Three Dimensional Ultra-short Echo Time MRI Can Depict Cholesterol Components of Gallstones Bright

Abstract

Purpose Non-calcified cholesterol stones that are small in size are hard to be depicted on CT or magnetic resonance cholangiopancreatography. This institutional review board (IRB)-approved retrospective in vitro study aims to characterize contrast behaviors of 3 main components of the gallstones, i.e., cholesterol component (CC), bilirubin calcium component (BC) and CaCO 3 (CO) on 3D radial scan with ultrashort TE (UTE) MRI, and to test the capability of depicting CC of gallstones as bright signals as compared to background saline. Methods Fourteen representative gallstones from 14 patients, including 15 CC, 6 BC and 4 CO, were enrolled. The gallstones underwent MRI including fat-saturated T1-weighted image (fs-T1WI) and UTE MRI with dual echoes. The contrast-to-noise ratio (CNR) and the chemical analysis for the 25 portions of the stones were compared. Results BC was bright on fs-T1WI, which did not change dramatically on UTE MRI and the signal did not remain on UTE subtraction image between dual echoes. Whereas the CC was negative or faintly positive signal on fs-T1WI, bright signal on UTE MRI and the contrast remained even higher on the UTE subtraction, which reflected their short T2 values. Median CNRs and standard errors of the segments on each imaging were as follows: on fs-T1WI, −10.2 ± 4.2 for CC, 149.7 ± 27.6 for BC and 37.9 ± 14.3 for CO; on UTE MRI first echo, 16.7 ± 3.3 for CC, 74.9 ± 21.3 for BC and 17.7 ± 8.4 for CO; on UTE subtraction image, 30.2 ±2.0 for CC, −11.2 ± 5.4 for BC and 17.8 ± 10.7 for CO. Linear correlations between CNRs and cholesterol concentrations were observed on fs-T1WI with r = −0.885, ( P < 0.0001), UTE MRI first echo r = −0.524 ( P = 0.0072) and UTE subtraction with r = 0.598 ( P = 0.0016). Conclusion UTE MRI and UTE subtraction can depict CC bright.

Automatic Classification of Magnetic Resonance Histology of Peripheral Arterial Chronic Total Occlusions Using a Variational Autoencoder: A Feasibility Study

“…Diagnostics 2023, 13, 1925 2 of 11 Poor calcium sensitivity of MRI has been a major barrier to the clinical adoption of the technique for chronic total occlusion (CTO) applications. Recent advances in ultrashort echo time (UTE) MRI have been used to separate calcium from other tissues which contain protons but possess a short T2* [5][6][7][8][9][10]. In particular for peripheral atherosclerotic lesions, UTE was shown to distinguish between soft tissue types (including fat, thrombus, microchannels, or loose fibrous tissue) as hyperintense and hard tissue types (dense collagen and/or speckled calcium signals and calcified nodules) as isointense and calcium as hypointense to relative to smooth muscle tissue signal [11].…”

Low-level blast exposure induces chronic vascular remodeling, perivascular astrocytic degeneration and vascular-associated neuroinflammation

“…The neurovascular unit also encompasses the glymphatic and intramural periarterial drainage systems. The glymphatic CSF waste clearance system utilizes perivascular channels, formed by astroglial cells, to promote elimination of soluble proteins and metabolites from the CNS [ 14 , 61 , 91 ]. In this sytem, CSF enters interstitial spaces after aquaporin 4 (AQP4)-dependent transport through the astroglial cytoplasm, drains into perivenous routes in a direction parallel to the blood flow, and then enters the subarachnoid CSF or bloodstream across cerebral vessels [ 142 ].…”