Acute Flank Pain Secondary to Urolithiasis: Radiologic Evaluation and Alternate Diagnoses

Relationship between microscopic haematuria and hydronephrosis in urolithiasis

AIM

The aim of this study was to investigate the relationship between the degree of hydronephrosis and the presence of microscopic haematuria in patients who presented to the emergency department (ED) with ureteral stones.

METHODS

The records of patients who presented to our ED due to urolithiasis between January 2017 and December 2020 were retrospectively analysed. Patients aged 18 years or older who underwent non-contrast computed tomography (CT abdomen/pelvis) and urinalysis (UA) and were diagnosed with ureteral stones were included in the study. Radiology reports were reviewed for stone size, localisation and degree of hydronephrosis. Patients with and without microscopic haematuria and the degree of hydronephrosis were compared.

RESULTS

A total of 476 patients were included, which consisted of 391 with microscopic haematuria and 85 without microscopic haematuria. The median stone size was 4.1 mm in the presence of microscopic haematuria and 5.5 mm in the absence of microscopic haematuria. Logistic regression analysis was performed to determine the factors associated with the development of hydronephrosis. Stone size [odds ratio (OR):2.15, 95% confidence interval (CI):1.12-4.16, P < .001), presence of pyuria (OR: 2.58, 95% CI: 1.78-3.48, P < .001) and absence of microscopic haematuria (OR: 1.31, 95% CI 1.04-2.89, P = .017) were identified as risk factors for moderate and severe hydronephrosis.

CONCLUSION

We consider that imaging studies may be necessary for the diagnosis, and treatment of emergency cases in which microscopic haematuria is not detected in urinalysis since their stone size may be larger and degree of hydronephrosis may be more severe.

Doppler sonographic evaluation of resistive index of intra-renal arteries in acute ureteric obstruction

BACKGROUND

Acute ureteric colic is one of the most commonly encountered acute abdominal conditions. Diagnosis of obstruction caused by ureteric calculus occasionally becomes challenging if there is inadequate dilation of the urinary tract proximal to obstruction. In such a situation, intra-renal artery Doppler parameters can be used as a diagnostic tool. Our study compared intra-renal arterial Doppler in patients with obstructed and non-obstructed kidneys presenting within 24 h of onset of symptoms of unilateral acute renal colic.

RESULTS

The resistivity index (RI) in the segmental arteries of all 54 patients with obstructed kidneys was significantly higher than in those with non-obstructed kidney: 0.75 vs. 0.56, with a p value less than 0.001, a sensitivity of 85% and a specificity of 93%.

CONCLUSION

Doppler ultrasound is a useful diagnostic tool in the evaluation of acute renal obstruction, thus enabling practitioners to avoid ordering unnecessary CT and exposing patients to ionizing radiation. An RI value > 0.7 has good sensitivity and specificity in our study. The results obtained in the study were comparable to those of pioneer studies conducted worldwide.

The Emergency Department Diagnosis and Management of Urinary Tract Infection

Urinary tract infection (UTI) is a common infection seen in the emergency department. The spectrum of UTI includes simple versus complicated infection and lower versus upper UTI. No one history or examination finding is definitive for diagnosis. Testing often includes urinalysis and/or urine dipstick, and several pitfalls may occur in interpretation. Urine cultures should be obtained in complicated or upper UTIs but not simple and lower tract UTIs, unless a patient is pregnant. Imaging often is not required. Most patients with simple cystitis and pyelonephritis are treated as outpatients. A variety of potentially dangerous conditions may mimic UTI and pyelonephritis.

A Comparison of Urolithiasis in the Presence and Absence of Microscopic Hematuria in the Emergency Department

Introduction

Urolithiasis is a common medical condition that accounts for a large number of emergency department (ED) visits each year and contributes significantly to annual healthcare costs. Urinalysis is an important screening test for patients presenting with symptoms suspicious for urolithiasis. At present there is a paucity of medical literature examining the characteristics of ureteral stones in patients who have microscopic hematuria on urinalysis versus those who do not. The purpose of this study was to examine mean ureteral stone size and its relationship to the incidence of clinically significant hydronephrosis in patients with and without microscopic hematuria.

Methods

This is a retrospective chart review of patient visits to a single, tertiary academic medical center ED between July 1, 2008, and August 1, 2013, of patients who underwent non-contrast computed tomography of the abdomen and pelvis and urinalysis. For patient visits meeting inclusion criteria, we compared mean stone size and the rate of moderate-to-severe hydronephrosis found on imaging in patients with and without microscopic hematuria on urinalysis.

Results

Out of a total of 2,370 patient visits 393 (16.6%) met inclusion criteria. Of those, 321 (82%) had microscopic hematuria present on urinalysis. Patient visits without microscopic hematuria had a higher rate of moderate-to-severe hydronephrosis (42%), when compared to patients with microscopic hematuria present (25%, p=.005). Mean ureteral stone size among patient visits without microscopic hematuria was 5.7 mm; it was 4.7 mm for those patients with microscopic hematuria (p=.09). For ureteral stones 5 mm or larger, the incidence of moderate-to-severe hydronephrosis was 49%, whereas for ureteral calculi less than 5 mm in size, the incidence of moderate-to-severe hydronephrosis was 14% (p < 0.0001).

Conclusion

Patients visiting the ED with single-stone ureterolithiasis without microscopic hematuria on urinalysis could be at increased risk of having moderate-to-severe hydronephrosis compared to similar patients presenting with microscopic hematuria on urinalysis. Although the presence of hematuria on urinalysis is a moderately sensitive screening test for urolithiasis, these results suggest patients without hematuria tend to have more clinically significant ureteral calculi, making their detection more important. Clinicians should maintain a high index of suspicion for urolithiasis, even in the absence of hematuria, since ureteral stones in these patients were found to be associated with a higher incidence of obstructive uropathy.

Abdominal radiograph pearls and pitfalls for the emergency department radiologist: a pictorial review

Abdominal plain films are often the first imaging examination performed on a patient with abdominal pain in the emergency department. Radiograph findings can help guide clinical management and the need for advanced imaging. A pictorial review of a range of abdominal radiograph findings is presented, including bowel gas patterns, abdominal organ evaluation, pathologic gas, calcifications, implanted devices, and foreign bodies.

Incidental findings on CT for suspected renal colic in emergency department patients: prevalence and types in 5,383 consecutive examinations

PURPOSE

This study aimed to determine the prevalence, importance, and types of incidental findings (IF) in non-enhanced CT scans performed for suspected renal colic, based on ACR white papers and other accepted radiographic recommendations.

METHODS

Retrospective review of 5,383 consecutive finalized reports of nonenhanced CT using renal colic protocol performed on adult patients at 2 emergency departments over a 5.5-year period. IF were defined as those unrelated to symptoms (as opposed to alternate causes of symptoms) and were categorized as "important" if follow-up was recommended based on recently published consensus recommendations. Subsets of reports of those with important IF were blindly re-reviewed to calculate inter-rater variability for presence and categorization of important IF.

RESULTS

Important IF were identified in 12.7% (95% confidence interval [CI]: 11.8%-13.6%) of scans. Prevalence of important IF increased with age: important IF in individuals age >80 years were 4 times more common than for those aged 18-30 years: 28.9% (95% CI: 22.4%-36.4%) versus 6.9% (95% CI: 5.5%-8.6%), respectively, P ≤ .05. Women had a higher prevalence of important IF compared with men: 13.4% (95% CI: 12.2%-14.7%) versus 11.9% (95% CI: 10.7%-13.2%), but the difference was not statically significant (P = .09). There was substantial inter-rater agreement (kappa ≥ 0.69) regarding presence and classification of important IFs using published guidelines.

CONCLUSIONS

Important IF occurred in 12.7% of non-enhanced CT scans performed for suspected renal colic in the emergency department and are more common in older individuals. Prospective studies that use radiographic recommendations to characterize IF and examine the outcome and cost of their workup are encouraged.

Urinary bladder stones in women

PURPOSE

The objective of this study was to review the history, epidemiology, diagnosis, and current management techniques for bladder stones (BS) in women.

METHODS

A MEDLINE search for articles published from 1950 to 2011 was done using a list of terms related to BS including calculi, cystolithiasis, stones, urinary bladder, and women.

RESULTS

Approximately 5% of all BS occur in women and are usually associated with foreign bodies (sutures, synthetic tapes, or meshes) or urinary stasis. Bladder stones can be asymptomatic but may result in hematuria, recurrent infections, and irritable symptoms. Stones can be detected by x-ray, ultrasound, or computed tomography scan and frequently at the time of routine cystourethroscopy performed during pelvic surgery. Because BS is a sign of an underlying problem, definite treatment of the underlying abnormality is nearly always indicated. The preferred treatment for BS is endoscopic transurethral fragmentation of the stone (cystolithotripsy). Any associated suture or synthetic mesh can be removed or cut flush with the bladder mucosa. Partial resection of the mesh with cystotomy should be considered whenever transurethral treatment failed. When stone burden is large, percutaneous endoscopic disintegration or open suprapubic cystolithotomy is preferable. Extracorporeal shockwave lithotripsy has been demonstrated to be simple, effective, and well tolerated. However, ancillary procedures are required in a significant number of patients.

CONCLUSIONS

The increased usage of synthetic material in reconstructive pelvic floor surgery in women will probably increase the incidence of BS on intravesical foreign bodies. Bladder stones should be ruled out in women investigated for irritable bladder symptoms or recurrent urinary infection.

Usefulness of computed tomography performed immediately after excretory urography in patients with delayed opacification or dilated upper urinary tract of unknown cause

PURPOSE

To evaluate the diagnostic value of computed tomography (CT) performed immediately after excretory urography (EU) in patients with delayed renal opacification or dilated upper urinary system with nonconclusive diagnosis after EU.

MATERIALS AND METHODS

CT was performed immediately after EU in 39 patients with delayed opacification or dilated upper urinary system of unknown cause, without additional intravenous contrast administration for the CT study. We classified EU + CT findings as benign or malignant causes and we compared our results with the final diagnosis.

RESULTS

The combination of EU + CT correctly diagnosed 38 out of the 39 cases with a sensitivity of 97%. Correct diagnosis was established in all malignant cases (n = 17) but one benign case consistent with blood clots in the upper urinary tract was incorrectly diagnosed as a multicentric urothelial carcinoma. Sensitivity, specificity, and accuracy for the diagnosis of the underlying cause with EU + CT was 100%, 95%, and 97%, respectively. The final diagnoses were: urothelial carcinoma (n = 10), stone disease (n = 10), bladder tumor (n = 4), benign post-treatment ureteral stenosis (n = 4), ureteral invasion (n = 3), benign bladder disease (n = 2), urinary tract infections (n = 2), crossing vessels (n = 1), ureteropelvic junction obstruction (n = 1), retrocaval ureter (n = 1), and blood clots in the upper urinary tract due to bleeding renal metastasis from lung cancer (n = 1).

CONCLUSION

Combined EU and CT study allowed correct diagnosis of the underlying cause of delayed excretion or upper urinary tract dilatation in 97% of cases. The combination of EU and CT provides diagnosis reducing time and radiation.

Comparison of conventional radiography combined with ultrasonography versus nonenhanced helical computed tomography in evaluation of patients with renal colic

The aim of this study is to determine whether kidneys ureters bladder X-ray (KUB) film combined with ultrasound (US) can be effectively used in evaluation of renal colic and miss stones with clinically significant size identified on nonenhanced computed tomography (NECT) in patients with urolithiasis. This retrospective study evaluated the clinical and radiological records of 300 patients at our institution undergoing KUB and/or US and/or NECT for the evaluation of renal colic from June 2007 to December 2010. Of patients with negative findings on KUB and/or US, 22 had renal stones on NECT (mean size 4.4 mm, range 3-8), 3 had lower ureteral stone (mean size 3.3 mm, range 2-5). In patients with isolated suspicious renal ectasia without stone image, two had renal stone on NECT (mean size 4 mm, range 2-6), 5 had upper ureteral stone (mean size 4.4 mm, range 4-6), 7 had middle ureteral stone (mean size 3.7 mm, range 3-4) and 14 had lower ureteral stone (mean size 4 mm, range 2-6). The cost-effective and almost radiation-free combination of KUB and US should be preferred for diagnosis of urolithiasis, as it detects most of the ureteral and renal calculi which are clinically significant.

Nephrolithiasis: what surgeons need to know

OBJECTIVE

In this article, we review the standard of care for imaging of nephrolithiasis as well as new technology and radiation concerns from the perspective of the urologic surgeon.

CONCLUSION

Nephrolithiasis is a common cause of morbidity with a lifetime prevalence of 5-10% worldwide. Increasingly, diagnostic evaluation and planning for medical or surgical intervention have become reliant on imaging.

[Intravenous urography is died. Long live the computerized tomography!]

Very important changes have happened in the field of the genitourinary image during the last half of the 20th century, so that for most of the historical intravenous urography indications, nowadays the computerized tomography (CT) is technique of choice. The aim of this report is to perform an update in the correct use of the imaging techniques in the adult-related most frequent urological pathology, including: urolithiasis, haematuria, infections, tumours, surgery follow-up and pyelectasis, specially focused in CT. A brief historical review of the urological imaging techniques is performed, emphasizing the physical principles. In the second part, the role played by plain X-ray, ultrasound, CT and MR in the different urological pathologies are reviewed, discussing the sensibility and specificity of each technique. A brief reflection is finally carried out over of the radiation doses.

Effect of low dose radiation computerized tomography protocols on distal ureteral calculus detection

PURPOSE

Unenhanced multidetector computerized tomography is the imaging modality of choice for urinary calculi but exposes patients to substantial radiation doses with a subsequent risk of radiation induced secondary malignancy. We compared ultra low dose and conventional computerized tomography protocols for detecting distal ureteral calculi in a cadaveric model.

MATERIALS AND METHODS

A total of 85 calcium oxalate stones 3 to 7 mm long were prospectively placed in 14 human cadaveric distal ureters in 56 random configurations. The intact kidneys, ureters and bladders were placed in a human cadaveric vehicle and computerized tomography was performed at 140, 100, 60, 30, 15 and 7.5 mA seconds while keeping other imaging parameters constant. Images were independently reviewed in random order by 2 blinded radiologists to determine the sensitivity and specificity of each mA second setting.

RESULTS

Overall sensitivity and specificity were 98% and 83%, respectively. Imaging using 140, 100, 60, 30, 15 and 7.5 mA second settings resulted in 98%, 97%, 97%, 96%, 98% and 97% sensitivity, and 83%, 83%, 83%, 86%, 80% and 84% specificity, respectively. Interobserver agreement was excellent (kappa >0.87). There was no significant difference in sensitivity or specificity at any mA second settings. All false-negative results were noted for 3 mm calculi at a similar frequency at each mA second setting.

CONCLUSIONS

Ultra low dose computerized tomography protocols detected distal ureteral calculi in a fashion similar to that of conventional computerized tomography protocols in a cadaveric model. These protocols may decrease the radiation dose up to 95%, reducing the risk of secondary malignancies.