Diagnostic value of dynamic magnetic resonance imaging for salivary gland diseases: a preliminary study.

OBJECTIVES: To determine the diagnostic value of dynamic MR imaging for the differentiation between benign tumours, malignant tumours, and inflammatory lesions in the major salivary glands. METHODS: T1- and T2-weighted spin-echo and dynamic gadolinium-enhanced T1-weighted spin-echo imaging sequences were performed in 27 patients (28 salivary gland lesions). The enhancement curve patterns and tumour margins on dynamic MR imaging were analysed. RESULTS: All pleomorphic adenomas showed a continuous gradual or rapid increase in the enhancement pattern, whereas other benign tumours had a rapid or gradual enhancement-attenuation pattern. Malignant tumours generally showed a gradual enhancement-attenuation pattern. Inflammatory lesions showed a rapid or gradual enhancement-attenuation pattern. A well-defined margin was observed in all 13 (100%) benign tumours and three of six (50%) malignant tumours. CONCLUSIONS: Our study suggests that dynamic curve patterns and tumour margin appearance may help to differentiate between benign tumours, malignant tumours and inflammatory lesions.

Dynamic scintigraphy with thallium-201 chloride (Tl-201) for the diagnosis of tumors of the head and neck.

OBJECTIVE: The purpose of this study was to differentiate between malignant tumors and benign tumors of the head and neck by means of thallium-201 chloride scintigraphy. STUDY DESIGN: Thallium-201 chloride (Tl-201) scintigraphy and Ga-67 citrate (Ga-67) scintigraphy were performed in 10 patients with a benign tumor and in 90 patients with a malignant tumor. The blood flow index and the tumor retention index were obtained by means of Tl-201 scintigraphy. The blood flow index = the count of tumor/the count of control in the early dynamic scan from 30 to 120 seconds after injection, and the tumor retention index = (the count of tumor/the count of control in the delayed dynamic scan 2.5 hours after injection)/(the count of tumor/the count of control in the early dynamic scan from 4 to 5 minutes after injection). RESULTS: The early and delayed scans with Tl-201 demonstrated a very high correlation with the blood flow index. The tumor retention index had a tendency to increase in malignant tumors, especially in the poorly differentiated tumors and the severely invasive tumors. Likewise, the tumor retention index decreased in benign tumors. These results proved to be statistically significant, and in turn Tl-201 scintigraphy was deemed superior to Ga-67 scintigraphy. Tl-201 scintigraphy was also useful in detecting small-size tumors. CONCLUSION: The tumor retention index of Tl-201 was useful for the differentiation of malignant tumors of the head and neck from benign tumors of the same areas.

Radiographic evaluation of malignant fibrous histiocytoma affecting maxillary alveolar bone: a report of 2 cases.

OBJECTIVE: The purpose of this study was to evaluate the radiographic findings of malignant fibrous histiocytoma (MFH) and to discuss the contribution of these findings to a differentiation of MFH from other malignant tumors of the head and neck. STUDY DESIGN: Two cases of MFH of the maxillary sinus affecting the alveolar bone were evaluated radiographically and scintigraphically. RESULTS: We reported the following findings, which have only seldom been described: the presence of fairly well-demarcated bone destruction in the intraoral radiograph; the relatively smooth surface, uniform density, or no necrotic area of the tumor; in computed tomograph images showing the clear separation of the tumor from surrounding soft tissues; bone scintigraphs reflecting the periosteal reaction to tumor invasion; and lymphoscintigraphy of the metastatic lymph nodes. CONCLUSION: We evaluated the radiographic findings from 2 cases of MFH and describe findings that may aid in the differentiation of MFH. These radiographic features may help dentists differentiate MFH from other malignant tumors in the head and neck, although MFH is a rare disease and there are no radiographic findings that would indicate a specific diagnosis of MFH.

A rare case of intraosseous polymorphous low-grade adenocarcinoma (PLGA) of the maxilla.

A rare case of intraosseous, polymorphous low-grade adenocarcinoma (PLGA) of the maxilla is presented. The lesion appeared to be cystic radiographically and the only finding which suggested malignancy was an irregular cortical border.

Lymphoscintigraphy for interpretation of changes of cervical lymph node function in patients with oral malignant tumors: comparison of Tc-99m-Re and Tc-99m-HSA-D.

OBJECTIVE: The purpose of this study is to compare the usefulness of technetium-99m-rhenium colloid (Tc-99m-Re) and technetium-99m-human serum albumin diethylene-triamine-pentaacetic acid (Tc-99m-HSA-D) as lymphoscintigraphic agents and to discuss the significance of lymphoscintigraphy in comparison with computed tomography (CT), magnetic resonance imaging (MRI), and ultrasonography (US). STUDY DESIGN: Dynamic and static lymphoscintigraphies were performed with Tc-99m-Re and Tc-99m-HSA-D. The usefulness of the 2 agents was evaluated statistically in comparison with pathologic findings and palpation. The significance of lymphoscintigraphy is discussed in comparison with CT, MRI, and US (by the literature of CT, MRI, and US). RESULTS: Lymphoscintigraphy was superior to palpation, and Tc-99m-Re was superior to Tc-99m-HSA-D in accuracy, specificity, and the incidence of true-positive and false-positive. Statistical significance was shown between the static lymphoscintigraphy with Tc-99m-Re and palpation. The reliability of lymphoscintigraphy seemed to be slightly inferior to CT and MRI in specificity and accuracy. However, lymphoscintigraphy had some advantages that CT and MRI lacked; for example, it showed very high sensitivity (100%) and no false-negative (0%). It also showed changes of lymph node function, showed all levels of neck nodes at one time, and showed a possibility of detecting small lymph node metastases. CONCLUSION: Lymphoscintigraphy was more useful than palpation in detecting lymph node metastases, and Tc-99m-Re was superior to Tc-99m-HSA-D as an agent. Lymphoscintigraphy is significant when it is performed as a preliminary examination before CT or MRI.

Clinical evaluation of lymphoscintigraphy with a new technetium compound for metastatic cervical lymphadenopathy.

OBJECTIVES: To evaluate the potential usefulness of lymphoscintigraphy for the detection of metastatic cervical lymphadenopathy. METHODS: Dynamic and static lymphoscintigraphy with 99Tcm-HSA-D was performed in 23 patients with malignant oropharyngeal tumors. The internal jugular nodes were excised and examined pathologically. The results of the lymphoscintigraphy were compared with the pathological examination and clinical palpation for accuracy. RESULTS: All cases showed abnormal findings on lymphoscintigraphy. The accuracy on dynamic scintigraphy was 69% for asymmetric drainage, 69% for delayed drainage and 100% for inverse drainage. The overall accuracy for each side was 71%. With static scintigraphy, the accuracy was 69% for asymmetry, 86% for fitting defect, 67% for mottled-patchy appearance, 70% in swelling and 100% for collateral pathway. The overall accuracy for each side was 74%. The agreement between lymphoscintigraphy and palpation was 44%. CONCLUSIONS: Lymphoscintigraphy with 99Tcm-HSA-D was superior to palpation. The method is useful as a supplementary modality for the evaluation of metastatic cervical lymphadenopathy because of its relatively high accuracy and a low false-negative rate.

Severity of synovium and bone marrow abnormalities of the temporomandibular joint in early rheumatoid arthritis: role of gadolinium-enhanced fat-suppressed T1-weighted spin echo MRI.

PURPOSE: Our goal was to evaluate the efficacy of dynamic contrast-enhanced fat-suppressed MRI of the temporomandibular joint (TMJ) in detecting early joint involvement in patients with rheumatoid arthritis (RA). METHOD: Conventional T1- and T2-weighted, gadolinium-enhanced T1-weighted, and dynamic gadolinium-enhanced fat-suppressed SE imaging sequences were performed in 22 patients with RA. RESULTS: The dynamic gadolinium-enhanced fat-suppressed T1-weighted SE sequence was more sensitive than the other techniques in detecting early changes in inflamed synovium of periarticular tissue and in detecting condylar bone marrow involvement. In patients with RA, 17 joints with joint pain showed synovial proliferation in 10 (59%) cases and joint effusion in 4 (24%). Of 14 joints with joint sound, 4 (29%) showed synovial proliferation and 7 (50%) showed joint effusion. A lower positional change of the disk was observed in joints with RA than in those with TMJ disorders (82 patients). CONCLUSION: Gadolinium-enhanced fat-suppressed MRI was extremely effective in diagnosing early changes of the inflamed TMJ.

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

OBJECTIVE: The purpose of this study was to assess the potential for improved lesion detection in the posterior disk attachment and its surrounding tissue in temporomandibular disorders when gadolinium-enhanced MR imaging performed with fat suppression is used. MATERIALS AND METHODS: Forty-five patients underwent MR imaging with conventional T1- and T2-weighted, gadolinium-enhanced T1-weighted, and gadolinium-enhanced fat-suppressed spin-echo imaging sequences. Qualitative and quantitative assessments of the contrast enhancement of each type of imaging were also performed. RESULTS: The contrast-enhanced fat-suppressed T1-weighted imaging sequence had several advantages over the other imaging techniques in detecting abnormalities of the posterior disk attachment and in detecting bone marrow lesions in the mandibular condyle. The most significant advantage was better enhancement of lesion conspicuity. The diagnostic accuracy of contrast-enhanced fat-suppressed imaging was 77% versus 70% for conventional contrast-enhanced imaging. The kappa value for interobserver agreement was .95 for contrast-enhanced fat-suppressed imaging and .72 for conventional contrast-enhanced imaging. CONCLUSION: Contrast-enhanced fat-suppressed T1-weighted spin-echo MR imaging is a valuable technique for visualizing the extent and degree of lesions in the posterior disk attachment and bone marrow lesions in the mandibular condyle.

Double dens in dente with a central cusp and multituberculism in bilateral maxillary supernumerary central incisors: report of a case.

A case of bilateral molarized teeth in the maxillary central incisor region is reported. The bilateral central incisor teeth were extracted in a 13-year-old boy and examined radiographically and histologically. Both malformed teeth were diagnosed as double dens in dente with a central cusp and multituberculism in maxillary supernumerary central incisors.

Interpretation of scintigraphy of papillary cystadenoma lymphomatosum (Warthin's tumor) on the basis of histopathologic findings.

OBJECTIVES: The accumulation of 99mTc-pertechnetate in Warthin's tumor was estimated scintigraphically and histopathologically to determine the role of the epithelial component in scintigraphy. STUDY DESIGN: Six cases underwent histopathologic examination and scintigraphic evaluation with 99mTc-pertechnetate. Histopathologically the tumors were classified into types according to the epithelial component and cystic space and compared with scintigraphic results evaluated by dynamic radioactive index and wash-out image. RESULTS: Histopathologic and scintigraphic observations showed an adequate correlation. Cases with a large epithelial component and poor cystic space showed a large radioactive index of dynamic scintigraphy and hot accumulation of wash-out image. CONCLUSION: The scintigraphic results were chiefly due to the epithelial component, but the influence of the cystic space could not be disregarded.

[Phase III trial of 99mTc-rhenium colloid for lymphoscintigraphy].

A multicenter study was carried out on 191 patients (196 examinations) with lymphatic system disorders to evaluate the efficacy and safety of 99mTc-rhenium Colloid, a tracer for lymphoscintigraphy (TCK-17). Local pain and swelling occurred at the site of injection in 79.6% and 5.1% of patients, respectively, and 2 patients experienced mild fever. The accuracy was calculated on the basis of the results obtained by other diagnostic methods. Lymphoscintigraphy using TCK-17 was sensitive diagnostic procedures, but low specificity. The efficacy was classified into five grades: "Excellent", "Good", "Moderate", "Equivocal", and "Poor". 67.3% of all examination were evaluated as "Excellent" or "Good". This study revealed TCK-17 was a useful radiopharmaceutical for lymphoscintigraphy because of its safety and effectiveness.

Autosomal recessive rough hypoplastic amelogenesis imperfecta. A case report with clinical, light microscopic, radiographic, and electron microscopic observations.

A case is presented of a 12-year-old Japanese girl with nearly complete lack of enamel in the deciduous and the permanent dentitions, coupled with a gross abnormality in the pattern of eruption. There was no family history of a similar condition. Deciduous molars were extracted, and hyperplastic gingival tissue was resected. On the basis of clinical, radiographic, and microscopic findings, a diagnosis of autosomal recessive rough hypoplastic amelogenesis imperfecta was made. The configuration of the abnormal enamel was examined with scanning and transmission electron microscopy as well as with light microscopy. Prismatic structure was virtually absent, and the scant enamel showed globular protrusions superficially. Two different surface structures were identified as covering parts of the enamel. At the ultrastructural level, calcified bodies located in the gingival tissue appeared to be composed, in part, of a dense enamel-like substance and, in part, of a tissue with features of afibrillar cementum.

Evaluation of submandibular gland function by sialo-scintigraphy following sialolithectomy.

Submandibular gland function following transoral sialolithectomy was examined by 99mTc-pertechnetate sialo-scintigraphy in 10 cases. An intraindividual comparison between the function of the treated gland and that of the contralateral normal gland was made using a time-activity curve. Although glandular recovery was not affected by the duration of symptoms or the existence of the symptom at mealtimes, it was inversely proportional to the size of the calculus. Furthermore, the prognosis was more favorable in patients when the anatomically normal orifice of the submandibular duct was preserved.