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Biomedical subjects

K W Marich

Publications and source records attributed to K W Marich.

At least 19 recordsLinked to original sources
PubMed1999

Noninvasive surgery of prostate tissue by high intensity focused ultrasound: an updated report.

OBJECTIVE: To establish clinical efficacy and safety of High Intensity Focused Ultrasound (HIFU) for the treatment of benign prostatic hyperplasia (BPH) in a multiple site clinical study. METHODS: Seven clinical sites were set up for the studies, five in the USA, one in Canada and one in Japan respectively. Sixty two patients were enrolled in these three studies. Transrectal ultrasound probes made to produce sufficient acoustic power required for focused ultrasound surgery of the prostate as well as to perform imaging of the prostate, were employed in the study. The probes ware made of 2.5, 3.0, 3.5, 4.0 and 4.5 cm focal length transducers to treat varying prostate sizes and shapes and operated at 4 MHz frequency for both imaging and treatment. The employed ultrasound device produced both transverse and longitudinal images of the prostate on the same display. The images were used for selection of tissue volume, treatment planning and monitoring of tissue during the HIFU treatment cycle. The patients in the USA and Canada were followed for two years and those in Japan were followed for one year on a regular interval. The results were evaluated for changes in the peak flow rate (Qmax in ml/s), quality of life (QOL) and International Prostate Symptom Score (IPSS). RESULTS: The average pre / post treatment results at 180 days were significantly different for Qmax, QOL and IPSS 8.5/14.2 (ml/s), 4.7/2.1 and 22/10 respectively. CONCLUSION: Under this protocol, HIFU was found safe and efficacious for the treatment of BPH. The HIFU treatment produced statistically significant results for the parameters measured with least complications. Additionally, the HIFU treatment was found to be durable.

Follow-Up Studies↗
PubMed1997

Early experience with high-intensity focused ultrasound for the treatment of benign prostatic hypertrophy.

OBJECTIVE: To evaluate the safety and effectiveness of high-intensity focused ultrasound (HIFU) in patients with benign prostatic hypertrophy (BPH). PATIENTS AND METHODS: The study comprised 25 patients (mean age 67 years: range 47-84) with BPH treated using the Sonoblate HIFU device. Patients were evaluated before and after one treatment of HIFU using the American Urological Association (AUA) symptom score, peak urinary flow rate (Qmax) and a quality-of-life (QOL) score, and any complications were noted. RESULTS: Five patients with large glands were withdrawn because the failure rate was high in these patients. The remaining 20 patients showed a mean improvements in the AUA symptom score (20.25 to 9.56), Qmax (9.2 to 13.7 mL/s) and QOL score (4.75 to 2.50). There were no major complications. CONCLUSIONS: HIFU is safe, produces minimal side-effects or complications and relieves the symptoms of prostatism.

Aged↗
PubMed1992

Reflex transmission imaging improves ultrasonic visualization and characterization of calculi for lithotripsy applications.

A new ultrasound technique combining reflex transmission imaging (RTI) and integrated reflection C-scan (IRCS) imaging is being developed to enhance visualization of calculi for lithotripsy applications. Reflex transmission imaging/integrated reflection C-scan ultrasound produces orthographic images (similar to flat-field x-ray films) that improve the delineation of stone from soft tissue. Integrated reflection C-scan imaging is based on reflectivity while RTI is based on transmissivity of structures (stones) in the focal plane. Quantitative measurements of reflectance (IRCS) and attenuation (RTI) show potential for stone characterization and assessment of the degree of fragmentation. In vitro and in vivo images are presented.

Cholelithiasis↗
PubMed1988

Carotid duplex sonography: a multicenter recommendation for standardized imaging and Doppler criteria.

A complex duplex carotid evaluation involves high resolution imaging and characterization of the carotid plaque as well as quantitative Doppler spectral analysis to determine the presence and degree of flow restriction. Each of the components of the examination is essential to evaluate the carotid arteries adequately for the presence of disease. Both of these components should be assimilated into a final report that can be used to determine who is at risk for embolic as well as flow restrictive disease. By carefully following the reporting system described in this paper, an accurate and reproducible means of evaluating the carotid arteries can be achieved that permits comparison of studies. In addition, this will allow accurate communications among institutions and help to insure a better understanding of the etiology and pathogenesis of atherosclerotic carotid artery disease.

Arteriosclerosis↗
PubMed1985

Vasculogenic impotence evaluated by high-resolution ultrasonography and pulsed Doppler spectrum analysis.

Vasculogenic impotence was evaluated by high-resolution sonography and quantitative Doppler spectrum analysis in 21 patients and two normal volunteers. Erection was induced by intracorporeal injection of papaverine, and B-scan imaging and Doppler analysis were performed with the penis flaccid and erect. The corpora cavernosa and its deep arteries, median septum, and corpus spongiosum were clearly displayed in every subject, with the dorsal vein and dorsal artery seen ventral to the corpora cavernosa. In the flaccid state, in all subjects, Doppler analysis demonstrated flow in the dorsal arteries but not in the deep arteries. During erection, the B-mode image showed varying degrees of enlargement of the corpora cavernosa, with increased tissue echogenicity, as well as a hypoechoic area in the peri-arterial region. The diameter of the penile arteries and flow within them also increased by varying degrees. Quantification of blood flow through all deep and dorsal arteries is feasible with this technique.

Adult↗
PubMed1984

Preliminary study of the upper limb with the use of ultrasound transmission imaging.

A biologically safe, noninvasive method for visualizing bone and soft tissue relationships has been developed recently. Termed the ultrasonic transmission imaging system, its advantages include visualization of soft tissues in real time while motion is underway. The image can be correlated to standard x-ray films, but since no ionizing radiation is involved, repeated risk-free visualization of extremities for either diagnostic assessment or biomechanical studies is permitted. Resolution of 1 mm and a depth of field of 8 mm are adequate for visualization of neurovascular bundles, tendons, ligaments, bones, and joints. The image can be digitized and stored for later analysis on computer graphic systems. Pilot studies have correlated the ultrasonic anatomy of normal and abnormal living and cadaver hands with known anatomic structures. The benefits to biomechanical analysis include the ability to visualize and accurately measure in a noninvasive manner the in vivo changes of position of tendons and other structures during movement. These initial efforts indicate the growing diagnostic and analytic capabilities of this instrument.

Evaluation Studies as Topic↗
PubMed1975

Real-time imaging with a new ultrasonic camera: part I, in vitro experimental studies on transmission imaging of biological structures.

Results are described of in vitro biological experimentation using a new through-transmission ultrasonic camera system developed at the Stanford Research Institute. The camera system produces real-time focused, orthographic images of a 15 times 15 cm field. The in vitro studies, which demonstrate the diagnostic potential of the new technique, include transmission images of selected excised organs such as liver, kidney, spleen, and uterus. In addition, preliminary studies evaluating ultrasonic image quality and the effect of out-of-focus structures are discussed.

Animals↗
PubMed1975

Potential for clinical use of the analytical laser microprobe for element measurement.

Use of the laser microprobe for rapid emission spectroscopic analysis of elements in microscopic samples of biological material is described. The technique depends on vaporization of the microsample with a focused laser beam at a temperature that renders the vapor incandescent for spectrochemical analysis. Spectral line intensities are recorded photographically with densitometry of the negatives or photoelectrically. Current capability permits analysis of about 10(-8) to 10(-10) g of tissue, with detection limits of 10-12 to 10-15 g of element. Groups of elements can be simultaneously analyzed. Minimum sample preparation is required, and the analysis is done on the stage of a light microscope, usually on an air-dried sample on a plastic slide. We exemplify the technique in analysis of gold in cultured fibroblasts treated with gold salts and in human skin after treatment with gold salts for rheumatoid arthritis, in element changes in biopsies of transplanted human hearts, and in unique profiles of groups of elements in human cancer tissue.

Adenocarcinoma↗