patients required repeated nimodipine infusions. Conclusion Our small series of patients suggests that the simultaneous endovascular management of ruptured cerebral aneurysms and vasospasm is a viable approach in patients presenting with subarachnoid hemorrhage and severe vasospasm.

Improved Diagnostic Accuracy of Alzheimer’s Disease by Combining Regional Cortical Thickness and Default Mode Network Functional Connectivity: Validated in the Alzheimer’s Disease Neuroimaging Initiative Set

Objective To identify potential imaging biomarkers of Alzheimers disease by combining brain cortical thickness (CThk) and functional connectivity and to validate this models diagnostic accuracy in a validation set. Materials and Methods Data from 98 subjects was retrospectively reviewed, including a study set (n = 63) and a validation set from the Alzheimers Disease Neuroimaging Initiative (n = 35). From each subject, data for CThk and functional connectivity of the default mode network was extracted from structural T1-weighted and resting-state functional magnetic resonance imaging. Cortical regions with significant differences between patients and healthy controls in the correlation of CThk and functional connectivity were identified in the study set. The diagnostic accuracy of functional connectivity measures combined with CThk in the identified regions was evaluated against that in the medial temporal lobes using the validation set and application of a support vector machine. Results Group-wise differences in the correlation of CThk and default mode network functional connectivity were identified in the superior temporal (p < 0.001) and supramarginal gyrus (p = 0.007) of the left cerebral hemisphere. Default mode network functional connectivity combined with the CThk of those two regions were more accurate than that combined with the CThk of both medial temporal lobes (91.7% vs. 75%). Conclusion Combining functional information with CThk of the superior temporal and supramarginal gyri in the left cerebral hemisphere improves diagnostic accuracy, making it a potential imaging biomarker for Alzheimers disease.

Multidisciplinary Approach to Decrease In-Hospital Delay for Stroke Thrombolysis

Background and Purpose Decreasing the time delay for thrombolysis, including intravenous thrombolysis (IVT) with tissue plasminogen activator and intra-arterial thrombectomy (IAT), is critical for decreasing the morbidity and mortality of patients experiencing acute stroke. We aimed to decrease the in-hospital delay for both IVT and IAT through a multidisciplinary approach that is feasible 24 h/day. Methods We implemented the Stroke Alert Team (SAT) on May 2, 2016, which introduced hospital-initiated ambulance prenotification and reorganized in-hospital processes. We compared the patient characteristics, time for each step of the evaluation and thrombolysis, thrombolysis rate, and post-thrombolysis intracranial hemorrhage from January 2014 to August 2016. Results A total of 245 patients received thrombolysis (198 before SAT; 47 after SAT). The median door-to-CT, door-to-MRI, and door-to-laboratory times decreased to 13 min, 37.5 min, and 8 min, respectively, after SAT implementation (P<0.001). The median door-to-IVT time decreased from 46 min (interquartile range [IQR] 36–57 min) to 20.5 min (IQR 15.8–32.5 min; P<0.001). The median door-to-IAT time decreased from 156 min (IQR 124.5–212.5 min) to 86.5 min (IQR 67.5–102.3 min; P<0.001). The thrombolysis rate increased from 9.8% (198/2,012) to 15.8% (47/297; P=0.002), and the post-thrombolysis radiological intracranial hemorrhage rate decreased from 12.6% (25/198) to 2.1% (1/47; P=0.035). Conclusions SAT significantly decreased the in-hospital delay for thrombolysis, increased thrombolysis rate, and decreased post-thrombolysis intracranial hemorrhage. Time benefits of SAT were observed for both IVT and IAT and during office hours and after-hours.

Quantitative Analysis Using High‐Resolution 3T MRI in Acute Intracranial Artery Dissection

Quantitative measurements, as well as qualitative characterizations, of the vessel walls of the small intracranial arteries became clinically available and reliable beyond the resolution limit of 1.5 T high‐resolution magnetic resonance imaging (HR‐MRI) with the development of 3 T HR‐MRI. We present the quantitative dissection findings of spontaneous and unruptured acute intracranial artery dissection (SID) using 3 T HR‐MRI and investigate the differences between each cerebral artery.

Anomalous External Carotid Artery-Internal Carotid Artery Anastomosis in Two Patients with Proximal Internal Carotid Arterial Remnants

Two angiographic instances of anomalous external carotid artery (ECA) and internal carotid artery (ICA) anastomosis are described, each occurring at the C2-3 level and bearing remnants of proximal ICA. The ICA remnant of one patient (identifiable immediately upon bifurcation of the common carotid artery) was hypoplastic, and that of the other patient was an occluded arterial stump. These features are not typical of non-bifurcating ICA. The occipital artery originated from an anomalous connection in one instance and from the main trunk of the ECA (just past the ECA-ICA connection) in the other.

Imaging prediction of isocitrate dehydrogenase (IDH) mutation in patients with glioma: a systemic review and meta-analysis

ObjectivesTo evaluate the imaging features of isocitrate dehydrogenase (IDH) mutant glioma and to assess the diagnostic performance of magnetic resonance imaging (MRI) for prediction of IDH mutation in patients with glioma.MethodsA systematic search of Ovid-MEDLINE and EMBASE up to 10 October 2017 was conducted to find relevant studies. The search terms combined synonyms for ‘glioma’, ‘IDH mutation’ and ‘MRI’. Studies evaluating the imaging features of IDH mutant glioma and the diagnostic performance of MRI for prediction of IDH mutation in patients with glioma were selected. The pooled summary estimates of sensitivity and specificity and their 95% confidence intervals (CIs) were calculated using a bivariate random-effects model. The results of multiple subgroup analyses are reported.ResultsTwenty-eight original articles in a total of 2,146 patients with glioma were included. IDH mutant glioma showed frontal lobe predominance, less contrast enhancement, well-defined border, high apparent diffusion coefficient (ADC) value and low relative cerebral blood volume (rCBV) value. For the meta-analysis that included 18 original articles, the summary sensitivity was 86% (95% CI, 79%–91%) and the summary specificity was 87% (95% CI, 78–92%). In a subgroup analysis, the summary sensitivity of 2-hydroxyglutarate magnetic resonance spectroscopy (MRS) [96% (95% CI, 91–100%)] was higher than the summary sensitivities of other imaging modalities.ConclusionsIDH mutant glioma consistently demonstrated less aggressive imaging features than IDH wild-type glioma. Despite the variety of different MRI techniques used, MRI showed the potential to non-invasively predict IDH mutation in patients with glioma. 2-Hydroxyglutarate MRS shows higher pooled sensitivity than other imaging modalities.Key Points• IDH mutant glioma showed frontal lobe predominance, less contrast enhancement, well-defined border, high ADC value, and low rCBV value.• The diagnostic performance of MRI for prediction of IDH mutation in patients with glioma is within a clinically acceptable range, the summary sensitivity was 86% (95% CI, 79–91%) and the summary specificity was 87% (95% CI, 78–92%).• In a subgroup analysis, the summary sensitivity of 2-hydroxyglutarate MRS [96% (95% CI, 91–100%)] was higher than the summary sensitivities of other imaging modalities.

Amide proton transfer imaging seems to provide higher diagnostic performance in post-treatment high-grade gliomas than methionine positron emission tomography

ObjectivesTo compare the diagnostic performance of amide proton transfer (APT) imaging and 11-C methionine positron emission tomography (MET-PET) for in vivo molecular imaging of protein metabolism in post-treatment gliomas.Materials and methodsThis study included 43 patients (12 low and 31 high grade) with post-treatment gliomas who underwent both APT and MET-PET imaging within 3 weeks. APT-weighted voxel values and semi-quantitative tumour-to-normal ratios (TNR) were obtained from tumour portions. The voxel-wise relationships between TNR and APT were assessed. The diagnostic performance for recurrence of high-grade gliomas was calculated, using the area under the receiver operating characteristic curve (AUC) with maximum (TNRmax and APTmax) and 90% histogram values (TNR90 and APT90).ResultsA moderate positive correlation between TNR and APT was found in low-grade recurrences (r = 0.47, p < 0.001), but not in high-grade ones (r = −0.24, p < 0.001). For distinguishing recurrence in post-treatment high-grade gliomas, APTmax (AUC, 0.88) and APT90 (AUC, 0.78–0.83) had a similar to better diagnostic performance than TNRmax (AUC, 0.71, p = 0.08) or TNR90 (AUC, 0.53–0.59, p = 0.01–0.05).ConclusionsIn post-treatment high-grade gliomas, APT provides different regional information to MET-PET and provides higher diagnostic performance. This difference needs to be considered when using APT or MET-PET as a surrogate marker for tumour protein metabolism.Key Points• APT and TNR values in low-grade recurrence showed a moderate voxel-wise correlation.• APT and TNR demonstrated regional differences in post-treatment high-grade gliomas.• APT90 showed better diagnostic performance than TNR90 in high-grade recurrence.