Biomedical subjects

N M Rawool

Publications and source records attributed to N M Rawool.

21 records · Page 2Linked to original sources

PubMed1995

Laparoscopic gray-scale and color Doppler US: preliminary animal and clinical studies.

PURPOSE: To evaluate a semiflexible ultrasound (US) transducer inserted through a laparoscopic port to image abdominal structures. MATERIALS AND METHODS: Laparoscopic US with a 9.6-mm-diameter, 5.0-7.5-MHz semiflexible transducer with gray-scale, color, and spectral Doppler capabilities was performed in three miniature swine and in 25 patients with a variety of abdominal abnormalities. RESULTS: This miniature US probe was used to locate normal structures such as blood vessels, allowing the surgeon to decide the best approach for dissection. Color and spectral Doppler US proved especially useful in differentiating vascular from nonvascular structures. The presence or absence of stones in the gallbladder and common bile duct was readily determined. It was possible to detect masses and to provide guidance for their aspiration or biopsy within abdominal organs. In 10 cases (40%), laparoscopic US helped the surgeon make the decision for clinical management and altered the surgical procedures. CONCLUSION: Laparoscopic US was useful in assisting laparoscopic evaluation of abnormalities in the abdomen.

Abdomen↗

PubMed1995

Synovial fluid in the hindfoot and ankle: detection of amount and distribution with US.

PURPOSE: To determine the amount and distribution of synovial fluid detectable with ultrasonography (US) of the hindfoot and ankle in asymptomatic volunteers. MATERIALS AND METHODS: US was performed with a 7.5- or 10-MHz linear transducer of 60 hindfeet and ankles in 30 volunteers. Presence and amount of fluid were assessed in the ankle joint recesses, adjacent bursae, and tendon sheaths. Symmetry of bilateral fluid was evaluated. RESULTS: Fluid was detected in the anterior recess in 20 ankles (bilaterally in eight volunteers), retrocalcaneal bursa in 30 ankles (bilaterally in 12 volunteers), posterior tibial tendon sheath in 46 ankles (bilaterally in 19 volunteers), and common peroneal tendon sheath in seven ankles (bilaterally in three volunteers). No fluid was seen in the posterior recess. On average, symmetry was present for only the retrocalcaneal bursal and peroneal tendon sheath fluid. CONCLUSION: US of the hindfoot and ankle commonly depicts articular, bursal, and tendon sheath fluid in asymptomatic volunteers. The presence of fluid in these locations, even when unilateral or asymmetric, does not necessarily imply underlying abnormality.

Adult↗

PubMed1995

Parenchymal enhancement and tumor visualization using a new sonographic contrast agent.

The purpose of this study was to assess the ability of a sonographic contrast agent to increase parenchymal echogenicity and improve tumor visibility. The agent is an emulsion that changes at body temperature from nonechogenic submicrometer liquid droplets to echogenic 1 to 5 microns microbubbles, capable of transversing the pulmonary and capillary circulations. Peripheral venous injections (dosages of 0.05 to 0.8 ml/kg) were administered to five woodchucks (three with multiple hepatomas), 12 rabbits (with renal VX-2 tumors), and four dogs. Ultrasonograms were acquired from kidney, liver, tumors (including tumor vessels) and normal vessels. Uptake and washout curves were generated via videodensitometry. Finally, Doppler shifts from a cuff transducer around the celiac trunk were analyzed to provide an in vivo dose-response curve. Vascular enhancement, including hepatoma and VX-2 tumor vessels, was seen for 2 to 3 min. Maximum enhancement was 18.7 dB for a 0.6 ml/kg dose. Enhancement of normal liver and kidney parenchyma was observed in all three species for up to 20 min. Small hepatomas became more echogenic centrally, but larger tumors showed no increase in central echogenicity. In conclusion, improved tumor visibility and parenchymal enhancement was demonstrated in animals.

Animals↗