Publications by authors named "Tomohiko Masumoto"

The hyaline-vascular variant of Castleman disease (HVCD) is relatively uncommon and demonstrates no specific clinical or laboratory findings; therefore, its preoperative diagnosis warrants a radiological evaluation. This study aimed to review imaging findings of HVCD, focusing on perilesional fat stranding and fatty proliferation. Patients with a pathologically confirmed HVCD diagnosis who had undergone CT were recruited from five hospitals from January 2000 to March 2023.

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Purpose: To re-evaluate images recovered from JCOG0911, a randomized phase 2 trial for newly diagnosed glioblastoma (nGBM) conducted by the Japan Clinical Oncology Group (JCOG) Brain Tumor Study Group.

Methods: The correlation between tumor volumes and survival was evaluated, followed by progression-free survival (PFS) analysis by independent central review based on Response Assessment in Neuro-Oncology (RANO) criteria using MRI recovered from 118 nGBM patients enrolled in the JCOG0911 trial. A radiomic analysis was also performed to identify radiomic features predictive of nGBM prognosis.

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Congenital absence of the internal carotid artery is a rare anatomical variant. The primarily reported origins of the ophthalmic artery associated with this variant are the posterior communicating, middle cerebral, and external carotid arteries. We report the case of a patient without an internal carotid artery whose ophthalmic artery originated from the contralateral internal carotid artery.

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Background And Purpose: Flat panel conebeam CT (CBCT) is essential for detecting hemorrhagic complications during neuroendovascular treatments. Despite its superior image quality and trajectory over conventional CBCT (circular scan), the dual-axis butterfly scan has a slightly higher radiation dose relative to conventional CBCT. This study evaluates the image quality in dose-reduction mode to uncover the appropriate radiation dose for the butterfly scan.

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Purpose: Silent corticotroph pituitary adenomas (SCAs)/pituitary neuroendocrine tumors (PitNETs) are common non-functioning pituitary adenomas (NFAs)/PitNETs with a clinically aggressive course. This study aimed to investigate the ability of time-intensity analysis of dynamic magnetic resonance imaging (MRI) for distinguishing adrenocorticotropic hormone (ACTH)-positive SCAs and ACTH-negative SCAs from other NFAs.

Materials And Methods: We retrospectively evaluated the dynamic MRI findings of patients with NFAs.

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Article Synopsis
  • Invasive lobular carcinoma (ILC) tends to grow in a subtle, single-cell pattern, making it challenging to detect axillary lymph node (ALN) metastases through MRI, especially when compared to invasive ductal carcinoma (IDC).
  • A study analyzed MRI findings in 120 female patients with ILC to identify characteristics correlated with ALN metastasis, revealing that 29% had metastasis.
  • The results indicated that focal cortical thickening (FCT) is possibly the most significant MRI indicator for predicting ALN metastasis in ILC, though further validation of this finding is necessary.
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Purpose: Cone-beam computed tomography (CBCT) is useful in the diagnosis of complications after neuro-endovascular treatment. However, the image quality of conventional CBCT is inferior to that of conventional CT. To solve this problem, a dual-axis butterfly CBCT available with an angiography suite has been developed.

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Background: Intraosseous schwannomas are extremely rare and they have not yet been reported to occur in the clivus. We report a schwannoma in the clivus mimicking chordoma and review intraosseous schwannomas of the skull.

Case Description: A 62-year-old man presented with gradually worsening hoarseness with dysphagia and atrophy of the left tongue, trapezius muscle, and sternocleidomastoid muscle.

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Article Synopsis
  • The study investigated the effectiveness of temporal subtraction computed tomography (TS CT) combined with deep learning techniques for detecting vertebral bone metastases in cancer patients.
  • A retrospective analysis involved training on paired CT images from patients without metastases, followed by evaluations of patients with and without new vertebral metastases, interpreted by experienced radiologists and residents.
  • Results showed that TS CT significantly improved detection accuracy, as indicated by better overall figures of merit, especially for osteoblastic lesions and specific lesion locations.
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Purpose: To compare the diagnostic performance of deep learning models using convolutional neural networks (CNN) with that of radiologists in diagnosing endometrial cancer and to verify suitable imaging conditions.

Methods: This retrospective study included patients with endometrial cancer or non-cancerous lesions who underwent MRI between 2015 and 2020. In Experiment 1, single and combined image sets of several sequences from 204 patients with cancer and 184 patients with non-cancerous lesions were used to train CNNs.

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Hybrid assistive limb (HAL) is a wearable robot, which has recently been used for the treatment of patients with movement disorders including spinal cord injury (SCI). Although several studies have indicated the effectiveness of HAL for SCI patients, changes in brain activity during the HAL intervention have not yet been fully characterized. A 19-year-old man with a chronic SCI resulting in complete C4 quadriplegia underwent five weeks of HAL training for a total of ten sessions.

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Purpose: To investigate the relationship between dynamic magnetic resonance imaging (MRI) findings and hormonal activity in pituitary adenomas.

Methods: We retrospectively evaluated the dynamic MRI findings in 244 patients with pathologically confirmed pituitary adenomas and a diagnosis of clinically active prolactin (PRL)-producing adenomas. Among the 244 pituitary adenomas, 55, 16, 6, and 4 produced growth hormone (GH), PRL, adrenocorticotropic hormone, and thyroid-stimulating hormone, respectively, while 163 were non-functioning (NF) adenomas.

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Purpose: To compare deep learning with radiologists when diagnosing uterine cervical cancer on a single T2-weighted image.

Methods: This study included 418 patients (age range, 21-91 years; mean, 50.2 years) who underwent magnetic resonance imaging (MRI) between June 2013 and May 2020.

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Purpose: To clarify imaging and clinical characteristics of ovarian carcinosarcoma (CS) compared with high-grade serous carcinoma (HGSC).

Methods: We retrospectively reviewed MR imagings of 12 patients with CS and 30 patients with HGSC and evaluated tumor size, shape, appearance, nature of cystic and solid components, hemorrhage, and necrosis. Age, premenopausal or postmenopausal, histologic subtype, presence of endometriosis, tumor markers, and stage were also evaluated.

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Teratoma is a germ cell tumor (GCT) derived from stem cells of the early embryo and the germ line. Teratoma is the most common neoplasm of the ovaries and is usually diagnosed easily using imagings by detecting fat components. However, there are various histopathological types and the imaging findings differ according to the type.

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Purpose: To plan a treatment strategy for a spinal arteriovenous shunt (SAVS), identifying the artery of Adamkiewicz (AKA) and its origin is indispensable. However, detecting the AKA is very difficult in patients with an SAVS when using computed tomography angiography (CTA) by the usual method to find the hairpin curved artery because dilated drainage veins nearly always coexist with the hairpin curved AKA. We designed a method to identify the AKA by focusing on the diameter and pathway of the anterior radiculomedullary arteries (RMAs).

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A number of cases have been reported in recent years regarding the use of proton beam therapy to mitigate adverse events affecting important cranial organs in cases of rhabdomyosarcoma at parameningeal sites. However, few reports have described the use of proton beam therapy as urgent radiotherapy for parameningeal rhabdomyosarcoma with intracranial extension. We treated 3 patients diagnosed with parameningeal rhabdomyosarcoma extending into the cranium who were assessed at other hospitals as suitable for urgent radiotherapy and transferred to our hospital for proton beam therapy.

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Objective: Rathke's cleft cyst (RCC) is a benign cystic lesion with a relatively high incidence of local recurrence that occasionally requires repeat surgery. To prevent recurrence, simple cyst fenestration and drainage of the cyst contents to the sphenoid sinus is recommended, but it occasionally recurs. The authors postulated that obstruction of fenestration is a main cause of recurrence, and they developed a method, named the "mucosa coupling method (MC method)," that maintains persistent drainage.

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Purpose: The purpose of this study was to determine whether temporal subtraction (TS) computed tomography (CT) contributes to the detection of vertebral bone metastases.

Method: The calculation of TS CT was composed of bony landmark detection, bone segmentation with a multiatlas-based method, and spatial registration. Temporal increase and decrease of the CT values were visualized in blue and red, respectively.

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Primary intracranial germinoma is a rare central nervous system tumor that usually arises in the pineal and the supra-sellar region. Here, we report a rare case of primary intracavernous sinus germinoma with an atypical extension pattern, with a comparison to germinomas originating from the cavernous sinus as described in the existing literature. A 12-year-old boy was admitted to our hospital with the chief complaint of the left-side ptosis and double vision.

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Aim: To assess the feasibility of transferring to the University of Tsukuba Hospital for proton beam therapy (PBT) during intensive chemotherapy in children with Ewing sarcoma family of tumors (ESFT) who had been diagnosed and started their first-line treatment at prefectural or regional centers for pediatric oncology.

Background: The treatment of ESFT relies on a multidisciplinary approach using intensive neoadjuvant and adjuvant chemotherapies with surgery and radiotherapy. Multi-agent chemotherapy comprising vincristine, doxorubicin, cyclophosphamide, ifosfamide, and etoposide (VDC-IE) is widely used for ESFT, and the interval between each course is very important for maintaining the intensity and effect of chemotherapy.

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Objective: MRI scans obtained within 48-72 hours (early postoperative MRI [epMRI]), prior to any postoperative reactive changes, are recommended for the accurate assessment of the extent of resection (EOR) after glioma surgery. Diffusion-weighted imaging (DWI) enables ischemic lesions to be detected and distinguished from the residual tumor. Prior studies, however, revealed that postoperative reactive changes were often present, even in epMRI.

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Article Synopsis
  • The study investigates the role of the CTNNB1 mutation in adamantinomatous craniopharyngioma (adaCP) and its relationship to various clinical and biological factors, given that the mutation's impact on tumor development is unclear.
  • Researchers analyzed 42 patients with either adaCP or papillary craniopharyngioma (papCP), focusing on genetic mutations, mRNA expression, and immunohistochemistry.
  • Findings revealed that CTNNB1 mutations are present in 68% of adaCP cases and are associated with higher Axin2 mRNA levels, but do not significantly correlate with other clinical and pathological features, though mutation-positive patients showed shorter progression-free survival when not receiving adjuvant radiation
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Carotid endarterectomy (CEA) and carotid artery stenting (CAS) are not appropriate treatment procedure for internal carotid artery stenosis (ICAS) in some patients. The importance of plaque vulnerability and the treatment risk evaluation has been reported. We analyzed whether treatment selection contributes to the outcome.

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