Okayama Diagnostic Imaging Center

Okayama-shi, Japan

Okayama Diagnostic Imaging Center

Okayama-shi, Japan

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Alafate A.,Okayama University of Science | Shinya T.,Okayama University of Science | Okumura Y.,Fukuyama City Hospital | Sato S.,Okayama University of Science | And 8 more authors.
Acta Medica Okayama | Year: 2013

We retrospectively evaluated the accumulation of fluorodeoxy glucose (FDG) in pulmonary malignancies without local recurrence during 2-year follow-up on positron emission tomography (PET)/com-puted tomography (CT) after radiofrequency ablation (RFA). Thirty tumors in 25 patients were studied (10 non-small cell lung cancers; 20 pulmonary metastatic tumors). PET/CT was performed before RFA, 3 months after RFA, and 6 months after RFA. We assessed the FDG accumulation with the maximum standardized uptake value (SUVmax) compared with the diameters of the lesions. The SUVmax had a decreasing tendency in the first 6 months and, at 6 months post-ablation, FDG accumulation was less affected by inflammatory changes than at 3 months post-RFA. The diameter of the ablated lesion exceeded that of the initial tumor at 3 months post-RFA and shrank to pre-ablation dimensions by 6 months post-RFA. SUVmax was more reliable than the size measurements by CT in the first 6 months after RFA, and PET/CT at 6 months post-RFA may be more appropriate for the assessment of FDG accumulation than that at 3 months post-RFA. © 2013 by Okayama University Medical School.


Matsuo T.,Okayama University of Science | Ogino Y.,Okayama University of Science | Ichimura K.,Okayama University of Science | Tanaka T.,Okayama University of Science | Kaji M.,Okayama Diagnostic Imaging Center
International Journal of Clinical Oncology | Year: 2014

Background: The purpose of this study was to redefine the role of whole-body 2-[18F]fluoro-2-deoxy-D-glucose (FDG) positron emission tomography fused with computed tomography (PET/CT) in the clinical diagnosis of choroidal malignant melanoma. Methods: The study design was a retrospective case series involving 7 consecutive patients with choroidal malignant melanoma who underwent enucleation to reach the final pathological diagnosis. FDG-PET/CT was performed together with magnetic resonance imaging and ophthalmological examinations before the surgery. The area, thickness, longest diameter, and circumference of the tumor mass were measured on pathological sections, and were correlated with maximum standardized uptake values (SUVmax) of the tumors on FDG-PET/CT. Results: Abnormally high uptake of FDG was noted in the affected eyes of 5 patients, but not in the eyes of 2 patients. The 5 patients with high uptake showed nodular tumors extruding into the vitreous cavity while the 2 patients with absence of uptake showed diffusely infiltrating tumors in the wide area of the choroid with or without a small mushroom-like protrusion. One patient with diffuse infiltration showed concurrent liver metastases with high uptake on PET/CT while another patient with a nodular tumor developed liver metastases a year later. The tumors with higher SUVmax had a tendency to have a wider area and greater thickness on pathological sections (ρ = 0.775, P = 0.0557, Spearman rank correlation test). Conclusions: FDG-PET/CT showed correlation of the uptake with tumor sizes but was limited in detecting diffusely infiltrating tumors in the choroid without nodular formation. © 2013 Japan Society of Clinical Oncology.


Yoshio K.,Okayama University | Sato S.,Okayama University | Okumura Y.,Okayama University | Katsui K.,Okayama University | And 5 more authors.
Clinical Nuclear Medicine | Year: 2011

Purpose: The aim of this study was to evaluate the local efficacy of I-131 for F-18 fluorodeoxyglucose positron emission tomography (FDG PET)-positive lesions. Methods: Whole-body FDG PET/CT was performed on 37 patients (55 cases: 16 men, 21 women; age range: 24-82 years; mean age ± standard deviation: 60.5 ± 16.0 years) with differentiated thyroid cancer after total thyroidectomy. The metastatic or recurrent lesions were divided into 5 categories: primary tumor bed, lymph node, lung, bone, and other. The well-defined lesions were measured on CT, and the sizes were compared before and after radioactive iodine therapy. Results: The analysis was performed on 37 patients with 44 lesions (lymph node:24, lung:16, bone:4). Sixteen lesions (70%) were increased and 7 (30%) showed no change or reduction when there was positive accumulation on FDG PET/CT and negative accumulation on I-131 (F(+)I(-)) group. In the positive accumulation for both FDG PET/CT and I-131 (F(+)I(+)) group, 5 lesions (63%) were increased and 3 (37%) showed no change or reduction. There was no significant difference for the tendency to increase in size between the F(+)I(-) and the F(+)I(+) groups. Conclusions: Lesions which show positive accumulations on FDG PET/CT have a greater tendency to increase in size. FDG-avid lesions are resistant to radioactive iodine therapy with or without I-131 uptake. Copyright © 2011 by Lippincott Williams &Wilkins.


Harada S.,Okayama University of Science | Sato S.,Okayama University of Science | Suzuki E.,Okayama University of Science | Okumura Y.,Okayama University of Science | And 6 more authors.
Acta Medica Okayama | Year: 2011

The aim of the present study was to assess the diagnostic usefulness of Fluorine-18 fluorodeoxyglucose ( 18F-FDG) positron emission tomography/computed tomography (PET/CT) in the prediction of local recurrence of malignant lung tumors by analyzing the pre-radiofrequency ablation (RFA) maximal standardized uptake value (SUV max). We performed a historical cohort study of consecutive malignant lung tumors treated by RFA from January 2007 to May 2008 at Okayama University Hospital. We selected only lung tumors examined by PET/CT within 90 days before RFA and divided them (10 primary and 29 metastatic) into 3 groups according to their tertiles of SUV max. We calculated recurrence odds ratios in the medium group and the high group compared to the low group using multivariate logistic analysis. After we examined the relationship between SUV max and recurrence in a crude model, we adjusted for some factors. Tumors with higher SUV max showed higher recurrence odds ratios (medium group; 1.84, high group; 4.14, respectively). The tumor size also increased the recurrence odds ratio (2.67); we thought this was mainly due to selection bias because we excluded tumors less than 10 mm in diameter. This study demonstrated the pre-RFA SUV max in PET/CT may be a prognostic factor for local recurrence of malignant lung tumors. © 2011 by Okayama University Medical School.


Matsuo T.,Okayama University of Science | Ichimura K.,Okayama University of Science | Tanaka T.,Okayama University of Science | Kaji M.,Okayama Diagnostic Imaging Center
Clinical Nuclear Medicine | Year: 2012

Four consecutive patients presented with extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) in the conjunctiva. After the initial resection, long-term follow-up without additional therapy showed the clinical relapse. Fluorodeoxyglucose positron emission tomography fused with computed tomography (PET/CT) showed abnormal uptake in the conjunctival relapsed lesions, which were, on reresection, again proven as MALT lymphoma. Small and thin lesions of MALT lymphoma in the conjunctiva can be detected by fluorodeoxyglucose PET/CT. The resolution of PET/CT, delineated in this study, could be applied to the other areas of the body to achieve more accurate staging of lymphoma. © 2012 Lippincott Williams & Wilkins, Inc.


Takiguchi S.,Okayama University of Science | Maekawa K.,Okayama University of Science | Ono T.,Okayama University of Science | Sasai N.,Okayama Diagnostic Imaging Center | And 3 more authors.
Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology and Endodontology | Year: 2010

Objectives: The aim of this study was to investigate the intramuscular metabolic state in chronically painful muscles using positron-emission tomography/computerized tomography (PET/CT). Study design: The study included 140 consecutive noncancer subjects who underwent PET/CT screening for a physical checkup (mean age 56.0 ± 10.22 y). The demographic data and information on pain in the neck/shoulder region were obtained using a questionnaire. The subjects who had an awareness of pain in the neck/shoulder region for >6 months were regarded to be pain subjects (n = 39). The minimal and maximal standardized uptake values (SUV) of [18F]fluorodeoxyglucose ( 18F-FDG) of the trapezius muscle in each subject were automatically calculated. Results: The unpaired t test revealed that both the minimal and the maximal SUVs were significantly lower in the pain subjects than in the asymptomatic subjects. A multiple linear regression analysis also demonstrated a significant association between pain in the neck/shoulder region and the SUVs in the trapezius muscle. Conclusions: Uptake of 18F-FDG was lower in the chronically painful trapezius muscle. © 2010 Mosby, Inc. All rights reserved.


Tanabe S.,Okayama University of Science | Naomoto Y.,Okayama University of Science | Shirakawa Y.,Okayama University of Science | Fujiwara Y.,Okayama University of Science | And 10 more authors.
Clinical Nuclear Medicine | Year: 2011

Purpose: Evaluating the status of disease progression is critical for planning a therapeutic strategy for esophageal cancer. In this regard, F-18 fluorodeoxyglucose-labeled positron emission tomography (PET) is one of the most useful diagnostic modalities. However, there is room to improve its diagnostic performance, such as distinguishing lymph nodal metastases from false positives. In this study, we examined the diagnostic accuracy of fluorodeoxyglucose PET accompanied by computed tomography imaging (PET/CT) to detect regional lymph nodal metastasis from esophageal squamous cell carcinoma (ESCC). Methods: A total of 102 patients diagnosed as ESCC were subjected to this study. These patients had a preoperative PET/CT examination to evaluate the existence of metastasis. The values of maximum standardized uptake value (SUV max) in primary tumors and in metastasized lymph nodes were measured to analyze their relationship with various clinicopathologic characteristics including the status of tumor cell proliferation, which was assessed by immunohistochemistry for Ki-67. Results: The SUV max of the primary tumor was positively correlated with tumor size and vessel invasion, and was positively related with the SUV max of lymph nodal metastasis, especially in cases of poorly differentiated ESCC. The SUV max of metastasized lymph nodes was higher in larger-sized metastasized lymph nodes, whereas the Ki-labeling index of lymph nodal metastasis was positively related with the SUV max per unit area (SUV max/mm 2). The diagnostic accuracy of PET/CT (87.3%) was higher than that of conventional CT scans (78.4%). Conclusions: The improved diagnostic accuracy of PET/CT can be explained by its ability to detect actively progressive metastasis at an early phase regardless of size. Copyright © 2011 by Lippincott Williams & Wilkins.


PubMed | Kawasaki Medical School, Okayama Diagnostic Imaging Center and Okayama University
Type: Journal Article | Journal: Japanese journal of clinical oncology | Year: 2016

Endobronchial ultrasound-guided transbronchial needle aspiration is of diagnostic value in hilar/mediastinal (N1/N2) lymph node staging. We assessed the utility of endobronchial ultrasound-guided transbronchial needle aspiration in lung cancer patients with N1/N2 lymph nodes detected on (18)F-fluorodeoxyglucose positron emission tomography/computed tomography.Fifty lung cancer patients with N1/N2 disease on (18)F-fluorodeoxyglucose positron emission tomography/computed tomography underwent endobronchial ultrasound-guided transbronchial needle aspiration for pathological lymph nodes between November 2012 and April 2015. The diagnostic performance of endobronchial ultrasound-guided transbronchial needle aspiration, lymph node site and size, number of needle passes and complications were evaluated retrospectively from patients medical records. Malignancy was defined as a maximum standardized uptake value (SUVmax) >2.5.The median longest diameter of the 61 lymph nodes (29 subcarinal, 21 right lower paratracheal, 6 left lower paratracheal, 4 right hilar and 1 upper paratracheal) was 23.4 mm (range: 10.4-45.7); the median number of needle passes was 2 (range: 1-5). There were no severe complications. A definitive diagnosis was made by endobronchial ultrasound-guided transbronchial needle aspiration in 39 patients (31 adenocarcinomas, 3 small-cell carcinomas, 2 squamous-cell carcinomas, 3 large-cell neuroendocrine carcinomas). In the remaining 11 patients, the diagnosis was indefinite: insufficient endobronchial ultrasound-guided transbronchial needle aspiration material was collected in two patients and non-specific lymphadenopathy was confirmed by endobronchial ultrasound-guided transbronchial needle aspiration or thoracotomy in the other nine patients. The mean lymph node SUVmax was 7.09 (range: 2.90-26.9) and was significantly higher in true-positive than in false-positive nodes (P < 0.05, t-test). Non-specific lymphadenopathy was diagnosed by expert visual interpretation of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography images in five of the nine patients.Endobronchial ultrasound-guided transbronchial needle aspiration accurately diagnoses N1/N2 disease detected on (18)F-fluorodeoxyglucose positron emission tomography/computed tomography.


Katayama N.,Red Cross | Takemoto M.,Okayama University | Yoshio K.,Okayama University | Katsui K.,Okayama University | And 6 more authors.
Journal of Radiation Research | Year: 2011

Computed tomography (CT)/magnetic resonance imaging (MRI) fusion is considered to be the best method for postimplant dosimetry of permanent prostate brachytherapy; however, it is inconvenient and costly. In T2*-weighted image (T2*-WI), seeds can be easily detected without the use of an intravenous contrast material. We present a novel method for postimplant dosimetry using T2*-WI/T2-weighted image (T2-WI) fusion. We compared the outcomes of T2*-WI/T2-WI fusion-based and CT/T2-WI fusion-based postimplant dosimetry. Between April 2008 and July 2009, 50 consecutive prostate cancer patients underwent brachytherapy. All the patients were treated with 144 Gy of brachytherapy alone. Dose-volume histogram (DVH) parameters (prostate D90, prostate V100, prostate V150, urethral D10, and rectal D2cc) were prospectively compared between T2*-WI/T2-WI fusion-based and CT/T2-WI fusion-based dosimetry. All the DVH parameters estimated by T2*-WI/T2-WI fusion-based dosimetry strongly correlated to those estimated by CT/T2-WI fusion-based dosimetry (0.77 ≤ R ≤ 0.91). No significant difference was observed in these parameters between the two methods, except for prostate V150 (p = 0.04). These results show that T2*-WI/T2-WI fusion-based dosimetry is comparable or superior to MRI-based dosimetry as previously reported, because no intravenous contrast material is required. For some patients, rather large differences were observed in the value between the 2 methods. We thought these large differences were a result of seed miscounts in T2*-WI and shifts in fusion. Improving the image quality of T2*-WI and the image acquisition speed of T2*-WI and T2-WI may decrease seed miscounts and fusion shifts. Therefore, in the future, T2*-WI/T2-WI fusion may be more useful for postimplant dosimetry of prostate brachytherapy.


Sasai N.,Okayama Diagnostic Imaging Center | Ida K.,Okayama Diagnostic Imaging Center | Kaji M.,Okayama Diagnostic Imaging Center | Kanazawa S.,Okayama Diagnostic Imaging Center
Japanese Journal of Clinical Radiology | Year: 2011

The radiological findings of IgG4- related sclerosing cholangitis are similar to those of cholangiocarcinoma, and a differential diagnosis between them is often difficult. These diseases must be diagnosed correctly because they require different treatments. Our case showed hyperenhancement during the arterial phase contrast-enhanced CT, which could be a differential finding from cholangiocarcinoma.

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