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Volume 38 (1998)
- Issue 4 Pages 221-
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Volume 38, Issue 4
Displaying 1-8 of 8 articles from this issue
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Mutsumasa TAKAHASHI1998 Volume 38 Issue 4 Pages 221-230
Published: December 30, 1998
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSHead and neck radiology has been established recently as a branch of diagnostic radiology, because 1) multiple organ systems are included in the head and neck region, 2) multimodality imaging techniques areapplied to the diagnosis, 3) numerous pathologic processes occur in this area, and 4) diseases should be treated in cooperation of multiple clinical disciplines, including interventional radiology and radiation therapy. At first, the importance of proper selection of pulse sequences for MR imaging of the head and neck has been emphasized with particular attention to the fatty tissue. Dynamic MR imaging is very important to evaluate extent and dif-ferential diagnosis of tumors. MR sialography has been used to demonstrate salivary ducts with use of heavily T 2-weighted images such as HASTE sequences. Fast and high resolution MR an-giography has been available with use of turbo MR technique and Gd - DTPA. Virtual endoscopy is a very important diagnostic technique when direct endoscopy cannot be performed in patients with obstruction of the airways and in severely ill patients. This endoscopic technique can be used tovisualize the internal surface of the vascular lumen as well. Arterial infusion for car-cinomas of thetongue and the floor of the mouth has been perfomed with injection of chemoth-erapeutic agents via a superselectifve catheter. This technique can be used to reduce the tumor size before surgical or radiation treatments. With development of computer technology a logistic model has been applied to evaluate benignity of tumors, so was multivariate or univariate anal-ysis for pretreatment evaluation of laryngeal tumors. Thallium-201 scintigraphy is also very use-ful for predicting curable tumors with radiation therapy. In recent years, there has been many advances in head and neck radiology with use of helical CT, MR imaging, ultrasonography and nuclear medicine. Head and neck radiology will be promoted further with collaboration of physi-cians of many fields as well as through international collaboration.View full abstractDownload PDF (14163K) -
Kaoru KOBAYASHI, Chinami IGARASHI, Masao YUASA, Masahiro IMANAKA, Tosh ...1998 Volume 38 Issue 4 Pages 231-241
Published: December 30, 1998
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSThe purpose of this study was to evaluate and review the diagnostic accuracy, sensitivity, specificity, positive predictive value and negative predictive value of imaging diagnosis for temporomandibular disorders. The role of diagnostic imaging is to detect and document specific anatomic abnormalities associated with the signs and symptoms in the temporomandibular joint. Magnetic resonance imaging (MR imaging) can accurately depict disc displacement and discdeformity. MR imaging is our first choice among the various imaging modalities for the patients with clinical signs and symptoms. However, it has been shown that intra-capsular adhesions and perforations of the disc and retrodiscal tissue are sometimes not detected by MR imaging. To improve the diagnostic technique for adhesions and perforations, double-contrast arthrotomography with fluoroscopy should be employed. The irregular surface of the eminences and the glenoid fossae shown by MR imaging and tomo-graphy are correlated with subchondral bone exposure by arthroscopy. Erosion of the condyles detected by MR imaging, tomography and rotational panoramic radiography is correlated with subchondral bone exposure detected by arthroscopy.View full abstractDownload PDF (9683K) -
Eiichi HONDA, Norio YOSHINO, Takehito SASAKI1998 Volume 38 Issue 4 Pages 242-249
Published: December 30, 1998
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSThe Radiation Protection Committee of the Japanese Society for Oral and Maxillofacial Radiology promotes the use of higher speed dental film according to the recommendation of ICRP for a quality assurance (QA) program in diagnostic radiology. However, a number of general dental practitioners have insufficient knowledge regarding the advantages of using higher speed dental film and the optimal method of dental film processing. We designed a questionnaire for the QA program and used it to assess the postgraduate training course on dental radiology in Tokyo Medical and Dental University. Using two dental films currently used at a given dental clinic, an aluminum step was exposed under the exposure condition of lower incisal teeth. After exposure, 1 film was processed at the dental clinic and 2 films were sent to the university. The unprocessed film was developed in the university. A reference radiogram was obtained as exposed film using the same aluminum step and processed at the university. Three types of radiograms, 1 exposed and processed at a dental clinic, 1 exposed but not processed at a dental clinic and 1 reference film, were compared. Using these films, we evaluated the condition of exposure and processing in general dental practice. When we compared 2 postgraduate training courses given before and after C speed group dental films were commercially unavailable, the number of private practices that used D or E type speed dental film was found to increase. However, a significant number of these dental practitioners used an instant type of processing in daylight with over-exposure and under-development conditions. Our QA method was useful to evaluate of the current status of exposure and development conditions in general dental practices and to promote the use of higher speed dental film and optimal processing.View full abstractDownload PDF (1143K) -
Satoru SHOJI, Yoshiyuki SHIRAKURA, Masanori SHOZUSHIMA, Kimio SAKAMAKI1998 Volume 38 Issue 4 Pages 250-257
Published: December 30, 1998
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSThe purpose of this study was to evaluate the usefulness of power Doppler sonography to detect possible differences in blood flow patterns between malignant and benign cervical lymph nodes. We performed preoperative power Doppler sonography in 63 patients with squamous cell carcinoma of the oral cavity and detected 116 nodes. Sixty-nine of the nodes were considerd to be malignant adenopathy according to their size, shape, boundary and internal echos and we performed histopathological examination. The other 47 nodes couldn't be made pathological finding because they were clearly benign lymph nodes. Based on the power Doppler findings, 5 vascular patterns were identified: Type 1 (absent vascularity), Type 2 (spot pattern vascularity in the node), Type 3 (hypertrophic vascular pole in the node), Type 4 (peripheral vascularity of the node), and Type 5 (central hilar vascularity). The vascularity index was defined as number of colored pixels that expressed blood flow signals. Of the 116 nodes, 35 nodes were classified into Type 5 and were nonmetastatic lymph nodes. Type 1, Type 2, Type 3 and Type 4 were predominantly found in the metastatic lymph nodes. Fifteen of the 62 (24.2 %) metastatic lymph nodes and 10 of the 54 (18.5 %) nonmetastatic lymph nodes were classified into Type 1. The vascularity index on power Doppler images of metastatic lymph nodes was significantly higher than nonmetastatic lymph nodes (p<0.05) . However, no significant correlations were found between the size of lymph nodes and the vascularity index. The results suggest that typical vascular patterns and the vasculary index determined by power Doppler sonography are helpful to differentiate between benign and malignant adenopathy.View full abstractDownload PDF (2625K) -
Yasuyuki SHIMIZU, Yoshiko ARIJI, Tsuneichi OKANO, Osamu MATSUI, Jin-ic ...1998 Volume 38 Issue 4 Pages 258-265
Published: December 30, 1998
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSThe aim of this study was to assess the influence of horizontal and vertical angulation of the X-ray beam on the detectability of approximal caries with a charge coupled device-based digital dental imaging system (digital system) in comparison with that of conventional film-based radi-ography (film system). A total of 40 teeth were mounted in plaster blocks to maximally simulate their anatomical interproximal relationships and to stand the long axis of the teeth perpendicularly. Radiography was performed at different projection angles within a range of ±20° in horizonatal and vertical directions using both digital and film systems. The approximal surfaces of the resultant images were evaluated by 6 observers in relation to the caries depth. After X-ray imaging assessment, the surfaces of each tooth were rated histologically by 2 examiners according to the same rating scores used for the X-ray imaging assessment. The sensitivity, specificity, and diagnostic accuracy of both systems were calculated using the 2 thresholds (threshold A and B) for enamel and dentin caries, respectively. No significant differnce was found in any diagnostic parameter between the 2 systems at any beam threshold at any beam angulation. The parameters at the threshold B were higher than those at the threshold A. Deviations from the best horizontal angulation mainly resulted in loss of sensitivity, while the vertical misangulation mainly caused a decrease in the specificity at the threshold B. The results of this in vitro study, in which there was no discrepancy in the influence of the beam misangulation on diagnostic abilities, suggested that the digital system is useful for clinical caries diagnosis, considering the reduction of radiation exposure.View full abstractDownload PDF (6468K) -
Masao ARAKI, Yoshinori ARAI, Eiji SHIMADA, Kaoru KUSAMA, Koji HASHIMOT ...1998 Volume 38 Issue 4 Pages 266-267
Published: December 30, 1998
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSDownload PDF (1831K) -
1998 Volume 38 Issue 4 Pages 268-271
Published: December 30, 1998
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSDownload PDF (613K) -
1998 Volume 38 Issue 4 Pages 271-273
Published: December 30, 1998
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSDownload PDF (475K)
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