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Biomedical subjects

J Harada

Publications and source records attributed to J Harada.

115 records · Page 7Linked to original sources
PubMed1977

Contrast nasopharyngography.

Contrast nasopharyngography was performed in 25 cases of nasopharyngeal lesions, 15 of which were carcinoma, six malignant lymphoma, and four benign lesions including neurofibroma, haemangioma, angiofibroma and tuberculosis. Nasopharyngography was also performed in 22 cases with extranasopharyngeal lesions, including nine of head and neck malignant lymphoma and 13 of tumours originating in adjacent organs. To describe the extent and site of the tumour, the nasopharyngeal walls were labelled segment 1 to 15 on axial and lateral views. The lateral skull films were negative in five of eight small malignancies involving no more than five wall segments, and also negative in six of 10 cases of unilateral involvement. Small lesions involving the unilateral fossa of Rosenmueller and/or the superolateral wall were frequently undetected. Nasopharyngography is indicated in cases where clinical suspicions of a lesion remain after a normal straight film. When malignancies were treated with radiation therapy a pre-irradiation nasopharyngogram clearly depicted the site and extent of the disease, and a post-irradiation study showed a marked shrinkage of the tumour mass and/or markedly improved raggedness of the wall of the nasopharynx. Four benign lesions showed large space-occupying lesions. In the case of tuberculosis, for example, the nasopharyngeal cavity was totally obliterated by the granulomatous tissue. In nine cases of malignant lymphoma involving the neck nodes or the palatine tonsil, the nasopharyngogram was normal.

Contrast Media↗
PubMedDate not supplied

Application of fast Fourier transform to auditory evoked brainstem response.

The current application of fast Fourier transform (FFT) to the analysis of auditory evoked brainstem response (ABR) is reviewed under four categories: (1) digital filtering, which facilitates isolation of fast and slow components from the same ABR wave, is the most common use of FFT; (2) power spectral analysis: this seems significant in ABR for isolating and analysing slow, middle and fast components from the Fourier components around each peak of the power spectrum with a three-peak pattern by inverse fast Fourier transform; (3) cross correlation function shows the relationship between two signals being analysed from the viewpoint of their phase. Clinical applications are used in the diagnosis of multiple sclerosis and for automatic detection of ABR; and (4) phase spectral analysis: the synchrony measure method (Fridman, 1984) is a type of phase spectral analysis. In this method, the phase variances of selected Fourier components are calculated, from among 10 averaging groups of 200 sweeps in the same stimulating conditions, to determine the presence or absence of a response. The clinical application of this method to the automatic evaluation of ABR is discussed.

Adult↗
PubMedDate not supplied

CT-guided percutaneous laser disk decompression (PLDD) for cervical disk hernia.

OBJECTIVE: Percutaneous laser disk decompression (PLDD) is an effective treatment for bulging or protruding disk. The aim of this study was to present a method of PLDD for cervical disk hernia under CT guidance and to evaluate the efficacy and safety of this procedure. MATERIALS AND METHODS: Seven patients with radiculalgia caused by cervical disk hernia were treated overnight by PLDD. A laser fiber was inserted through an 18 G needle into the target disk under CT guidance. A Nd-Yag laser (1,064 nm) was used for ablation. A CT scan was obtained every 60 joule (J) at the slice of the target disk to visualize the vaporized area during the procedure. The Japan Orthopedic Association (JOA) score of cervical radiculopathy (full score 15) and MacNab criteria were used for assessment of treatment response. RESULTS: Puncture of the needle to the target disk was safely performed under CT guidance. The total dosage of laser ablation ranged from 120 to 500 J (average, 266 J). The overall success rate according to MacNab criteria was good in all cases. No complications were observed in our series. CONCLUSION: The CT-guided technique provides safe, accurate PLDD for cervical disk hernia. PLDD for cervical disk hernia shows promise in the management of radiculalgia.

Cervical Vertebrae↗
PubMedDate not supplied

Initial experience of percutaneous renal cryosurgery under the guidance of a horizontal open MRI system.

OBJECTIVE: The aim of this study was to obtain preliminary results of cryoablation of renal tumors by using a percutaneous approach guided by a horizontal open MRI system, and to assess the safety and efficacy of this procedure. MATERIALS AND METHODS: Four patients with renal tumors underwent percutaneous cryosurgery with local anesthesia using a horizontal open MRI system (AIRIS II, Hitachi Medical Corp., Tokyo, Japan). The size of the mass was radiographically documented as 4 cm or less in diameter. A 2- or 3-mm cryoprobe was advanced into the renal mass under real-time MR monitoring. Growth of the iceball during cryoablation was monitored by two-dimensional MR images. Follow-up dynamic CT and physical examination were done after two weeks and six weeks. RESULT: MR imaging demonstrated the iceballs as sharply marginated regions of signal loss that expanded and engulfed the renal mass with clear contrast between the iceball and surrounding tissue. Cryoablated tumors resolved, and there were no serious complications and no clinically significant changes during the procedures and follow-up study. CONCLUSION: In this limited clinical trial of percutaneous renal tumor surgery, cryoablation demonstrated its feasibility with minimal morbidity. Intraprocedual MR-guided cryosurgery can be used as a safe modality, although further studies are necessary to determine the long-term efficacy of this procedure.

Aged↗