Biomedical subjects

Hitoshi Tanigawa

Publications and source records attributed to Hitoshi Tanigawa.

4 recordsLinked to original sources

PubMed2005

[Development of a breath pacemaker for 2D-PACE respiratory gated MRCP: efficacy of image quality improvement].

Two-dimensional prospective acquisition correction (2D-PACE) is a human body motion-correction technique that uses the navigator echo sequence. Clinically, this respiratory-gated technique is used to improve the image quality of magnetic resonance cholangiopancreatography (MRCP). However respiratory motion artifact caused by a mismatch in respiratory rhythm has been experienced. The newly developed breath pacemaker was developed with the aim of providing the best match between the breath cycle and 2D-PACE trigger. The breath pacemaker is composed of two stimulators, an auto voice (AV) system and an auto light (AL) system. The two systems can be controlled separately or concurrently. Using the new breath pacemaker, improvement in MRCP image quality was evaluated in normal volunteers, and definite improvement was noted. Particularly good efficacy was obtained with concurrent control of the AV system and AL system. The results clearly demonstrated that the breath pacemaker can provide good synchronization of 2D-PACE and can lead to enhanced quality of MRCP images.

Adult↗

PubMed2004

[Angiography].

The clinical usefulness of three dimensional images was widely recognized. The three dimensional digital subtraction angiography (3D-DSA) well demonstrated anatomical structures of cerebral arteries with high special resolution. This 3D observation allowed high quality planning for aneurysmal coil packing and neck clipping. Because of the bony structure and curvy arterial anatomy in the skull base region, 3D-CTA and MRA was sometimes distureved the demonstration of the anatomical relationship adjacent to the aneurysm. However, 3D-DSA not only demonstrated arterial anatomy, but also analyzed of vascular structure, quantifiably. And it was useful in radiation dose reduction by reduction of DSA exposure number. We believe that 3D-DSA should provided useful information for planning of surgical and endovascular treatment in the field of cerebro-vascular disease.

Angiography, Digital Subtraction↗

PubMed2002

Hepatoid adenocarcinoma in Barrett's esophagus associated with achalasia: first case report.

We report an unusual hepatoid adenocarcinoma in Barrett's esophagus with achalasia, which developed in a 44-year-old Japanese woman. The patient received an esophago-gastrectomy after diagnosis of the tumor and achalasia at the lower esophagus, 4 months before her death due to multiple metastatic tumors of the liver. The main granular tumor removed surgically was a hepatoid adenocarcinoma, mainly composed of clear cancer cells (alpha-1 antitrypsin, albumin and alpha-fetoprotein positive), with elements of choriocarcinoma and tubular adenocarcinoma. Non-neoplastic specialized columnar epithelium was present extensively near the oral side of the tumor edge in the esophagus, indicating Barrett's esophagus. This unusual tumor was therefore considered to have originated in Barrett's esophagus. The gastroesophageal reflux was presumed to have occurred for a long period, as there was a well-preserved fundic gland in the stomach and a history of frequent vomiting from the patient's youth, accounting for the appearance of achalasia.

Adenocarcinoma↗

PubMed2002

[Experimental study of pseudo-stenosis artifact on three-dimensional DSA].

Rotational three-dimensional digital subtraction angiography (3D-DSA) is very useful for interventional neuroradiology, especially in the endovascular therapy of cerebral aneurysms. However, pseudo-stenosis artifact on the vessel, which runs vertically to the rotational axis, was observed clinically. In this study, this artifact was confirmed in an experiment with 4.5-millimeter diameter vessel phantoms. The attenuation of the phantom at each degree of exposure (44 directions) was measured on the workstation (DSA pixel value). DSA pixel values were plotted from data of 10, 20, 30, 40, and 50 millimeter lengths, respectively. The saturated DSA pixel value of tangent projection on phantoms of 30 millimeters or more in length was observed. This phenomenon induces pseudo-stenosis artifact on 3D-DSA. The maximum reduction in the diameter of the phantom was 27.4% on the length of 50 millimeters. We confirmed that the two-dimensional data vertical to the rotational axis were inaccurate when a straight-coursed, long, segmented vessel was present. Under this special condition, vessels on 3D-DSA were displayed as smaller than their actual diameter.

Angiography, Digital Subtraction↗