Retrospective Study
Copyright ©The Author(s) 2023. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Radiol. Jan 28, 2023; 15(1): 20-31
Published online Jan 28, 2023. doi: 10.4329/wjr.v15.i1.20
Diagnostic efficacy of diffusion-weighted imaging and semiquantitative and quantitative dynamic contrast-enhanced magnetic resonance imaging in salivary gland tumors
Erkan Gökçe, Murat Beyhan
Erkan Gökçe, Murat Beyhan, Department of Radiology, Tokat Gaziosmanpasa University, Faculty of Medicine, Tokat 60100, Turkey
Author contributions: Gökçe E designed the study; Beyhan M supervised the study; Gökçe E and Beyhan M participated in literature research and manuscript preparation, and read and approved the final version.
Institutional review board statement: This study was reviewed and approved by the Ethics Committee of the Tokat Gaziosmanpasa University Faculty of Medicine (20-KAEK-105).
Informed consent statement: Patients were not required to give informed consent for the study as figures from picture archiving and communication systems were studied retrospectively.
Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Erkan Gökçe, MD, Professor, Department of Radiology, Tokat Gaziosmanpasa University, Faculty of Medicine, Kaleardı Neighborhood, Muhittin Fisunoglu Street, Tokat 60100, Turkey. drerkangokce@gmail.com
Received: July 5, 2022
Peer-review started: July 5, 2022
First decision: September 5, 2022
Revised: September 15, 2022
Accepted: December 13, 2022
Article in press: December 13, 2022
Published online: January 28, 2023
ARTICLE HIGHLIGHTS
Research background

Conventional magnetic resonance imaging (MRI) provides more data than other radiological modalities in determining the extent of tumor spread in salivary gland tumors (SGTs) and assessing its relationship to vascular and neural structures, but falls short of distinguishing subtypes of SGTs. As the malignant or benign nature of SGTs affects the treatment protocol, it is important to differentiate between malignant (MTs) and benign tumors (BTs) noninvasively with high diagnostic accuracy.

Research motivation

In recent years, advanced MRI techniques such as diffusion-weighted imaging (DWI) and semi-quantitative MRI have been increasingly used in the radiological evaluation of SGTs. However, various studies on quantitative dynamic contrast-enhanced (DCE) perfusion MRI parameters (Ktrans, Kep, and Ve) in SGTs are limited. Therefore, in this study, the effectiveness of advanced MRI applications, including all three methods, in the diagnosis of SGTs was evaluated in light of the literature.

Research objectives

To determine the diagnostic efficiency of DWI and DCE (semiquantitative perfusion) MRI and quantitative perfusion MRI parameters in SGTs.

Research methods

Apparent diffusion coefficient (ADC) values of SGTs on DWI were measured with manually inserted regions of interest, excluding the cystic components of the tumors. Time intensity curve (TIC) patterns were created for semiquantitative perfusion MRI based on Tpeak and washout ratios (WRs) of tumors. On quantitative DCE MRI, perfusion parameters such as Ktrans [volume transfer constant between blood plasma and extracellular extravascular space (EES)], Kep (flux rate constant between the EES and plasma), and Ve (EES fractional volume) were used.

Research results

The ADC values of pleomorphic adenomas (PMAs) were significantly higher than those of Warthin's tumors (WTs), other benign tumors (OBTs), and MTs (P < 0.001). However, there was no significant difference in ADC values for OBTs, WTs, and MTs. PMAs had type A and WTs had type B TIC pattern while the vast majority of MTs and OBTs (54.5% and 45.5%, respectively) displayed type C TIC pattern. PMAs showed no washout, while the highest mean WR was observed in WTs. For quantitative perfusion MRI parameters, the Kep value of WTs was significantly higher than those of other tumors (P < 0.001). For the Ve value, WTs and OBTs differed significantly from PMAs and MTs (P < 0.001). Ktrans values of PMAs, WTs, OBTs, and MTs were not significantly different.

Research conclusions

DWI and semiquantitative and quantitative perfusion MRI, which provide more information on the microstructure, cellularity, interstitial distance, and vascularity of tumors, have increased the discrimination power for subtypes of SGTs.

Research perspectives

Although there is some overlap in the findings of the subtypes of SGTs obtained by advanced MRI methods, the combined use of DWI and semiquantitative and quantitative perfusion MRI will increase the power for distinguishing subtypes of SGTs.