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Junta Harada

Publications and source records attributed to Junta Harada.

9 recordsLinked to original sources
PubMed2006

Percutaneous cryoablation of renal cell carcinoma guided by horizontal open magnetic resonance imaging.

BACKGROUND: Cryoablation is a treatment option for some patients with small exophytic lesions of the kidney. The purpose of this study is to determine the feasibility, safety, and intermediate-term treatment outcome of percutaneous cryoablation of renal cell carcinoma guided by horizontal open magnetic resonance imaging (MRI). METHODS: We prospectively used cryoablation to treat 13 patients with radiographically confirmed enhancing small, solid renal tumors (< or =4.8 cm). An argon gas-based cryoablation system was used. One to four cryoprobes with 2 or 3-mm diameters were placed percutaneously into the tumor under local anaesthesia and MRI guidance. Ice ball dimensions were monitored by 2-D MR images. Double freeze-thaw cycles were conducted throughout the procedure. After successful cryoablation, patients were followed on a regular basis to evaluate the treatment's clinical outcome. RESULTS: Median follow up from time of procedure is 35 months (range, 28-42). In all cases the entire procedure was accomplished without significant morbidity or complications. A mild retroperitoneal hematoma, which subsided spontaneously, was noted in one patient. Follow-up dynamic computed tomography (CT) at 3 months after operation confirmed the absence of enhancement in resolved tumor masses for 11 of 13 cases. None of these 11 patients had clinical evidence of recurrent disease at last follow up. The remaining two patients had lesions with some enhanced areas. Subsequent partial nephrectomy histologically confirmed the presence of vital tumor in, respectively, the center and the periphery of the residual masses. One of these patients developed multiple lung and ipsilateral adrenal metastases 13 months after surgical resection. CONCLUSIONS: Percutaneous cryoablation of small renal cell carcinomas under horizontal open MRI guidance appears to be safe and feasible. An intermediate-term follow up continues to demonstrate efficacy in most patients; however, a few patients experience incomplete ablation with risk of treatment failure. The ideal candidates for this procedure still need to be determined in longer follow up with diligent observation.

Adult↗
PubMed2004

[Minimally invasive therapy under image guidance--emphasizing MRI-guided cryotherapy].

Cryotherapy may provide a method for the focal destruction of cancerous tissue while preserving most of the surrounding normal tissue. The mechanisms of tissue injury in cryotherapy are 1) intracellular ice formation, 2) dehydration of cells, and 3) stagnation of microcirculation. MR images were superior to CT and ultrasound in monitoring interstitial cryotherapy, because the very short T2 relaxation time of ice affords excellent contrast between the ice and surrounding tissue, allowing an accurate depiction of the entire extent of the iceball. MR imaging demonstrates the iceball as sharply marginated regions of signal loss that expanded and engulfed the renal and hepatic masses with clear contrast between the iceball and surrounding tissue. Recently, a fast Joule-Thomson cryocycling device for MR-compatible cryotherapy application was developed and clinical trials under MRI-guided monitoring were performed in several sites of the body. In our series, cryotherapy was performed in 14 cases of renal tumor and 4 cases of hepatic malignancy under the guidance of a horizontal open MR system. Fourteen of the 18 cases were discharged a day after cryotherapy. One of the residual tumors at the margin of a renal cancer required re-cryoablation. All cryoablated tumors resolved and there were no serious complications and no clinically significant changes-during the follow-up study.

Clinical Trials as Topic↗
PubMed2004

[Evaluation of enhancement patterns using three-dimensional dynamic contrast-enhanced MR imaging in 209 cases of breast cancer].

PURPOSE: To evaluate contrast-enhanced patterns using three-dimensional (3D) dynamic MR imaging in 209 cases of breast cancer. MATERIALS AND METHODS: Three-dimensional dynamic imaging of the breast (1.5-T scanner) was performed in 755 cases. Of 227 breast carcinomas, 209 cases that were histologically confirmed were enrolled in this study. The histological diagnoses included ductal carcinoma in situ (DCIS) (n=12), invasive ductal carcinoma (n=176), mucinous carcinoma (n=10), medullary carcinoma (n=4), invasive lobular carcinoma (n=6), and other (n=1). Tumor size was a mean 24.6 mm in diameter (range, 7-110 mm), including 110 cases of small breast carcinomas (< or = 2 cm). The contrast-enhancement pattern was analyzed from the early phase of 3D-MRI and the post-contrast T1-weighted SE image acquired before the delayed phase of 3D-MRI. The type of peripheral enhancement (PE) was evaluated on the early and delayed phases of 3D-MRI. These enhancement patterns were also compared with the histological findings of small breast carcinomas. RESULTS: The sensitivity of the 209 cases of breast carcinoma was 99% (207/209) on 3D dynamic MRI. Two hundred six cases (98.6%), including all DCIS, showed strong enhancement on the early phase of 3D MRI. An increased washout pattern showing signal intensity lower than that of fat on post-contrast T1-weighted imaging was noted in 201 cases (96.1%), of which 179 cases (85.6%) showed washout patterns. PE was identified in 63 cases (30.4%) and in 35 of 110 cases of small breast carcinoma (31.8%). Delayed PE following central washout was noted in 65% of 63 cases and 71.4% of 35 cases of small breast carcinoma. Delayed PE was well correlated with marginal fibrosis. CONCLUSION: Three-dimensional dynamic MRI of the breast was highly sensitive for breast carcinoma. Delayed PE following central washout was considered a specific finding of breast carcinoma. It is important to understand the enhancement patterns of 3D dynamic MRI for excellent specificity of breast carcinomas.

Adult↗
PubMed2003

MR-guided percutaneous cryotherapy of malignant liver tumor under horizontal-magnetic open system: initial experience.

BACKGROUND/PURPOSE: We describe the feasibility and accuracy of magnetic resonance (MR)-guided cryotherapy for malignant liver tumor, using a horizontal-magnetic open system. METHODS: Using an MR-compatible cryotherapy system and horizontal-magnetic open-configuration MR scanner, we performed percutaneous cryotherapy for four malignant liver tumors. RESULTS: All procedures were carried out safely and accurately without any serious complication. Residual tumor was observed in one patient with metastatic liver tumor located directly under the diaphragm. CONCLUSIONS: MR-guided cryotherapy appears to be ideal and desirable as a minimally invasive therapy for liver tumor.

Aged↗
PubMed2002

A new image navigation system for MR-guided cryosurgery.

PURPOSE: To evaluate the feasibility of Interactive Scan Control (ISC), a new MR image navigation system, during percutaneous puncture in cryosurgery. MATERIALS AND METHODS: With the ISC system in place, percutaneous MR-guided cryosurgery was performed in 26 cases, with the ISC system being used in 11 cases (five renal tumors, three uterine fibroids and three metastatic liver tumors). The ISC system comprised infrared cameras and an MR-compatible optical tracking tool that was directly connected to a cryoprobe. Tumor sizes ranged from 1.2 cm (metastatic liver tumor) to 9.0 cm (uterine fibroid), for a mean size of 3.9 cm. With ISC, one to three cryoprobes with a diameter of 2 mm or 3 mm were advanced into the tumors with the guidance of an MR fluoroscopic image. Two freeze-thaw cycles were used for cryosurgery. During the cryosurgery, the formation of iceballs was monitored on MR images. Follow-up dynamic CT or MRI as well as physical examinations were conducted after two weeks and six weeks. RESULTS: Placement of probes was successfully performed under the control of the ISC system. During cryosurgery, engulfment of the tumors by iceballs was carefully monitored by MRI. Necrosis of the cryoablated area was confirmed in all renal tumors by follow-up dynamic CT. The size regression of the uterine fibroids was observed through follow-up MRI. Two of the three cases of metastatic liver tumor were ablated completely. Additional therapy for a residual tumor was performed on one patient with a metastatic liver tumor. A small amount of pneumothorax was the only complication found in a patient with a metastatic liver tumor. CONCLUSION: MR-guided cryosurgery with this new navigation system was feasible with low morbidity and allowed for safe and accurate puncture with a cryoprobe.

Adult↗
PubMed2002

Correlation of urine type I collagen-cross-linked N telopeptide levels with bone scintigraphic results in prostate cancer patients.

The diagnostic potential of a new bone resorption marker, type I collagen-cross-linked N telopeptide (NTx), for bone metastasis of prostate cancer was evaluated. Ninty-one prostate cancer patients underwent bone scintigraphy, and urine NTx/creatinine (NTx/Cr) was measured. Urine NTx/Cr levels were compared with bone scintigraphic results. Urine NTx/Cr levels in the bone metastasis-positive group (n = 47) were 92.9 +/- 105.1 nmol/L of bone collagen, which is equivalent to per millimole of urinary creatinine (nmol/L BCE/mmol/L Cr), significantly higher than the level of the bone metastasis-negative group (n = 44) (59.0 +/- 41.6 nmol/L BCE/mmol/L Cr). When patients were classified by the extent of disease grade (EOD grade) nomenclature, the urine NTx/Cr level of the EOD (4+) group was 209.5 +/- 186.5 nmol/L BCE/mmol/L Cr. This level was significantly higher than those of the EOD (-) group (59.0 +/- 41.6 nmol/L BCE/mmol/L Cr), EOD (1+) group (59.0 +/- 47.8 nmol/L BCE/mmol/L Cr), and EOD (2+) group (81.1 +/- 41.3 nmol/L BCE/mmol/L Cr). However, no significant difference was observed between the EOD (-) and EOD (1+) groups. The mean change in urine NTx/Cr level 3 to 17 months after the first bone scintigraphy and urine NTx/Cr examination in the bone metastasis-progression group (n = 8) was 11.0 +/- 31.2 nmol/L BCE/mmol/L Cr, significantly higher than that in the bone metastasis-regression group (n = 15) (-26.8 +/- 40.7 nmol/L BCE/mmol/L Cr). In conclusion, urine NTx /Cr can be measured noninvasively and reflects the state of bone metastasis. However, the sensitivity of urine NTx/Cr is not as high as that of bone scintigraphy. Therefore, it may provide an auxiliary diagnostic index for bone scintigraphy.

Aged↗
PubMedDate not supplied

Wireless local area networking for linking a PC reporting system and PACS: clinical feasibility in emergency reporting.

Although local area networks (LANs) are commonplace in hospital-based radiology departments today, wireless LANs are still relatively unknown and untried. A linked wireless reporting system was developed to improve work throughput and efficiency. It allows radiologists, physicians, and technologists to review current radiology reports and images and instantly compare them with reports and images from previous examinations. This reporting system also facilitates creation of teaching files quickly, easily, and accurately. It consists of a Digital Imaging and Communications in Medicine 3.0-based picture archiving and communication system (PACS), a diagnostic report server, and portable laptop computers. The PACS interfaces with magnetic resonance imagers, computed tomographic scanners, and computed radiography equipment. The same kind of functionality is achievable with a wireless LAN as with a wired LAN, with comparable bandwidth but with less cabling infrastructure required. This wireless system is presently incorporated into the operations of the emergency and radiology departments, with future plans calling for applications in operating rooms, outpatient departments, all hospital wards, and intensive care units. No major problems have been encountered with the system, which is in constant use and appears to be quite successful.

Emergency Service, Hospital↗
PubMedDate not supplied

MR-guided transvaginal cryotherapy of uterine fibroids with a horizontal open MRI system: initial experience.

PURPOSE: We evaluated the feasibility of MR-guided transvaginal cryotherapy for treating intramural, submucosal, and sub-serosal uterine fibroids with a horizontal open MRI system. MATERIALS AND METHODS: Using an MR-compatible cryotherapy system and a horizontal magnetic open-configuration MR scanner, we performed transvaginal cryotherapies using a Cusco speculum on eight uterine fibroids whose longest diameter ranged from 2.9 to 10.0 cm. We assessed the ratio of pre-treatment to post-treatment volume of the uterine fibroids as well as the patients' symptoms (anemia, abdominal pain, dysfunctional uterine bleeding, etc.). RESULTS: All procedures were carried out safely and accurately without any complications that required surgical treatment. MRI enabled clear visualization of the cryoneedle and freezing area as band-like and ellipsoid-like signal losses, respectively. The mean ratio of reduction in uterine fibroid volume was 31.0% at 9-12 months (0-75.0%). Symptoms caused by uterine fibroids improved in seven cases. CONCLUSION: This is the first report on a transvaginal approach to cryotherapy for uterine fibroids. MR-guided transvaginal cryotherapy appears to be feasible and promising as a minimally invasive therapy for symptomatic uterine fibroids.

Abdominal Pain↗