Sonography during early pregnancy: dependence of threshold and discriminatory values on transvaginal transducer frequency

OBJECTIVE

Our goal was to determine if normal and abnormal pregnancies could be distinguished at smaller sac sizes with a higher frequency transvaginal transducer than with a 5-MHz transducer.

SUBJECTS AND MATERIALS

Thirty-nine patients with potentially abnormal pregnancies identified with a 5-MHz transvaginal transducer were immediately reimaged with a 9-5-MHz transducer. We compared our ability to visualize the yolk sac, embryo, and cardiac activity relative to mean sac diameter on imaging at both frequencies in women with normal and abnormal pregnancies.

RESULTS

Of the 39 pregnancies, 22 (56%) were normal or probably normal. Using the 5-MHz transducer, a yolk sac was first seen in a 6.4-mm gestational sac but was not definitively seen in 12 gestational sacs measuring 5-13 mm. Using the 9-5-MHz transducer, yolk sacs were identified in all gestational sacs measuring 4.6-13 mm, and live embryos were seen in five of eight sacs measuring 8.1-13 mm. The largest normal gestational sac without a live embryo measured 11 mm. When we compared these pregnancies with 17 (44%) abnormal pregnancies, we found that all pregnancies that had no yolk sac by the time the gestational sac measured 5.0 mm or no live embryo by 13 mm had abnormal findings on higher frequency imaging.

CONCLUSION

The ability to visualize the yolk sac and embryo in early pregnancy is critically dependent on transvaginal transducer frequency. Threshold values and discriminatory sizes used to distinguish normal and abnormal pregnancies are smaller on higher frequency than on lower frequency imaging and, therefore, should be redetermined for specific transducer frequencies.

Comparison of resistive index versus pulsatility index in assessing the benign etiology of adnexal masses

Retrospective analysis of pelvic sonograms with colorguided spectral Doppler evaluation of 189 adnexal masses yielded four malignancies, 20 benign neoplasms, 32 cysts, and 14 endometriomas. Fifty-eight masses were presumed benign on additional imaging. Pulsatility index (PI) < 1.0 was seen in 70% neoplasms, 63% benign cysts and 50% endometriomas. Thirteen percent of benign cysts and no neoplasms had resistive index (RI) < 0.4. Fifty percent malignancies had PI < 1.0. None had RI < 0.4. Both thresholds lack sufficient sensitivity and specificity for distinguishing benign and malignant lesions.

Sonography of transjugular intrahepatic portosystemic shunts: detection of elevated portosystemic gradients and loss of shunt function

PURPOSE

To evaluate the role of ultrasound (US) in the detection of elevated portosystemic gradients and loss of shunt function in patients with a transjugular intrahepatic portosystemic shunt (TIPS).

MATERIALS AND METHODS

The authors' prospectively compared 151 Doppler hepatic sonograms with follow-up portal venograms in 64 patients with TIPS. Sonographic data from within the portal system, hepatic arteries, and three areas within the TIPS were collected. Statistical analysis of these parameters was used to establish the US criteria for shunt dysfunction.

RESULTS

Midshunt velocity thresholds of less than 50 and less than 60 cm/sec yielded sensitivities and specificities of 46% and 93%, and 57% and 89%, respectively, for the detection of portosystemic gradients exceeding 15 mm Hg. Use of a threshold midshunt velocity of less than 60 cm/sec or main portal vein velocity of less than 40 cm/sec raised the shunt dysfunction detection sensitivity to 86%, with a specificity of 54%.

CONCLUSION

Doppler US is an effective noninvasive screening tool for detecting elevated portosystemic gradients and evaluating the functional status of a TIPS. Midshunt velocities of less than 60 cm/sec or main portal vein velocities less than 40 cm/sec are a useful threshold for detecting shunt dysfunction.

First-trimester US parameters of failed pregnancy

PURPOSE

To test the reliability of established ultrasound (US) parameters in predicting the outcome of first-trimester pregnancy.

MATERIALS AND METHODS

The authors retrospectively reviewed 2,655 first-trimester US scans in 2,285 patients. Parameters tested against outcome were (a) a yolk sac and mean gestational sac diameter of 8 mm on transvaginal US scans, (b) an embryo and mean sac diameter of 16 mm on transvaginal US scans, and (c) a difference between the mean sac diameter and crown-rump length of less than 5 mm (oligohydramnios) at 5.5-9.0 weeks gestation.

RESULTS

Thirty (22%) of 135 patients without yolk sacs and with an 8-mm mean sac diameter developed live embryos: 24 had normal follow-up or delivery; six were lost to follow-up. Five (8%) of 59 patients with no depiction of embryos and with a 16-mm mean sac diameter developed live embryos: Two delivered, one spontaneously aborted, one had death of one twin embryo before being lost to follow-up, and one was lost to follow-up. Seventeen (0.74%) of 2,285 patients had early oligohydramnios: Six (35%) had normal follow-up scans or delivery, two (12%) spontaneously aborted, and nine (53%) were lost to follow-up.

CONCLUSION

Established parameters predictive of early pregnancy failure potentially result in misdiagnosis of nonviability or poor prognosis when applied to a large, unselected patient population. Close follow-up is necessary in cases with borderline abnormal findings.

Intrauterine low density in women over 50. Assessment of significance and recommendations for follow-up

Patients over 50 years old with intrauterine low density on enhanced computed tomography were analyzed. Uterine volume and volume of intrauterine low density were calculated. Intrauterine low density was expressed as a percent of uterine volume. At 1-year follow-up, 23 (63.9%) had uterine malignancy and 13 (36.2%) had benign findings. All patients whose intrauterine low density exceeded 35% of the total uterine volume had a malignancy (p < 0.001). If intrauterine low density exceeds 35% of uterine volume, evaluation of uterine malignancy should be performed regardless of symptoms.

Prenatal diagnosis of a chest wall hamartoma and sternal cleft

We present the prenatal evaluation and diagnosis of a disorganized chest wall hamartoma with underlying sternal cleft in a family with a prior offspring with the VATER association. The possibility that these conditions are linked to mesodermal defects with a common pathogenic etiology is suggested.

Strategy for repeat biopsy of patients with prostatic intraepithelial neoplasia detected by prostate needle biopsy

PURPOSE

We evaluated the strategy for repeat biopsy of patients with prostatic intraepithelial neoplasia without concurrent carcinoma detected on prostate needle biopsy.

MATERIALS AND METHODS

Of 1,275 consecutive patients undergoing prostate needle biopsy 61 were identified with prostatic intraepithelial neoplasia but without concurrent prostate carcinoma. Of the 61 patients 53 had undergone repeat biopsy. The medical records, transrectal ultrasound, and operative and pathological reports of these patients were reviewed.

RESULTS

Repeat biopsy was done in 53 patients with prostatic intraepithelial neoplasia, yielding carcinoma in 15, prostatic intraepithelial neoplasia without carcinoma in 8 and benign tissue in 30. The yield of carcinoma from repeat biopsy of a prostatic intraepithelial neoplasia site was 8.3% (7 of 84 sites). A total of 18 sites of carcinoma was detected by repeat biopsy of a previous random biopsy site (8), a prostatic intraepithelial neoplasia site only (5), a transrectal ultrasound nodule (3), a palpable nodule and prostatic intraepithelial neoplasia site (1), and a transrectal ultrasound nodule and prostatic intraepithelial neoplasia site (1). Carcinoma was as frequently detected by repeat biopsy of a prostatic intraepithelial neoplasia site (6 patients) as by random repeat biopsy (6 patients).

CONCLUSIONS

Repeat prostate needle biopsy of patients with prostatic intraepithelial neoplasia should include random repeat biopsy and repeat biopsy of transrectal ultrasound abnormalities as well as previous sites of prostatic intraepithelial neoplasia.

Follow-up of benign hypoechoic peripheral zone lesions of the prostate gland: US characteristics and cancer prevalence

PURPOSE

To evaluate the role of biopsy-proved benign peripheral zone hypoechoic lesions of the prostate gland, ultrasonographic (US) characteristics at follow-up, prostate-specific antigen (PSA) levels, and digital rectal examination (DRE) in prediction of cancer risk.

MATERIALS AND METHODS

Retrospective analysis was performed for 105 consecutive patients with 148 benign hypoechoic lesions discovered at transrectal US (TRUS) and diagnosed with US-guided needle biopsy. At least one repeat TRUS study was performed in each patient.

RESULTS

Among the benign lesions, 72% changed at follow-up TRUS, either disappearing or becoming smaller, less hypoechoic, and more vague. Cancer developed in 13% of patients. In 93% of patients in whom cancer developed, the appearance changed in the peripheral zone at follow-up TRUS. In this patient population, the positive predictive value for development of cancer was 16% with a changing TRUS appearance, 19% with an abnormal DRE result, and 27% with an elevated level of PSA; only the latter was statistically significant.

CONCLUSION

The PSA value, alone or in combination with a changing TRUS appearance, is the best indicator for development of cancer.

Emergency department screening for ectopic pregnancy: a prospective US study

PURPOSE

To determine the effectiveness of pelvic sonography as a screening test for ectopic pregnancy.

MATERIALS AND METHODS

Pelvic sonograms were prospectively analyzed in 1,427 consecutive patients with a serum level of the beta subunit of human chorionic gonadotropin of over 1,500 IU/L.

RESULTS

Sonograms were diagnostic in 1,158 patients and indeterminate in 269. When indeterminate studies were considered falsely negative, the diagnostic accuracy was 81%. Twenty-four percent of patients with indeterminate studies were subsequently proved to have ectopic pregnancy. In ectopic pregnancy (n = 103), the most common finding was a complex adnexal mass (specificity = 92% [P < .001]). The sensitivity and specificity of screening sonography for ectopic pregnancy were 99% and 84%, respectively.

CONCLUSION

Pelvic sonography is an effective screening test for ectopic pregnancy. Having a one in four chance of harboring an ectopic pregnancy, patients with indeterminate studies require close follow-up. The presence of a complex adnexal mass is a strong predictor of ectopic pregnancy.

Pancreatic sparing of focal fatty infiltration

PURPOSE

To describe typical findings of focal fatty sparing of the pancreas.

MATERIALS AND METHODS

Computed tomography, ultrasonography, and/or magnetic resonance imaging were performed in seven patients.

RESULTS

In these patients, the area of sparing of fatty change was within the head or uncinate process of the pancreas.

CONCLUSION

Differentiating pancreatic fatty sparing from true neoplasm by means of cross-sectional imaging obviates the need for invasive diagnostic studies.

Transvaginal sonography of adnexal masses

In conclusion, the clinical utility of TVS has expanded since its inception so that numerous gynecologic applications now exist. TVS has most certainly had a major impact upon the diagnosis of adnexal disease. The addition of duplex and color Doppler capability to vaginal probes has expanded further the scope of TVS. In our laboratory, TVS is used as an adjunctive tool to complement TAS in cases of inadequate bladder distention, incomplete evaluation of the pelvis, and equivocal findings that require improved visualization for diagnosis. TVS is now recognized as the procedure of choice in the evaluation of patients who have a suspected ectopic pregnancy. It also can be used as the initial procedure in the follow-up of a known adnexal process. This article has emphasized how TVS can contribute to the diagnosis of cystic, complex, and solid adnexal masses. With continued technologic advancements, additional applications for TVS are likely to emerge.

Shoulder soft tissue width as a predictor of macrosomia in diabetic pregnancies

Sonographic evaluation of 43 pregnant women with diabetes mellitus was performed in the third trimester of gestation for evidence of fetal macrosomia. The width of the soft tissues of the shoulder from the skin surface to the proximal humerus was compared with previously reported measurements for their ability to predict fetal macrosomia. The abdominal circumference and shoulder soft tissue measurements were the best individual predictors of macrosomia, but a combination of an abdominal circumference greater than the 90th percentile for gestational age or a shoulder soft tissue width greater than 12 mm was the best predictor with a sensitivity of 96%, specificity of 89%, and accuracy of 93%. The shoulder soft tissue width should be evaluated for evidence of macrosomia in diabetic pregnancies.

Recurrent esophageal carcinoma at thoracotomy incisions: diagnostic contributions of CT

Three cases of surgical implantation of esophageal carcinoma during esophagogastrectomy are presented. The CT and radiographic appearance is demonstrated. A possible etiology and method for decreasing the risk of surgical spread of tumor are discussed.

Renal allografts: prospective analysis of Doppler sonography

Fifty-six consecutively transplanted renal allografts were prospectively evaluated with serial Doppler sonographic examinations. Thirty-eight episodes of transplant rejection in 32 patients (63% proved pathologically) and 24 episodes of acute tubular necrosis (ATN) in 24 patients were encountered. The Doppler spectral waveform was characterized by means of the pulsatility index (PI), systolic/diastolic ratio (SDR), diastolic/systolic ratio (SDR), diastolic/systolic ratio (DSR), and resistive index (RI). Accuracy was optimized with use of top normal values as follows: PI = 1.8, SDR = 4.0, DSR = 0.25, RI = 0.75. There were no significant differences in the indices for those patients undergoing rejection versus those with ATN. The sensitivity for predicting transplant rejection was adversely affected by the history of either ATN or a previous rejection episode in the same allograft. Comparison with concurrent radionuclide examinations revealed similar sensitivities for rejection with scintigraphy and sonography. Differentiation of ATN from rejection was more reliable with scintigraphy than with sonography.

Transvaginal and transabdominal sonography: prospective comparison

Transvaginal (TV) and transabdominal (TA) sonography were compared in a prospective study. A total of 230 examinations (126 pelvic, 104 pregnancy) were performed on 215 patients, ranging in age from 14 to 80 years. The improved anatomic detail on TV scans yielded new information in 138 (60%) examinations and better visualization of pelvic structures in 51 (22%) examinations. There was no important difference in diagnostic information provided by the two imaging modalities in 36 (16%) cases, and TV images were worse in five (2%). The clinical diagnosis was altered on the basis of TV sonographic findings in 54 (24%) cases and confirmed with certainty in 166 (72%). Diagnostic problems posed by TA scanning were not resolved by TV scanning in ten (4%) instances. Statistical analysis indicated that TV scanning was significantly better than TA scanning in the visualization of gestational sac contents (P less than .005), detection of fetal heart motion (P less than .001), and evaluation of the endometrial canal in the retroverted or retroflexed uterus (P less than .001). TV scanning was significantly better than TA scanning in visualization of the ovaries in patients with uterine leiomyomas (P less than .005) but not significantly better in peri- and postmenopausal patients (P greater than .05).

Radiographically negative avascular necrosis: detection with MR imaging

To correlate the morphologic appearance on magnetic resonance (MR) images of radiographically negative avascular necrosis (AVN) of the femoral head with that on computed tomographic (CT) and radionuclide scans, the radiographic and clinical records of 24 patients were reviewed retrospectively. In 18 patients the MR signal intensity features were monitored by means of serial imaging. All MR studies included T1-weighted (short repetition time [TR], short echo delay time [TE] ) imaging and T2-weighted imaging (long TR, long TE). Thirty-one hips were determined with MR to be involved by AVN; 27 were staged on the basis of signal intensity characteristics within the low-intensity rim. Core decompression was performed on 18 hips. Afterward, progression of disease occurred in only one hip. Fourteen of the 16 asymptomatic patients (88%) had early-stage focal lesions. CT scans were obtained in 15 patients and radionuclide scans in 21. Ten hips at radionuclide imaging and five at CT appeared normal when MR results were distinctly abnormal. MR can depict early radiographically negative AVN in asymptomatic individuals. At this early stage, the lesions in this series appear to be nonprogressive after treatment.

Aneurysmal dilatation of a patent umbilical vein masquerading as a pancreatic pseudocyst: CT characteristics

A large cystic mass in a jaundiced patient had the appearance by sonography of a pancreatic pseudocyst. Computed tomography showed that the mass represented an aneurysmally dilated patent umbilical vein.

Hyperdense pelvic and inguinal lymph nodes

This small series reports on the computed tomography appearance of hyperdense iliac, inguinal, and femoral lymph nodes in four cases of lymphoma and one case each of ovarian and breast carcinoma. The mean attenuation value of the lymph nodes was 93.8 Hounsfield units (HU), compared to 61 HU for adjacent muscle and 110.7 HU for blood vessels. A relatively homogeneous enhancement pattern was noted, which could not be directly related to hypervascularity, inflammation, or previous treatment with drugs or radiation.

Twin gestations: monitoring of complications and anomalies with US

An evaluation of 227 consecutive twin gestations was undertaken to assess the role of ultrasound (US) in the diagnosis of major obstetric complications and congenital anomalies. US accurately depicted the growth and development of fetuses in 65 patients with underlying maternal disorders that produced additional risks to the pregnancy. Complications such as malpresentations (104 cases), polyhydramnios (15 cases), oligohydramnios (five cases), and uterine myomas (seven of 11 cases) were demonstrated prenatally with US. Fetal anomalies included anencephaly (two cases), hydrocephalus (two cases), conjoined twins (three cases), twin-twin transfusion syndrome (five cases), and acardiac monsters (two cases). Demise of one twin in 20 gestations and demise of both twins in 18 gestations (overall mortality of 17%) were correctly identified with US. These 38 gestations included intrauterine demise in 12, spontaneous abortion in 13, and neonatal deaths in 13. Therefore, when multiple gestations are suspected clinically, serial real-time US scans should be obtained beginning in the first trimester.

Leiomyomas in pregnancy: sonographic study

With ultrasound monitoring, analysis of the behavior of uterine leiomyomas (fibroids) and their impact on the course of pregnancy was undertaken in a group of 113 patients. Fibroid size changes were analyzed on the basis of trimesters. In the second trimester, smaller fibroids increased in size, whereas larger fibroids decreased in size. In the third trimester, a decrease in size was documented regardless of initial size. The most common patterns of echotexture were hypoechoic, heterogeneous, and echogenic rim. The development of a heterogeneous pattern or anechoic/cystic spaces on a follow-up study was accompanied in seven of ten patients by severe abdominal pain, compared with 12 cases of abdominal pain in 103 patients without such echotexture changes. Although the number of patients was small, the development of these patterns apparently indicates significant degeneration of the fibroid. Fibroids located in the lower uterine segment were accompanied by a higher frequency of cesarean section and retained placenta. Fibroids located in the uterine corpus were more frequently associated with early abortions. Multiple fibroids were accompanied by a higher frequency of malpresentation and premature contractions compared with cases with one or two fibroids.

CT evaluation of gracilis myocutaneous vaginal reconstruction after pelvic exenteration

After pelvic exenteration for cancer, the gracilis muscles, skin, and subcutaneous fat from the inner aspect of both thighs may be raised as a pedicle flap and tunneled under the skin into the pelvic space to create a neovagina. We reviewed nine pelvic CT examinations in six patients to evaluate the CT appearance of this procedure and its complications. Five patients are alive and without complications. One patient died 6 months after surgery and had a small-bowel fistula to the neovagina. Normal CT findings included air in the vaginal canal in six of nine examinations, gracilis muscle atrophy in two patients who had early and late CT studies, and early separation of the anterior and posterior approximation of the flaps in one patient. Abnormal findings were seen in two patients: one had an abscess near the vaginal apex that was drained per vagina; the other had extraluminal air in the retropubic and subcutaneous fatty tissues due to a small-bowel fistula into the vagina.

Effects of maternal hydration on fetal renal pyelectasis

Fetal renal pyelectasis is a frequent finding on routine obstetrical sonography. The cause of this pelvocalyceal dilatation is often not apparent, although urinary tract obstruction is the most important condition to be excluded. One of the many hypothetical explanations for minimal fetal renal pyelectasis suggests that aggressive maternal hydration before sonography leads to fetal diuresis with resultant pelvocalyceal dilatation. In this study, 20 pregnant volunteers underwent sonography after 10-12 hours of dehydration, after which 1,000 ml of fluid was administered and repeat sonography was performed. Despite a significant increase in the state of maternal hydration as determined by a decrease in urine specific gravity, there was no significant change in the degree of fetal renal pyelectasis before and after hydration. Therefore, pelvocalyceal dilatation identified prenatally should not be attributed to maternal hydration.

Adnexal masses: MR imaging observations at 1.5 T, with US and CT correlation

To assess the role of 1.5-T magnetic resonance (MR) imaging in evaluation of the adnexa, 43 consecutive examinations that revealed 61 adnexal masses were retrospectively reviewed. T1- and T2-weighted images in coronal, axial, and/or sagittal planes were included. Available ultrasound (US) (n = 30) and/or computed tomographic (CT) (n = 9) scans were then correlated with the MR images. On T2-weighted images at least part of all adnexal masses was of higher signal intensity than surrounding muscle and adipose tissue, and therefore the adnexal masses were best seen with these sequences. T1-weighted imaging improved tissue characterization by revealing signal characteristics of fat in teratomas and characteristics of blood in endometriomas or hemorrhagic cysts, pelvic inflammatory disease, ovarian carcinomas, serous cystadenomas, and teratomas. MR imaging provided additional information or increased diagnostic confidence in 25 of 30 patients who underwent US or CT. MR imaging is a promising problem-solving modality after US in the study of adnexal abnormalities.

Kidney changes after extracorporeal shock wave lithotripsy: CT evaluation

Computed tomography (CT) was performed in 50 patients before and after extracorporeal shock wave lithotripsy (ESWL) to determine the effects of ESWL on the kidney and perinephric tissues. Bilateral treatments were performed in three patients. Post-ESWL scans demonstrated subcapsular hematomas in eight (15%) patients (two large, six small, none symptomatic) and intrarenal hematomas in two (4%) patients. In three (6%) patients small subcapsular fluid collections of uncertain cause were seen. Treated kidneys showed a statistically significant mean increase in size (9%) after ESWL, as measured at the axial level of the major stone fragment. Perinephric soft-tissue stranding and fascial thickening were seen in 37 (70%) of 53 treated renal fossae, with the changes ranging from mild to severe. The authors conclude that while most patients undergoing ESWL will show some posttreatment abnormality on CT scans, the procedure appears to be associated with a low frequency of serious renal trauma.

Computed tomography in the diagnosis of renal pseudotumors

If the initial evaluation of the urinary tract raises the possibility of renal mass, one must decide what study or studies to perform to confirm or deny its presence. Radionuclide imaging has been the study of choice in this situation. Six cases are presented in which computed tomography definitively demonstrated that a suspicious renal mass represented normal renal parenchyma. Comparison with other renal imaging modalities is discussed.

CT diagnosis of villous adenoma

Villous adenoma may have a specific appearance on barium enema examination but specific CT findings of villous adenoma have not been previously described. Two recently encountered cases of villous adenoma in the rectum had a distinctive pattern on CT. Suggested criteria for CT diagnosis of villous adenoma include a homogeneous water density component of less than 10 HU, occupying more than half the lesion and eccentric on the luminal side of the mass. This low density component interfaces with the majority of the luminal surface of the lesion. No air-fluid level is seen and the lesion should not have a round cystic configuration. A description of these findings is illustrated and discussed.

Vascular and soft tissue calcification in systemic oxalosis: CT diagnosis

Hyperoxaluria may result in diffuse deposition of calcium oxalate crystals in multiple organs. A patient with primary hyperoxaluria presented with peripheral ischemia on this basis. Computed tomography clarified the diagnosis and helped to direct the appropriate management.

Concurrent duplication and azygos continuation of the inferior vena cava

Duplication of the inferior vena cava and azygos continuation of the inferior vena cava arise from separate embryologic anlage. The former arises from persistence of both supracardinal veins and the latter from arrested development of the right subcardinal vein. Individually these entities are uncommon, but their occurrence together in one patient is exceedingly rare. A patient with both these anomalies of the venous system concurrently is described. This combination has been reported only once before in the radiologic literature.

CT demonstration of pulmonary effects of tangential beam radiation

Breast cancer is sometimes treated with an excisional biopsy and a radiation portal limited to the breast and the adjacent chest wall, especially in patients with negative lymph node dissections. The beam passes through this portion of the chest wall tangentially. Such radiation can result in changes in the included lung parenchyma that are pleural-based and sharply demarcated from the normal lung on CT lung windows. In our experience CT lung windows were more sensitive than chest radiography in showing these changes. Such changes must be recognized and differentiated from pleural metastases. Computed tomography also resulted in a more specific diagnosis than chest radiography because it better localized the abnormality to the radiation portal.

Gastrointestinal tract focal mass lesions: role of CT and barium evaluations

Fifty-eight patients with focal mass lesions involving the gastrointestinal tract were studied retrospectively. The diagnostic value of CT scans was seen by assessing the barium studies alone, then by combined review of radiographs and CT scans. Patient management decision making was similarly evaluated. CT scanning aided in diagnosis of the focal masses in 17 patients (29%), changing the differential diagnosis in eight (14%) and increasing diagnostic confidence significantly in nine (16%). In 21 (36%) additional cases, the diagnosis did not change, but CT scanning improved the understanding of disease extent. In the remaining 20 cases (34%), CT scanning did not help diagnostically. CT scanning altered patient management decisions in 19 of the 58 patients (33%). CT study was most helpful in cases of benign extrinsic cystic disease, lymphoma, and smooth-muscle tumors and less helpful for adenocarcinomas of the bowel. The value of the CT data increased as one moved from mucosal lesions to submucosal or extrinsic lesions.

CT characteristics of cervical mucocele mimicking a cystic adnexal mass

An unusual case of a cervical mucocele (focal hydrometra) was diagnosed only after correlation of ultrasonic, CT, and physical examination findings.

Twin and singleton growth patterns compared using US

Sonography has been used widely in the evaluation of singleton fetal growth. Twin gestations, however, have received less careful attention. In a statistical study of 103 twin pregnancies, the growth patterns of twin biparietal diameter (BPD), fetal femur length (FFL), and abdominal circumference (AC) were compared with those of singletons. The results of the study revealed a decrease in twin BPD growth after 31 to 32 weeks of gestation relative to singletons. Twin AC growth rate decreases after 32-33 weeks of gestation relative to singletons, but the twin FFL growth pattern does not deviate from that of singletons throughout gestation. Because of the significant difference in growth patterns of BPD and AC between twins and singletons in our population, new growth charts for twin BPD and AC are proposed.

Ultrasonography of the upper genitourinary tract

Ultrasonography is now well established as an accurate, noninvasive means of evaluating the genitourinary tract in patients of all age groups. Ease, speed, and portability of real-time have made ultra-sonography one of the most readily accessible imaging procedures. Most authorities concede that it is best utilized as a complement to other imaging modalities. This article describes and illustrates the many pathologic processes involving the upper genitourinary tract that can be accurately diagnosed utilizing real-time ultrasonography.

Sonographic evaluation of bile duct size during pregnancy

Real-time sonography was used to examine the biliary tracts of 103 pregnant women. Common hepatic duct size, degree of right hydronephrosis, and presence of gallstones were noted. There were three important observations: (1) The top normal size of the common hepatic duct was 5 mm; (2) no correlation was found between common hepatic duct size and stage of pregnancy or degree of right hydronephrosis; and (3) gallstones were incidentally noted in 3.9% of patients.

Routine fetal genitourinary tract screening

To evaluate routine fetal genitourinary tract obstetrical ultrasound screening, and to determine what size renal pelvis is indicative of significant renal disease, we reviewed 4,832 examinations, which had been performed over 2 years, of 3,530 consecutive obstetrical patients. Any fetus that had a renal pelvis greater than 5 mm or a definable cystic area was identified for follow-up. The fetuses of 39 patients (1.1%) who underwent 112 examinations fulfilled these criteria and constitute the basis of this report. A variety of examination criteria were recorded and analyzed in relationship to the follow-up, which ranged from 2-3 days to 21 months. The fetuses of the 39 patients were grouped into three categories: those with renal pelves between 5 and 9 mm in size; those with renal pelves larger than 10 mm; and those with cystic abnormalities. Those with renal pelves larger than 10 mm had either an obstructing lesion or exceptional extrarenal pelves. The clinical and pathologic aspects of these three groups are detailed, discussed, and analyzed. Criteria for significant fetal renal hydronephrosis and aspects of a loculated appearance are given.

Computed tomography findings in clinically normal and abnormal thyroid patients

Fifty normal volunteers had unenhanced thyroid computed tomography scans. A range of normal computed tomography densities and volumes was established for each age group. Pre- and postcontrast scans were done on 47 abnormal patients with hemorrhagic cysts, multinodular goiter, thyroiditis, papillary carcinoma, and benign adenomas. The computed tomography characteristics of each of the pathologic groups was noted for both the abnormal areas and the uninvolved part of the gland. Preliminary observations of the computed tomography characteristics of each abnormality are discussed.

Contrast medium pooling in cystic renal carcinoma: CT findings

This case report describes a serendipitously diagnosed renal carcinoma in a transplant donor. Computed tomography was instrumental in establishing the true nature of this mass based on its ability to demonstrate pooling of contrast material and staining of discrete septae on dynamic postcontrast scans.

Thyroid imaging: comparison of high-resolution real-time ultrasound and computed tomography

High-resolution real-time ultrasound (US) and computed tomography (CT) were compared in 48 patients with a clinical diagnosis of thyroid abnormality and also correlated with biopsy or surgery. The modalities were considered comparable in 38 cases (79%), while CT was superior in 5 and US in 5. CT illustrated substernal extension of a goiter, demonstrated a 5-mm nodule not seen in US, showed 2 cases of thyroiditis better than US, and diagnosed a suspected thyroid mass as a lipoma anterior to the thyroid. US detected 4 nodules not seen on CT and resolved contiguous nodules that appeared to be a single nodule on CT. Both techniques lacked histopathological specificity. CT appears to be advantageous in detecting substernal thyroid extension and confirming thyroiditis, while the ability of US to detect small nodules makes it the procedure of choice in evaluating suspected intrinsic thyroid abnormalities.

CT features of endobronchial granular cell myoblastoma

The CT features of endobronchial granular cell myoblastoma are reported in an acknowledged heavy smoker without pulmonary complaints. Computed tomography confirmed the intraluminal location of the mass, demonstrated associated atelectasis, and detected the lack of adenopathy or invasion into the mediastinum, thus contributing significantly to surgical planning.

Hyperdense renal masses: a computed tomographic dilemma

High-density renal masses are atypical lesions that represent a diagnostic dilemma for computed tomography (CT). The differential diagnosis includes mainly complicated benign cysts and malignant neoplasms. This report analyzes the CT findings in 17 cases of discrete, sharply marginated masses that initially exceeded the density of the uninvolved renal parenchyma, averaging 50 H or more. The subsequently proven pathologic entities responsible for these high attenuation values included primary malignancies in six patients, one of whom also had multiple retention cysts containing highly proteinaceous, gelatinous material; a hemorrhagic cysts with an associated desmoplastic, fibrotic reaction in one patient; and single or multiple hemorrhagic cysts in four patients. No histologic proof was obtained in six patients, three with neoplastic disease and one mentally retarded youth who underwent renal aspiration without sufficient material obtained for analysis. Two patients with presumed hemorrhagic cysts have had serial CT scans without interval change in 8-12 months. An approach to the therapeutic management of affected patients is described.

Case report: computed tomography in the diagnosis of Yersinia infection in a patient with thalassemia major

Yersinia enterocolitica is becoming increasingly recognized as a source of abscess formation in patients with numerous underlying disease entities, most notably hepatic and hematologic disorders. Patients ranging in age from infancy to adulthood can become infected with this worldwide pathogen, which seems to be relatively rare in the United States. We present the appearance of a Yersinia abscess on computed tomography in the hope that an increased awareness of this infection will result in earlier diagnosis and improved therapeutic management.

Computed tomography in soft tissue calcification layering

Soft tissue calcification occurs in a variety of disorders. When it is associated with an abnormal calcium phosphorous product, it may present as large, periarticular masses that demonstrate layering on horizontal beam radiographs or computed tomography (CT). Previous reports have shown this phenomenon in idiopathic tumoral calcinosis. We report two patients with metastatic calcification of different etiologies: one patient with tumoral calcinosis and one with secondary hyperparathyroidism complicating chronic renal failure. Both showed layering on CT. The pathology of this phenomenon as well as therapeutic implications are discussed.

Pseudocyesis in an adolescent patient. Case report and radiologic analysis

The physical and psychological changes of pseudocyesis have bewildered physicians since the time of Hippocrates. We present the case of a 14-year-old girl as a reminder that pseudocyesis needs to be considered in adolescents and that the diagnosis may not be obvious, even with current technologies. We document that gaseous distension and abdominal fat deposits can lead to dramatic abdominal fullness and can mimic a term pregnancy.

Mediastinal computed tomography in myasthenia gravis

Thirty-six of 119 patients with myasthenia gravis examined by computed tomography for possible thymic mass had a thymectomy. The computed tomographic findings were compared to the findings of chest x-ray and linear tomography and then correlated with the surgical histopathologic results. Computed tomography detected all cases of thymoma or thymic enlargement due to hyperplasia. Chest x-ray correctly demonstrated 50% of thymomas present while linear tomography demonstrated 88%. Computed tomography was not able to distinguish between enlargement due to thymoma or hyperplasia unless calcification was present. The role of computed tomography is detailed and discussed in relationship to the other diagnostic modalities.

CT of sarcomatous degeneration in neurofibromatosis

Neurofibromatosis is a relatively common disorder that often involves many organ systems. One of the least understood aspects of this malady is a well documented potential for sarcomatous degeneration of neurofibromas. The inability to identify patients at risk and the lack of noninvasive screening methods for symptomatic patients often leads to late diagnosis. In six of seven subsequently proven neurofibrosarcomas, CT demonstrated low-density areas that histopathologically appeared to be due to necrosis, hemorrhage, and/or cystic degeneration. The density differences within these sarcomas were enhanced by the intravenous administration of iodinated contrast agents.