Biomedical subjects

Masakatsu Hatagawa

Publications and source records attributed to Masakatsu Hatagawa.

6 recordsLinked to original sources

PubMed2005

[Experience in IVR performed using a posture support device designed especially for a patient unable to take the decubitus position].

We were requested to perform IVR for uterine artery embolotherapy of a patient who was unable to take the decubitus position. Because of extreme overweight, the patient was limited to a sitting posture on a bed in the living environment. Therefore, a device to support her sitting posture on the IVR patient table was designed and created. The support device was used to hold the patient's body in a half-sitting posture and distribute her weight load appropriately so that the weight load applied to the patient's body could be minimized. Using this support device, IVR could be performed smoothly during a period of 2 hours 40 minutes.

Arteries↗

PubMed2004

[Clinical study with angiography system using a flat panel detecter].

We have been using an X-ray angiography system that incorporates a flat panel detector (FPD) since December 2001. This system is equipped with the scintillator-type FPD PaxScan 4030A from Varian Medical Systems, and for objective comparison of the image intensifier (I.I.) and FPD, the system is constructed so that these detectors can be used alternatively. Using this system and other X-ray angiography systems, visual studies have been conducted on the digital subtraction angiography (DSA) images acquired by FPD and I.I. We have found from the clinical images that the FPD is superior to the I.I. in depiction of fine blood vessels as well as of physical characteristics. Fluoroscopy images acquired by the FPD were not entirely satisfactory, however the improvement made in its performance now permits equal use of the FPD and I.I. systems.

Angiography, Digital Subtraction↗

PubMed2004

[Newly developed monitor for IVR: liquid crystal display (LCD) replaced with cathode ray tube (CRT)].

For physicians who monitor images during interventional radiology (VR), we have built and been using a system that employs a liquid crystal display (LCD) instead of the conventional cathode ray tube (CRT). The system incorporates a ceiling-suspension-type monitor (three-display monitor) with an LCD on each of the three displays for the head and abdominal regions and another ceiling-suspension-type monitor (5-display monitor) with an LCD on each display for the cardiac region. As these monitors are made to be thin and light in weight, they can be placed in a high position in the room, thereby saving space and allowing for more effective use of space in the X-ray room. The system has also improved the efficiency of operators in the IVR room. The three-display folding mechanism allows the displays to be viewed from multiple directions, thereby improving the environment so that the performance of IVR can be observed.

Data Display↗

PubMed2002

Clinical evaluation of digital radiography based on a large-area cesium iodide-amorphous silicon flat-panel detector compared with screen-film radiography for skeletal system and abdomen.

The aim of this clinical study was to compare the image quality of digital radiography using the new digital Bucky system based on a flat-panel detector with that of a conventional screen-film system for the skeletal structure and the abdomen. Fifty patients were examined using digital radiography with a flat-panel detector and screen-film systems, 25 for the skeletal structures and 25 for the abdomen. Six radiologists judged each paired image acquired under the same exposure parameters concerning three observation items for the bone and six items for the abdomen. Digital radiographic images for the bone were evaluated to be similar to screen-film images at the mean of 42.2%, to be superior at 50.2%, and to be inferior at 7.6%. Digital radiographic images for the abdomen were judged to be similar to screen-film images at the mean of 43.4%, superior at 52.4%, and inferior at 4.2%; thus, digital radiographic images were estimated to be either similar as or superior to screen-film images at over 92% for the bone and abdomen. On the statistical analysis, digital radiographic images were also judged to be preferred significantly in the most items for the bone and abdomen. In conclusion, the image quality of digital radiography with a flat-panel detector was superior to that of a screen-film system under the same exposure parameters, suggesting that dose reduction is possible with digital radiography.

Adult↗

PubMed2002

[An experience of the clinical study with angiography system using a Flat Panel Detector].

We had the chance of clinical studies by new proto-type Digital Subtraction Angiography (DSA) System with the Flat Panel Detector (FPD). That system has two types of detector, FPD and I.I.-CCD camera, and we can compare with image quality in clinical. We measured and discussed about the physical characteristic data of both detectors. Up to physical characteristic evaluation, FPD has good MTF and SNR performance, comparing with I.I.-CCD camera. In clinical evaluation, DSA image of FPD was superior to that of I.I.-CCD camera by visual comparison of medical doctors. Finally we discussed about the feasibility of replacement of detectors. We expect that DSA system will accept FPD in near future.

Angiography, Digital Subtraction↗

PubMedDate not supplied

Percutaneous ethanol injection under CT fluoroscopy for hypervascular hepatocellular carcinoma following transcatheter arterial embolization.

BACKGROUND/AIMS: The present study was conducted to accurately monitor the pattern of ethanol distribution during percutaneous ethanol injection by computed tomography fluoroscopy and to examine the relationship between the distribution pattern and therapeutic effect. METHODOLOGY: Twenty-five hypervascular hepatocellular carcinomas were studied. Each was treated with transcatheter arterial embolization. However, as residual parts were detected, percutaneous ethanol injection under real-time computed tomography fluoroscopy was performed. For analysis, ethanol distribution and local recurrence rate were compared. RESULTS: Ethanol distribution in a tumor was classifiable into 3 patterns. In pattern 1, ethanol solution was distributed spherically. In pattern 2, ethanol solution spread forming linear boundaries indicating interruption of distribution by septa. In pattern 3, ethanol spread circumferentially only along the periphery sparing the central part of a tumor. The 6-month recurrence rate of the tumors in which ethanol solution was distributed to the whole viable part was 25% (pattern 1), 100% (pattern 2) and 0% (pattern 3), respectively. CONCLUSIONS: In the tumors showing distribution pattern 3 by computed tomography fluoroscopy, a combination therapy of transcatheter arterial embolization and percutaneous ethanol injection was more effective than in other patterns. Computed tomography fluoroscopy was useful for accurate monitoring and predicting the therapeutic effect of percutaneous ethanol injection.

Aged↗