Advantage in Bright-blood and Black-blood Magnetic Resonance Imaging with High-resolution for Analysis of Carotid Atherosclerotic Plaques / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>About 50% of the cerebral ischemia events are induced by intracranial and extracranial atherosclerosis. This study aimed to evaluate the feasibility and accuracy for displaying atherosclerotic plaques in carotid arteries and analyzing their ingredients by using high-resolution new magnetic resonance imaging (MRI) techniques.</p><p><b>METHODS</b>Totally, 49 patients suspected of extracranial carotid artery stenosis were subjected to cranial MRI scan and magnetic resonance angiography (MRA) examination on carotid arteries, and high-resolution bright-blood and black-blood MRI analysis was carried out within 1 week. Digital subtraction angiography (DSA) examination was carried out for 16 patients within 1 month.</p><p><b>RESULTS</b>Totally, 103 plaques were detected in the 49 patients, which were characterized by localized or diffusive thickening of the vessel wall, with the intrusion of crescent-shaped abnormal signal into lumens. Fibrous cap was displayed as isointensity in T1-weighted image (T1WI) and hyperintensities in proton density weighted image (PDWI) and T2-weighted image (T2WI), lipid core was displayed as isointensity or slight hyperintensities in T1WI, isointensity, hyperintensities or hypointensity in PDWI, and hypointensity in T2WI. Calcification in plaques was detected in 11 patients. Eight patients were detected with irregular plaque surface or ulcerative plaques, which were characterized by irregular intravascular space surface in the black-blood sequences, black hypointensity band was not detected in three-dimensional time-of-flight, or the hypointensity band was not continuous, and intrusion of hyperintensities into plaques can be detected. Bright-blood and black-blood techniques were highly correlated with the diagnosis of contrast-enhanced MRA in angiostenosis degree, Rs = 0.97, P < 0.001. In comparison to DSA, the sensitivity, specificity, and accuracy of MRI diagnosis of stenosis for ≥50% were 88.9%, 100%, and 97.9%, respectively.</p><p><b>CONCLUSIONS</b>High-resolution bright-blood and black-blood sequential MRI analysis can accurately analyze ingredients in atherosclerotic plaques. Determined by DSA, MRI diagnosis of stenosis can correctly evaluate the serious degree of arteriostenosis.</p>

Evaluation of soft tissue lesions affecting the masticator space with dynamic contrast enhanced MRI / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To determine the characteristics and diagnostic value of dynamic contrast enhanced MRI (DCE-MRI) in differentiating benign soft tissue lesions from malignant tumors affecting the masticator space (MS).</p><p><b>METHODS</b>Prior to managements, conventional MRI and DCE-MRI were performed in 53 patients who suffered from primary or secondary soft tissue lesions affecting the MS. The time to peak (TTP), relative maximum enhancement (RME) and relative washout ratio (RWO) were separately calculated.</p><p><b>RESULTS</b>Mean TTP of benign and malignant lesions were (130.3 ± 13.2) and (69.6 ± 6.9) s, respectively. Mean RWO of benign and malignant lesions were (29.7 ± 5.5)% and (8.7 ± 2.1)%, respectively. Malignant lesions had a significantly shorter TTP(P = 0.001) and lower RWO (P = 0.003) than benign lesions. When TTP was less than 92.2 s and RWO less than or equal to 16.0%, malignant tumors were considered. DCE-MRI had a sensitivity of 72.3%, specificity of 93.5%, accuracy of 84.9%, positive predictive value of 88.9%, and negative predictive value of 82.9%.</p><p><b>CONCLUSIONS</b>As a non-invasive imaging technique, DCE-MRI is valuable to differentiate benign soft tissue lesions from malignant tumors affecting the MS.</p>