Ultrasound in the diagnosis of a palpable abdominal mass. A prospective study of 107 patients

Ultrasound of the palpable abdominal mass

A retrospective study was made of adult patients with a palpable abdominal mass referred by Hospital Practitioners to the ultrasound department over an 11 month period. One hundred and four patients were included in the study. Sixty-nine patients had an abnormality responsible for the clinically palpable mass and 35 patients did not . There was one false positive ultrasound diagnosis and one false negative. The correct organ of origin was suggested in 60 patients and the correct pathological diagnosis in 53 patients. The high positive predictive value (99%) and negative predictive value (97%) for the presence or absence of a lesion in these patients compare very well with the investigation of such patients by computed tomography and we suggest that ultrasound should be the initial investigation.

Abdominal masses

The more common abdominal masses of the pediatric age group are discussed along with current thoughts regarding preoperative imaging modalities. A careful physical examination is indispensable, and masses should be evaluated with consideration given to mobility, location, consistency, contour, and site. A rectal examination is essential. The more unusual clinical presentations are discussed in appropriate sections.

Indications for laparoscopy before and after the introduction of ultrasonography

We compared the outcome of laparoscopy performed from 1973 to 1974, prior to the introduction of routine ultrasound diagnostics, with that of examinations during the period 1980-1981 when ultrasound had become a well-established technique in the diagnosis of hepatic lesions. Our data reveal statistically significant changes in the use of laparoscopy in the diagnosis of cholestasis and tumors of the hepatic parenchyma. Laparoscopy now has fewer indications in the study of the jaundiced patient with suspected extrahepatic cholestasis which is easily identified at ultrasound. Given the high sensitivity and specificity of ultrasonography in detecting metastases, laparoscopy has become a secondary examination. However, there has been an increase in the use of laparoscopy to identify benign hepatic lesions, particularly hemangiomas.

Ultrasonography in Crohn's disease

Eighteen patients with acute and subacute Crohn's disease were examined by ultrasound. In 7, ultrasound was the initial screening procedure leading to the diagnosis of Crohn's disease. This diagnosis was subsequently proved by results of barium studies. The most frequent ultrasonographic finding was conglomeration: an irregular mass containing scattered echodense and sonolucent areas that represented matted inflamed bowel loops. Some of the conglomerations showed a fine diffuse echo pattern with ill-defined posterior borders due to poor transmission. These areas denoted mesenteric fat covering the matted loops (fatty conglomeration). Other ultrasonographic findings were the "target" or "bull's eye" sign, abscess formation, and fluid in the cul-de-sac.

Computed tomography in 101 patients with a palpable abdominal mass

A total of 101 patients with a palpable or suspected abdominal mass of unknown origin were examined by computed tomography (CT). In 69 patients an abnormality was demonstrated at the site of the palpable mass; only in one patient was this finding erroneous (false positive). In 32 patients no lesion was demonstrated (one false negative). Such high positive and negative predictive values (99% and 97%) indicate the value of CT in determining the presence or absence of a lesion to account for a clinically apparent mass, especially when there is doubt as to its presence or organ of origin. As to the cause of the mass, CT correctly identified the responsible organ or structure in 64 out of 69 patients with a lesion (93%) and suggested the likely nature in 61 (88%).