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Biomedical subjects

G C Hansen

Publications and source records attributed to G C Hansen.

16 recordsLinked to original sources

US-guided core biopsy of the breast with a coaxial system.

From July 1993 through June 1994, the authors performed 42 ultrasound (US)-guided core biopsies with use of a coaxial technique in which a 14- or 15-gauge core biopsy needle was passed through a 12-gauge introducer needle. This technique proved to be effective in all 42 biopsies. Use of the coaxial technique decreased the procedure time necessary for US-guided core biopsy and may be less traumatic than the standard core biopsy technique.

Adult

Imaging of gallbladder carcinoma.

Although carcinoma of the gallbladder has a low overall prevalence, it is the most common malignant tumor of the biliary tract. Retrospectively, 59 cases of histologically proved gallbladder carcinoma were reviewed. The series consisted of 42 women and 17 men, ranging in age from 35 to 86 years. Clinical manifestations of gallbladder carcinoma include right upper quadrant pain, anorexia, weight loss, and jaundice. Radiologic findings included focal or diffuse thickening of the gallbladder wall (49%), a mass in the gallbladder fossa (37%), and an intraluminal mass (14%). Associated findings were cholelithiasis (64%), biliary duct dilatation (38%), invasion of the adjacent structures (67%), distant metastases other than those of the liver (3%), and porcelain gallbladder (4%). The histologic diagnoses were adenocarcinoma (90%) and squamous cell carcinoma (10%). Differential diagnoses include all conditions in which the gallbladder wall appears thickened. A general awareness of the radiologic features of gallbladder carcinoma enhances preoperative diagnoses.

Adult

Transvaginal sonographic evaluation of endometrial polyps.

The purpose of this study was to correlate the sonographic and histologic findings of focal lesions of the endometrium as depicted by transvaginal sonography. Sixteen focal endometrial masses were encountered during an 8 month period. The transvaginal sonographic appearance was correlated with findings at surgery or hysteroscopy. All uniformly hyperechoic endometrial masses were benign endometrial polyps. Five heterogeneous lesions were complicated endometrial polyps; one of these showed a focus of endometrial carcinoma. Four small and uniformly hypoechoic lesions were all prolapsed submucosal leiomyomata. Our results showed that a well-defined, uniformly hyperechoic mass within the endometrial cavity is most suggestive of a benign endometrial polyp. Larger masses with a heterogeneous appearance are nonspecific and warrant further evaluation and biopsy.

Adenocarcinoma

Imaging of pregnancy-related complications.

Thirty-six cases of pregnancy-related complications were studied with plain radiography, ultrasonography (US), computed tomography (CT), and magnetic resonance (MR) imaging alone or in combination. Among the complications diagnosed with these various techniques were venous thromboembolic disorders, deep vein thrombosis, ovarian vein thrombosis, endometritis and pyometra, HELLP syndrome (hemolysis, elevated liver enzyme levels, and low platelet counts), hepatic hematoma and rupture, fatty liver, uterine rupture, various hematomas and a foreign body, tubo-ovarian abscess, cerebral venous thrombosis, cerebral ischemia, and cerebral edema. Prompt detection and appropriate management of many of these complications could result in decreased maternal and fetal mortality and morbidity. Although US should be considered first because it can be performed bedside, does not require use of ionizing radiation, and is cost-effective, CT is superior in demonstrating the extent of the abnormality and MR imaging is best for detection of neurologic complications of pregnancy. The radiologist should select the best available method and tailor the examination according to the presumptive clinical diagnosis and the individual problem to be solved.

Adult

Endoluminal catheter-assisted transcervical US of the human embryo. Work in progress.

To enhance visualization of anatomic structures of the human embryo, the authors used a commercially available catheter-based ultrasound (US) transducer (12.5 MHz) introduced through the cervix and into the endometrial cavity of seven women about to undergo voluntary termination of first-trimester pregnancy. The authors term this technique endoluminal catheter-assisted transcervical (ELCAT) sonography. In none of the patients did the US catheter rupture the fluid-filled chorionic/amniotic cavity. The duration of pregnancy ranged from 5.2 to 10.0 menstrual weeks. The most prominent anatomic structures visualized were the heart and neural tube. As an investigational technique, ELCAT US can be used to image anatomic structures of the developing human embryo.

Catheterization

Computed tomography in the evaluation of mediastinal lipomatosis.

Mediastinal abnormalities can present a challenging differential diagnosis. One of the many causes of superior mediastinal widening is excess deposition of fat or mediastinal lipomatosis. Mediastinal widening was evaluated by routine chest radiography, conventional tomography, and computed tomography in four patients with steroid induced Cushing's syndrome or simple obesity. Computed tomography was the only modality that definitively diagnosed mediastinal lipomatosis in each case.

Cushing Syndrome

Computed tomography diagnosis of renal angiomyolipoma.

Angiomyolipomas with a high fat content can be diagnosed by CT, thus eliminating the need for angiography. Surgery can then be tailored for maximal renal tissue preservation. One unilateral and two bilateral surgically confirmed cases of renal angiomyolipoma are presented with a typical fourth case in which surgery was cancelled based on the pathognomonic CT findings.

Adult

The value of sialography in the diagnosis of parotid tumors. A clinicopathological correlation.

The importance of sialography in the diagnostic evaluation of the condition of a patient with a parotid mass remains uncertain; some proponents advise use of sialography routinely, while others believe it to be worthless. To help resolve these conflicting opinions, a retrospective study of 40 patients was carried out that compared sialographical interpretations with respective surgical-histological findings. The results of this study show that generally reliable information, which may serve to influence therapeutic decisions concerning these patients, can be gleaned from sialography.

Humans

Cholelithiasis in the gravid Hispanic population.

Ultrasound examinations were performed to determine the prevalence of cholelithiasis in 585 pregnant Hispanic patients. The ultrasound findings were correlated with age and country of birth. The overall prevalence of gallstones was 5.3%. This is not statistically different from the prevalence of gallstones in age-matched groups from previously published studies not selected for country of birth or ethnic background. We found no statistically significant different in prevalence rates for gallstones between Mexican-born and non-Mexican-born pregnant Hispanic women in the 20-year to 49-year age group. Unlike prior studies, this study does not support the use of increased ultrasound examination for cholelithiasis in a pregnant Hispanic population.

Adult