Benign intratesticular cystic lesions: US features.

Benign intratesticular lesions are rare, but recognition is important to avoid unnecessary surgical intervention. The ultrasonographic (US) features that help differentiate benign from malignant intratesticular lesions are emphasized by the authors. Benign lesions include intratesticular simple cysts, tubular ectasia, epidermoid cyst, tunica albuginea cyst, intratesticular varicocele, abscess, and hemorrhage (infarction). US features of cystic malignant neoplasms that help in differentiation of them from benign cystic lesions are also presented. The US appearance of epidermoid cysts varies with the maturation, compactness, and quantity of keratin present. Of the cystic malignant testicular tumors, which can occur anywhere in testicular parenchyma, teratomas are the most frequent to manifest as cystic masses. An abnormal rind of parenchyma with increased echogenicity usually surrounds these lesions. An intratesticular spermatocele communicates with the seminiferous tubules, whereas simple ectasia of the rete testis does not do so directly. These cysts contain spermatozoa and can be septate. The US findings of intratesticular varicocele are similar to those of extratesticular varicocele and include multiple anechoic, serpiginous, tubular structures of varying sizes. Improvements in gray-scale and Doppler US technology allow subtle distinctions between benign and malignant testicular lesions that were not possible a decade earlier.

Testicular epidermoid cysts: sonographic features with histopathologic correlation.

Testicular epidermoid cysts are rare, accounting for 1% of all testicular tumors. We present the sonographic appearances of epidermoid cysts in 3 cases, together with the histopathologic correlation. In case 1, sonography showed an intratesticular hypoechoic mass with a well-defined echogenic rim; the mass measured 1.8 x 1.5 x 1.5 cm, and there was no evidence of calcification. In case 2, sonography showed a well-circumscribed mass measuring 1.3 x 1.3 x 1.0 cm, with alternating hypoechoic and hyperechoic rings (onion-ring appearance) and no calcifications. In case 3, sonography showed a 2.4- x 2.3- x 2.3-cm, well-circumscribed, oval mass with a heterogeneous echotexture and an outer hypoechoic halo. The mass contained plaque-like regions of increased echogenicity, with peripheral acoustic shadowing from refraction artifact. Hypoechoic clefts were visualized posterior to the plaque-like areas. The triad of findings-sonographic appearance of an onion ring, avascularity on Doppler sonography, and negative results of tumor marker studies-is highly suggestive of an epidermoid cyst.

Evaluation of a training program for detection of carotid artery calcifications on panoramic radiographs.

OBJECTIVE: To evaluate the effectiveness of the American Academy of Oral and Maxillofacial Radiology-sponsored training packet for identification of carotid artery calcifications on panoramic radiographs. STUDY DESIGN: Two examiners, who completed the training (trainees), examined 778 panoramic radiographs. The sample included 298 men, with a mean age of 66, and 480 women, with a mean age of 68. Findings were compared with those obtained by an oral and maxillofacial radiologist. A kappa statistic was used to determine agreement between the 2 trainees. The positive predictive value (PPV) of the program was estimated by comparing the trainees rating of disease status with an expert in case identification. RESULTS: Examiners 1 and 2 identified 99 and 78 positive cases, respectively. A kappa statistic of 0.87 (95% CI, 0.81-0.92) was obtained, indicating good interexaminer agreement. The expert identified 27 positive cases, resulting in a PPV of 34.6% (95% CI, 24.4-46.3). CONCLUSION: Although the training packet offers valuable training, it does not provide a high PPV, suggesting the need to modify it or to seek an expert opinion before classification of a patient as having calcification on a panoramic radiograph.

Delayed computed tomographic characterization of renal masses: preliminary experience.

BACKGROUND: To evaluate the performance of delayed contrast enhanced computed tomography (DCT) in characterizing renal masses. METHODS: Twenty-four patients with suspected renal masses or indeterminate renal masses on previous imaging studies were prospectively evaluated with preintravenous contrast imaging, conventional contrast-enhanced computed tomography (imaging initiated 2 min after intravenous contrast injection), and DCT (imaging initiated 13 min after injection of intravenous contrast). Only lesions larger than 1.0 cm were evaluated, with scanning parameters kept constant across the three scans. RESULTS: All pathologically confirmed renal cell carcinomas (n = 6) were detected on DCT using a threshold attenuation decrease of 10 Hounsfield units (HU). A significant decrease (p = 0.031) in attenuation occurred in renal cell carcinomas (mean = 29.6 +/- 23.6 HU) compared with the attenuation change (mean decrease = 1.1 +/- 7.1 HU), which occurred in non-neoplastic renal cysts (n = 34). Non-neoplastic renal cysts were correctly classified by DCT 32 of 34 times (94%). CONCLUSIONS: In this study, DCT distinguished renal cell carcinomas from non-neoplastic cysts in a vast majority of cases and may aid in characterizing incidentally discovered renal lesions on postcontrast CT.

Doppler respiratory patterns in the femoral veins with pelvic vein obstruction.

An appropriate Doppler response to valsalva in the common femoral veins has been described previously as excluding a more proximal venous obstruction. We describe our experience in three patients in whom an appropriate response to valsalva did not exclude a more proximal pelvic venous obstruction. Dampening of the Doppler waveforms on the affected side when compared with the opposite limb led to the diagnosis of proximal venous obstruction.

Calf sonography for detecting deep venous thrombosis in symptomatic patients: experience and review of the literature.

PURPOSE: We determined the accuracy of sonography in the detection of isolated calf deep venous thrombosis (DVT) and the rate of indeterminate ultrasound examinations in patients with physical signs or symptoms suggestive of DVT. METHODS: We reviewed the medical literature (MEDLINE) to determine the accuracy of sonography and the frequency of indeterminate studies in detecting isolated calf DVT in patients with physical signs or symptoms suggestive of DVT. A meta-analysis was used to derive summary measures of sensitivity, specificity, and accuracy from studies in which 5 or more isolated calf DVT were identified. Frequencies of indeterminate examinations were recorded for studies in which these data were provided, and we pooled these results with our own data for 196 patients. RESULTS: The meta-analysis revealed that sonography correctly identified isolated calf DVT in 49 of 53 extremities (sensitivity, 92.5%; 95% confidence interval, 81.8-97.9%) and correctly identified the absence of calf DVT in 157 of 159 extremities (specificity, 98.7%; 95% confidence interval, 95.5-99. 9%), yielding an accuracy of 97.2% (95% confidence interval, 93.9-99. 0%) for ultrasound examinations considered diagnostic. However, when evaluating our patient population and the literature, we found a substantial number of indeterminate studies (overall rate of 54.6% in 463 extremities), with a wide variation in the reported frequency of indeterminate studies (9.3-82.7%). CONCLUSIONS: Sonography is highly accurate in detecting isolated calf DVT in symptomatic patients, but indeterminate studies occur frequently, with a wide range of reported rates. Each ultrasound laboratory should evaluate its own rate of indeterminate studies.

Sonography: a useful tool to detect the mechanical causes of renal transplant dysfunction.

PURPOSE: The purpose of this study was to evaluate the utility of sonography in distinguishing between mechanical and nonmechanical causes for renal transplant dysfunction. METHODS: We reviewed all ultrasound examination reports (n = 286) for 63 consecutive patients who received 64 renal transplants. We assessed the sensitivity and specificity of different degrees of hydronephrosis (mild, moderate, or severe) in detecting urinary tract obstruction; different volumes of new or increasing peritransplant fluid in detecting urine leaks; different total volumes of peritransplant fluid in predicting significant compression of the transplant; and Doppler vascular criteria for predicting arterial and venous occlusion. RESULTS: All mechanical complications were detected (100% sensitivity) with specificities of 91.9% for ureteral obstruction (criterion, moderate hydronephrosis), 83.4% for urine leaks (criterion, any new fluid or any increase), 91.4% for fluid collections that compressed the transplant (criterion, > 100 ml), and 100% for vascular occlusion (criteria, no flow for arterial occlusion; no venous flow and reversal of arterial flow during diastole for venous occlusion). CONCLUSIONS: Sonography is very useful in distinguishing between mechanical and nonmechanical causes for renal transplant dysfunction. It has high sensitivity and acceptable specificity in this setting.

Effect of angiotensin converting enzyme inhibition on the Doppler waveform in dogs with renal artery stenosis.

Our objective was to investigate whether the angiotensin converting enzyme inhibitor enalaprilat improves detection of hemodynamically significant renal artery stenoses in dogs. Renal artery stenoses of 50 to 99% were surgically created unilaterally in five dogs. Doppler ultrasonographic evaluation was performed at baseline (no stenosis), after creation of the stenosis, and after the administration of enalaprilat. The resistive index increased in the nonstenotic kidney (P < 0.01) but not in the stenotic kidney after administration of enalaprilat. The difference in resistive indices between nonstenotic and stenotic kidneys increased significantly (P < 0.05) after administration of enalaprilat. Measurement of the resistive index after administration of an angiotensin converting enzyme inhibitor in humans may improve the performance of Doppler ultrasonography in detecting hemodynamically significant renal artery stenoses.

Clinical outcomes of untreated symptomatic patients with negative findings on sonography of the thigh for deep vein thrombosis: our experience and a review of the literature.

OBJECTIVE: Our objective was to determine whether immediate venography or other additional imaging is necessary in symptomatic patients who have negative findings on sonography of the thigh for deep vein thrombosis (DVT). MATERIALS AND METHODS: We retrospectively evaluated the clinical outcomes of 146 patients with physical signs or symptoms consistent with DVT in whom sonography of the thigh was negative for DVT. We combined our results with those of three prospective studies that evaluated symptomatic patients with suspected DVT in whom sonography of the thigh had negative findings. Propagated DVT (from calf to thigh) and pulmonary emboli were considered adverse outcomes. RESULTS: Only one pulmonary embolus (0.7%) occurred in our patient population. However, one (7.7%) of 13 patients who underwent second examinations because of persistent symptoms developed thigh DVT. Review of the literature found four (0.2%) of 1797 patients subsequently developed pulmonary emboli after undergoing sonography of the thigh that was initially interpreted as having negative findings. Fifteen (12.5%) of 120 patients who underwent second sonographic examinations developed DVT of the thigh. No deaths from pulmonary emboli occurred in patients in our study or patients in the studies published in the medical literature. CONCLUSION: Immediate venography or other additional imaging is not necessary in symptomatic patients in whom sonography of the thigh is negative for DVT, given the exceedingly low risk of a pulmonary embolus. Follow-up sonography is indicated in persistently symptomatic patients to detect propagation of calf DVT into the thigh.

Urine leaks in renal transplant patients. Diagnostic usefulness of sonography and renography.

We evaluated the utility of sonography and nuclear medicine renography in the detection of urine leaks in 57 renal transplant patients. Sonography and renography were equally sensitive in detecting leaks. But renography was more specific and therefore accurate (p < 0.0001) in detecting leaks. Urine leaks should be considered on sonography, which is often the first imaging study ordered in evaluating renal transplants, with new or increasing peritransplant fluid collections. Leaks should be confirmed by renography before performing additional invasive radiologic or surgical procedures.

Clinically important pulmonary emboli: does calf vein US alter outcomes?

PURPOSE: To assess whether calf imaging is necessary to identify patients at risk for developing clinically important pulmonary emboli (PE) or propagation of calf deep venous thrombosis (DVT) when the initial thigh ultrasonographic (US) scan is negative for DVT. MATERIALS AND METHODS: The authors retrospectively evaluated the radiology reports from 283 patients (168 female and 115 male patients; mean age, 55.7 years; age range, 1-93 years) in whom US was performed to rule out lower extremity DVT. In all patients, the initial thigh examination was negative for DVT. All patients were classified as to the reason for the examination, risk factors for DVT (including recent surgery), whether they received anticoagulation therapy, and findings on calf US scans. Adverse outcomes were considered a clinically important PE or DVT in the thigh. RESULTS: Only 1.1% of patients (95% CI = 0.2%, 3.1%) had adverse outcomes. Adverse outcomes occurred only in postsurgical patients (P = .028) and were not related to the presence or absence of calf DVT or method of treatment. CONCLUSION: US of the calf is unnecessary at initial evaluation to identify patients at risk of clinically important PE or propagation of DVT into the thigh.

Extravisceral masses in the peritoneal cavity: sonographically guided biopsies in 52 patients.

OBJECTIVE: Our objective was to determine the effectiveness of sonographically guided biopsies of extravisceral masses (masses outside the solid organs) in the peritoneal cavity. MATERIALS AND METHODS: We retrospectively reviewed the results of sonographically guided biopsies of extravisceral masses found in the peritoneal cavity of 52 patients (age range, 25-90 years old; mean age, 52 years) from June 1990 to December 1996. Fifty-one patients underwent biopsy through the abdominal wall, and one patient underwent transvaginal biopsy. Sonographic guidance was obtained using 3.5- to 7.0-MHz vector probes. The size, depth, and sonographic characteristics of the mass and the type of biopsy (aspirate versus core) were determined for all lesions. Pathology reports and clinical courses were reviewed. RESULTS: Placement of the biopsy needle within the lesion was successful in all patients. The mean depth from skin surface to lesion was significantly less (p < .0001) when shown by sonography (2.4 cm) than when shown by CT (3.8 cm). Biopsy results were true-positive for malignancy in 37 patients (no false-positives), true-negative for benign masses in 10 patients, and false-negative for malignancy in three patients (sensitivity, 93%; specificity, 100%; accuracy, 94%). Nondiagnostic samples were obtained in two patients (4%). Treatment was based on diagnostic biopsy results in 43 patients (86%). CONCLUSION: Sonography is an effective alternative to CT in guiding biopsy of extravisceral masses in the peritoneal cavity.

Magnetic resonance imaging: a cost-effective alternative to bone scintigraphy in the evaluation of patients with suspected hip fractures.

OBJECTIVE: To evaluate the cost-effectiveness of magnetic resonance imaging (MRI) compared with radionuclide bone scan in the evaluation of patients with clinically suspected hip fractures. DESIGN: The medical records of all patients who had been seen in the emergency room over a 4 1/2 year period with a clinically suspected hip fracture, negative or equivocal plain films, and either a subsequent bone scan or MRI examination were retrospectively reviewed. The time to diagnosis, admission rate, and time to surgery were determined. A two-sample t-test was used to assess the statistical significance of the results. A theoretical cost analysis was performed using current charges to estimate all expenses. PATIENTS: Forty patients (11 male, 29 female; age 28-99 years) satisfied our inclusion criteria. RESULTS AND CONCLUSIONS: Twenty-one patients had bone scans (six with fractures), and 19 had MRI (four with fractures). The time to diagnosis was 2.24 +/- 1.30 days for bone scanning and 0.368 +/- 0.597 days for MRI (P < 0.0001). Twenty patients in the bone scan group were admitted compared with 13 in the MRI group. The time to surgery was at least 1 day longer in patients undergoing bone scanning. Bone scanning resulted in higher patient costs compared with MRI because of the delay in diagnosis. In the evaluation of patients with suspected hip fractures, early MRI is more cost-effective than delayed bone scanning. Further prospective studies comparing the cost-effectiveness of early MRI with early bone scanning are needed.

Sonographic guidance of mediastinal biopsy: an effective alternative to CT guidance.

OBJECTIVE: Our objective was to determine the diagnostic and cost efficacy of sonographically guided mediastinal biopsy as an alternative to CT-guided mediastinal biopsy and to review our biopsy triage experience in switching from CT to sonography. CONCLUSION: Sonography is as safe and accurate as CT and is 25% less costly than CT. Sonography proved particularly valuable for identifying vessels and perfused tissue and for permitting upright biopsy positions in dyspneic patients. When using our triage criteria, radiologists should find sonographically guided mediastinal biopsy to be an attractive alternative to CT-guided mediastinal biopsy in most patients.

Effective ultrasonographically guided intervention for diagnosis of musculoskeletal lesions.

Current algorithms recommend computed tomography or fluoroscopic guidance rather than ultrasonography for musculoskeletal intervention. We analyzed our ultrasonographically guided experience to evaluate its efficacy. Forty-seven patients underwent needle aspirates or biopsies or both in 13 extremity and 34 axial locations for 12 inflammatory lesions, 23 soft tissue masses, and 12 lesions arising from bone. Four lesions were initially imaged by ultrasonography; the remaining lesions were identified by computed tomography (25) or magnetic resonance imaging (18). Forty-six samples were diagnostic; one needle aspirate of an inflammatory mass yielded no diagnostic material. No complications occurred. Ultrasonographically guided musculoskeletal aspiration and biopsy are diagnostic and effective throughout the body, and with appropriate lesion access, they should be considered as an alternative to computed tomographic-guided procedures.

Renal sonography: can it be used more selectively in the setting of an elevated serum creatinine level?

The objectives of our study were to (1) assess the outcomes resulting from the use of sonography in patients referred to our institution's ultrasound laboratory for an elevated serum creatinine level and (2) determine relevant clinical parameters in these patients to better triage them for sonography. We retrospectively identified and determined outcomes of 60 patients (20 women, 40 men; mean age, 61 years; range, 33 to 100 years) referred for sonographic evaluation because of an increased serum creatinine level (> or = 1.3 mg/dL). Ultrasound findings (hydronephrosis, renal size, and echogenicity) were correlated with clinical outcomes. Twenty-one patients (35%) had hydronephrosis, with 14 of these patients confirmed to be obstructed and five not obstructed. Two were indeterminate for obstruction. Eight of 14 obstructed patients were successfully treated. All obstructed patients had a suggestive history for obstruction with at least one of the following: pelvic mass (n = 9), stone disease (n = 4), or flank pain (n = 1). Only 2 of 44 patients, who were not obstructed, had any of these parameters (statistically significant difference, P < 0.0001). Thirty of the patients, who were not obstructed, had more likely alternative causes for renal failure, with sonography having no effect on patient management. Renal size and echogenicity had little effect on patient management. Sonography was efficacious in guiding management in patients with a suggestive history for obstruction (eg, pelvic mass, stone disease, or flank pain) but not in most patients who had no suggestive history and other more likely causes for renal failure.