Tatsumi Kaji

An Intravoxel Incoherent Motion Diffusion-Weighted Imaging Study of Prostate Cancer

OBJECTIVE The purpose of this study is to investigate whether the intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) parameters are different between prostate cancer, benign prostatic hyperplasia (BPH), and healthy peripheral zone (PZ). MATERIALS AND METHODS Detailed diffusion measurements of 26 patients with histologically proven prostate cancer have been made in this retrospective study. Trace IVIM DWI was performed using 10 b values (0, 10, 20, 30, 50, 80, 100, 200, 400, and 1000 s/mm2). Biexponential fits were applied to diffusion decay curves to calculate molecular diffusion coefficient, perfusion-related diffusion coefficient, and perfusion fraction on the basis of the IVIM model. Decay curves were also fit with monoexponential decay functions, and a statistical comparison between mono- and biexponential fits was performed. Paired t tests were performed to evaluate the statistical significance of the parameters of IVIM DWI and apparent diffusion coefficient (ADC) between prostate cancer, BPH, and PZ. RESULTS The chi-square values of biexponential fits were smaller than those from monoexponential fits in all cases. Biexponential functions provided statistically improved fits over monoexponential functions in 81% of cases. The ADC, molecular diffusion coefficient, and perfusion fraction in prostate cancer were significantly lower than those found in the PZ; however, perfusion fractions in prostate cancer and BPH were not significantly different. There were no significant differences in the prostate cancer, BPH, and PZ for the perfusion-related diffusion coefficient, which had large SDs. CONCLUSION IVIM DWI parameters are significantly different between prostate cancer and PZ. IVIM DWI may offer additional information for tissue characterization in the prostate gland.

Diffusion kurtosis imaging study of prostate cancer: Preliminary findings

To evaluate the differences in parameters of diffusion kurtosis imaging (DKI) between prostate cancer, benign prostatic hyperplasia (BPH), and benign peripheral zone (PZ).

Atypical MRI features of Wilson's disease : high signal in globus pallidus on T1-weighted images

Abstract Most reports of MRI in Wilsons disease have been of abnormal low-signal lesions on T1-weighted images and high signal intensity on T2-weighted images. In contrast, we report three patients who had high-signal lesions in the globus pallidus on T1-weighted images, a finding seen in patients with portal-systemic encephalopathy. The possible causes include the paramagnetic effect of copper or iron and accumulation of Alzheimer type II glial cells.

Clinical evaluation of the effect of percutaneous transluminal angioplasty and intra-arterial papaverine infusion for the treatment of vasospasm following aneurysmal subarachnoid hemorrhage.

The clinical efficacy of percutaneous transluminal angioplasty and intra-arterial papaverine infusion for treatment of vasospasm following subarachnoid hemorrhage was investigated. Between 1990 and 1993, 84 patients were treated for cerebral vasospasm in National Defense Medical College Hospital. Angioplasty was performed for asymptomatic vasospasm in 18 patients and for symptomatic vasospasm in 12 patients. Intra-arterial papaverine infusion was performed for asymptomatic vasospasm in 10 patients and for symptomatic vasospasm in four patients. The other 40 patients were treated with standard conservative therapy including hypervolemic and hypertensive hemodilution. The outcomes of these patients were analyzed using the Glasgow Outcome Scale. The outcome tended to be better for patients treated with angioplasty, but not for those treated with papaverine infusion, than for those treated conservatively. Recurrence of vasospasm was more frequent after papaverine infusion than after angioplasty. Undesirable complications such as abrupt development of unconsciousness were experienced during papaverine infusion but not during angioplasty. We conclude that percutaneous transluminal angioplasty is superior to intra-arterial papaverine infusion for prevention and treatment of vasospasm following aneurysmal subarachnoid hemorrhage.

Magnetic resonance imaging findings of Machado-Joseph disease: histopathologic correlation.

Purpose To determine the characteristic magnetic resonance imaging (MRI) findings of early- and late-stage Machado–Joseph disease (MJD) and to examine correlation with pathologic specimens. Patients and Methods Four patients genetically diagnosed with MJD and a familial case of MJD were all examined using MRI. Machado–Joseph disease was pathologically confirmed in one of the four genetically diagnosed patients, and the findings were compared with the MRI results. Results In all three patients who had MJD for less than 8 years, MRI confirmed mild cerebellar atrophy, particularly in the vermis, and atrophic changes in the superior cerebellar peduncle. Mild pontine atrophy was observed in these three patients. Atrophic changes in the pontine tegmentum were more prominent than those of the pontine base in these patients. Two of the three patients showed mild frontal atrophy. Of the five total patients, two had the disease for over 10 years and showed progressive atrophy of the brainstem and mild frontal atrophy. These two patients also showed pallidal atrophy. One autopsied case in which the disease duration was 17 years showed a typical pathologic picture of MJD. Macroscopic findings for this patient showed marked atrophy of the pons, mild cerebellar atrophy (particularly in the vermis), marked atrophy of the superior cerebellar peduncle, severe involvement of motor nuclei, and atrophy and discoloration of the pallidum and subthalamic nuclei. Conclusion In the early stages of MJD, mild pontine atrophy, particularly in the tegmentum, and mild cerebellar atrophy are typical MRI findings. Atrophic changes in the brainstem may be progressive. Pallidal atrophy may be observed in patients with long disease duration. These findings correlated with the pathologic findings.

Preoperative embolization of meningiomas with pial supply: successful treatment of two cases

BACKGROUND The efficacy of preoperative embolization for hypervascular meningiomas fed by the pial branches of the internal carotid artery was evaluated. METHODS Two cases of hypervascular meningiomas fed by the cortical branches of the internal carotid arteries are presented. In the first patient, the left anterior frontal internal artery was embolized with gelatin sponge (Gelfoam) as a preoperative treatment using a microcatheter. The tumor was totally resected with 1,000 ml of blood loss. In the second patient, the right sulcal artery was embolized with Gelfoam. The patient subsequently underwent surgical resection with 100 mL of blood loss. RESULTS No neurological deficit appeared after the embolization or the surgery in either case. CONCLUSION Preoperative embolization of hypervascular meningiomas, mainly fed by the cortical branches of the internal carotid arteries, may be possible and effective.

Primary Sjögren's syndrome initially manifested by optic neuritis: MRI findings

Abstract. We herein describe the MRI findings in a patient clinically diagnosed with primary Sjögrens syndrome (SjS) initially manifested by retrobulbar optic neuritis. A 63-year-old woman suddenly had left ocular pain and progressive visual disturbance. MR T2-weighted images revealed hyperintensity in the left optic nerve, with swelling. Contrast-enhanced T1-weighted images showed no abnormal enhancement. Follow-up MRI 6 months after admission revealed no significant changes in the affected optic nerve. To our knowledge, optic neuritis as a complication of SjS has been reported in ten patients [1, 2, 3, 4, 5, 6] and MRI findings in only one of them [6]. We thought MR images were useful for visualizing optic nerve involvement in SjS and observing its course.

Bilateral adrenal leiomyosarcoma treated with multiple local therapies

A 62-year-old woman presented with right flank pain, and computed tomography (CT) showed bilateral adrenal tumors (right, 8 cm; left, 4 cm). There were no abnormal findings on physical examination, and adrenal hormone levels in serum and urine were within normal limits. Radiological studies showed a right adrenal tumor with intratumoral hemorrhage, a cystic tumor in the left adrenal gland, and no sign of distant metastasis. Because laboratory tests showed normal levels of adrenal hormones, we considered the tumors to be nonfunctioning adrenal tumors. The right adrenal tumor was surgically removed because it was thought to be malignant, and histological examination revealed that it was a leiomyosarcoma. Postoperative CT showed a pleural metastasis in the right chest wall. The patient received combination chemotherapy with cyclophosphamide, vincristine, adriamycin, and dacarbazine. The metastasis was also treated with radiofrequency ablation (RFA). Because the left adrenal tumor grew rapidly despite two courses of the chemotherapy, it too was surgically removed. After the operation, metastasis in the right iliac bone was treated with RFA and radiotherapy. Positron emission tomography detected bilateral femoral metastases, and these were treated with radiotherapy in combination with a low dose of cisplatin. A liver metastasis and a small metastasis in the left kidney were treated with RFA and a metastasis in the pancreatic tail was removed surgically. Sixteen months after the right adrenalectomy, the patient died due to systemic spread of the disease. Multiple local treatments including RFA, radiotherapy, and resection were effective for the local control of metastatic lesions of adrenal leiomyosarcoma.

Transcatheter embolization of a superior mesenteric artery pseudoaneurysm. A case report.

A 61-year-old man, with pseudoaneurysm of the superior mesenteric artery presenting with gastrointestinal bleeding, was successfully treated by transcatheter embolization using interlocking detachable coils. During the following observation time of 10 months, the patient had no sign of gastrointestinal bleeding. We underline the importance and feasibility of transcatheter embolization as the first-line treatment in such pseudoaneurysms.

An arteriovenous fistula between the internal mammary artery and the pulmonary vein following blunt chest trauma.

A 67-year-old man suffered a traffic accident and was transferred to an emergency hospital close to the scene. He was diagnosed to have bilateral pneumohemothorax with a lung contusion, an anterior fracture dislocation of the C6-vertebra and a cervical cord injury at the level of C7. On the 48th day, massive hemoptysis was suddenly recognized. He was transferred in a state of shock to our hospital to undergo hemostasis for the bleeding. On the day of admission, a selective arteriogram showed extravasation from the left bronchial artery, for which embolization was carried out using Gelfoam. In spite of this treatment, his hemoptysis continued. On the next day, a selective left internal mammary arteriogram showed an arteriovenous fistula between the left internal mammary artery and the left pulmonary vein without any apparent extravasation. The arteriovenous fistula was successfully embolized using platinum fiber coils. The patient no longer demonstrated any hemoptysis after embolization.