“…10 Computed tomography has low soft tissue resolution, ionizing radiation, and requires an iodine contrast agent, 1,11 which contributes to limited application in parotid gland diseases. Although fine needle aspiration cytology (FNAC) is often used to evaluate parotid tumors, it shows variable sensitivity (47-90%) and specificity (82-100%), [12][13][14] and small lesions or deep lobe lesions often provide insufficient specimen for analysis. 9,15 In addition, the procedure involved with FNAC creates a risk of facial nerve palsy and also has the potential to cause tumor cells spread along the needle path.…”
Section: Introductionmentioning
confidence: 99%
“…7,14,[17][18][19] Besides, the interobserver variation and limited availability of the examinations seem to be potential obstacles to their widespread use. 13,14 T2-weighted imaging, as a conventional sequence, can be used in all field strength equipment. The signal intensity on T2-weighted images is primarily judged by comparing the signal intensity of the lesion with that of normal parotid gland or adjacent muscles, and the observer subjectively evaluates the signal as high, equal, or low.…”
To investigate the value of the signal intensity on T2-weighted magnetic resonance (MR) imaging using quantitative analysis in the differentiation of parotid tumors. Materials and Methods: MR data of 80 pleomorphic adenomas (PAs), 68 Warthin tumors (WTs), and 34 malignant tumors (MTs) confirmed by surgery and histology were retrospectively analyzed. The signal intensities of tumor, normal parotid gland, spinal cord, and buccal subcutaneous fat were measured, and the signal intensity ratios (SIRs) between the tumor and the three references were calculated. Receiver operating characteristic curve was used to determine the optimal threshold and diagnostic efficiency of SIR for differentiating PAs, WTs, and MTs. Results: The area under the curve (AUC) of tumor to parotid gland SIR (SIR P ), tumor to spinal cord SIR (SIR C ), and tumor to buccal subcutaneous fat SIR (SIR F ) for differentiating PAs and WTs was 0.922, 0.918, and 0.934, respectively. The sensitivity and specificity at an optimal SIR threshold were 86.3% and 91.2%, 80.0% and 97.1%, and 85.0% and 94.1%, respectively. The AUC of SIR P , SIR C , and SIR F for distinguishing PAs from MTs was 0.793, 0.802, and 0.774, respectively. The sensitivity and specificity at an optimal SIR threshold was 86.3% and 61.8%, 80.0% and 73.5%, and 82.5% and 73.5%, respectively. The AUC of SIR P , SIR C , and SIR F for distinguishing WTs from MTs was 0.716, 0.709, and 0.759, respectively. The sensitivity and specificity at an optimal SIR threshold were 61.8% and 82.4%, 55.9% and 82.4%, and 64.7% and 86.8%, respectively. Conclusion: SIR P , SIR C , and SIR F on T2-weighted MR images had high diagnostic efficiency for differentiating between PAs and WTs, while SIR P and SIR C for differentiating between PAs and MTs, and SIR F for differentiating between WTs and MTs had relatively high diagnostic efficiency.
“…10 Computed tomography has low soft tissue resolution, ionizing radiation, and requires an iodine contrast agent, 1,11 which contributes to limited application in parotid gland diseases. Although fine needle aspiration cytology (FNAC) is often used to evaluate parotid tumors, it shows variable sensitivity (47-90%) and specificity (82-100%), [12][13][14] and small lesions or deep lobe lesions often provide insufficient specimen for analysis. 9,15 In addition, the procedure involved with FNAC creates a risk of facial nerve palsy and also has the potential to cause tumor cells spread along the needle path.…”
Section: Introductionmentioning
confidence: 99%
“…7,14,[17][18][19] Besides, the interobserver variation and limited availability of the examinations seem to be potential obstacles to their widespread use. 13,14 T2-weighted imaging, as a conventional sequence, can be used in all field strength equipment. The signal intensity on T2-weighted images is primarily judged by comparing the signal intensity of the lesion with that of normal parotid gland or adjacent muscles, and the observer subjectively evaluates the signal as high, equal, or low.…”
To investigate the value of the signal intensity on T2-weighted magnetic resonance (MR) imaging using quantitative analysis in the differentiation of parotid tumors. Materials and Methods: MR data of 80 pleomorphic adenomas (PAs), 68 Warthin tumors (WTs), and 34 malignant tumors (MTs) confirmed by surgery and histology were retrospectively analyzed. The signal intensities of tumor, normal parotid gland, spinal cord, and buccal subcutaneous fat were measured, and the signal intensity ratios (SIRs) between the tumor and the three references were calculated. Receiver operating characteristic curve was used to determine the optimal threshold and diagnostic efficiency of SIR for differentiating PAs, WTs, and MTs. Results: The area under the curve (AUC) of tumor to parotid gland SIR (SIR P ), tumor to spinal cord SIR (SIR C ), and tumor to buccal subcutaneous fat SIR (SIR F ) for differentiating PAs and WTs was 0.922, 0.918, and 0.934, respectively. The sensitivity and specificity at an optimal SIR threshold were 86.3% and 91.2%, 80.0% and 97.1%, and 85.0% and 94.1%, respectively. The AUC of SIR P , SIR C , and SIR F for distinguishing PAs from MTs was 0.793, 0.802, and 0.774, respectively. The sensitivity and specificity at an optimal SIR threshold was 86.3% and 61.8%, 80.0% and 73.5%, and 82.5% and 73.5%, respectively. The AUC of SIR P , SIR C , and SIR F for distinguishing WTs from MTs was 0.716, 0.709, and 0.759, respectively. The sensitivity and specificity at an optimal SIR threshold were 61.8% and 82.4%, 55.9% and 82.4%, and 64.7% and 86.8%, respectively. Conclusion: SIR P , SIR C , and SIR F on T2-weighted MR images had high diagnostic efficiency for differentiating between PAs and WTs, while SIR P and SIR C for differentiating between PAs and MTs, and SIR F for differentiating between WTs and MTs had relatively high diagnostic efficiency.
“…Isointense SI on T1W, mildly hyperintense SI on T2W, and moderate enhancement on CE-T1W images are generally described on MRI [ 86 , 93 ]. Lymphoma shows a restriction of diffusivity with very low ADC values (typical values suggestive of lymphoma: ≤ 0.60 × 10 –3 mm 2 /s) [ 85 , 86 , 94 ]. Fig.…”
The sphenoid bone is an unpaired bone that contributes to the formation of the skull base. Despite the enormous progress in transnasal endoscopic visualisation, imaging techniques remain the cornerstones to characterise any pathological condition arising in this area. In the present review, we offer a bird’s-eye view of the developmental, inflammatory, and neoplastic alterations affecting the sphenoid body and clivus, with the aim to propose a practical diagnostic aid for radiologists based on clinico-epidemiological, computed tomography, and magnetic resonance imaging features.
“…Because of the high-contrast resolution and the ability to study complex anatomical regions without the use of radiation, magnetic resonance imaging (MRI) is considered the most relevant imaging technique for the identification of head and neck lesions [16][17][18][19]. Diffusion-weighted imaging (DWI) is an established diagnostic tool that evaluates the tissue microanatomy by studying the spontaneous molecular diffusion of protons corresponding to the stochastic Brownian motion of water molecules [16,20,21].…”
The aim of this single-center, observational, retrospective study was to investigate magnetic resonance imaging (MRI) biomarkers for the assessment of radiotherapy (RT)-induced xerostomia. Twenty-seven patients who underwent radiation therapy for oropharyngeal cancer were divided into three groups according to the severity of their xerostomia—mild, moderate, and severe—clinically confirmed with the Common Terminology Criteria for Adverse Events (CTCAE). No severe xerostomia was found. Conventional and functional MRI (perfusion- and diffusion- weighted imaging) performed both pre- and post-RT were studied for signal intensity, mean apparent diffusion coefficient (ADC) values, k-trans, and area under the perfusion curves. Contrast-enhanced T1 images and ADC maps were imported into 3D slicer software, and salivary gland volumes were segmented. A total of 107 texture features were derived. T-Student and Wilcoxon signed-rank tests were performed on functional MRI parameters and texture analysis features to identify the differences between pre- and post-RT populations. A p-value < 0.01 was defined as acceptable. Receiver operating characteristic (ROC) curves were plotted for significant parameters to discriminate the severity of xerostomia in the pre-RT population. Conventional and functional MRI did not yield statistically significant results; on the contrary, five texture features showed significant variation between pre- and post-RT on the ADC maps, of which only informational measure of correlation 1 (IMC 1) was able to discriminate the severity of RT-induced xerostomia in the pre-RT population (area under the curve (AUC) > 0.7). Values lower than the cut-off of −1.473 × 10−11 were associated with moderate xerostomia, enabling the differentiation of mild xerostomia from moderate xerostomia with a 73% sensitivity, 75% specificity, and 75% diagnostic accuracy. Therefore, the texture feature IMC 1 on the ADC maps allowed the distinction between different degrees of severity of RT-induced xerostomia in the pre-RT population. Accordingly, texture analysis on ADC maps should be considered a useful tool to evaluate salivary gland radiosensitivity and help identify patients at risk of developing more serious xerostomia before radiation therapy is administered.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
