Dai Kakizaki

Tokyo Medical University, Edo, Tōkyō, Japan

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Publications (43)55.98 Total impact

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    ABSTRACT: Bone-targeted radiopharmaceuticals such as rhenium-186 hydroxyethylidine diphosphonate (HEDP), rhenium-188 HEDP, and strontium-89 (Sr) are used not only for pain reduction, but also for their tumoricidal effect, the efficacy of which is believed to be enhanced by combining them with chemotherapy and/or radiation therapy. The tumoricidal effect of Sr is sometimes estimated from prostate-specific antigen response and/or improved survival of patients with prostate cancer. We confirmed this effect of Sr using magnetic resonance imaging and Tc-99m methoxyisobutylisonitrile (MIBI).
    No preview · Article · Apr 2011 · Clinical nuclear medicine
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    ABSTRACT: To evaluate the effect of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) on T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI) for the diagnosis of hepatocellular carcinoma (HCC). The phantom signal intensity was measured. We also evaluated 72 patients including 30 patients with HCC. T2WI and DWI were obtained before and then 4 and 20 min after injecting the contrast medium. The signal to noise ratio (SNR), contrast to noise ratio (CNR), and apparent diffusion coefficient (ADC) were calculated in the tumor and liver parenchyma. The phantom signal intensity increased on T2WI at a concentration of contrast medium less than 0.2 mmol/L but decreased when the concentration exceeded 0.4 mmol/L. SNR of the liver parenchyma on T2WI was significantly different between before and 4 min after injecting the contrast medium, while there were no significant differences between before and 4 and 20 min after injection. On T2WI, SNR, and CNR of HCC showed no significant differences at any time. SNR, CNR, and ADC of the liver parenchyma and tumor on DWI also showed no significant differences at any time. It is acceptable to perform T2WI and DWI after injection of Gd-EOB-DTPA for the diagnosis of HCC.
    No preview · Article · Jul 2010 · Journal of Magnetic Resonance Imaging
  • S. Xu · D. Kakizaki · H. Kaise · Y. Nakata · K. Saito · J. Park · K. Yamada · S. Akata · N. Kohno · K. Tokuue
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    ABSTRACT: In recent years, because breast conserving surgery is widely performed the accuracy of preoperative diagnostic imaging is becoming more important. Supine MR mammography (MRM) is a minimally invasive technique. It has high spatial resolution and only minor differences in relation to surgical location. We used supine MRM to perform histology estimation for breast carcinoma and evaluate the intraductal spread and axillary lymph node metastasis. We scanned 134 patients with breast cancer and 7 patients with benign breast tumor by 1.5-T MRI before treatment. Dynamic MRI was performed at 20 seconds (early arterial phase), 50 seconds (late arterial phase), and 180 seconds (equilibrium phase) after the beginning of injection of contrast medium. Dynamic imaging was performed with 15 ml gadoterate meglumine injected at a rate of 3.0 ml/sec. We compared MRM imaging findings with pathological findings. The accuracy of the histologic estimation for breast cancer was 60.5%. The accuracy for prediction of intraductal spread and axillary lymph node metastasis were 69.4% and 92.5% respectively. The supine MRM was useful for the diagnosis of histologic estimation of breast tumor, evaluation of ductal spread as well as diagnosis of axillary lymph node metastasis. However, the histological classification and diagnosis of DCIS, scirrhous carcinoma and solid-tubular carcinoma with intraductal spread were difficult. Further research is needed on improving imaging diagnosis for small lymph node metastasis, mastitis carcinomatosa and carcinoma with intraductal spread. It is also necessary to improve MRI resolution and establish diagnosis standard for imaging studies.
    No preview · Article · Jan 2010
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    ABSTRACT: We performed a perfusion study with superparamagnetic iron oxide (SPIO) and evaluated the possibility of acquiring hemodynamic imaging in hypervascular hepatocellular nodules. Single-slice computed tomography during arteriography (SCTA) and an SPIO perfusion study were performed and compared. The findings of the direction of blood flow in the lesion and the findings corresponding to the corona enhancement on the SPIO perfusion study agreed well with the findings of SCTA. In conclusion, SPIO perfusion is useful in evaluating the hemodynamics of hypervascular hepatocellular nodules.
    No preview · Article · Nov 2009 · Clinical imaging
  • K. Saito · J. Park · S. Xu · R. Nishio · Y. Shimazaki · D. Kakizaki
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    ABSTRACT: Purpose: The purpose of this study was to evaluate the effect of the concentration of contrast material to obtain good quality arterial phase images with a multi-detector CT. Materials and method: We divided 77 patients into the following 2 groups: the moderate concentration group (300 mgI/mL, maximum dose 150 mL, 37 cases), and the high concentration group (370 mgI/mL, maximum dose 100 mL, 40 cases). The contrast material dose was adjusted by the patient's body weight (600 mgl/kg) and administration was followed by saline flush. The injection duration was fixed (30 seconds). A monitoring scan was used with the trigger threshold set at 200 HU. Quantitative evaluation of the aorta, liver parenchyma and tumor-liver contrast between moderate and high concentration contrast material was performed. We qualitatively evaluated the conspicuity of the hepatic artery, portal vein, hepatic vein and tumor. Results: There was no significant difference in the time to reach the trigger threshold and the beginning of the arterial phase scan. Quantitative and qualitative evaluation of the aorta, hepatic parenchyma and tumor-liver contrast also revealed no significant difference. Interobserver agreement was good for the qualitative evaluation of the conspicuity of the hepatic artery, portal vein and hepatic vein. Conclusion: Similar arterial phase images could be obtained by both moderate and high concentration of contrast material.
    No preview · Article · Apr 2009
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    ABSTRACT: We investigated magnetic resonance imaging T2-star (MRI-T2*) values and left ventricular ejection fraction (LVEF) in 7 adult patients with bone marrow failure with heavy transfusion to elucidate the correlation between cardiac iron overload and dysfunction. We demonstrated a positive correlation between the total volume of red blood cells (RBC) transfusion and ejection fraction. The normal T2* limit value, which represents cardiac siderosis, is probably 200 mL/kg RBC transfusion. Patients with serum ferritin levels of under 5000 ng/mL and who received 200-400 mL/kg RBC transfusion showed mild but progressive decrease of the T2* value without obvious reduction of the ejection fraction, indicating that the T2* value of MRI could be a predictor for cardiac iron deposition before the appearance of myocardial dysfunction. Transfused RBC amount of >400 mL/kg or rapid elevation of ferritin level of >5000 ng/mL might be warning sign for critical cardiac dysfunction. Since iron overload of the heart is a major factor affecting co-morbidity of bone marrow failure, MRI evaluation of cardiac iron overload and functional disturbance in adult non-thalassemic patients is essential.
    No preview · Article · Dec 2008 · Leukemia research
  • A Kawamoto · M Kurotsuchi · H Kaise · D Kakizaki · K Abe
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    ABSTRACT: PURPOSE/AIM: 1. To review the sonographic criteria of axillary lymph node status in breast cancer patients. 2. To understand imaging pathologic correlations that the false-negative cases of axillary ultrasonography. CONTENT ORGANIZATION: The sonographic criteria, the accuracy of sonographic axillary ultrasonography, imaging pathologic correlations in false-negative cases, measurement of largest malignant focus size in lymph node, classification of ratio of malignant focus size, ratio of micro metastasis. SUMMARY: 1. Recently, lymph node evaluation that using serial section and immunohistochemical stains makes it difficult to detect imaging modalities. 2. Ultrasonography is limited how to detect the example of sentinel lymph node biopsy non-indications.
    No preview · Article · Aug 2008 · Nippon Hoshasen Gijutsu Gakkai zasshi
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    ABSTRACT: With the spread of high-resolution computed tomography (HRCT) screening for lung cancer, we are increasingly faced with the need to determine whether certain small lesions are benign or malignant. The features of small adenocarcinomas have been clarified but not those of squamous cell carcinoma. The objective of our study was therefore to clarify the HRCT findings of peripherally located squamous cell carcinomas less than 2 cm in maximum dimension. Subjects consisted of 27 consecutive pathologically proven cases of peripherally located squamous cell carcinoma that were less than 2 cm in maximum dimension. HRCT findings of all 27 cases were analyzed retrospectively and independently by three radiologists who were unaware of the pathological diagnosis, and decisions were reached by consensus with special attention to 10 review points. Internal characteristic features included calcification, cavity formation, and air bronchogram. Tumor margin features included spiculation, notching, irregularity, and ground-glass opacity. Surrounding structural features consisted of pleural indentation, pulmonary emphysema, and satellite lesions. The presence of irregularity (70.4%), surrounding pulmonary emphysema (70.4%), and pleural indentation (51.9%) was observed frequently. No mass was accompanied by calcification. HRCT images of peripherally located squamous cell carcinoma suggested that the demonstration of irregularity, surrounding pulmonary emphysema, pleural indentation, and absence of calcification may contribute to the accurate CT diagnosis of small peripheral squamous cell carcinoma.
    No preview · Article · Jul 2008 · Clinical imaging
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    ABSTRACT: We report a case of left main bronchial glomus tumor in a 39-year-old man who presented with a cough he had had for 1 month. A computed tomography (CT) scan revealed a polypoid tumor in the membranous portion of the left main bronchus. The tumor showed marked enhancement on the early phase of dynamic contrast-enhanced CT, and it was thought to be a hypervascular tumor. The tumor was carefully resected by a rigid bronchoscope, and the pathological and immunohistochemical findings yielded a diagnosis of glomus tumor. Marked enhancement of early phase dynamic contrast-enhanced CT may be useful for a diagnosis of bronchial glomus tumor.
    No preview · Article · May 2008 · Lung Cancer
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    S Akata · N Kajiwara · J Park · M Yoshimura · D Kakizaki · K Abe · T Hirano · T Ohira · M Tsuboi · H Kato
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    ABSTRACT: Conventional CT or MRI has low accuracy in assessing chest wall invasion in patients with peripheral lung cancer. For preoperative evaluation of chest wall invasion by peripheral lung cancer, respiratory dynamic (RD) MRI was carried out in 98 patients in whom conventional CT scan showed that the tumour was abutting the pleural surface, but there was no evidence of definite tumour invasion. We used 1.5-T MR equipment. RD MR images were acquired by snapshot fast field echo sequence (repetition time = 8, echo time = 3, flip angle = 100) and 25 consecutive images were taken while the patient took deep breaths. These images were evaluated in cine mode to assess tumour movement along the chest wall. Sixty-one patients underwent surgical resection of the tumour and RD MR findings were compared with those in pathological specimens. RD MR showed free tumour movement along the chest wall in 34 patients. At pathological examination, the RD MR findings were proved correct in all patients. Pathologically, 20 patients had chest wall invasion and their RD MR was positive (sensitivity 100%). There were seven false-positive results among the 41 patients without chest wall invasion (specificity 82.9%). RD MR may improve the accuracy of conventional CT scan or MRI in the prediction of chest wall invasion of lung cancer, especially in patients in whom the results of conventional CT scan or MRI appear equivocal in the presence of a peripheral mass abutting the chest wall surface without obvious chest wall invasion.
    Full-text · Article · Mar 2008 · Journal of Medical Imaging and Radiation Oncology
  • S Akata · J Park · H Shindo · M Yoshimura · D Kakizaki · K Abe
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    ABSTRACT: We encountered a case showing a crazy-paving appearance on high-resolution computed tomography (HRCT), which mimicked various pulmonary diseases, e.g. pulmonary alveolar proteinosis, or non-specific interstitial pneumonia, but which we ultimately determined to be due to barium aspiration. The initial radiological findings were considered to be most likely due to pulmonary alveolar microlithiasis, because the crazy-paving appearance had high density, resembling calcification. However, distribution was limited to the area of dependent drainage of the right lung. Since a barium swallowing study had been performed 2 weeks before the CT examination, and since the follow-up HRCT showed improvement we reached a diagnosis of barium aspiration. Although barium aspiration may yield findings similar to other diseases with crazy-paving appearance, it is possible to identify it because of the limited distribution and high density.
    No preview · Article · Jan 2008 · Australasian Radiology
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    ABSTRACT: The purpose of our study was to describe the computed tomography (CT) findings of large cell neuroendocrine carcinoma (LCNEC) and to correlate radiological and pathological findings. We reviewed the CT findings of 36 patients [including the high-resolution computed tomography (HRCT) findings of 29 patients] with resected LCNEC specimens. There were 33 men (92%), and 30 patients had a smoking history (83%). Only one case was of the central type. Mediastinal or hilar lymphadenopathy was seen in 12 (33%), but only one showed bulky lymphadenopathy. The HRCT findings of LCNEC consisted of irregular margins (66%), surrounding emphysema (41%), notching (38%), calcifications (21%), and pleural indentation (24%). Our study indicates that the CT image of LCNEC generally shows a peripherally located, expansively growing, irregularly margined pulmonary mass, with or without calcification, and without bulky lymphadenopathy. While the CT image of LCNEC resembles that of squamous cell carcinoma, cavitation is infrequent. LCNEC cannot be differentiated from poorly differentiated adenocarcinoma or atypical carcinoid on the basis of CT findings.
    No preview · Article · Nov 2007 · Clinical Imaging
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    ABSTRACT: Focal nodular hyperplasia (FNH) is a benign localized lesion in the liver first reported by Edmondson in 1956. Histologically, FNH is defined as a type of tumorlike lesion. Histopathologically, it is sometimes difficult to differentiate FNH from adenoma. Macroscopically FNH is a nodule without a capsule showing a central stellate fibrous scar spreading from the center of the nodule radially toward the periphery. These features have been regarded as the determining factors for imaging diagnosis. In dynamic computed tomography (CT) studies, the FNH is isoattenuating before contrast, showing homogenous hyperattenuation in the early arterial phase and isoenhancement during the portal venous phase. Diagnosis is facilitated by the presence of a central scar, but this feature can only be observed in approximately 50% of cases. Although the vascular structure of FNH is said to be characterized by a typical spoke-wheel pattern and a stellate fibrous scar, these features are not readily visualized in small FNH lesions. In such cases, it is necessary to differentiate from other hypervascular malignant tumors such as hepatocellular carcinoma (HCC) and metastatic lesions. The recent advent of multi-detector row CT, 3-dimensional CT, and single-level dynamic CT during hepatic arteriography has allowed detailed visualization of the hemodynamics of FNH. According to these evaluations, the drainage veins of FNH are mainly the hepatic veins, although they sometimes drain directly into the sinusoids surrounding the tumor. However, angiography is invasive, and 3-dimensional volume imaging does not allow real-time presentation. In this case, contrast-enhanced sonography using Levovist (SH U 508A; Schering AG, Berlin, Germany) enhanced the FNH in real time in the early arterial phase and clearly depicted subsequent drainage into the hepatic veins.
    No preview · Article · Jul 2006 · Journal of ultrasound in medicine: official journal of the American Institute of Ultrasound in Medicine
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    ABSTRACT: LEARNING OBJECTIVES An awareness of the various MRI findings of the different types of thymic epithelial tumors, as reflected in the 2004 WHO histologic classification, may be helpful in clinical practice for the assessment and treatment of patients with thymoma and thymic carcinomas. ABSTRACT Our purpose was to assess the MRI features of various subtypes of thymoma and thymic carcinoma on the basis of the 2004 World Health Organization classification. Thymic epithelial neoplasms in 43 patients who underwent thymectomy were retrospectively assessed histologically according to the 2004 WHO classification. Thymomas were classified as: type A (medullary), type AB (mixed), and type B (cortical), with subtypes B1, B2, and B3. Two observers independently assessed the MRI findings without knowledge of the histologic findings. These findings were correlated with pathologic findings. A smooth contour and round shape are most suggestive of a type-A, whereas an irregular contour most strongly suggests cancer. At T2WI, lobular internal architecture is more prominent in type-B than in others, and most B2 and B3 thymomas manifest scattered high-intensity areas, shown at pathologic examination to correspond to cystic spaces. Type-AB shows two separate signal intensities at T2WI. DISCLOSURE
    No preview · Conference Paper · Nov 2005
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    ABSTRACT: We produced virtual hysteroscopy (VH) images from the images obtained after expanding the uterine cavity of patients with submucosal myomas and performing multidetector-row computed tomography scans, and assessed them in comparison with hysteroscopic imaging and in relation to the advantages of VH. Cohort-control study (Canadian Task Force classification II-2). Tokyo Medical University Hospital department of obstetrics and gynecology. Thirty-one patients with submucosal myomas treated by endoscopic surgery. The expandability of the uterine cavity by CO(2) gas was favorable in all 31 patients in whom imaging was performed, and it was possible to obtain clear VH images. The sites of origin of the submucosal myomas were clearly visualized; their imaging was consistent with imaging by hysteroscopy; and as a method of establishing the orientation of the uterine cavity, it was possible to obtain a greater amount of information than by hysteroscopy. Although the invasiveness of radiation exposure and contrast medium cannot be denied, the possibilities of and indications for VH, which by expanding and visualizing the uterine cavity enables the acquisition of navigation images of the uterine cavity that varies in morphology from patient to patient, are expected to continue to expand.
    No preview · Article · Jun 2005 · Journal of Minimally Invasive Gynecology
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    ABSTRACT: To assess myometrial invasion and cervical invasion by endometrial carcinoma, using CO2-volumetric interpolated breathhold examination (VIBE) enabling more precise evaluation of depth of tumor invasion. CO2-VIBE was performed in 21 cases of endometrial carcinoma (Stage Ia-IIb) prior to treatment. The images were interpreted by performing multiplanar reconstruction (MPR), and the findings obtained from the images (degree of myometrial invasion and presence or absence of cervical invasion) were assessed in comparison with the histopathological diagnosis. The sites of the endometrial carcinoma lesions were clearly visualized by the CO2-VIBE method. Evaluation of the degree of myometrial invasion enabled a high correct diagnosis rate of 90.5%, and evaluation for the presence of cervical invasion also allowed a high correct diagnosis rate of 90.5%. VIBE permits evaluation of any plane desired by means of thin slices, and it is a truly revolutionary method for preoperative evaluation of depth of invasion of endometrial carcinoma that enables highly accurate determination of the extent of lesion sites and degree of invasion before treatment.
    No preview · Article · Feb 2005 · Journal of Magnetic Resonance Imaging
  • Dai Kakizaki
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    ABSTRACT: LEARNING OBJECTIVES We conducted MDCT whereby CO2 gas was infused in the uterine cavity ( CO2-pelvic CT), and examined the utility for diagnosing cancer of uterine body cancer, submucosal myoma or other uterine endometrial disease filling the uterine cavity. And we aimed to create an endoscopic image of the uterine cavity , and to evaluate its utility. ABSTRACT Using 8-detector multislice CT, images were obtained at both arterial and venous phases under a single breath-hold. There were 5 cases of uterine body cancer , 24 cases of submucosal myoma and 8 cases of endometrial polyp. MIP and MPR image processing was conduted after the images wrer taken, and all cases CT uteroscopy were performed.In the 5 cases an accurate diagnosis was obtained for advanced stage classification of the uterine body cancer . And in the 22 cases (91.7%)of submucosal myoma and 8cases (100%) of endometrial polyp , we identified the area of attachment to the muscular tunic by CT endoscopy.We were able to accurately classify the advanced stages of uterine body cancer. The utility of this is considered extremely high. It is also thought to be of some help during endoscopic surgical operation on submucosal myoma occupying the uterine cavity. We have not seen any previous reports of uterine CO2-pelvic CT and CT uteroscopy, so this reports is the first of its kind.
    No preview · Conference Paper · Nov 2004
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    ABSTRACT: T2-weighted fast spin echo images and T2*-weighted gradient-echo images of superparamagnetic iron oxide magnetic resonance imaging (SPIO-MRI) have been reported to reflect the number and function of macrophages in reticuloendothelial organs and be useful to differentiate malignant tumors from benign nodules of liver. We tried to prove that contrast-enhanced ultrasound can diagnose hepatocellular carcinoma (HCC) by comparing the findings of SPIO-MRI and the findings of the liver parenchyma on the delayed parenchymal phase of ultrasound imaging using the intravenous contrast agent Levovist, not through the evaluation of vascular imaging. Forty-six patients (52 nodules) with histopathological diagnosis of hepatic tumors were studied. They consisted of 11 non-malignant nodules (six regenerative nodules and five dysplastic nodules) and 41 HCC. All the patients were examined by Levovist contrast-enhanced ultrasonography and SPIO-MRI. The delayed liver parenchymal images of contrast-enhanced ultrasound using the intravenous contrast agent Levovist were similar to those observed on SPIO-MRI. The similarity of both findings suggests that delayed phase imaging by Levovist is closely related to the number and function of Kupffer cells in liver tumors. The diagnostic accuracy of contrast-enhanced ultrasound for HCC was high (90.4%) demonstrating that it is as reliable as SPIO-MRI.
    No preview · Article · Jul 2004 · Hepatology Research
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    ABSTRACT: Three dimensional volumetric interpolated breath-hold examination magnetic resonance imaging(3D-VIBE MRI) has the advantage of improving z-axis resolution, which makes it possible to obtain high quality multi-planar reconstruction (MPR) and 3-D reconstruction images. Using these capabilities of 3D-VIBE MRI, we have attempted to diagnose and evaluate breast tumors for preoperative planning. One hundred patients with breast cancer and 5 patients with benign breast tumors were scanned by 1.5-T MR imaging, and the findings were compared with pathological findings. Triple-phase contrast-enhanced 3D-VIBE MRI was performed at 20 seconds (early arterial phase), 50 seconds (late arterial phase) and 180 seconds (equilibrium phase) after the beginning of injection of contrast material. Dynamic imaging was performed with 20 ml Gd-DOTA injected at a rate of 3.0 ml/sec. We also attempted to diagnose breast tumor for the detection of the primary lesion, estimation of histologic type, prediction of extensive intraductal components (EIC) and axillary lymph node metastases from breast cancer. (1) The diagnostic accuracy for breast cancer was 96.0% and it was 100.0% for benign disease. (2) The accuracy of the histologic estimation for breast cancer was 56.4%, and it was 83.3% for benign disease. (3) The accuracy of evaluation of ductal spread of breast cancer was 52.4%. (4) The accuracy was 72.4% for lymph node metastasis from breast cancer. This method provides useful information about the location of the primary tumor and lymph nodes. 3D-VIBE method is considered especially important for the preoperative evaluation of axillary lymph node status.
    No preview · Article · May 2004 · Nippon rinsho. Japanese journal of clinical medicine
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    ABSTRACT: A sixty-five-year-old woman was hospitalized for examination of swelling in the left arm. Gallium-67 scintigraphy showed the same radioactivity in the left lobe of the thyroid gland and the junction of the internal jugular vein and the subclavian vein. Operation then proved obstruction of the left internal jugular vein and subclavian vein due to tumor thrombus accompanied by anaplastic thyroid cancer. Gallium-67 scintigraphy was extremely useful in grasping the extent and feature of the tumor.
    No preview · Article · Jan 2004 · Annals of Nuclear Medicine