Benign pelvic masses: sonographic spectrum.

Detection and characterization of pelvic masses are universal and vital applications of sonography. Despite the considerable overlap in the morphologic patterns of different pelvic masses, a characteristic sonographic appearance frequently allows at least a narrow differential diagnosis and often allows a specific diagnostic choice, particularly when the imaging findings are coupled with sufficient clinical data. Color flow and spectral Doppler techniques are evolving and have promising roles in diagnosis of pelvic masses; however, basic sonographic morphology coupled with the necessary clinical input remains the mainstay of sonographic differential diagnosis of pelvic masses. Considerable research is being done on enhancing sonographic differentiation between benign and malignant neoplasms. The most common sonographic features of benign pelvic masses should permit clinically useful characterization. Benign pelvic masses include uterine masses (leiomyoma, hematometra, hematocolpometra), ovarian masses (functional cysts, polycystic ovaries, parovarian cyst, endometrioma, epithelial tumors, dermoid cyst), and miscellaneous masses (pelvic inflammatory disease, ectopic pregnancy).

Endometrioma: analysis and sonographic classification of 51 documented cases.

We analyzed 51 proven cases of endometrioma and characterized the sonographic patterns as purely cystic, cystic with few septations or minimal debris, complex combinations of cystic and solid elements, and largely solid. In this series, 30% were purely cystic, 62% showed various degrees of complexity with septation or debris, and 8% appeared essentially solid. The broad spectrum of patterns is in keeping with the evolutionary process of endometriomas, which follow essentially the same transitions from homogeneous gelatinous (cystic) through partially resolved (liquified) complex and ultimately returning to nearly purely cystic, as do hematomas. The average diameter of endometriotic masses was 6.1 cm (range, 2.0 to 20.0 cm), and the average age of the patients at diagnosis was 31.3 years (range, 15 to 45 years). The diversity of sonographic appearance, the span of essentially all the child-bearing years, and the presence of endometriomas without a history of infertility or dysmenorrhea (and even after hysterectomy) keep this entity a constant differential diagnostic consideration in sonographically identified pelvic masses. We believe this to be the largest documented series of sonographically identified endometriomas in the literature.

Abdominal CT scans in patients with blunt trauma: low yield in the absence of clinical findings.

This study undertook to determine the yield of abdominal CT scans ordered only because the patient's sensorium was decreased or general anesthesia was planned. The abdominal CT scans and hospital charts of 191 consecutive patients examined following blunt trauma were reviewed with respect to clinical indications prompting the study. In 143, some clinical or laboratory justification was in evidence. In this group, 55 patients (38.5%) were found to have trauma-related pathology at CT scan. In 48 patients, no clinical or laboratory suggestion of abdominal pathology was evident. Instead, the primary indications for ordering the CT scan were decreased sensorium (28 cases), the planning of general anesthesia for orthopedic procedures (8 cases), and a variety of non-abdominal-trauma-related reasons. In this group, only a single positive finding was identified (small pneumothorax), and in no case was the clinical course altered by findings at abdominal CT scan. Performance of abdominal CT scans without clinical or laboratory evidence of trauma, merely because of decreased patient sensorium or prophylactically prior to general anesthesia for non-abdomen-related surgery, is an extremely low yield study and should be discouraged. In the current study, no significant abdominal pathology would have been overlooked by omission of such scans. Similar findings have been reported in children. To our knowledge, this is the first such report in a largely adult population.

Nonfatal venous air embolism after contrast-enhanced CT.

Contrast material-enhanced computed tomography (CT) was performed in 100 patients. Fifty milliliters of contrast material was intravenously injected by hand and followed by a drip infusion of 100 mL of contrast material. Venous air embolism occurred in 23% of the patients. The amount of embolism was minimal in 20 patients and moderate in three. Although large amounts of embolism have been reported to be associated with considerable morbidity and mortality, none of the patients in this study had immediate or delayed complications as a result of the small degree of embolism. The locations of the emboli were in the subclavian or axillary vein in nine, right or left brachiocephalic vein in three, internal jugular vein in two, superior vena cava in two, right ventricle in two, and main pulmonary artery in 12 patients. In patients at high risk for cerebral air embolism, such as those with intracardiac shunts or pulmonary arteriovenous malformations, extreme caution should be used--even in the routine administration of intravenous fluids or contrast media--to prevent venous air embolism and resultant neurologic deficits.

Annular pancreas associated with diffuse chronic pancreatitis.

A patient with longstanding diabetes and renal failure presented with painless vomiting due to duodenal obstruction was found to have an annular pancreas. Initial operative evaluation, later pathologically confirmed, demonstrated involvement of not only the annulus, but also the entire gland by diffuse atrophic chronic pancreatitis. We speculate on the possible influence of the underlying diabetes and renal disease on the pathogenesis of the unusual generalized chronic inflammatory changes and the precipitation of duodenal obstruction in this patient.

Tomographic levels for intravenous urography: CT-determined guidelines.

The selection of levels for tomographic sections of the kidneys during intravenous urography has previously been based on empirical observation. Three hundred abdominal computed tomographic scans were analyzed for the anteroposterior (AP) midpoints of the kidneys and their relationship to the patient's AP abdominal diameter. A graph for selection of tomographic levels was generated and compared with existing methods. These guidelines enable a more objective approach to urographic tomography.

Ovarian carcinoma follow-up: US versus laparotomy.

Ultrasound (US) was compared with surgical findings in 98 patients with carcinoma of the ovary undergoing follow-up laparotomy after chemotherapy. US had an overall accuracy of 94% in the pelvis, with only small and sheetlike lesions escaping detection. It was more sensitive than clinical examination. Overall accuracy for the liver was 91% with very few false-positive results. For the peritoneal cavity in general, however, accuracy was low, with even large masses escaping detection. Ascites is reliably detected (accuracy of 97%) but is a poor indicator of peritoneal involvement. US is a useful noninvasive complement to laparoscopy in the follow-up of patients with carcinoma of the ovary.

Update: the radiographic features of pulmonary tuberculosis.

Pulmonary tuberculosis produces a broad spectrum of radiographic abnormalities. During the primary phase of the disease these include pulmonary consolidation (50%), which often involves the middle or lower lobes or the anterior segment of an upper lobe; cavitation (29%) or pneumatocele formation (12%); segmental or lobar atelectasis (18%); pleural effusion (24%); hilar and mediastinal lymphadenopathy (35%); disseminated miliary disease (6%); and a normal chest radiograph (15%). During the postprimary phase of the disease, common abnormalities include exudative and/or fibroproductive parenchymal densities (100%), predominantly in the apical and posterior segments of the upper lobes (91%); cavitation (45%) with bronchogenic spread of disease (21%); marked fibrotic response in the lungs (29%); and pleural effusion, empyema, and fibrosis (18%, 4%, and 41%, respectively). Upper-lobe masslike lesions are seen occasionally (7%); spontaneous pneumothorax and intrathoracic lymphadenopathy are rare (5% each). Common causes of a missed diagnosis of tuberculosis are (1) failure to recognize hilar and mediastinal lymphadenopathy as a manifestation of primary disease in adults, (2) exclusion of tuberculosis because disease predominates in or is limited to the anterior segment of an upper lobe or the basilar segment of a lower lobe, (3) overlooking of minimal fibroproductive lesions or reporting them as inactive, (4) failure to recognize that an upper-lobe mass surrounded by satellite fibroproductive lesions might be tuberculous, and (5) failure to consider healed sequelae of primary disease or a positive purified protein derivative skin test as contributory to identifying the patient's pulmonary disease.

The sonographic fat/muscle ratio.

A wide variety of biochemical and morphometric parameters have been applied to estimation of nutritional status. A-mode ultrasound has been used to estimate subcutaneous fat thickness in humans; similar studies are reported in the veterinary literature. We applied B-mode ultrasonography to the triceps region of the nondominant arm. Subcutaneous fat and triceps muscle thickness were measured and the ratio of fat to muscle calculated.

Echogenicity of fetal lung: relation to fetal age and maturity.

Reports of echogenicity of the fetal lung as it relates to maturity of that organ are scant and at variance. A study was undertaken to determine if any correlation between fetal age and/or lung maturity and echogenicity could be determined in a clinical setting. Studies were performed with either linear array or mechanical sector real-time devices. Echogenicity of the fetal lung was compared with that of the fetal liver in the same longitudinal (parasagittal or coronal) sonogram. Lung echogenicity was judged to be hypodense, isodense, slightly hyperdense, or markedly hyperdense as compared with the liver texture. One hundred eighty-five studies were evaluated; of these, some 37 patients also underwent amniocentesis for determination of lecithin/sphingomyelin ratios (L/S) and presence of phosphatidyl glycerol (PG). Linear regression analyses were performed to determine if lung echogenicity would serve as an indicator of fetal maturity. No clinically applicable relation was established between fetal lung echogenicity and gestational age, L/S, or presence of PG in amniotic fluid with current methodology. The possibility persists that tissue characterization techniques may find application in such an investigation.

The diaphragmatic echo complex: an in vitro study.

The brightly echogenic appearance of the diaphragm on routine clinical scans is not easily reconciled with the well-documented echo-poor appearance of muscle elsewhere in the body. A series of specimens of normal human diaphragm freshly excised at autopsy were suspended in a water bath. Articulated arm scans were done varying the angle of the incident beam to the specimen by 5-degree increments and recording the maximum attenuation which allowed visualization (ie, an extinction point). This was accomplished for intact diaphragm, peritoneal membrane alone, and diaphragmatic muscle alone with both membranes stripped. The bright specular echoes seen are due almost exclusively to the membranes (parietal pleura and peritoneum) and the diaphragmatic muscle itself produces only low-level scattered echoes as elsewhere. However, these scattered echoes account for persistent visualization of the diaphragm at steep angles of the incident beam. A considerable portion of the in vivo thickness of the diaphragmatic echo complex is, therefore, produced by diaphragm-lung interface.

The hepatic interlobar fissure: combined in vitro and in vivo study.

A densely echogenic line is seen connecting the right portal vein and the neck of the gallbladder on longitudinal views in at least 70% of sonograms. The origin of the line has been taken to be the fissure between the right and left lobes of the liver, but no documentation has been provided. Intact liver specimens were studied in a water bath; metallic markers were placed to coincide with the line under real-time guidance. The line does, indeed, correspond to the interlobar fissure. Factors affecting visualization include position of the gallbladder neck and orientation of the fissure as well as fat deposition within the fissure.

Accuracy of serum human chorionic gonadotropin concentrations and ultrasonic fetal measurements in determining gestational age.

Prior to 60 days' gestation, the maternal serum concentration of human chorionic gonadotropin (hCG) can predict the estimated date of confinement, but later in pregnancy, hCG concentrations vary widely. The current study was performed to compare the accuracy of hCG measurements with other determinants of gestational age. Fifteen patients in whom gestational age was documented were monitored prospectively throughout pregnancy. One to two determinations of hCG (beta subunit) were obtained during the first 60 days. Then, ultrasonographic measurements of crown-rump length were obtained between 8 and 16 weeks' gestation and two measurements of biparietal diameter were performed between 18 and 32 weeks. These results were compared to actual dates of gestation. The mean (+/- SD) difference between gestational age predicted by single measurements of hCG and actual gestational age was 3.2 +/- 2.5 days (r = 0.94, p less than 0.0001), which compared favorably with estimates by crown-rump measurements (6.7 +/- 6.5 days) and measurements of biparietal diameter (6.3 +/- 5.3 days). These results demonstrate that hCG measurements during the first 60 days accurately predict gestational age and complement ultrasonic determinations of gestational age used later in pregnancy.

The medullary pyramid index: an objective assessment of prominence in renal transplant rejection.

Prominence of the medullary pyramids at sonography has been considered a sign of renal transplant rejection. A search of the literature reveals no previously published objective assessment of this phenomenon. Medullary pyramids of 67 normal kidneys, 53 nonrejecting transplanted kidneys, and 71 transplanted kidneys in rejection were measured. The area of the pyramid was related to the thickness of the overlying renal cortex by a "medullary pyramid index" (MPI): MPI (formula; see text) The median MPI was 4.17 for normal kidneys, 6.0 for nonrejecting transplanted kidneys, and 7.50 for transplanted kidneys in rejection. The results are significantly different (P = 0.0001) for all possible pairs. Overlap between rejection and nonrejection distributions is, however, considerable, rendering the discriminatory value of an individual observation quite low (0.69). Prominence of the medullary pyramids is therefore of very limited predictive value in the determination of transplant rejection in an individual patient.

Hysterosalpingography and laparoscopy: a comparative study.

Twenty-six women were evaluated with both hysterosalpingography and laparoscopy. The hysterosalpingograms were reviewed independently by two radiologists. Postdrainage films were obtained in 19 of 26 patients. A high false-negative rate (44.9% overall) and low specificity (20.6%) were observed. The postdrainage film contributed to a correct diagnosis in only four of 38 tubes evaluated by the first radiologist and in none evaluated by the second radiologist. Hysterosalpingography is valuable as a screening procedure for identifying abnormals but is not specific in differentiating tubal adhesions from tubal obstructions. It is recommended that preliminary films not be obtained routinely and that postdrainage films be reserved for cases where fluoroscopic and spot-film findings are equivocal.