Assessment of squamous cell carcinoma of the floor of the mouth with magnetic resonance imaging.

PURPOSE: We aimed to use magnetic resonance imaging (MRI) to determine the relationship between the pathological depth of invasion (DOI), undetectability, and tumor thickness of squamous cell carcinoma of the floor of the mouth. MATERIALS AND METHODS: We retrospectively evaluated the relationship between pathological DOI and MRI detectability, as well as the relationship between pathological DOI and tumor thickness on coronal fat-suppressed contrast-enhanced T1-weighted imaging or coronal T2-weighted imaging. RESULTS: We analyzed 30 patients with squamous cell carcinoma of the floor of the mouth; MRI revealed that the pathological DOI of the 11 undetectable lesions (median 2 mm) was smaller than that of the 19 detectable lesions (median 14 mm) (p < 0.001), and the cut-off value was 3 mm (sensitivity, 0.84; specificity, 0.91; area under the curve, 0.89). Tumor thickness on coronal fat-suppressed contrast-enhanced T1-weighted imaging was assessed in all 19 detectable lesions; however, tumor thickness on coronal T2-weighted imaging could not be assessed in eight cases. Tumor thickness on coronal fat-suppressed contrast-enhanced T1-weighted imaging was found to be significantly associated with the pathological DOI. CONCLUSIONS: Undetectability on MRI indicates superficial lesions with a pathological DOI value that is less than 3 mm. In detectable lesions, tumor thickness on coronal fat-suppressed contrast-enhanced T1-weighted imaging is associated with pathological DOI.

MR imaging of palatine gland lesion-associated IgG4-related disease: a preliminary study.

PURPOSE: The purpose of this study was to present the novel MRI findings of palatine gland lesion-associated IgG4-related disease (PGL-IgG4-RD) and to compare the imaging features with those in normal individuals. MATERIALS AND METHODS: We retrospectively evaluated the MRI scans of 12 patients with PGL-IgG4-RD and 12 control individuals. We measured the thickness of the palatal regions and calculated the T2-weighted signal intensity ratio of palatal regions to cerebral white matter (HWR) and compared them between the PGL-IgG4-RD and control groups. RESULTS: In univariate analysis, the HWR of the palatal regions on T2-weighted imaging was smaller in the PGL-IgG4-RD group than in the control group (average = 1.2 vs. 1.9, p < 0.001). The palate thickness in patients with PGL-IgG4-RD was significantly greater than that in controls (average = 12 vs 6 mm, p < 0.001). The cut-off value of the between-group palate thickness on coronal MRI was 8 mm. CONCLUSION: The thickening of the palatal regions seen with low signal intensity on T2-weighted imaging may be a characteristic imaging feature of PGL-IgG4-RD. Such findings will be useful for the timely diagnosis and subsequent treatment planning of IgG4-RDHP.

Symposium: Imaging modalities for drug-related osteonecrosis of the jaw (4), CT and MR imaging findings of antiresorptive agent-related osteonecrosis of the jaws/medication-related osteonecrosis of the jaw (secondary publication).

Generally, CT and MR images of antiresorptive agent-related osteonecrosis of the jaw (ARONJ)/medication-related osteonecrosis of the jaw (MRONJ) show nonspecific findings as seen in active osteomyelitis．However, there are some characteristics as follows; unilateral maxillary sinusitis adjacent to ipsilateral maxillary ARONJ/MRONJ, DRONJ presenting larger sequestrum and periosteal reaction more frequently than BRONJ, BRONJ resulting from intravenous administration of the drug presenting larger and more frequent buccolingual cortical bone perforations than BRONJ from oral administration, and better diagnostic accuracy of extent of perilesional soft tissue inflammation on MR imaging than CT. The CT and MR imaging features of ARONJ/MRONJ are summarized in this report.

Hourglass-shaped sublingual dermoid cyst: MRI features.

Dermoid cysts located in the floor of the mouth are classified as submental or sublingual based on their location with respect to the mylohyoid muscle. The lesion was located in the midline, involved the genioglossus and geniohyoid muscles, and extended down to the area superior to the mylohyoid muscle. An hourglass-shaped cyst of the floor of mouth was seen. Such magnetic resonance imaging findings appear to be characteristic of an extended sublingual dermoid cyst.