Diagnostic imaging in head and neck disease: current applications of ultrasound.

Diagnostic ultrasound has become firmly established as a key imaging modality in obstetrics and gynecology. Its role in abdominal and retroperitoneal disease is also well known and continues to expand. Although usage of ultrasound in the head and neck had its beginnings many years ago, the advent of newer high-resolution transducers has allowed for further investigation of diseases in this area. Of particular interest are the thyroid gland and the extracranial carotid arteries. This review summarizes the current utility of gray-scale and real-time ultrasound in evaluating head and neck disease, and discusses potential future applications of the modality.

Ultrasonic features of Gartner's duct cyst.

Gartner's duct cysts will usually be incidental findings during pelvic sonography. Of developmental origin, they may present anywhere along the lateral aspect of the female genital tract. When the cysts are of parovarian origin, they will mimic other fluid-filled adnexal masses, and no specific diagnosis can be made. When alongside the vagina or cervix, however, their ultrasonographic appearance is probably characteristic.

Oriental cholangiohepatitis: preoperative radiographic and ultrasonographic diagnosis.

The recent influx of immigrants from Southeast Asia into the United States has increased the likelihood of encountering unusual diseases heretofore rarely seen in this country. Among these disorders is Oriental cholangiohepatitis, a potentially life-threatening process whose early diagnosis is facilitated by roentgenographic findings. Ultrasonography can also provide useful information, although potential pitfalls in diagnosis should be recognized.

Sonography of the thickened gallbladder wall: a nonspecific finding.

Twenty cases of sonographically visualized thickening of the gallbladder wall were reviewed and the clinical diagnoses compiled. In only eight of these patients was cholecystitis considered responsible for the finding. The rest had hepatitis, alcoholic liver disease with hypoproteinemia, heart failure, renal disease, and multiple myeloma; however, all lacked clinical evidence of gallbladder disease. Because of these findings, caution is urged in making the diagnosis of cholecystitis on the basis of wall thickening alone.

Ultrasonography of testis tumors.

Intratesticular masses can be identified with a high degree of accuracy using recently refined techniques of scrotal ultrasonography. In an attempt to correlate sonographic findings with histopathologic features the sonograms performed on 17 consecutive patients with testis tumors were reviewed. Two distinct categories were identified. Seminomas and lymphomas appeared hypoechoic and homogeneous, and had sharply demarcated intratesticular borders. Nonseminomatous germ cell tumors, although also of lower echogenicity than normal testis, appeared to have cystic spaces, acoustic shadowing and irregular margins extending into the testis parenchyma. Preoperative characterization of a scrotal mass with ultrasound can facilitate surgical excision of the tumor. Scrotal ultrasonography also is useful in the detection of tumor in a palpable normal testis and is a convenient method for the examination of patients who have had a testis tumor previously.

Appearance of renal infarction on computed tomography.

We have recently seen three cases of renal infarction secondary to occlusion of renal arteries. Two of these cases had similar clinical presentations and were not diagnosed until computed tomographic (CT) scans were performed (1). The third case was a serendipitous finding. The abnormal findings on CT led to angiography, which confirmed the CT findings in all cases. The CT appearance in those cases was diagnostic, whereas the changes on urography were minimal, if any. We believe that angiography and surgery may be obviated when cases exhibit these characteristic findings on CT.

High-resolution ultrasonography of scrotal pathology.

A prototype high-resolution (10-MHz) real-time ultrasonic system was used to study 22 patients who were ultimately proved to have intra- and extratesticular tumors, scrotal fluid collections, and inflammatory processes. In 5 of 6 patients with primary testicular masses, there were areas of decreased echogenicity within the testis when compared with surrounding normal tissue. In general, the method was highly effective in differentiating and characterizing testicular and extratesticular processes.

Genetic amniocentesis in multiple pregnancy.

Eleven cases of twin pregnancy presenting for genetic diagnosis in the second trimester are reported. In all 11 cases, a correct chromosomal diagnosis was made on each of the twins. The technique used required only ultrasound and Evan's blue dye for direction of the amniocentesis. Amniography was not performed. The technique used is described in detail, and its advantages over more standard techniques are described.

Sensitivity of gray scale ultrasound in detecting urinary tract obstruction.

To determine the reliability of gray scale ultrasound in detecting urinary tract obstruction, a prospective study of 67 patients examined by both excretory urography and ultrasound was undertaken. The degree of hydronephrosis was defined by urographic criteria, and the corresponding echograms were analyzed without knowledge of the urographic results. Hydronephrosis was correctly diagnosed by ultrasound in 46 of 47 kidneys shown to be obstructed on urography, for a sensitivity of 98%. Our results show that when obstruction is the sole clinical question, ultrasound is an effective screening test. Thus many patients with a variety of medical diseases of the kidney can be spared excretory urography.

Perfluoroctylbromide: a liver/spleen-specific and tumor-imaging ultrasound contrast material.

The effect of perfluoroctylbromide (PFOB) on liver and tumor echogenicity was evaluated in rabbits. The echogenicity of the kidney, which is not affected by PFOB, was used as the basis for comparison in the liver studies. For the liver echogenicity study, sonography was performed on four rabbits, two with PFOB and two without PFOB, and four rabbits prior to and following the intravenous administration of 5 ml/kg PFOB. All livers were equal to or less echogenic than kidney in the control animals. All livers became more echogenic than kidney two days after administration of PFOB. The effect of PFOB on tumor echogenicity was evaluated in 18 rabbits with VX2 tumor implanted in the liver. Ultrasound studies of all rabbits were performed by the same physician before and two days after half the rabbits had received PFOB (5 ml/kg intravenously). The reviewers correctly identified all rabbits that received PFOB by visualization of an echogenic rim around the hepatic tumors.

Perfluorochemicals as liver- and spleen-seeking ultrasound contrast agents.

In this study, Fluosol-DA, 20 per cent (composed of perfluorodecalin and perfluorotripropylamine) was tested as a liver-specific ultrasound contrast agent. Twelve normal rabbits were scanned, utilizing the Picker Microview (10 MHz), prior to and two days following the intravenous administration of 24 ml/kg of Fluosol (or 4.8 g/kg of perfluorochemicals) emulsion to ten of the rabbits and 24 ml/kg of Ringer's solution to two rabbits as control. In all ten rabbits given Fluosol, liver echogenicity increased relative to that of the kidney, whereas the liver remained less echogenic than the kidney in the two rabbits given Ringer's solution. Four independent reviewers correctly identified all rabbits that received Fluosol and both rabbits that received Ringer's solution. It is demonstrated that, similar to PFOB, Fluosol serves as an echogenic contrast material for ultrasound and opacifies the normal rabbit liver.

Oriental cholangiohepatitis: diagnostic imaging and interventional management.

Diagnostic and therapeutic radiologic experience with six patients who had oriental cholangiohepatitis is described. These patients combined had 10 prior operations. Postoperatively each had recurrent cholangitis, numerous stones, concretions, and/or bile duct strictures. Diagnostically, sonography was valuable in the detection of intra- and extrahepatic stones and extrahepatic dilatation of ducts. An important pitfall in sonography was poor visualization of intrahepatic ductal dilatation (due to echogenic sludge filling the ducts) in most patients. CT was helpful diagnostically in all respects. Interventional procedures used postoperatively included percutaneous transhepatic intrahepatic stones, and flushing techniques. Most patients were treated during multiple sessions as outpatients. Cholangitis was the only complication from the procedures. Sectional imaging and interventional radiology perform valuable diagnostic and therapeutic roles in the pre- and postoperative management of patients with oriental cholangiohepatitis.

Cholecystokinin cholecystography, sonography, and scintigraphy: detection of chronic acalculous cholecystitis.

Because the efficacy of cholecystokinin cholecystography in the detection of chronic acalculous cholecystitis remains in doubt, the procedure is rarely used in clinical practice. However, the ability to observe gallbladder contraction with sonography and 99mTc-para-isopropylacetanilido-iminodiacetic acid cholescintigraphy (PIPIDA) offers a possibility to improve the sensitivity of the test. To determine if the degree of gallbladder contraction after cholecystokinin is the same as measured by the three techniques and if it differs in symptomatic patients compared to the normal population, cholecystokinin cholecystography, cholecystokinin sonography, and cholecystokinin PIPIDA were performed in 10 symptomatic patients and 10 normal volunteers. The mean maximum contraction of the gallbladder during the three studies was 63%, 61%, and 68%, respectively, for the volunteers, and 72%, 63%, and 73%, respectively, for the patients. The mean maximum gallbladder contraction during all three procedures was 64% +/- 26% SD in the volunteers and 74% +/- 17% SD in the patients. The differences were not statistically significant. Although there was good correlation in the degree of maximum gallbladder contraction among cholecystokinin cholecystography, cholecystokinin sonography, and cholecystokinin PIPIDA, marked variation in both the volunteers and the patients makes it unlikely that the degree of contraction as observed by any of these techniques can be used to indicate the presence of chronic acalculous cholecystitis.