18F-FDG PET/CT for Detecting Sarcoma of the Aorta in a Patient with Takayasu Arteritis

Takahashi, Tomoko,Watanabe, Naoto,Wakasa, Minoru,Kajinami, Kouji,Tonami, Hisao The Korea Society of Nuclear Medicine 2016 핵의학 분자영상 Vol.50 No.2

MRI Reveals Edema in Larynx (But Not in Brain) During Anaphylactic Hypotension in Anesthetized Rats

Ichiro Toyota,Mamoru Tanida,Toshishige Shibamoto,Mofei Wang,Yasutaka Kurata,Hisao Tonami 대한천식알레르기학회 2013 Allergy, Asthma & Immunology Research Vol.5 No.6

Purpose: Anaphylactic shock is sometimes accompanied by local interstitial edema due to increased vascular permeability. We performed magneticresonance imaging (MRI) to compare edema in the larynx and brain of anesthetized rats during anaphylactic hypotension versus vasodilator-inducedhypotension. Methods: Male Sprague Dawley rats were subjected to hypotension induced by the ovalbumin antigen (n=7) or a vasodilator sodiumnitroprusside (SNP; n=7). Apparent diffusion coefficient (ADC) and T2-relaxation time (T2RT) were quantified on MRI performed repeatedly for upto 68 min after the injection of either agent. The presence of laryngeal edema was also examined by histological examination. Separately, the occurrenceof brain edema was assessed by measuring brain water content using the wet/dry method in rats with anaphylaxis (n=5) or SNP (n=5) andthe non-hypotensive control rats (n=5). Mast cells in hypothalamus were morphologically examined. Results: Mean arterial blood pressure similarlydecreased to 35 mmHg after an injection of the antigen or SNP. Hyperintensity on T2-weighted images (as reflected by elevated T2RT) was foundin the larynx as early as 13 min after an injection of the antigen, but not SNP. A postmortem histological examination revealed epiglottic edema inthe rats with anaphylaxis, but not SNP. In contrast, no significant changes in T2RT or ADC were detectable in the brains of any rats studied. In separateexperiments, the quantified brain water content did not increase in either anaphylaxis or SNP rats, as compared with the non-hypotensive controlrats. The numbers of mast cells with metachromatic granules in the hypothalamus were not different between rats with anaphylaxis and SNP,suggesting the absence of anaphylactic reaction in hypothalamus. Conclusion: Edema was detected using the MRI technique in the larynx duringrat anaphylaxis, but not in the brain.

Diagnostic Performance of Whole-Body Diffusion-Weighted Imaging Compared to PET-CT Plus Brain MRI in Staging Clinically Resectable Lung Cancer

Usuda, Katsuo,Sagawa, Motoyasu,Maeda, Sumiko,Motono, Nozomu,Tanaka, Makoto,Machida, Yuichiro,Matoba, Takuma Matsui Munetaka,Watanabe, Naoto,Tonami, Hisao,Ueda, Yoshimichi,Uramoto, Hidetaka Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.6

Background: Precise staging of lung cancer is usually evaluated by PET-CT and brain MRI. Recently, however, whole-body diffusion-weighted magnetic resonance imaging (WB-DWI) has be applied. The aim of this study is to determine whether the diagnostic performance of lung cancer staging by WB-DWI is superior to that of PET-CT+brain MRI. Materials and Methods: PET-CT + brain MRI and WB-DWI were used for lung cancer staging before surgery with 59 adenocarcinomas, 16 squamous cell carcinomas and 6 other carcinomas. Results: PET-CT + brain MRI correctly identified the pathologic N staging in 67 patients (82.7%), with overstaging in 5 (6.2%) and understaging in 9 (11.1%), giving a staging accuracy of 0.827. WB-DWI correctly identified the pathologic N staging in 72 patients (88.9%), with overstaging in 1 (1.2%) and understaging in 8 patients (9.9%), giving a staging accuracy of 0.889. There were no significant differences in accuracies. PET-CT + brain MRI correctly identified the pathologic stages in 56 patients (69.1%), with overstaging in 7 (8.6%) and understaging in 18 (22.2%), giving a staging accuracy of 0.691. WB-DWI correctly identified the pathologic stages in 61 patients (75.3%), with overstaging in 4 (4.9%) and understagings in16(19.7%), giving a staging accuracy of 0.753. There were no significant difference in accuracies. Conclusions: Diagnostic efficacy of WB-DWI for lung cancer staging is equivalent to that of PET-CT + brain MRI.

Diffusion Weighted Imaging Can Distinguish Benign from Malignant Mediastinal Tumors and Mass Lesions: Comparison with Positron Emission Tomography

Usuda, Katsuo,Maeda, Sumiko,Motono, Nozomu,Ueno, Masakatsu,Tanaka, Makoto,Machida, Yuichiro,Matoba, Munetaka,Watanabe, Naoto,Tonami, Hisao,Ueda, Yoshimichi,Sagawa, Motoyasu Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.15

Background: Diffusion-weighted magnetic resonance imaging (DWI) makes it possible to detect malignant tumors based on the diffusion of water molecules. It is uncertain whether DWI is more useful than positron emission tomography-computed tomography (PET-CT) for distinguishing benign from malignant mediastinal tumors and mass lesions. Materials and Methods: Sixteen malignant mediastinal tumors (thymomas 7, thymic cancers 3, malignant lymphomas 3, malignant germ cell tumors 2, and thymic carcinoid 1) and 12 benign mediastinal tumors or mass lesions were assessed in this study. DWI and PET-CT were performed before biopsy or surgery. Results: The apparent diffusion coefficient (ADC) value ($1.51{\pm}0.46{\times}10^{-3}mm^2/sec$) of malignant mediastinal tumors was significantly lower than that ($2.96{\pm}0.86{\times}10^{-3}mm^2/sec$) of benign mediastinal tumors and mass lesions (P<0.0001). Maximum standardized uptake value (SUVmax) ($11.30{\pm}11.22$) of malignant mediastinal tumors was significantly higher than that ($2.53{\pm}3.92$) of benign mediastinal tumors and mass lesions (P=0.0159). Using the optimal cutoff value (OCV) $2.21{\times}10^{-3}mm^2/sec$ for ADC and 2.93 for SUVmax, the sensitivity (100%) by DWI was not significantly higher than that (93.8%) by PET-CT for malignant mediastinal tumors. The specificity (83.3%) by DWI was not significantly higher than that (66.7%) for benign mediastinal tumors and mass lesions. The accuracy (92.9%) by DWI was not significantly higher than that (82.1%) by PET-CT for mediastinal tumors and mass lesions. Conclusions: There was no significant difference between diagnostic capability of DWI and that of PET-CT for distinguishing mediastinal tumors and mass lesions. DWI is useful in distinguishing benign from malignant mediastinal tumors and mass lesions.

Recurrence and Metastasis of Lung Cancer Demonstrate Decreased Diffusion on Diffusion-Weighted Magnetic Resonance Imaging

Usuda, Katsuo,Sagawa, Motoyasu,Motomo, Nozomu,Ueno, Masakatsu,Tanaka, Makoto,Machida, Yuichiro,Maeda, Sumiko,Matoba, Munetaka,Tonami, Hisao,Ueda, Yoshimichi,Sakuma, Tsutomu Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.16

Background: Diffusion-weighted magnetic resonance imaging (DWI) is reported to be useful for detecting malignant lesions. The purpose of this study is to clarify characteristics of imaging, detection rate and sensitivity of DWI for recurrence or metastasis of lung cancer. Methods: A total of 36 lung cancer patients with recurrence or metastasis were enrolled in this study. While 16 patients underwent magnetic resonance imaging (MRI), computed tomography (CT) and positron emission tomography-computed tomography (PET-CT), 17 underwent MRI and CT, and 3 underwent MRI and PET-CT. Results: Each recurrence or metastasis showed decreased diffusion, which was easily recognized in DWI. The detection rate for recurrence or metastasis was 100% (36/36) in DWI, 89% (17/19) in PET-CT and 82% (27/33) in CT. Detection rate of DWI was significantly higher than that of CT (p=0.0244) but not significantly higher than that of PET-CT (p=0.22). When the optimal cutoff value of the apparent diffusion coefficient value was set as $1.70{\times}10^{-3}mm^2/sec$, the sensitivity of DWI for diagnosing recurrence or metastasis of lung cancer was 95.6%. Conclusions: DWI is useful for detection of recurrence and metastasis of lung cancer.

Diagnostic Performance of Diffusion - Weighted Imaging for Multiple Hilar and Mediastinal Lymph Nodes with FDG Accumulation

Usuda, Katsuo,Maeda, Sumiko,Motono, Nozomu,Ueno, Masakatsu,Tanaka, Makoto,Machida, Yuichiro,Matoba, Munetaka,Watanabe, Naoto,Tonami, Hisao,Ueda, Yoshimichi,Sagawa, Motoyasu Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.15

Background: It is sometimes difficult to assess patients who have multiple hilar and mediastinal lymph nodes (MHMLN) with FDG accumulation in PET-CT. Since it is uncertain whether diffusion-weighted magnetic resonance imaging (DWI) is useful in the assessment of such patients, its diagnostic performance was assessed. Materials and Methods: Twenty-three patients who had three or more stations of hilar and mediastinal lymph nodes with SUVmax of 3 or more in PET-CT were included in this study. Results: For diagnosis of disease, there were 20 malignancies (lung cancers 17, malignant lymphomas 2 and metastatic lung tumor 1), and 3 benign cases (sarcoidosis 2 and benign disease 1). For diagnosis of lymph nodes, there were 7 malignancies (metastasis of lung cancer 7 and malignant lymphoma 1) and 16 benign lymphadenopathies (pneumoconiosis/silicosis 7, sarcoidosis 4, benign disease 4, and atypical lymphocyte infiltration 1). The ADC value ($1.57{\pm}0.29{\times}10^{-3}mm^2/sec$) of malignant MHMLN was significantly lower than that ($1.99{\pm}0.24{\times}10^{-3}mm^2/sec$) of benign MHMLN (P=0.0437). However, the SUVmax was not significantly higher ($10.0{\pm}7.34$ as compared to $6.38{\pm}4.31$) (P=0.15). The sensitivity (86%) by PET-CT was not significantly higher than that (71%) by DWI for malignant MHMLN (P=1.0). The specificity (100%) by DWI was significantly higher than that (31%) for benign MHMLN (P=0.0098). Furthermore, the accuracy (91%) with DWI was significantly higher than that (48%) with PET-CT for MHMLN (P=0.0129). Conclusions: Evaluation by DWI for patients with MHMLN with FDG accumulation is useful for distinguishing benign from malignant conditions.

Relationships between EGFR Mutation Status of Lung Cancer and Preoperative Factors - Are they Predictive?

Usuda, Katsuo,Sagawa, Motoyasu,Motono, Nozomu,Ueno, Masakatsu,Tanaka, Makoto,Machida, Yuichiro,Matoba, Munetaka,Taniguchi, Mitsuru,Tonami, Hisao,Ueda, Yoshimichi,Sakuma, Tsutomu Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.2

Background: The epidermal growth factor receptor (EGFR) mutation status of lung cancer is important because it means that EGFR-tyrosine kinase inhibitor treatment is indicated. The purpose of this prospective study is to determine whether EGFR mutation status could be identified with reference to preoperative factors. Materials and Methods: One hundred-forty eight patients with lung cancer (111 adenocarcinomas, 25 squamous cell carcinomas and 12 other cell types) were enrolled in this study. The EGFR mutation status of each lung cancer was analyzed postoperatively. Results: There were 58 patients with mutant EGFR lung cancers (mutant LC) and 90 patients with wild-type EGFR lung cancers (wild-type LC). There were significant differences in gender, smoking status, maximum tumor diameter in chest CT, type of tumor shadow, clinical stage between mutant LC and wild-type LC. EGFR mutations were detected only in adenocarcinomas. Maximum standardized uptake value (SUVmax:$3.66{\pm}4.53$) in positron emission tomography-computed tomography of mutant LC was significantly lower than that ($8.26{\pm}6.11$) of wild-type LC (p<0.0001). Concerning type of tumor shadow, the percentage of mutant LC was 85.7% (6/7) in lung cancers with pure ground glass opacity (GGO), 65.3%(32/49) in lung cancers with mixed GGO and 21.7%(20/92) in lung cancers with solid shadow (p<0.0001). For the results of discriminant analysis, type of tumor shadow (p=0.00036) was most significantly associated with mutant EGFR. Tumor histology (p=0.0028), smoking status (p=0.0051) and maximum diameter of tumor shadow in chest CT (p=0.047) were also significantly associated with mutant EGFR. The accuracy for evaluating EGFR mutation status by discriminant analysis was 77.0% (114/148). Conclusions: Mutant EGFR is significantly associated with lung cancer with pure or mixed GGO, adenocarcinoma, never-smoker, smaller tumor diameter in chest CT. Preoperatively, EGFR mutation status can be identified correctly in about 77 % of lung cancers.

Diagnostic Performance of Diffusion Weighted Imaging of Malignant and Benign Pulmonary Nodules and Masses: Comparison with Positron Emission Tomography

Usuda, Katsuo,Sagawa, Motoyasu,Motono, Nozomu,Ueno, Masakatsu,Tanaka, Makoto,Machida, Yuichiro,Maeda, Sumiko,Matoba, Munetaka,Kuginuki, Yasuaki,Taniguchi, Mitsuru,Tonami, Hisao,Ueda, Yoshimichi,Sakuma Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.11

Background: Diffusion-weighted imaging (DWI) makes it possible to detect malignant tumors based on the diffusion of water molecules. However, it is uncertain whether DWI has advantages over FDG-PET for distinguishing malignant from benign pulmonary nodules and masses. Materials and Methods: One hundred-forty-three lung cancers, 17 metastatic lung tumors, and 29 benign pulmonary nodules and masses were assessed in this study. DWI and FDG-PET were performed. Results: The apparent diffusion coefficient (ADC) value ($1.27{\pm}0.35{\times}10^{-3}mm^2/sec$) of malignant pulmonary nodules and masses was significantly lower than that ($1.66{\pm}0.58{\times}10^{-3}mm^2/sec$) of benign pulmonary nodules and masses. The maximum standardized uptake value (SUVmax: $7.47{\pm}6.10$) of malignant pulmonary nodules and masses were also significantly higher than that ($3.89{\pm}4.04$) of benign nodules and masses. By using optimal cutoff values for ADC ($1.44{\times}10^{-3}mm^2/sec$) and for SUVmax (3.43), which were determined with receiver operating characteristics curves (ROC curves), the sensitivity (80.0%) of DWI was significantly higher than that (70.0%) of FDG-PET. The specificity (65.5%) of DWI was equal to that (65.5%) of FDG-PET. The accuracy (77.8%) of DWI was not significantly higher than that (69.3%) of FDG-PET for pulmonary nodules and masses. As the percentage of bronchioloalveolar carcinoma (BAC) component in adenocarcinoma increased, the sensitivity of FDG-PET decreased. DWI could not help in the diagnosis of mucinous adenocarcinomas as malignant, and FDG-PET could help in the correct diagnosis of 5 out of 6 mucinous adenocarcinomas as malignant. Conclusions: DWI has higher potential than PET in assessing pulmonary nodules and masses. Both diagnostic approaches have their specific strengths and weaknesses which are determined by the underlying pathology of pulmonary nodules and masses.