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Purpose: We aimed to assess the contrast enhancement patterns of the retrodiscal tissue with dynamic contrast-enhanced MR imaging (DCE-MRI) with respect to different temporomandibular joint disc pathologies. Additionally, we questioned the relationship between the temporomandibular joint (TMJ) pain and the contrast enhancement pattern of the retrodiscal tissue regardless of the TMJ disc position., Materials and Methods: 52 joints of 26 patients (4 males and 22 females) who have pain in at least at one of their TMJ were included in this study. For the qualitative analysis, the joints were divided into four groups in terms of their disc positions: normal (1), partially displaced with or without reduction (2), totally dislocated with reduction (3) and totally dislocated without reduction (4). Besides, two different joint groups were constituted, namely the painful group and painless group according to the clinical findings without taking the TMJ disc positions into account. Quantitative analyses were made by means of measuring signal intensity ratios (SI) ratio at the retrodiscal tissue (from internal side and external side of the each joint) using DCE-MRI and these measurements were analyzed with paired samples t test to define the difference between the measurements. At the second stage, the time-dependent arithmetical mean values of the SI ratios were calculated for each joint group and significant differences between the groups were questioned using analysis of variance (ANOVA) test. Besides, painful and painless groups which were classified on the basis of the clinical data were compared according to the mean SI ratios found for each joint and the significant differences between these two groups were assessed by means of Student's T test. The results were assessed in 95% confidence interval where the significance level was p<0.05., Results: A significant difference was observed between the internal and external contrast enhancement of the joints with partial displacement. Another significant difference was found between the average time versus SI ratio curves of the four groups. In consequence of the comparison made between the joints classified as painful and painless on the basis of the clinical data, one more significant difference was observed according to the mean SI ratios of the groups without taking the TMJ disc position into account., Conclusion: The contrast enhancement patterns in the retrodiscal tissues of the painful joints showed significant differences in comparison with the painless joints. This result supports the hypothesis defending that inflammation and increased vascularity are responsible from the TMJ pain. Besides, the measurements from the retrodiscal tissues of the joints with partial displacement show significant difference between the signals of the displaced and non-displaced parts of the joints. Dynamic contrast-enhanced imaging revealed that different disc malpositions create different contrast enhancement patterns. On this basis, it is assessed that the types of the disc malpositions, which are believed to be acquired pathologies, are correlated with the retrodiscal inflammation degrees., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Objective: The purpose of this study was to investigate the diagnostic value of dynamic MRI dacryocystography (dMR-DCG) for the assessment of nasolacrimal drainage system (NLDS)., Methods: The study population consisted of 35 patients with a history of epiphora. Each patient underwent bilateral dMR-DCG and conventional dacryocystography (DCG) to assess the NLDS. Two radiologists, who were unaware of the clinical data, evaluated the images separately for the level of obstruction at the nasolacrimal passage and the presence or absence of lacrimal sac dilatation. The findings from the dMRI-DCG and DCG images were compared. DCG was considered to be the gold standard imaging technique., Results: dMRI-DCG had a sensitivity of 90.5% and a specificity of 89.3% to detect nasolacrimal passage. In 24 out of 70 NLDS that were assessed, there was 100% agreement between the dMRI-DCG and DCG images in the detection of the obstructed level in the nasolacrimal pathway. The lacrimal sac dilatation finding detected by DCG was not observed by dMRI-DCG in only two patients, in whom there was a prior history of dacryocystorhinostomy (DCR) operation. These findings suggest that dMRI-DCG has 94.3% sensitivity and 100% specificity for the diagnosis of lacrimal sac dilatation., Conclusion: dMRI-DCG is an easily performed, minimally invasive imaging technique to identify the presence or absence of obstruction and its level, and lacrimal sac dilatation in the evaluation of NLDS. dMRI-DCG does not require the use of contrast material and ionizing radiation and provides functional information by depicting dynamic behaviour. Thus, dMRI-DCG could be useful as a reliable diagnostic imaging technique in many patients prior to surgery., (Copyright (c) 2008 Elsevier Ireland Ltd. All rights reserved.)