Gadolinium-enhanced MR imaging of temporomandibular disorders: improved lesion detection of the posterior disk attachment on T1-weighted images obtained with fat suppression.

Abstract

OBJECTIVE. The purposeof this studywas to assessthe potentialfor improvedlesion detection in the posterior disk attachment and its surrounding tissue in temporomandibular disorderswhengadolinium-enhanced MR imagingperformedwith fat suppression is used. MATERIALSAND METHODS. Forty-five patients underwent MR imaging withconventional Ti-and T2-weighted, gadolinium-enhanced Ti-weighted, and gadolinium-enhanced fat suppressed spin-echo imaging sequences. Qualitative and quantitative assessments of the contrast enhancement of eachtypeof imagingwerealsoperformed.RESULTS. The contrast-enhanced fat-suppressed Ti-weightedimagingsequence had severaladvantages over theotherimagingtechniquesin detectingabnormalitiesof the poste rior disk attachment and in detecting bone marrow lesions in the mandibular condyle. The most significant advantage was better enhancement of lesion conspicuity. The diagnostic ac curacy of contrast-enhanced fat-suppressed imaging was 77% versus70% for conventional contrast-enhanced imaging. The kappa value for interobserver agreement was .95 for contrast enhancedfat-suppressed imagingand.72 for conventional contrast-enhanced imaging. CONCLUSION. Contrast-enhanced fat-suppressed Tl-weightedspin-echo MR imagingis a valuable technique for visualizing the extent and degree of lesions in the posterior disk at tachment and bone marrow lesions in the mandibular condyle. M R imagingis becomingevermoreeffective in characterizing internal derangement and arthrosis of the temporomandibular joint [1â€"51.Prominent contrast enhancement of the posteriordiskat tachmenton spoiled gradient-echoMR images is useful for differentiating intraarticular from extraarticular causes of pain in and around the temporomandibularjoint [6]. roundingfattytissue. To our knowledge,thecombineduseof fat suppression and gadoliniumenhancement in the imaging of the temporomandibular joint has not been reported in the literature. The purpose of our study was to optimize con trast-enhanced fat-suppressed MR imagingof the temporomandibular joint and to deter mine whether this technique improves the contrast enhancement of images obtained in patients with temporomandibular disorders. Materialsand Methods PhantomStudiesSix stationaiy phantom studies were conducted us ing plastic vials appmximately 1 inch (2.54 cm) in di ameterand 5 inches(12.7 cm)in lengththatcontained gadopentetate dimeglumine in plasmain concentra tionsof 0-2.5 mmol/l.Weexamined therelationship betweenthe concentrationof gadopentetatedimeglu minein plasma andthesignal intensitywhenimages were obtained using spoiled gradient-echoand Ti weighted spin-echo sequences.Parameters for the spoiled gradient-echo MR im agingof thephantoms included TRITE= 35/8,flipangle of 600 20-cm field of view, and two excita tions.Imagematrixwas256x 192pixels.Thesec tion thicknesswas 10mm.Ti-weightedspin-echo MRimagingwasperformed usingTRIFE= 300/12,

Evaluation of the relationships between contrast-enhanced magnetic resonance characteristics and joint pain in patients with temporomandibular disorders

“…In the present study, we used a fat-suppressed T1-weighted FSE sequence to obtain the contrast enhancement of the posterior disk attachment. Our previous study indicated that the effectiveness of contrast enhancement with a T1-weighted FSE sequence was superior to that with a spoiled gradient-echo sequence [57]. In the synovial membrane tissue of the posterior disk attachment region and the TMJ capsule, more highly innervated and inflamed tissues are sources and causes of greater pain [58].…”

“…T2-weighted fat-suppressed MR imaging was used to evaluate the T2-weighted SI of the posterior disk attachment, because the area is abundant in fatty tissue [8]. In an earlier study, we demonstrated that the effectiveness of contrast enhancement is often limited by fat tissue for components such as the posterior disk attachment and mandibular condyle [57]. The presence of fat tissue is greatly problematic for evaluating the correlation between the severity of pain symptoms and the degree of contrast enhancement of the posterior disk attachment.…”

“…In this report, it has been demonstrated that the rapid enhancement pattern and higher degree of contrast enhancement, suggestive of an abundant vascular supply, in painful TMJs may indicate inflammatory diseases caused by mechanical stress on the posterior disk attachment [25,57]. Pain-free joints are characterized by low contrast enhancement and decreased vascularization, which may arise through fibrosis during the degenerative changes in the TMJ region [59].…”

The usefulness of diagnostic imaging for the assessment of pain symptoms in temporomandibular disorders

“…Fatty tissue within the posterior disk attachment and lateral pterygoid muscle has high signal intensity on T1-weighted MR images and occasionally obscures anatomic structures in the TMJ region by means of chemical artifact [50]. Therefore, dynamic fat-suppressed MR imaging with contrast material appears to be highly sensitive for the diagnosis of posterior disk attachment abnormalities.…”

Utility of frequency-selective fat saturation T2-weighted MR images for the detection of joint effusion in the temporomandibular joint.

“…Therefore, FS T1-weighted images may be used to distinguish between periarticular fatty tissue and synovial tissue. 15,16 It has also been reported that FS T1-weighted images are highly eective for the evaluation of bone marrow lesions, including those of the mandible. 10,15,17 The aims of this study are to (1) compare FS T2-weighted imaging versus conventional sequences for the detection of joint eusion in the TMJ and (2) to determine if an association exists between TMJ eusion (FS T2-weighted images) and bone marrow abnormalities and disk displacements.…”