Placenta previa: avoiding false-negative diagnoses

A retrospective analysis of 102 patients with clinically suspected placenta previa revealed that ten women (10%) were correctly diagnosed as having placenta previa, while two women (2%) had false-positive diagnoses. Three of the ten women who were correctly diagnosed as having placenta previa had scans that could easily have been misinterpreted as normal. Because a false-negative diagnosis of placenta previa is clinically much more serious than a false-positive diagnosis, these cases are elaborated upon. Recognition of a laterally positioned placenta previa and observation of blood in the region of the internal cervical os should minimize false-negative diagnostic errors.

The oblique bending view in oral cholecystography

The oblique bending projection, when incorporated into routine radiographs during oral cholecystography, was found to be at least as effective as fluoroscopic spot radiographs in obtaining information about the gallbladder.

Dermoid cysts of the ovary: their ultrasonographic appearances

Ultrasonograms of 45 patients with 51 surgically proved benign cystic teratomas (dermoid cysts) of the ovary were reviewed to evaluate the ultrasonographic appearance of this entity. Contrary to several recent reports stressing a "typical" appearance for ovarian dermoid cysts, ie, an echogenic focus with acoustic shadowing situated within a predominantly cystic mass, the authors observed a much broader spectrum of appearances. Thirty-three percent of the cases demonstrated "typical" findings, 23.5% were predominantly solid, 20% were almost entirely cystic, and 23.5% were not visible. Ultrasound and conventional radiography in patients with dermoid cysts were compared: Ultrasonography contributed significantly to the correct diagnosis in the majority of cases. Because ultrasonography lacks ionizing radiation, and its use may reveal unrelated pelvic pathology, it should be the initial diagnostic modality in the examination of patients with suspected dermoid cysts of the ovary.

Ultrasonic demonstration of endometrial fluid collections unassociated with pregnancy

Intrauterine fluid collections were demonstrated by ultrasound in 17 non-pregnant patients. In nearly all instances, the surrounding echoes were of low to moderate amplitude. This has been noted previously in women with an ectopic or abnormal intrauterine pregnancy. In 2 patients, a well-defined thick rind of high-amplitude echoes encompassed the fluid, simulating an early gestational sac. Small intrauterine fluid collections were seen most frequently in non-pregnant patients who had vaginal bleeding or inflammation of the endometrium or adnexa.

Sonographic demonstration of portal hypertension: the patent umbilical vein

The remnant of the umbilical vein, the ligamentum teres, is seen on a high percentage of normal ultrasonograms. In patients with portal hypertension, the umbilical vein often reopens as a collateral vessel and can be visualized sonographically; the authors have recently demonstrated this finding in 30 patients. Recognition of a patent umbilical vein is important, since it currently is the only ultrasonographic finding specific for portal hypertension.

Ultrasonographic evidence of gallbladder wall thickening in association with hypoalbuminemia

Retrospective evaluation of 125 consecutive gallbladder sonograms was done to determine the conditions under which a thickened gallbladder wall is identified. The population studied included a large number of chronic alcoholics. Forty-two patients (Group A) had thickened (greater than or equal to 3 mm) gallbladder walls, while 48 patients (Group B) had walls of normal thickness. Forty patients in Group A had markedly depressed serum albumin levles, significantly lower (p less than 0.001) than albumin levels in Group B. Ten patients in Group B had cholecystitis, compared to two in Group A. The authors conclude that a thick gallbladder wall can be seen in severe hypoalbuminemic states in the absence of acute or chronic cholecystitis.

The pseudo-dilated common bile duct: ultrasonographic appearance created by the gallbladder neck

A retrospective analysis of 111 ultrasonograms was performed in order to evaluate the relationship of the gallbladder neck to the common bile duct and portal vein. Of the 100 studies deemed technically adequate, eight contained scans that demonstrated a potentially confusing pattern of a pseudo-dilated common bile duct caused by either a redundant or folded neck of the gallbladder. Recognition of this entity as well as the use of real-time ultrasound equipment should minimize false-positive diagnoses of extrahepatic bile duct dilatation.

The decidual cast of ectopic pregnancy: a confusing ultrasonographic appearance

The appearance of the central uterine cavity was analyzed in 39 cases of ectopic pregnancy. In nearly 20% of cases, a fluid collection surrounded by an echogenic ring was present which could be mistaken for a normal early intrauterine pregnancy. When ectopic pregnancy is suspected clinically, and there is fluid in the cul-de-sac or an adnexal mass on ultrasound, a fetal pole should be evident within the central fluid collection before a definitive diagnosis of intrauterine pregnancy is made.

Rapid water infusion: a technique in the ultrasonic discrimination of the gas-free stomach from a mass in the pancreatic tail

A technique of rapid water infusion into the stomach is described as an ultrasonic method to differentiate the gas-free stomach presenting as a solid mass from a mass in the tail of the pancreas. The infusion permits delineation of the tail of the pancreas as a discrete structure.

Analysis of ultrasonographic criteria in the evaluation for ectopic pregnancy

To assess the usefulness of ultrasound in diagnosing ectopic pregnancy, the ultrasonographic findings, pregnancy test results, and proven diagnoses in 148 patients referred for evaluation for ectopic pregnancy were reviewed. Of these patients, 33 were subsequently proven to have ectopic gestations. The ultrasonograms were coded for uterine size, intrauterine gestation sac, adnexal mass, adnexal ring, cul-de-sac fluid, or normal findings. With a positive pregnancy test, the presence of an intrauterine gestation sac excludes the diagnosis of ectopic pregnancy. Of those patients with positive pregnancy tests and no intrauterine gestation sac, 73% had ectopic pregnancy. All patients with normal ultrasonograms had other diagnoses. With a negative pregnancy test, the intrauterine findings are not helpful, and evaluation of the adnexa is more important. An adnexal ring is a significant, though not absolute, indicator of ectopic pregnancy. A normal scan excludes this diagnosis. Other criteria were not significant. A clinical approach to the evaluation for ectopic pregnancy, based on the data accumulated in this study, is suggested.

Vaginitis emphysematosa. Importance of its radiologic recognition

Vaginitis emphysematosa (VE) is a benign, self-limited condition characterized by a myriad of gas-filled spaces in the subepithelial lining of the vaginal wall, which give it a distinct radiographic appearance. Failure to make the correct diagnosis may lead to an inappropriate course of treatment, including surgery. Although it is considered rare, we have encountered five cases of VE in the course of a year.

Problems in the application of ultrasonography for the evaluation of pleural opacities

Fifty-nine patients with pleural abnormalities on chest radiographs were evaluated by B-mode ultrasonography; the lesions were categorized as echo-free or complex. Echo-free lesions included pleural fluid collections, and abnormalities which did not yield "fluid" through an appropriately positioned large caliber needle. "Complex appearing" lesions yielded fluid through a needle in all cases. Ultrasonography could not accurately predict which lesions were amenable to successful thoracocentesis. Findings from recent radiographs and clinical history must be known when the ultrasonographic findings in patients with chest abnormalities are interpreted.

Use of simethicone as a patient preparation for abdominal sonography

Fifty-eight patients about to undergo abdominal ultrasonography were randomly assigned into groups receiving preparation with oral simethicone and into control groups. A percentage value of sound transmission through the abdomen was calculated for each patient using sonographic measurements taken from a series of prescribed scans by a sonographer unaware of the patient preparation employed. Results indicate a statistically significant improvement in through sound transmission for those groups receiving simethicone preparation.

The variable roentgen appearance of traumatic diaphragmatic hernia

Alteration of the diaphragmatic contour should be added to the list of radiographic signs of traumatic diaphragmatic hernia (TDH). Such changes may sometimes be appreciated prior to gross herniation of abdominal viscera into the hemithorax. Alterations of the hemidiaphragmatic contour are non-specific, but suggestive of TDH in the appropriate clinical setting.

Gallstones preventing ultrasonographic visualization of the gallbladder

Ultrasonography can be used to diagnose the presence of multiple gallstones, despite the fact that the gallbladder, per se, may not demonstrated. The finding of many echoes in the area occupied by the gallbladder that cast a large acoustical shadow is strongly suggestive of gallstones.

Value of ultrasonography in the detection of retroperitoneal inflammatory masses

The ultrasonographic and radiologic findings for 7 patients with retroperitoneal inflammatory processes are presented. Ultrasonographic findings were critical to the diagnosis in 6 of the 7 patients and allowed for rapid evaluation and the institution of successful therapy. The relative sensitivity and specificity of ultrasonography is compared with conventional radiologic modalities. The application of diagnostic ultrasound to the problem of retroperitoneal inflammation is advocated.

Invasion of the duodenum by carcinoma of the stomach

It has frequently been stated that extension to the duodenum occurs commonly in patients with gastric lymphoma but almost never in those with carcinoma of the stomach. We found radiographically detectable invasion of the duodenum in six of 111 consecutive patients (5%) with gastric carcinoma. The duodenum was involved microscopically in 18%. Radiographic abnormalities in the duodenum in 11 patients with proven transpyloric spread of tumor varied from irregularity of the base of the bulb narrowing and distortion extending well into the second portion of the duodenum. On the basis of these data and the reported frequency of transpyloric extension in gastric lymphoma, carcinoma appears to be the more likely diagnosis in a patient with duodenal involvement by an antral tumor.

Stratification in the gallbladder on intravenous cholangiography. The value of delayed or 24-hour radiographs

Errors in interpretation of intravenous cholangiograms are often made if 24-hour radiographs are not obtained. Three cases are presented in which radiographs, obtained 1/2--4 hours after administration of contrast material, failed to demonstrate gallstones in the visualized gallbladder. However, 24-hour radiographs revealed calculi in all three patients. Stratification of bile is thought to be the mechanism responsible. Delayed radiographs assure proper mixing of contrast material and bile, and provide optimal visualization of the gallbladder in patients undergoing intravenous cholangiography.

The usefulness of ultrasonography in postoperative patients

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