# Application value of isotropic acquisition with simultaneous multi-slice diffusion weighted imaging in subacute early small artery occlusive cerebral infarction

## TL;DR

This study compares different MRI techniques for detecting brain infarctions, finding that SMS+SS-EPI-ISO DWI offers faster scanning with good image quality.

## Contribution

The study evaluates SMS+RESOLVE-ISO DWI and SMS+SS-EPI-ISO DWI for subacute cerebral infarction detection, highlighting their efficiency and image quality.

## Key findings

- SMS+SS-EPI-ISO DWI reduces scanning time while maintaining lesion detection comparable to SS-EPI-ISO DWI.
- SMS+RESOLVE-ISO DWI provides superior image quality with fewer artifacts and distortions.
- Objective metrics like SNR and tSNR differ significantly among the sequences, but CNR and ADC values do not.

## Abstract

To compare the application value of conventional single-shot echo planar imaging (SS-EPI), simultaneous multi-slice single-shot echo planar imaging (SMS + SS-EPI), and simultaneous multi-slice segmented readout isotropic acquisition in diffusion weighted imaging (SMS + RESOLVE-ISO DWI) for subacute early small artery occlusive cerebral infarction.

A retrospective analysis was conducted on 60 patients with subacute early small artery occlusive cerebral infarction, who were treated with SS-EPI-ISO DWI, SMS + SS-EPI-ISO DWI, and SMS + RESOLVE-ISO DWI sequence was used for 1.5 mm isovoxel acquisition. Two radiologists independently assessed the image quality, combining multi-planar reconstruction (MPR), 3-Dimensional fluid attenuated inversion recovery (3D-FLAIR), and apparent diffusion coefficient (ADC) images to evaluate the number of infarct lesions. And subjective and objective evaluations of the image quality were conducted. Objective evaluations include contrast, signal-to-noise ratio (SNR), time SNR (tSNR), contrast-to-noise ratio (CNR) and ADC. Friedman’s test was used to analyze image indicators, Weighted Kappa test was employed to assess the consistency of subjective score, and intraclass correlation coefficient (ICC) was used to analyze the consistency of measurement results.

The scanning times for SS-EPI-ISO DWI, SMS + SS-EPI-ISO DWI, and SMS + RESOLVE-ISO DWI were 3:06, 1:38, and 4:51 min, respectively. The number of infarcted lesions showed that both SS-EPI-ISO DWI and SMS + SS-EPI-ISO DWI detected 129 lesions, while SMS + RESOLVE-ISO DWI detected 123 lesions. Subjective evaluation showed that SMS + RESOLVE-ISO DWI was superior to the other sequences in terms of overall image quality, artifacts, and geometric distortions (p < 0.001). Objective evaluation revealed significant differences in contrast, SNR, and tSNR among the three sequences (p < 0.001), but no significant differences in CNR and ADC values (p > 0.05).

SMS + SS-EPI-ISO DWI achieves image quality comparable to that of SS-EPI-ISO DWI while shortening the scanning time. Although its suppression effect on artifacts and geometric distortion is not as good as that of the SMS + RESOLVE-ISO DWI sequence, the clarity of lesion display is similar to that of the SS-EPI-ISO DWI sequence. Therefore, it is suitable for the diagnosis of subacute early small artery occlusive cerebral infarction.