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Biomedical subjects

G Rizzatto

Publications and source records attributed to G Rizzatto.

At least 37 records · Page 2Linked to original sources

[Role of ultrasonics in the diagnosis of subclinical carcinoma of the breast].

The authors report the results of a retrospective multicentric study concerning the sonographic diagnosis of subclinical breast cancer, 11,254 patients were examined by means of mammography, with last-generation mammographic equipment, and by means of real-time US with 7.5-10 MHz transducer. Fifty-seven subclinical breast cancers were identified and histologically confirmed. US detected 30/57 neoplastic lesions, versus mammography 47/57; in particular, US identified 10 cancers missed at mammography, while the latter detected 27 malignant lesions missed at US. Mammographic accuracy in the early detection of breast cancers was 82.4%, while US accuracy was 52.6%. Mammographic false negatives were due to opacity of the glandular parenchyma. US false negatives presented at mammography as microcalcifications (67%), lesions less than 1 cm phi (22%), and indirect signs (11%). The results of this study demonstrate the important role of US in women with radiographically-dense parenchymal patterns, but confirm the superiority of mammography in the detection of subclinical breast cancer.

Biopsy↗

Normal anatomy and pathologic changes of the small bowel mesentery: US appearance.

The ultrasonographic (US) appearance of the normal small bowel mesenteric leaves was evaluated in two in vitro studies and in 30 patients. Such structures had an elongated shape, echogenic surfaces, and small vessels in their center and could be recognized in 28 of the 30 patients. They did not show active movements, and at their distal end, the small bowel loops could be seen and peristalsis detected. Doppler signals were obtained from the small vascular structures in their center in three additional cases. On the basis of these anatomic findings, pathologic changes such as lymphoma, desmoid tumor, metastatic lesions, dilated vessels, and edema could be detected in 15 patients. When examining with US patients with diseases prone to involve the mesentery, careful attention should be given to this structure, since useful information about the abdominal spread of the disease can be obtained.

Adult↗

Ultrasonography of the normal adrenal glands: a study using linear-array real-time equipment.

The adrenal glands were evaluated in 70 normal volunteers using linear-array real-time ultrasonography. All the scanning approaches described for manual B-scanning were used and, on the left side, longitudinal scans along the axillary lines were also performed. The right adrenal gland was imaged in 68 of the 70 volunteers and the left gland in 63. The dynamic capabilities of real-time equipment were of great help for proper localisation and identification of the glands. Changes in the scanning plane demonstrated variations in the adrenal morphology, because different portions of the gland were encountered by the scanning beam.

Adrenal Glands↗

The sonographic appearance of duodenal lesions.

The sonographic findings in 17 patients with duodenal tumors and in one patient with a benign ulcer and stricture of the duodenum were reviewed. An abdominal mass was detected sonographically in all patients; in 15 of 18 cases, such lesions presented high-level central echoes and hypoechoic periphery. Identification of the duodenal origin of the disease was possible by sonography in only 16 of 18 patients: by evaluation of the relationship of the mass with abdominal vessels in eight patients; by demonstrating that the lesion was continuous with a normal duodenum in seven patients; or by demonstrating the mass within the duodenum itself in one patient. Signs and symptoms of duodenal tumors are usually nonspecific, and sonography can be used as the first imaging method in these cases. A careful analysis of the relationship of the tumor to surrounding structures may allow correct identification of its origin.

Adenocarcinoma↗

The thyroid gland with low uptake lesions: evaluation by ultrasound.

An ultrasound examination was performed in 401 patients who had isotopically cold, solitary lesions of the thyroid gland. Of the parameters studied, the level of echoes was the most useful in making the sonographic diagnosis: the rate of malignancy was extremely low both in hyperechoic and echo-free lesions. The presence of a peripheral, complete "halo" appeared to be helpful in differentiating benign lesions from malignant lesions. Approximately 20-25% of the lesions thought to be solitary on the radionuclide study were found to be multinodular on US. When fine-needle aspiration biopsy was used with US the need for surgical exploration of the thyroid gland was obviated in selected cases.

Adenocarcinoma↗

Metastatic tumors in the breast: sonographic findings.

The sonographic findings observed in eight patients with metastatic tumors in the breast were reviewed. Solitary breast nodules were present in four patients; multiple metastases were seen in the other four patients, with bilateral lesions in two of them. A total number of 20 breast masses was appreciated. All lesions had a round or oval shape and hypoechoic, solid echopattern, when compared with the surrounding breast parenchyma. In three patients, they presented with many small medium-level internal echoes while, in the other five patients they were almost anechoic, with only a few low-level echoes within. Regular and well-defined margins were seen in four patients; in the remaining four patients, irregular walls were seen. The posterior walls of the lesions were well defined, and great acoustic attenuation was never seen. In one case, slight acoustic enhancement was present posterior to the lesions from non-Hodgkin's lymphoma. Multiple masses in the same patient always had the same sonographic features. While evaluating a breast mass in a patient with a known malignancy elsewhere in the body, the absence of an acoustic shadow posterior to the lesion may allow the metastatic nature of the disease to be considered as a diagnostic possibility.

Adolescent↗

Gas-containing gallstones: their influence on ultrasound images.

The ultrasound image of gas-containing gallstones was evaluated in three cases. In two, the stones were studied in vitro in a phantom gallbladder by ultrasound, and then by microradiographic techniques. The third case was investigated in vivo by ultrasound and computerized tomography (CT). The presence of gas-containing fissures, which are not detectable on ultrasound, was demonstrated. In contrast, wider fissures, or a true gas bubble, produce reverberation echoes which depend upon the quantity of gas present within the gallstone.

Cholecystectomy↗

Ultrasonographic patterns in hepatic hemangiomas.

Twenty-one cases of hepatic hemangioma were examined by ultrasound, and three main sonographic patterns were identified. In 14 cases hyperechoic focal areas were observed, in five cases larger hemangiomas exhibited a complex pattern, and in two cases hemangiomas appeared as rounded sonolucent areas with distal enhancement mimicking cysts. Hemangiomas may have significantly variable ultrasonographic features. According to the authors' experience, only in cases of hyperechoic well-defined lesions in asymptomatic patients can a definite diagnosis of hemangioma be made.

Adult↗

Pancreatic cystadenocarcinoma: diagnostic problems.

Eleven cases of pancreatic cystadenocarcinoma were studied with respect to the differential diagnosis from that of pancreatic pseudocysts, using diagnostic ultrasound as the initial investigative technique. Most of the cases presented an ultrasonic picture that correlated well with the gross pathology, but this correlation was not reliable enough to be considered characteristic in differentiating such masses from pseudocysts. The authors divide the cystadenocarcinomas of the pancreas into four echographic classes. In all but one of the classes, diagnostic ultrasound was insufficient by itself to render an accurate diagnosis. In such cases other techniques, i.e. CT, tissue biopsy, and especially angiography, were required for a reliable diagnosis.

Adult↗

Grey-scale ultrasonography in the evaluation of primary carcinomas of the bile ducts.

The authors report the echographic findings observed in 24 proven cases of primary carcinoma of the bile ducts. Most tumours, either vegetating or infiltrating with extraductile extension, were recognized on ultrasound. This technique turned out to be accurate in detecting peripheral, hilar and distal ductal carcinomas. Ultrasonography complements PTC and ERCP. Their combined use allows the surgeon a better selection of the cases and of the proper operative procedure.

Adenoma, Bile Duct↗

Ultrasonographic aspects of inflammatory and neoplastic diseases of the gallbladder.

The authors present the incidence of the typical ultrasonographic signs of acute cholecystitis (46 cases), chronic cholecystitis (25 cases), cholecystosis (9 cases), empyema (28 cases) and carcinoma of the gallbladder (30 cases). Ultrasonography, together with the clinical picture, enables the identification of the lesion, its extension and evolution in most of the cases. Rarely do differential diagnostic problems exist. The ultrasonographic follow-up examination has been useful in acute inflammatory diseases to evaluate the efficiency of medical therapy and to detect complications which require immediate surgery. The authors emphasize the value of high-resolution real-time technique.

Adult↗

Combined use of ultrasonography and transhepatic percutaneous cholangiography in obstructive jaundice.

The authors have evaluated the results of ultrasonography (US) and transhepatic percutaneous cholangiography (PTC) in 85 patients. The comparative results of US and PTC in the diagnosis of the level (proximal or distal) and the nature (benign or malignant) of the obstruction and in the evaluation of the extension and the site of the lesion are illustrated. PTC is superior in the evaluation of the level and the nature of the obstruction while US gives more information about extension and site of the lesion. It is concluded that US and PTC should be considered as two complementary modalities.

Cholangiography↗