Ultrasonography by emergency physicians in patients with suspected ureteral colic

Renal ultrasound

Renal US is one of several imaging modalities available to the EP in the evaluation of patients with acute urologic disorders. It offers excellent anatomic detail without exposure to radiation or contrast agents but is limited in its assessment of renal function. It is an important alternative to helical CT scanning for evaluating renal colic, especially in children and pregnant women. It has an important role in excluding bilateral renal obstruction as the cause of acute renal failure. It is likely that Doppler renal US also will take on a prominent role in the evaluation of renal vascular disorders. It already has become the standard of care in the management of renal transplant patients. Bedside emergency renal US performed and interpreted by EPs with limited training and experience is increasing in use and gaining acceptance. At present, the primary role of renal US is to identify hydronephrosis in patients with renal colic or acute renal failure but, in the future, its role likely will expand as technology advances and its use increases. In many patients, bedside renal US may obviate the need for further diagnostic workup and speed the diagnosis and treatment of an emergency patient.

Can conventional examinations contribute to the diagnostic power of unenhanced helical computed tomography in urolithiasis?

INTRODUCTION

To investigate whether ordinary tests used in urolithiasis can increase the diagnostic value of unenhanced helical computed tomography (HCT).

MATERIALS AND METHODS

Of all patients admitted with acute flank pain, 137 without radiocontrast allergy, pregnancy and renal insufficiency were included in the study. After urinalysis (Ur) and ultrasonography (USG), HCT without a contrast agent was taken by 5-mm collimation, thereafter excretory urography (EU) was obtained. Confirmation of a stone was done by various tests and/or treatment methods. Statistically, the predictive values of HCT, USG, EU and Ur and their combinations were evaluated using the area under the receiver operating characteristic curve (AROC).

RESULTS

The patients' mean age was 38 (range 4-72) years. Sensitivity values of HCT, USG, EU and Ur were 97, 69, 71 and 81%, respectively. Their specificity values were 96, 87, 91 and 65%, respectively. The widest AROC was found for HCT (97%). The best test combination was [HCT or USG] according to the AROC value (93%), but none of the AROC values of the test combinations was higher than that of HCT. However, 95% confidence intervals of the AROC values of these tests and their combinations overlapped.

CONCLUSIONS

Because the HCT combinations with other tests improved the diagnostic value of HCT, they should be preferred in some individuals suspected of having urolithiasis. However, the most feasible single test meeting the all usage purposes was HCT in terms of the AROC value, and the combination was [HCT or USG] in which either HCT or USG was positive.

[Ultrasound of acute abdomen]

Ultrasound is an important tool in the diagnosis of acute abdominal pain, which is mainly caused by gastrointestinal diseases. This article gives an overview on the important differential diagnosis related to pain localization. Sonomorphological signs and their sensitivity and specificity are discussed. In contrast to other imaging methods ultrasound is hand guided. The present article differentiates the diagnostic capability of ultrasonic diagnosis depending on technical equipment and sonographer's educational level. These facts are important to stabilize the position of ultrasound in the ensemble of other imaging methods. The use of mobile ultrasound machines and an improved training (e.g. by computer assisted sonosimulator systems) will lead to an increasing importance of ultrasound.

Nonenhanced helical CT and US in the emergency evaluation of patients with renal colic: prospective comparison

PURPOSE

To compare nonenhanced helical computed tomography (CT) with ultrasonography (US) for the depiction of urolithiasis.

MATERIALS AND METHODS

During 9 months, 45 patients (mean age, 44 years; mean weight, 92.5 kg) prospectively underwent both nonenhanced helical CT (5-mm collimation; pitch of 1.5) and US of the kidneys, ureters, and bladder. US evaluation included a careful search for ureteral calculi. Presence of calculi and obstruction and incidental diagnoses were recorded. Clinical, surgical, and/or imaging follow-up data were obtained in all patients. The McNemar test was used to compare groups.

RESULTS

Diagnoses included 23 ureteral calculi and one each of renal cell carcinoma, appendicitis, ureteropelvic junction obstruction, renal subcapsular hematoma, cholelithiasis, medullary calcinosis, and myelolipoma. CT depicted 22 of 23 ureteral calculi (sensitivity, 96%). US depicted 14 of 23 ureteral calculi (sensitivity, 61%). Differences in sensitivity were statistically significant (P: =.02). Specificity for each technique was 100%. When modalities were compared for the detection of any clinically relevant abnormality (eg, unilateral hydronephrosis and/or urolithiasis in patients with an obstructing calculus), sensitivities of US and CT increased to 92% and 100%, respectively. One case of appendicitis was missed at US, whereas medullary calcinosis and myelolipoma were missed at CT.

CONCLUSION

Nonenhanced CT has a higher sensitivity for the detection of ureteral calculi compared with US.

Physician training requirements in sonography: how many cases are needed for competence?

OBJECTIVE

Physician competence in the performance of sonographic studies was assessed after their involvement in predetermined increments of cases to determine whether the case volumes currently required by the American Institute of Ultrasound in Medicine and the American College of Radiology for training in sonography can be lowered substantially.

MATERIALS AND METHODS

Sonographic competence tests were administered to 10 first-year diagnostic radiology residents after their involvement in increments of 50 cases, up to a total of 200 cases (four competency tests). Each competency test consisted of the resident's independently scanning and interpreting 10 clinically mandated studies that were scored in comparison with the examination performed by the sonographer and interpreted by an attending radiologist. Trainee studies were graded on the percentage of anatomic landmarks depicted, the number of reporting errors, the number of clinically significant reporting errors, and the percentage of cases receiving a passing score.

RESULTS

Although resident performance improved progressively with increasing experience for all parameters assessed, performance of the group was poor even after their involvement in 200 cases. At this testing level, the mean percentage of anatomic landmarks depicted successfully was 56.5%; the mean total reporting errors per case was 1.2; the mean clinically significant errors per case was 0.5; and the mean percentage of cases receiving a passing score was 16%. Impressive performance differences were observed among residents for all parameters assessed, and these differences were not explained by the number of months of radiology training the resident had taken before the sonography rotation.

CONCLUSION

Involvement in 200 or fewer cases during the training period is not sufficient for physicians to develop an acceptable level of competence in sonography.