|Mayumi Shimizu||Last modified date：2023.09.20|
Lecturer / Department of Oral and Maxillofacial Radiology / Comprehensive Dentistry / Kyushu University Hospital
|Mayumi Shimizu||Last modified date：2023.09.20|
|1.||Yoshitaka Kise , Anne Moystad , Tore Bjornland , Mayumi Shimizu, Yoshiko Ariji, Chiaki Kuwada, Masako Nishiyama, Takuma Funakoshi, Kazunori Yoshiura, Eiichiro Ariji, Effects of 1 year of training on the performance of ultrasonographic image interpretation: A preliminary evaluation using images of Sjogren syndrome patients, Imaging Science in Dentistry, 10.5624/isd.20200294, 21, 2, 129-136, 2021.06.|
|2.||Maehara T, Munemura R, Shimizu M, Kakizoe N, Kaneko N, Murakami Y, Masafumi M, Kiyoshima T, Kawano S, Nakamura S., Tissue-infiltrating immune cells contribute to understanding the pathogenesis of Kimura disease: A case report, Medicine, 10.1097/MD.0000000000018300, 98, 50, 2019.12.|
|3.||Yoshitaka Kise, Mayumi Shimizu, Haruka Ikeda, Takeshi Fujii, Chiaki Kuwada, Masako Nishiyama, Takuma Funakoshi, Yoshiko Ariji, Hiroshi Fujita, Akitoshi Katsumata, Kazunori Yoshiura, Eiichiro Ariji, Usefulness of a deep learning system for diagnosing Sjögren’s syndrome using ultrasonography images, Dentomaxillofac Radiol, 10.1259/dmfr.20190348, 49, 3, 20190348-20190348, 2020.02.|
|4.||Sakamoto M, Moriyama M, Shimizu M, Chinju A, Mochizuki K, Munemura R, Ohyama K, Maehara T, Ogata K, Ohta M, Yamauchi M, Ishiguro N, Matsumura M, Ohyama Y, Kiyoshima T, Nakamura S., The diagnostic utility of submandibular gland sonography and labial salivary gland biopsy in IgG4-related dacryoadenitis and sialadenitis: Its potential application to the diagnostic criteria., Mod Rheumatol., 10.1080/14397595.2019.1576271, 30, 2, 379-384, 2019.03.|
|5.||Mayumi Shimizu, Warangkana Weerawanich, Sonographic diagnosis in the head and neck region – From the educational lecture in the 56th general assembly and annual scientific congress of Japanese Society for Oral and Maxillofacial Radiology –, Oral Radiology, 10.1007/s11282-018-0353-9, 35, 2, 101-126, 2018.11, Sonography is a simple, inexpensive, and non-invasive diagnostic modality. Although tissues behind bony structures and deep
tissues are not delineated, sonography can depict superficial soft tissues very clearly. In the head and neck region, however,
it has not yet been used widely, as the anatomical structures are complicated, and considerable experience is needed both to
perform an examination and to make a diagnosis. To perform examinations efficiently, operators must be familiar with the
sonographic system in use, and take images at standard planes. To make a correct diagnosis, operators require knowledge
of the sonographic anatomy on standard planes, representative sonographic signs and artifacts, and common diseases and
their typical sonographic findings. In this paper, we have explained the sonographic anatomy on standard planes, and the
sonographic findings of common diseases in the oral and maxillofacial region..
|6.||Warangkana Weerawanich, Mayumi Shimizu, Yohei Takeshita, Kazutoshi Okamura, Shoko Yoshida, Gainer R Jasa, Kazunori Yoshiura., Determination of optimum exposure parameters for dentoalveolar structures of the jaws using the CB MercuRay system with cluster signal-to-noise analysis, Oral Radiology, 10.1007/s11282-018-0348-6, 2018.09, Objectives: To find the optimum cone beam CT exposure parameters for specific
Methods: A Teflon phantom attached to a half mandible in a large container was
scanned in dental (D), implant (I) and panoramic (P) modes. An identical phantom in a
small container was scanned in D mode. Both were scanned at 60, 80, 100, and 120
kV. The image quality of anatomical structures: dentin-enamel junction (1), lamina dura
and periodontal ligament (PDL) space (2), trabecular pattern (3), cortex-spongy bone
junction (4) and pulp chamber and root canal (5) was evaluated by observers, and the
diagnostic image quality was analyzed with cluster signal-to-noise analysis. We then
evaluated correlations between the two image qualities and calculated the threshold of
acceptable diagnostic image quality. Optimum exposure parameters were determined
from images with an acceptable diagnostic image quality level.
Results: For small container, the optimum exposure parameters were D mode, 80 kV
for 1, 3 and 4 and D mode, 100 kV for 5. For large containers, they were D mode, 120
kV for 1, 3 and 5 and D mode, 100 kV for 4. I mode, 120 kV reached the acceptable
level for 4. No images reached acceptable level for 2.
Conclusions: There were no optimum exposure parameters for evaluation of lamina
dura and PDL space. D mode was sufficient for the other structures; however, the tube
voltage required for each structure was different. Smaller patients required lower tube
voltage. I mode, 120 kV may be used for larger lesions..
|7.||Junko Yoshizumi Hiroko Wada, Mayumi Shimizu, Yasufumi Horinouchi, Tamotsu Kiyoshima, Tetsuro Ikebe, Akimitsu Hiraki, A rare case of cemento-osseous dysplasia arising from a dislocated impacted tooth in the maxillary sinus, Journal of Oral and Maxillofacial Surgery, Medicine, and Pathology, 20180803, 2018.08.|
|8.||Warangkana Weerawanich, Mayumi Shimizu, Yohei Takeshita, Kazutoshi Okamura, Shoko Yoshida, Gainer R Jasa, Kazunori Yoshiura., Evaluation of cone-beam computed tomography diagnostic image quality using cluster signal-to-noise analysis, Oral Radiology, https://doi.org/10.1007/s11282-018-0325-0, 35, 3, 59-67, 2018.04, Objectives: 1) We sought to assess correlation among four representative parameters from a cluster signal-to-noise curve (true positive rate [TPR] corresponding to background noise, accuracy corresponding to background noise, maximum TPR, and maximum accuracy) and the diagnostic accuracy obtained in the identification of the mandibular canal using data from observers in a previous study, under the same exposure conditions. 2) We sought to clarify the relationship between the hole depths of a phantom and diagnostic accuracy.
Materials and Methods: CBCT images of a Teflon plate phantom with holes of decreasing depths from 0.7–0.1 mm were analysed using the FindFoci plugin of ImageJ. Subsequently, we constructed cluster signal-to-noise curves by plotting TPRs against false-positive rates (FPRs). The four parameters were assessed in the correlation with diagnostic accuracy obtained from observers. To analyse image contrast ranges related to detection of mandibular canals, we determined five ranges of hole depths, to represent different contrast ranges: 0.1–0.7, 0.1–0.5, 0.2–0.6, 0.2–0.7 and 0.3–0.7 mm; and evaluated their correlations with diagnostic accuracy obtained from observers.
Results: Accuracy corresponding to background noise had the highest correlation with the diagnostic accuracy among the four representative parameters. Regarding the ranges of hole depths, 0.3–0.7 and 0.1–0.7 mm had the highest correlation with diagnostic accuracy in the mandibles with distinct and indistinct mandibular canals, respectively.
Conclusions: The accuracy corresponding to background noise obtained from the cluster signal-to-noise curve can be used to evaluate the effects of exposure conditions on diagnostic accuracy..
|9.||Yohei Takeshita, Mayumi Shimizu, Gainer Raul Jasa, Warangkana Weerawanich, Kazutoshi Okamura, Shoko Yoshida, Kenji Tokumori, Junichi Asaumi, Kazunori Yoshiura, Prediction of detectability of the mandibular canal by quantitative image quality evaluation using cone beam CT, Dentomaxillofacial Radiology, in press, 2018.01, Objectives: To compare the results of a new quantitative image quality evaluation method that requires no observers with the results of receiver operating characteristic (ROC) analysis in detecting the mandibular canal in cone beam CT (CBCT) images.
A Teflon (polytetrafluoroethylene) plate phantom with holes of different depths was scanned with two CBCT systems. One CBCT system was equipped with an image intensifier (Experiment 1), and the other was equipped with a flat panel detector (Experiment 2). Holes that were above the threshold gray value (ΔG), calculated using just-noticeable difference (JND), were extracted. The number of extracted holes was used as the index of the image quality, and was compared with the Az values calculated by ROC analysis to detect the mandibular canal.
Results: The number of extracted holes reflected the influence of different scanning conditions, and showed a strong correlation with the Az values calculated by ROC analysis. Indices of the number of extracted holes corresponding to high Az values for detecting the mandibular canal were obtained in both experiments.
Conclusions: Our image quality evaluation method applying JND to images of a standardized phantom is a quantitative method that could be useful for evaluating the detectability of the mandibular canal in CBCT images.
|10.||Warangkana Weerawanich, Mayumi Shimizu, Kazutoshi Okamura, Shoko Yoshida, Kazunori Yoshiura, Cluster signal-to-noise analysis for evaluation of the information content in an image, Dentomaxillofacial Radiology, in press, 2017.10, Objectives: 1) To develop an observer-free method of analyzing image quality related to the observer performance in the detection task and 2) to analyze observer behavior patterns in the detection of small mass changes in CBCT images. Materials and Methods: Thirteen observers detected holes in a Teflon phantom in CBCT images. Using the same images, we developed a new method, cluster signal-tonoise analysis, to detect the holes by applying various cut-off values using ImageJ and reconstructing cluster signal-to-noise curves. We then evaluated the correlation between cluster signal-to-noise analysis and the observer performance test. We measured the background noise in each image to evaluate the relationship with false positive rates (FPRs) of the observers. Correlations between mean FPRs and intra and inter-observer variations were also evaluated. Moreover, we calculated true positive rates (TPRs) and accuracies from background noise and evaluated their correlations with TPRs from observers. Results: Cluster signal-to-noise curves were derived in cluster signal-to-noise analysis. They yield the detection of signals (true holes) related to noise (false holes). This method correlated highly with the observer performance test (R² = 0.9296). In noisy images, increasing background noise resulted in higher FPRs and larger intra- and inter-observer variations. TPRs and accuracies calculated from background noise had high correlation with actual TPRs from observers; R² was 0.9244 and 0.9338, respectively. Conclusion: Cluster signal-to-noise analysis can simulate the detection performance of observers and thus replace the observer performance test in the evaluation of image quality. Erroneous decision-making increased with increasing background noise..|
|11.||Yohei Takeshita, Mayumi Shimizu, Kazutoshi Okamura, Shoko Yoshida, Warangkana Weerawanich, Kenji Tokumori, Gainer Raul Jasa, Kazunori Yoshiura, A new method to evaluate image quality of CBCT images quantitatively without observers, Dentomaxillofacial Radiology, in press, 2017.03, Objectives: To develop an observer-free method for quantitatively evaluating the image quality of CBCT images by applying just-noticeable difference (JND).
Methods: We used two test objects: (1) a Teflon (polytetrafluoroethylene) plate phantom attached to a dry human mandible; and (2) a block phantom consisting of a Teflon step phantom and an aluminum step phantom. These phantoms had holes with different depths. They were immersed in water and scanned with a CB MercuRay at tube voltages of 120, 100, 80, and 60 kV. Superimposed images of the phantoms with holes were used for evaluation. The number of detectable holes was used as an index of image quality. In detecting holes quantitatively, the threshold gray value (ΔG) which differentiated holes from the background was calculated using a specific threshold (the JND), and we extracted the holes with gray values above ΔG. The indexes obtained by this quantitative method (the extracted hole values) were compared with the observers’ evaluations (the observed hole values). In addition, the contrast-to-noise ratio (CNR) of the shallowest detectable holes and the deepest undetectable holes were measured to evaluate the contribution of CNR to detectability.
Results: The results of this evaluation method corresponded almost exactly with the evaluations made by observers. The extracted hole values reflected the influence of different tube voltages. All extracted holes had an area with a CNR of ≥1.5.
Conclusions: This quantitative method of evaluating CBCT image quality may be more useful and less time-consuming than evaluation by observation..
|12.||Gainer Raul Jasa, Mayumi Shimizu, Kazutoshi Okamura, Kenji Tokumori, Yohei Takeshita, Warangkana Weerawanich, Kazunori Yoshiura, Effects of exposure parameters and slice thickness on detecting clear and unclear mandibular canals using cone beam CT, Dentomaxillofacial Radiology, in press, 2017.03, Objectives The purpose of this study was to clarify the effects of exposure parameters and image processing methods when using cone beam CT (CBCT) to detect clear and unclear mandibular canals (MCs).
Methods Twenty-four dry half mandibles were divided into two groups with clear and unclear MCs based on a previous CBCT study. Mandibles were scanned using a CBCT system with varying exposure parameters (tube voltages 60, 70, and 90 kV; and tube currents 2, 5, 10 and 15 mA) to obtain a total of 144 scans. The images were processed with different slice thicknesses using ImageJ software. Five radiologists evaluated the cross-sectional images of the first molar region to detect the MCs. The diagnostic accuracy of varying exposure parameters and image processing conditions was compared with areas under the curves (Az) in receiver operating characteristic (ROC) analysis.
Results: The Az values for clear MCs were higher than those for unclear MCs. With increasing exposure voltages and currents, Az values increased, but no significant differences were found with high voltages and currents in clear MCs (p = 0.6825 and p = 0.7156). The Az values of serial images were higher than those of overlaid images (p Conclusions: Our findings indicate that detection of unclear MCs requires either higher exposure parameters or processing of the images with thicker slices. To detect clear MCs, lower exposure parameters can be used..
|13.||Mayumi Shimizu, Kazutoshi Okamura, Yoshitaka Kise, Yohei Takeshita, Hiroko Furuhashi, Warangkana Weerawanich, Moriyama Masafumi, Yukiko Ohyama, Furukawa Sachiko, Seiji Nakamura, Kazunori Yoshiura, Effectiveness of imaging modalities for screening IgG4-related dacryoadenitis and sialadenitis (Mikulicz’s disease) and for differentiating it from Sjögren’s syndrome (SS), with an emphasis on sonography., Arthritis Research & Therapy, 10.1186/s13075-015-0751-x, 17, 233, 2015.08, Introduction: The aim of this study was to clarify the effectiveness of various imaging modalities and characteristic imaging features in the screening of IgG4-related dacryoadenitis and sialadenitis (IgG4-DS), and to show the differences in the imaging features between IgG4-DS and Sjögren’s syndrome (SS).
Methods: Thirty-nine patients with IgG4-DS, 51 with SS and 36 with normal salivary glands were enrolled. Images of the parotid and submandibular glands obtained using sonography, 2-[18F]-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (FDG-PET/CT), computed tomography (CT) and magnetic resonance imaging (MRI) were retrospectively analyzed. Six oral and maxillofacial radiologists randomly reviewed the arranged image sets under blinded conditions. Each observer scored the confidence rating regarding the presence of the characteristic imaging findings using a 5-grade rating system. After scoring various findings, diagnosis was made as normal, IgG4-DS or SS, considering all findings for each case.
Results: On sonography, multiple hypoechoic areas and hyperechoic lines and/or spots in the parotid glands and obscuration of submandibular gland configuration were detected mainly in patients with SS (median scores 4, 4 and 3, respectively). Reticular and nodal patterns were observed primarily in patients with IgG4-DS (median score 5). FDG-PET/CT revealed a tendency for abnormal 18F-FDG accumulation and swelling of both the parotid and submandibular glands in patients with IgG4-DS, particularly in the submandibular glands. On MRI, SS had a high score regarding the findings of a salt-and-pepper appearance and/or multiple cystic areas in the parotid glands (median score 4.5). Sonography showed the highest values among the four imaging modalities for sensitivity, specificity and accuracy. There were significant differences between sonography and CT (p = 0.0001) and between sonography and FDG-PET/CT (p = 0.0058) concerning accuracy.
Conclusions: Changes in the submandibular glands affected by IgG4-DS could be easily detected using sonography (characteristic bilateral nodal/reticular change) and FDG-PET/CT (abnormal 18F-FDG accumulation). Even inexperienced observers could detect these findings. In addition, sonography could also differentiate SS. Consequently, we recommend sonography as a modality for the screening of IgG4-DS, because it is easy to use, involves no radiation exposure and is an effective imaging modality..
|14.||Mayumi Shimizu, Dai Ogawa, Kazutoshi Okamura, Toshiyuki Kawazu, Toru Chikui, Kazunori Yoshiura, Dentigerous cysts with calcification mimicking odontogenic tumors: differential diagnosis by CT, Oral Radiol, 10.1007/s11282-014-0173-5, 31, 14-22, 2015.01.|
|15.||Moriyama Masafumi, Tanaka A, Maehara T, YUKIKO OHYAMA, Mayumi Shimizu, Nakashima H, Hayashida Jun-Nosuke, Shinozaki S, Kubo Y, Furukawa S, Kikuta T, Seiji Nakamura, Clinical characteristics of Mikulicz's disease as an IgG4-related disease., Clin Oral Invest, 10.1007/s00784-012-0905-z, 2013.05.|
|16.||Kazutoshi Okamura, Kazunori Yoshiura, Masato Tatsumi, Toshiyuki Kawazu, Toru Chikui, Mayumi Shimizu, Tazuko K. Goto, A new method for evaluating perceptible contrast information in digital intraoral radiographic systems., Oral Radiol, 27, 98-101, 2011.01.|
|17.||Chikui T, Shimizu M, Kawazu T, Okamura K, Shiraishi T, Yoshiura K., A quantitative analysis of sonographic images of the salivary gland: A comparison between sonographic and sialographic findings., Ultrasound in Med. & Biol., 35, 8, 1257-1264, 2009.12.|
|18.||Shimizu M, Moriyama M, Okamura K, Kawazu T, Chikui T, Goto TK, Ohyama Y, Nakamura S, Yoshiura K., Sonographic diagnosis for Mikulicz disease, Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 108：105-113, 2009.07.|
|19.||Shimizu M, Okamura K, Yoshiura K, Ohyama Y, Nakamura S, Sonographic diagnosis of Sjögren’s syndrome -Evaluation of the parotid gland’s vascularity as a diagnostic tool-, Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 106、4、587-594, 2008.10.|
|20.||Chikui T, Okamura K, Tokumori K, Nakamura S, Shimizu M, Koga M, Yoshiura K., Quantitative analysis of sonographic images of the parotid gland in patients with Sjogren's syndrome., Ultrasound in Med. & Biol., 32, 617-622, 2006.12.|
|21.||Shimizu M, Osa N, Okamura K, Yoshiura K., CT analysis of the Stafne's bone defects of the mandible, Dentomaxillofac Radiol, 35：95-102, 2006.01.|
|22.||Shimizu M, Okamura K, Yoshiura K, Ohyama Y, Nakamura S, Kinukawa N., Sonographic diagnostic criteria for screening Sjoegren's syndrome, Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 102：85-93, 2006.01.|
|23.||Yoshiura K, Okamura K, Tokumoti K, Nakayama E, Chikui T, Goto TK, Shimizu M, Kawazu T., Correlation between diagnostic accuracy and perceptibility., Dentomaxillofac Radiol, 34, 350-352, 2005.10.|
|24.||Yoshiura K, Nakayama E, Shimizu M, Goto TK, Chikui T, Kawazu T, Okamura K., Effect of automatic exposure compensation on the proximal caries diagnosis., Dentomaxillofac Radiol, 34, 140-144, 2005.04.|
|25.||Chikui T, Shimizu M, Goto TK, Nakayama E, Yoshiura K, Kanda S, Oobu K, Nakamura S., Interpretation of the origin of a submandibular mass by CT and MRI imaging., Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 98, 721-729, 2004.10.|
|26.||Yoshiura K, Welander U, McDavid WE,Li G, Shi X-Q, Nakayama E, Shimizu M, Okamura K,Kanda S., Comparison of the psychophysical properties of various intraoral film and digital systems by means of the perceptibility curve test., Dentomaxillofac Radiol, 33, 98-102, 2004.04.|
|27.||Goto TK, Yoshiura K, Nakayama E, Yuasa K, Tabata O, Nakano T, Kawazu T, Tanaka T, Miwa K, Shimizu M, Chikui T, Okamura K, Kanda S., The combined use of US and MR imagng for the diagnosis of masses in the parotid region, Acta Radiologica, 42, 88-95, 2001.03.|
|28.||Shimizu M, Tokumori K, Okamura K, Chikui T, Yoshiura K, Kanda S., Possibility of sialographic sonography: a Doppler phantom study., Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 10.1067/moe.2001.113832, 91, 6, 719-727, 91：719-727, 2001.01.|
|29.||Shimizu M, Tokumori K, Saitoh M, Miwa K, Yoshiura K, Kanda S., Sonographic analysis of rat submandibular glands with experimentally induced sialadenitis., Dentomaxillofac Radiol, 10.1038/sj.dmfr.4600508, 29, 2, 90-96, 29:90-96, 2000.01.|
|30.||Mayumi Shimizu, Ussmuller J, Hartwein J, Donath K. , A comparative study of sonographic and histopathologic findings of tumorous lesions in the parotid gland, Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology, 88, 6, 723-737, 1999.12, Objective. The purpose of this study was to clarify characteristic sonomorphologic features of parotid lesions statistically and to propose new criteria for the differential diagnosis. Study design. Eighty-six tumorous lesions were analyzed with regard to the following sonomorphologic features: boundary, shape, echo intensity level, distribution of internal echoes, and acoustic enhancement. Stepwise polychotomous logistic regression analysis was performed to assess characteristic sonographic features. As dependent variables, we used "pleomorphic adenoma," "Warthin tumor," "malignant tumors" and "other benign lesions"; as predictor variables, we used the aforementioned sonomorphologic features. Proportion of the occurrence of each dependent variable was calculated. Results. Lobular shape and homogeneous internal echoes predicted pleomorphic adenoma. A lesion with multiple anechoic areas would be Warthin tumor with very high sensitivity. Malignant tumors showed either heterogeneous internal echoes without characteristic structures or polygonal shape. Conclusions. These sonomorphologic features should be observed to make more exact differential diagnoses for operation and therapy planning..|
|31.||Mayumi Shimizu, N. Sekine, K. Nishimura, K. Tokumori, M. Saitoh, S. Kanda, Magnetic resonance imaging of experimentally-induced sialadenitis in rat submandibular glands, Dentomaxillofacial Radiology, 10.1038/sj.dmfr.4600470, 28, 6, 330-337, 1999.01, Objectives: To correlate the features of magnetic resonance (MR) images of experimentally induced obstructive sialadenitis in rat submandibular glands with the histopathological changes. Methods: Changes in MR images of ligated and non-ligated rat submandibular glands were compared with the histopathological changes and wet weight ratios. Spin echo T1 weighted images (SE T1WI), fast spin echo T2 weighted images (FSE T2WI), and gradient echo T2 weighted images (GE T2WI) were obtained at 1, 2, 3, 4, 5, 7 and 21 days after duct ligation with a 0.3 T MR imaging system. Results: There was a significant difference (P|
|32.||Mayumi Shimizu, Ussmuller J, Hartwein J, Donath K, Kinukawa N., Statistical study for sonographic differential diagnosis of tumorous lesions in the parotid gland, Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology, 10.1016/S1079-2104(99)70120-4, 88, 2, 226-233, 1999.01, Objective. The purpose of this study was to clarify characteristic sonomorphologic features of parotid lesions statistically and to propose new criteria for the differential diagnosis. Study design. Eighty-six tumorous lesions were analyzed with regard to the following sonomorphologic features: boundary, shape, echo intensity level, distribution of internal echoes, and acoustic enhancement. Stepwise polychotomous logistic regression analysis was performed to assess characteristic sonographic features. As dependent variables, we used "pleomorphic adenoma," "Warthin tumor," "malignant tumors" and "other benign lesions"; as predictor variables, we used the aforementioned sonomorphologic features. Proportion of the occurrence of each dependent variable was calculated. Results. Lobular shape and homogeneous internal echoes predicted pleomorphic adenoma. A lesion with multiple anechoic areas would be Warthin tumor with very high sensitivity. Malignant tumors showed either heterogeneous internal echoes without characteristic structures or polygonal shape. Conclusions. These sonomorphologic features should be observed to make more exact differential diagnoses for operation and therapy planning..|
|33.||Mayumi Shimizu, Jürgen Ußmüller, Karl Donath, Kazunori Yoshiura, Shigeo Ban, Shigenobu Kanda, Satoru Ozeki, Masanori Shinohara, Sonographic analysis of recurrent parotitis in children
A comparative study with sialographic findings, Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology, 10.1016/S1079-2104(98)90355-9, 86, 5, 606-615, 1998.01, Objective. The sonographic features of recurrent parotitis in children were studied to clarify a relationship between sonographic and sialographic findings in this disease. Study design. Twenty-one glands (7 on follow-up) were examined by 7.5 MHz ultrasonography and sialography. Echo intensity level, distribution of the internal echoes, and size of hypoechoic areas were compared with the size of punctate shadows on the sialograms. Twenty other histopathologic specimens were analyzed to investigate the entity of hypoechoic areas. Results. Sonography showed hypoechoic, heterogeneous internal echoes, the level of which increased as the punctate shadows enlarged. Hypoechoic areas, all of which were larger than the sialographic punctate shadows, were observed in 62% of the glands. Histopathologic analysis suggests that these hypoechoic areas represent dilated peripheral ducts with lymphocytic infiltration. Sonography was likely to detect changes over time more sensitively than sialography. Conclusions. Sonography should be performed as the test of first choice, both in the primary and follow-up stages, in cases of recurrent parotitis in children..
|34.||Kazunori Yoshiura, O. Tabata, K. Miwa, T. Tanaka, Mayumi Shimizu, Y. Higuchi, M. Shinohara, S. Kanda, Computed tomographic features of calcifying odontogenic cysts, Dentomaxillofacial Radiology, 10.1038/sj.dmfr.4600305, 27, 1, 12-16, 1998.01, Objectives: To describe the CT appearances of 4 cases of the calcifying odontogenic cyst (COC) with particular reference to the effect of varying the window settings. Methods: Conventional radiographs and CT scans of 4 calcifying odontogenic cysts were analyzed with respect to the presence of an impacted tooth, root resorption and calcification. In addition, increased attenuation by desquamated keratin was examined by varying the window settings on CT. Results: All lesions were located in the maxilla and on conventional radiographs, had unilocular radiolucency with a well-defined margin. Calcifications and inclusion of an impacted tooth were seen in all cases. Root resorption was observed in two cases, but was not prominent. On CT, calcification was detected at the periphery of the lesion and/or around the impacted tooth in all cases. Varying the window setting revealed an increased attenuation area due to desquamated keratin. Conclusions: Varying the window setting on CT is useful as a means of identifying both desquamated keratin and peripheral calcification in COC..|
|35.||K. Araki, E. Ariji, Mayumi Shimizu, S. Kanda, S. Ozeki, M. Shinohara, Y. Ariji, Computed tomography of carcinoma of the upper gingiva and hard palate
correlation with the surgical and histopathological findings., Dentomaxillofacial Radiology, 26, 3, 177-182, 1997.05, OBJECTIVES: To clarify the diagnostic utility of CT in the evaluation of carcinoma of the maxillary gingiva and hard palate. METHODS: The CT scans of 27 patients with squamous cell carcinoma of the upper gingiva and hard palate were reviewed. Tumor extent and bone destruction were compared with the surgical and histopathological findings to estimate the sensitivity, specificity and accuracy of CT. RESULTS: The primary tumor was detected by CT in 89% of patients. The grade of bone destruction determined by CT correlated well with that verified at surgery or by histopathological examination. The sensitivity, specificity, and accuracy of CT for invasion to the buccal mucosa were 64%, 89% and 75% respectively. For maxillary sinus invasion, CT showed low specificity but high sensitivity. The accuracy was 86% when the criterion for sinus invasion was the presence of an enhanced mass continuous with the primary tumor. CONCLUSION: CT is helpful for the evaluation of tumor extent in the upper gingiva and hard palate carcinoma. However, invasion of the maxillary sinus should be considered carefully, because CT findings suggestive of destruction of the floor of the maxillary sinus are not always consistent with sinus invasion..
|36.||Kenji Yuasa, Eiji Nakhyama, Shigeo Ban, Toshiyuki Kawazu, Toru Chikui, Mayumi Shimizu, Shigenobu Kanda, Submandibular gland duct endoscopy
Diagnostic value for salivary duct disorders in comparison to conventional radiography, sialography, and ultrasonography, Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology, 10.1016/S1079-2104(97)90276-6, 84, 5, 578-581, 1997.01, The purpose of this study is to evaluate the usefulness of endoscopy as a procedure for the diagnosis of submandibular gland duct disorders. Endoscopy of the submandibular glands was performed on 12 patients with symptoms of obstructive sialoadenitis to identify the cause of obstruction. The endoscopic findings were then compared to those of diagnostic procedures such as conventional radiography, sialography, and ultrasonography. Six normal subjects also underwent endoscopy to better understand the normal findings of the duct system. Endoscopy demonstrated salivary gland calculus in 5 of 12 patients, which was revealed as filling defects on sialograms and as strongly echogenic structures on ultrasonograms in 4 of the patients. Endoscopy revealed secretion plugs, secretion plaques, and/or stenosis, which could not be seen by any other diagnostic procedures in 5 patients, as the cause of recurrent swelling in all 7 patients not demonstrating siaiolith. Abnormal findings of the duct wall such as vasodilatation, fibrosis, edema, or erythema were seen in four patients, three of whom exhibited dilatation of the duct system on sialograms. In four patients, a decreasing internal echo level of the gland was seen on ultrasonograms. Our initial results for submandibular gland duct endoscopy thus appear to be promising..
|37.||Ultrasonographic analysis of the glandular damage caused by submandibualr sialolithiasis.|
|38.||Mayumi Shimizu, Kazunori Yoshiura, S. Kanda, Radiological and histological analysis of the structural changes in the rat parotid gland following release of Stensen's duct obstruction, Dentomaxillofacial Radiology, 10.1259/dmfr.23.4.7835524, 23, 4, 197-205, 1994.10, Sialography is the preferred method for diagnosis and treatment planning in obstructive sialadenitis. Although many experimental studies have reported changes following duct obstruction, those following release of obstruction have not been examined. The present study was undertaken to clarify: (1) the relationship between sialographic and histological changes; (2) the effects of duration and pressure of obstruction on gland recovery; (3) the possibility of establishing those sialographic features which indicate the prognosis for gland recovery. Stensen's ducts of rat parotid glands were obstructed for two different periods and at three different pressures in order to induce varying degrees of degenerative changes in the gland. The structural alterations resulting from release of obstruction were investigated by means of qualitative and quantitative microsialography and histology. Gland structure was assessed visually from the latter and classified into six groups: normal, recovery, and slight, moderate and severe degeneration and fibrous. Microsialograms were evaluated based on these groups. Qualitatively, microsialograms of the operated glands had a stricture in the obstructed region and dilation of the major ducts. Histological differences between recovery and degeneration glands were reflected in the morphology of peripheral ducts. The former showed a branch-like morphology similar to that of the normal group, and the latter contained small granule-like structures. Quantitatively, dilation of major ducts in the recovery group decreased compared with the other operated groups. There were no distinct sialographic features in the degeneration and fibrous groups which correlated with the degree of degeneration observed histologically. Duration and pressure of obstruction were highly predictive for prognosis for recovery. However, it was difficult to determine the prognosis for gland recovery from sialographic findings at the time of release of obstruction..|
|39.||Kazunori Yoshiura, S. Ban, T. Hijiya, K. Yuasa, K. Miwa, E. Ariji, O. Tabata, K. Araki, T. Tanaka, K. Yonetsu, E. Nakayama, Y. Ariji, Mayumi Shimizu, N. Fujiwara, S. Kanda, Analysis of maxillary sinusitis using computed tomography, Dentomaxillofacial Radiology, 10.1259/dmfr.22.2.8375560, 22, 2, 86-92, 1993.01, Odontogenic maxillary sinusitis can be defined as sinusitis induced by a dental lesion. We examined the CT findings of 68 patients with maxillary sinusitis in order to differentiate between inflammation of sinus origin and inflammation of dental origin. Maxillary sinusitis was classified into four types according to clinical symptoms, history and conventional radiographic findings: type 1, simple sinusitis; type 2, odontogenic sinusitis; type 3, mixed sinusitis; type 4, slight sinus abnormality with a dental lesion. The relationship between the type of maxillary sinusitis and CT findings was analysed. Type 1 sinusitis exhibited severe pathological changes in both mucosa and bone which often extended into the nasal cavity and other paranasal sinuses. Type 2 sinusitis exhibited localized pathology on the unilateral antral floor. Type 3 sinusitis exhibited severe pathology characteristic of type 1 combined with type 2 sinusitis. Type 4 sinusitis could be differentiated by the CT findings into type 1 or type 2 sinusitis. The classification of sinusitis in this manner has implications for treatment planning, and CT should therefore be performed when conventional radiography does not provide sufficient information..|
|40.||Identifying the major sublingual gland image on sialograms.|