Identification of Carotid Artery Microstructure and Plaque Rupture Using C-Arm Cone-Beam CT: A Case Report

C-arm cone-beam computed tomography (CBCT) offers a high imaging resolution with a wide range of contrast to visualize vessels, soft tissue, and bone. We report the usefulness of CBCT in observing neovascularization, microcalcification, and plaque rupture. A 56-year-old man presented with vertigo and complain of an unsteady gait for 5 months. Catheter angiography demonstrated right severe carotid stenosis with irregular filling defect, which on high-resolution MRI showed vessel wall enhancement. The CBCT showed high density structures and linear contrast enhancement from the vascular lumen to the plaque, related to microstructure and plaque rupture. Carotid endarterectomy was performed, and histopathology confirmed that the high-density areas represented neovascularization and microcalcification, with linear enhancement representing plaque rupture. This is the first report showing that microcalcifications and plaque rupture can be identified by CBCT. Thus, CBCT can be used as a promising supplement to current imaging modalities to evaluate plaque components more accurately.

Atrial cardiopathy and non-stenotic intracranial complicated atherosclerotic plaque in patients with embolic stroke of undetermined source

ObjectiveTo assess (1) the association between atrial cardiopathy (AC) and non-stenotic intracranial complicated atherosclerotic plaque (NICAP) in patients with embolic stroke of undetermined source (ESUS) or small-vessel disease (SVD), and (2) the performance of previously proposed biomarkers to identify AC as the underlying aetiology in ESUS.MethodsBased on our high-resolution MRI (HR-MRI) cohort, 403 subjects (243 ESUS and 160 SVD) were enrolled in the final analysis. All patients underwent intracranial HR-MRI to assess the presence of ipsilateral NICAP. Biomarkers of AC (ie, P-wave terminal force in lead V1 (PTFV1) on ECG, N-terminal probrain natriuretic peptide (NT-proBNP), high-sensitivity cardiac troponin T and left atrial diameter) were collected within 24 hours after admission.ResultsAmong patients without ipsilateral NICAP, we found an association between the presence of AC (adjusted OR (aOR): 4.76, 95% CI 2.48 to 9.14), increased PTFV1 (aOR: 5.70, 95% CI: 2.43 to 13.39) and NT-proBNP (aOR: 1.65, 95% CI: 1.16 to 2.35) with ESUS. This association was not evident among patients with ipsilateral NICAP. The discrimination between ESUS versus SVD by AC/AC-related biomarkers was significantly improved after excluding ipsilateral NICAP. Similarly, the discrimination between ESUS and SVD by ipsilateral NICAP was notably augmented after excluding AC, PTFV1 and NT-proBNP.InterpretationAC is more prevalent in patients who had ESUS without ipsilateral NICAP compared with patients with, implying that AC and ipsilateral NICAP are two distinct, competing aetiologies of ESUS. Among the AC biomarkers studied in this analysis, PTFV1 seems to be the most informative.

Syrinx reduction due to spontaneous spinal cord tear: demonstration on 3 T MRI and review of the literature

A holocord syringomyelia due to Chiari 1.5 malformation (CM) in a 12-year-old girl was serially imaged with 3 T MRI over 4 years. The serial MRI showed reduction in size of the syrinx, without any surgical intervention or CM improvement, but rather due to spontaneous spinal cord tear. The tear was clearly demonstrated by evidence of flow signal across the tear between syrinx and subarachnoid space at the upper thoracic level. The tear showed spontaneous closure at follow-up. A medullary tear has been described in the adult population as one of the putative causes of spontaneous syringomyelia reduction, but its clear demonstration with modern high-resolution MRI has not been reported in the paediatric population. Moreover, this is the first reported case of syrinx reduction due to spontaneous fissuration in a paediatric patient.

Gadolinium enhancement of cranial nerves: Implications for interstitial fluid drainage from brainstem into cranial nerves in humans

Drainage of interstitial fluid and solutes from the brainstem has not been well studied. To map one drainage pathway in the human brainstem, we took advantage of the focal blood–brain barrier disruption occurring in a multiple sclerosis brainstem lesion, coupled with intravenous injection of gadolinium, which simulates an intraparenchymal injection of gadolinium tracer within the restricted confines of this small brain region. Using high-resolution MRI, we show how it is possible for interstitial fluid to drain into the adjacent trigeminal and oculomotor nerves, in keeping with a pathway of communication between the extracellular spaces of the brainstem and cranial nerve parenchyma.

Noise-residue learning convolutional network model for magnetic resonance image enhancement

Magnetic Resonance Image (MRI) is an important medical image acquisition technique used to acquire high contrast images of human body anatomical structures and soft tissue organs. MRI system does not use any harmful radioactive ionized material like x-rays and computerized tomography (CT) imaging techniques. High-resolution MRI is desirable in many clinical applications such as tumor segmentation, image registration, edges & boundary detection, and image classification. During MRI acquisition, many practical constraints limit the MRI quality by introducing random Gaussian noise and some other artifacts by the thermal energy of the patient body, random scanner voltage fluctuations, body motion artifacts, electronics circuits impulse noise, etc. High-resolution MRI can be acquired by increasing scan time, but considering patient comfort, it is not preferred in practice. Hence, postacquisition image processing techniques are used to filter noise contents and enhance the MRI quality to make it fit for further image analysis tasks. The main motive of MRI enhancement is to reconstruct a high-quality MRI while improving and retaining its important features. The new deep learning image denoising and artifacts removal methods have shown tremendous potential for high-quality image reconstruction from noise degraded MRI while preserving useful image information. This paper presents a noise-residue learning convolution neural network (CNN) model to denoise and enhance the quality of noise-corrupted low-resolution MR images. The proposed technique shows better performance in comparison with other conventional MRI enhancement methods. The reconstructed image quality is evaluated by the peak-signal-to-noise ratio (PSNR) and structural similarity index (SSIM) metrics by optimizing information loss in reconstructed MRI measured in mean squared error (MSE) metric.

Combined high-resolution 3D CUBE T1-weighted imaging and non-contrast-enhanced magnetic resonance venography for evaluation of vein stenosis in May–Thurner syndrome

Purpose To explore the feasibility of high-resolution MRI 3-dimensional (3D) CUBE T1-weighted magnetic resonance imaging (MRI) in combination with non-contrast-enhanced (NCE) magnetic resonance venography (MRV) for the assessment of lumen stenosis in May–Thurner syndrome. Methods Twenty-nine patients underwent computed tomography venography (CTV) and high-resolution MRI-CUBE T1, and NCE MRV acquisitions. ANOVA and LSD tests were used to compare the stenosis rate and narrowest and distal diameters of the vessel lumen. Results There were no significant differences in the estimated stenosis rate between CTV, CUBE T1, and NCE MRV (p = 0.768). However, there were significant differences in the measured stenosis diameters of the left common iliac vein (LCIV), with CTV giving the largest mean diameter and CUBE had the smallest mean diameter (p < 0.05). The measured normal LCIV diameters did not significantly differ between MRV and CUBE (p = 0.075) but were significantly larger on CTV than on MRV and CUBE (p < 0.05). Conclusions Compared with CTV, a combination of CUBE and MRV could provide an improved assessment of the degree of lumen stenosis in May–Thurner syndrome and demonstrate acute thrombosis. MRI underestimates the diameter of the vessel in comparison with CTV. MRI can be a substitute tool for Duplex ultrasound and CTV.