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Dive into the research topics where Tsukasa Saida is active.

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Featured researches published by Tsukasa Saida.


Radiation Medicine | 2006

Systemic arterial supply to the normal basal segments of the left lower lobe treated by coil embolization, with long-term follow-up

Tsukasa Saida; Hiroki Ninomiya; Fumihiko Hojo; Masaharu Nakayama; Toshitada Yamauchi; Yukihisa Saida

We report a case of a 41-year-old woman who underwent therapeutic embolization of an aberrant systemic artery of the lung. Except for chest pains immediately after embolization, she recovered well and has not experienced hemoptysis in the past 6 years. In such patients, coil embolization could be an alternative choice of treatment, with the expectation of an excellent long-term result despite ischemia of the corresponding lung parenchyma.


Journal of Magnetic Resonance Imaging | 2011

Ovarian serous surface papillary borderline tumors form sea anemone-like masses.

Yumiko Oishi Tanaka; Satoshi Okada; Toyomi Satoh; Koji Matsumoto; Akinori Oki; Masato Nishida; Hiroyuki Yoshikawa; Tsukasa Saida; Manabu Minami

To clarify the imaging characteristics of ovarian serous surface papillary borderline tumor (SSPBT), whose prognosis is far better than that of serous surface papillary adenocarcinoma (SSPC).


Journal of Computer Assisted Tomography | 2012

Moyamoya disease: evaluation of postoperative revascularization using multiphase selective arterial spin labeling MRI.

Tsukasa Saida; Tomohiko Masumoto; Yasunobu Nakai; Masanari Shiigai; Akira Matsumura; Manabu Minami

Purpose The purpose of this study was to evaluate cerebral blood flow through the bypass in operated patients with Moyamoya disease using multiphase selective arterial spin labeling (ASL) technique. Materials and Methods Fifteen surgically treated cerebral hemispheres from 11 patients with Moyamoya disease were included. Selective ASL examinations were performed during the early postoperative period (mean, 5.5 days) on 4 hemispheres and late postoperative period (mean, 332.7 days) on 15 hemispheres. The labeling slab was positioned at the bypassed external carotid artery and 5 slices in each of the 10 sequential phases were acquired using a 3-T scanner. Results Two of 4 early postoperative ASL examinations and all late postoperative ASL examinations demonstrated blood flow through the bypass. The remaining 2 early postoperative ASL examinations showed absence of blood flow; however, blood flow improved on follow-up examinations. Conclusion Multiphase selective ASL technique can provide information about the dynamics of postoperative blood flow through the bypass in Moyamoya disease.


Journal of Vascular Surgery | 2012

Prospective intraindividual comparison of unenhanced magnetic resonance imaging vs contrast-enhanced computed tomography for the planning of endovascular abdominal aortic aneurysm repair

Tsukasa Saida; Kensaku Mori; Fujio Sato; Masashi Shindo; Hideto Takahashi; Nobuyuki Takahashi; Yuzuru Sakakibara; Manabu Minami

OBJECTIVE This study clarified whether unenhanced magnetic resonance imaging (MRI) is an alternative to contrast-enhanced computed tomography (CT) for aortoiliac arterial measurement before endovascular abdominal aortic aneurysm repair (EVAR). METHODS The institutional review board approved this prospective study. Twenty patients being considered for EVAR underwent MRI using a steady-state free-precession sequence in a 1.5-T system and contrast-enhanced CT within 4 weeks of each other. Two independent observers reviewed MRI and CT in random order using vessel analysis software and measured seven diameters, four lengths, and the angle of the aortoiliac arteries. The intermodality, interobserver, and intraobserver agreements were assessed for each measurement by intraclass correlation coefficients (ICCs) and the Altman-Bland method. Additionally, the observers independently recorded the number of bilateral renal arteries, decided EVAR suitability, and selected the main endograft on each modality. RESULTS Intermodality ICCs for observers A and B showed ranges of 0.83 to 0.99 and 0.70 to 0.98; interobserver ICCs for MRI and CT showed ranges of 0.73 to 0.99 and 0.65 to 0.99; and intraobserver ICCs for MRI and CT showed ranges of 0.59 to 0.99 and 0.59 to 0.99. In intermodality, interobserver, and intraobserver comparisons, mean differences in diameters were included within the range -1 to +1 mm, excluding three of seven diameters on CT in interobserver comparison and one of seven on CT in intraobserver comparison. Mean differences in lengths were included within the range -5 to +5 mm, excluding one of four lengths in observer B in intermodality comparison and one of four on MRI and CT in interobserver comparison. All mean differences in angles were included within the range -5° to +5°. Both observers detected all 40 bilateral main renal arteries on MRI and CT. Of the 13 accessory renal arteries, observers A and B detected four (31%) and nine (69%), respectively, on MRI; in contrast, both observers detected 11 (85%) on CT. The observers independently determined that the same seven patients were suitable for EVAR on MRI and CT. Of the seven selected main endografts, seven and six diameters and five and six lengths agreed exactly between MRI and CT for observers A and B, respectively. CONCLUSIONS Although contrast-enhanced CT remains the gold standard for preoperative EVAR planning, unenhanced MRI with steady-state free-precession sequence can be an alternative modality for patients with contraindications for CT, such as renal impairment, because the intermodality agreement for preoperative measurements is as good as interobserver and intraobserver agreement.


Radiology | 2010

Assessment of Uterine and Ovarian Arteries before Uterine Artery Embolization: Advantages Conferred by Unenhanced MR Angiography

Kensaku Mori; Tsukasa Saida; Yoko Shibuya; Nobuyuki Takahashi; Masanari Shiigai; Kayo Osada; Nami Tanaka; Manabu Minami

PURPOSE To clarify the benefits of unenhanced magnetic resonance (MR) angiography in planning uterine artery embolization (UAE). MATERIALS AND METHODS This retrospective study was approved by the institutional review board, and the informed consent requirement was waived. Fifty-five consecutive women (mean age, 42 years; age range, 26-52 years) who underwent UAE for symptomatic uterine fibroids were placed chronologically into groups 1, 2, or 3, which were composed of 20, 22, and 13 patients, respectively. Digital subtraction angiography was performed in groups 1 and 2 but not in group 3. In the 35 patients in groups 2 and 3, unenhanced MR angiography was performed before UAE, and two independent radiologists assessed the results. The parameters indicating performance of UAE were compared among the three groups with the Tukey test. RESULTS Forty-five patients underwent routine UAE (19, 16, and 10 patients in groups 1, 2, and 3, respectively). Sixty-eight (97%) of 70 uterine artery origins were demonstrated clearly at MR angiography. Among five ovarian arteries detected at MR angiography, collateral supply was confirmed in four (80%). The assessment of MR angiographic results and discontinuation of digital subtraction angiography led to a reduction in the mean performance time (from 96.2 minutes to 51.9 minutes [P = .004]), fluoroscopy time (from 28.5 minutes to 17.8 minutes [P = .036]), dose-area product (from 109.8 Gy.cm(2) to 25.4 Gy.cm(2) [P < .001]), and contrast medium volume (from 103.8 mL to 40.8 mL [P < .001]). CONCLUSION Unenhanced MR angiography provides useful information regarding uterine and ovarian arteries before UAE.


Journal of Magnetic Resonance Imaging | 2013

Diversity in size and signal intensity in multilocular cystic ovarian masses: new parameters for distinguishing metastatic from primary mucinous ovarian neoplasms.

Yumiko Oishi Tanaka; Satoshi Okada; Toyomi Satoh; Koji Matsumoto; Akinori Oki; Tsukasa Saida; Hiroyuki Yoshikawa; Manabu Minami

To differentiate primary mucinous ovarian neoplasms from metastatic ones with MR using diversity in size and signal intensity of multilocular cystic masses.


CardioVascular and Interventional Radiology | 2008

A Modified Metallic Coil Embolization Technique for Pulmonary Arteriovenous Malformations Using Coil Anchors and Occlusion Balloon Catheters

Kensaku Mori; Masanari Shiigai; Tsukasa Saida; Izumi Anno; Mitsuyoshi Wada; Manabu Minami

PurposeTo evaluate the feasibility and efficacy of a modified metallic coil embolization technique for pulmonary arteriovenous malformations (PAVMs) using coil anchors and occlusion balloon catheters.MethodsFive consecutive female patients with 6 PAVMs were included in the present study. One of the 6 PAVMs was of the complex type with four feeding arteries. An occlusion balloon catheter was inserted into the feeding artery as close to the venous sac as possible. The coil anchor, which was a simple W-shaped bent stainless steel wire with two markers at each end, was deployed prior to embolization to prevent the systemic migration of embolic materials. Then, metallic coils were deployed around the coil anchors under inflow stoppage using the inflated occlusion balloon catheter. In the complex-type PAVM, the main feeder was occluded by this technique and the other three small feeders were embolized with metallic coils only.ResultsIn all 5 cases, occlusion balloon catheters could be inserted into the feeding arteries just proximal to the venous sacs, coil anchors were easily deployed, and complete occlusion was achieved without any migration of metallic coils or paradoxical embolism during the procedure.ConclusionsThe modified metallic coil embolization technique with coil anchors and occlusion balloon catheters was feasible and considered to be useful in preventing procedure-related complications.


CardioVascular and Interventional Radiology | 2009

Hemosuccus Pancreaticus in a Patient with Iodine Allergy: Successful Diagnosis with Magnetic Resonance Imaging and Treatment with Transarterial Embolization Using Carbon Dioxide as the Contrast Medium

Soichiro Miki; Kensaku Mori; Shiigai Masanari; Toshihiro Furuta; Tsukasa Saida; Makiko Hiratsuka; Eriko Tohno; Manabu Minami

Hemosuccus pancreaticus (HP) is defined as gastrointestinal bleeding via the pancreatic duct and duodenal papilla. Since the bleeding is usually intermittent, it often remains undetected by endoscopy. Most cases are diagnosed by contrast-enhanced computed tomography (CT) or angiography, and the first-line treatment is transarterial embolization (TAE). However, in general, these modalities require a large amount of iodinated contrast medium. Here, we report the case of a 50-year-old female with HP due to chronic pancreatitis. Contrast-enhanced CT and ordinary angiography were contraindicated for her, as she was allergic to iodine. She was diagnosed with HP following gadolinium-enhanced magnetic resonance imaging and successfully treated by TAE of the splenic artery with metallic coils using carbon dioxide as the contrast medium.


Japanese Journal of Radiology | 2016

Revised FIGO staging system for cancer of the ovary, fallopian tube, and peritoneum: important implications for radiologists.

Tsukasa Saida; Yumiko Oishi Tanaka; Koji Matsumoto; Toyomi Satoh; Hiroyuki Yoshikawa; Manabu Minami

Ovarian cancer is the seventh most common cancer diagnosis among women worldwide. The International Federation of Gynecology and Obstetrics recently significantly revised staging criteria for cancer of the ovary. The latest revision was based on the concept that high-grade serous tubal intraepithelial carcinoma (STIC) may be the origin of some high-grade serous carcinomas of the ovary and peritoneum. Therefore, staging criteria for the ovary, fallopian tube, and peritoneum have been unified. Understanding this background and other important revised points are essential for radiologists concerned with imaging diagnosis in gynecologic oncology. Through this review, we introduce the STIC theory and show examples of diseases in accordance with the new staging criteria based on magnetic resonance imaging (MRI) and computed tomography (CT) results.


European Journal of Radiology | 2011

Solid non-invasive ovarian masses on MR: Histopathology and a diagnostic approach

Yumiko Oishi Tanaka; Satoshi Okada; Toyomi Satoh; Koji Matsumoto; Tsukasa Saida; Akinori Oki; Hiroyuki Yoshikawa; Manabu Minami

PURPOSE The purpose is to clarify the histopathology of the solid, non-invasive ovarian masses and to investigate the MR characteristics that distinguish benign from malignant. MATERIALS AND METHODS From 1996 to 2008, we identified 38 cases with predominantly solid non-invasive ovarian masses examined by contrast MR. We evaluated the signal intensity on T2WI and degree of contrast enhancement. In 31 of these cases with dynamic contrast study, we classified the enhancing patterns of the masses into gradually increasing and plateau after rapid increase patterns. RESULT Sixteen cases were benign sex-cord stromal tumors, three were other types of benign tumors, nine cases were diagnosed with primary malignant ovarian tumors, and 10 showed metastatic tumors. Low intensity on T2WI was observed in 15 benign and 2 malignant tumors. The gradually increasing pattern was observed in all 17 benignancies and 5 of the 14 malignancies. In the equilibrium phase, the masses were weakly enhanced in all 19 benignancies and only 4 of 19 malignancies. The diagnostic criteria, that low signal intensity masses with gradual weak enhancement are benign showed 93.3% accuracy and 100% positive predictive value. CONCLUSION Benign solid ovarian masses tended to show low signal intensity on T2WI and gradual weak enhancement.

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Yumiko Oishi Tanaka

Japanese Foundation for Cancer Research

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