鯉渕 晴美

Purpose. To determine whether a combination of contrast-enhanced ultrasound-guided methods and dye-guided methods can identify sentinel lymph nodes in animals. Methods. Seven pigs were put under general anesthesia and injected subcutaneously in the neck: three with 2 ml saline and four with 2 ml fluid comprising 0.4 ml 5% patent blue violet solution and 1.6 ml of hydroxyethylated starch (Salinhes) solution (PB + HS). The regional lymph nodes were observed by ultrasound blue-stained regional lymph nodes found after the skin was cut were situated as ultrasound had shown they would be. Results. The regional lymph nodes of the pigs given saline were unchanged, but in the pigs receiving PB + HS, the echo level in the lymph nodes nearest the injection site was altered, producing a clear contrast with the surrounding tissues. The area of the relevant regional lymph node in each PB + HS-injected pig increased significantly (t-test, P &lt 0.01 from 25.7, 39.6, 9.36, 70.2 mm2, and mean, 36.2 mm2 to 50.7, 65.5, 21.1, 98.3 mm2, and mean, 58.9 mm2, respectively). These enlarged regional lymph nodes were easily found by contrast-enhanced ultrasonography. When excised under ultrasound guidance, all were stained blue, indicating that they were sentinel lymph nodes. Conclusion. These results suggest that this combination of contrast-enhanced ultrasound-guided and dye-guided methods warrants use as a quick, simple procedure for detecting sentinel lymph nodes. © 2006 The Japan Society of Ultrasonics in Medicine.

Nocardiosis is an opportunistic infection caused by bacteria of the Actinomycetaceae family. The incidence of nocardial infections is increasing with the growing number of transplant and HIV-positive patients. Lung involvement is frequent, which causes soft-tissue and cerebral involvement by hematogeneous dissemination. We emphasize ultrasonographic findings in describing two cases of abscesses in soft tissue. Case 1: A woman aged 39 years had received daily doses of predonisolone (30 mg) and cyclosporin (200 mg) for subcutaneous panniculitic T-cell lymphoma. Some nodules on her back and lower extremities developed without inflammatory signs. Chest X-ray showed an abnormal shadow. Nocardia farcinica was isolated from aspiration material of the mass on her back, sputum and blood. Ultrasonograms showed a smoothly outlined hypoechoic mass in the latissimus dorsi muscle. The internal echo pattern was homogeneous and contained amorphous anechoic areas. Color Doppler ultrasonography detected no blood-flow signal in the mass. Case 2: A man aged 67 years had been treated with daily administration of predonisolone (50 mg) and double filtration plasmapheresis for bullous pemphigoid. Multiple nodules on his right upper arm, nuchal region, back, and left buttock were diagnosed as nocardial abscesses on biopsy of the mass on the buttock. The ultrasonogram showed a smoothly outlined hypoechoic mass with a central anechoic area in the subcutaneous layer of the right arm, and an irregularly outlined hypoehoic mass with heterogeneous internal echo texture in the nuchal region. Because ultrasonographic images of nocardial abscesses in soft tissue often appear atypical as abscesses, these findings should be borne in mind when diagnosing these lesions.

A 6 year-old female patient with fever was hospitalized. Chest radiogram showed uniform opacity, probably an abscess, at the base of the left lung. Ultrasound images showed a wedge-shaped echogenic mass with an artery running into it. These findings suggested pulmonary sequestration. Intravenous administration of an antibiotic reduced the fever and the inflammatory reaction. Our diagnosis of pulmonary sequestration was confirmed by selective angiography. Ultrasound examination was useful in diagnosing this case of pulmonary sequestration.

We ultrasonographically measured renal length in the major axis in children. Here we discuss the differences in measured lengths in the supine and prone positions. In study 1, which included 214 children, more than 60 percent of the kidneys measured longer in the supine than in the prone position. The difference (S-P : length in the supine position minus length in the prone position) was substantially greater in the left kidney. In study 2, we observed the relation between the kidney and the liver or spleen in 60 children prospectively to determine if artifacts had contributed to the observed differences. When the location of the liver or spleen was above the kidney, which may induce velocity displacement and renal duplication artifacts, the kidney tended to measure longer. We conclude that kidneys tend to measure longer in the supine than in the prone position. Difference in renal length in different positions was greater in the left kidney than in the right kidney. Sonographic artifacts are presumed to contribute to differences in measured length.