Contrast-enhanced or noncontrast CT for renal colic: utilizing urinalysis and patient history of urolithiasis to decide

ACR Appropriateness Criteria® Acute Pelvic Pain in the Reproductive Age Group: 2023 Update

This review focuses on the initial imaging in the reproductive age adult population with acute pelvic pain, including patients with positive and negative beta-human chorionic gonadotropin (β-hCG) levels with suspected gynecological and nongynecological etiology. For all patients, a combination of transabdominal and transvaginal pelvic ultrasound with Doppler is usually appropriate as an initial imaging study. If nongynecological etiology in patients with negative β-hCG is suspected, then CT of the abdomen and pelvis with or without contrast is also usually appropriate. In patients with positive β-hCG and suspected nongynecological etiology, CT of the abdomen and pelvis with contrast and MRI of the abdomen and pelvis without contrast may be appropriate. In patients with negative β-hCG and suspected gynecological etiology, CT of the abdomen and pelvis with contrast, MRI of pelvis without contrast, or MRI of pelvis with and without contrast may be appropriate. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

ACR Appropriateness Criteria® Hydronephrosis on Prior Imaging-Unknown Cause

Initial imaging evaluation of hydronephrosis of unknown etiology is a complex subject and is dependent on clinical context. In asymptomatic patients, it is often best conducted via CT urography (CTU) without and with contrast, MR urography (MRU) without and with contrast, or scintigraphic evaluation with mercaptoacetyltriglycine (MAG3) imaging. For symptomatic patients, CTU without and with contrast, MRU without and with contrast, MAG3 scintigraphy, or ultrasound of the kidneys and bladder with Doppler imaging are all viable initial imaging studies. In asymptomatic pregnant patients, nonionizing imaging with US of the kidneys and bladder with Doppler imaging is preferred. Similarly, in symptomatic pregnant patients, US of the kidneys and bladder with Doppler imaging or MRU without contrast is the imaging study of choice, as both ionizing radiation and gadolinium contrast are avoided in pregnancy. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

ACR Appropriateness Criteria® Acute Onset Flank Pain-Suspicion of Stone Disease (Urolithiasis)

Noncontrast CT (NCCT) is the imaging study of choice for initial evaluation of patients with acute onset of flank pain and suspicion of stone disease without known prior stone disease. NCCT can reliably characterize the location and size of an offending ureteral calculus, identify complications, and diagnose alternative etiologies of abdominal pain. Although less sensitive in the detection of stones, ultrasound may have a role in evaluating for signs of obstruction. Radiography potentially has a role, although has been shown to be less sensitive than NCCT. For patients with known disease and recurrent symptoms of urolithiasis, NCCT remains the test of choice for evaluation. In pregnancy, given radiation concerns, ultrasound is recommended as the initial modality of choice with potential role for noncontrast MRI. In scenarios where stone disease suspected and initial NCCT is inconclusive, contrast-enhanced imaging, either with MRI or CT/CT urogram may be appropriate. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

A systematic review and meta-analysis of clinical signs, symptoms, and imaging findings in patients with suspected renal colic

Study Objective

The objective of this study was to conduct a systematic review and meta-analysis of the diagnostic accuracy of the clinical signs, symptoms, laboratory investigations, and imaging modalities commonly used in patients with clinically suspected renal colic.

Methods

We conducted this systematic review and meta-analysis according to an a priori, registered protocol (PROSPERO CRD42017055153). A literature search was performed using MEDLINE and EMBASE from inception to July 2, 2020. We assessed the risk of bias using Quality Assessment of Diagnostic Accuracy Studies-2, calculated likelihood ratios (LRs), and applied a random-effects model for meta-analysis.

Results

Among 7641 references screened, 76 were included in the systematic review and 53 were included in the meta-analyis. The overall pooled prevalence for ureteral stones was 63% (95% confidence interval [CI], 58%-67%). No individual demographic feature, symptom, or sign when present had an LR+ ≥2.0 for identifying ureterolithiasis. A (Sex, Timing and Origin of pain, race, presence or absence of Nausea, and Erythrocytes) STONE score ≥10 increased (sensitivity 0.49, specificity 0.91, LR 5.3 [95% CI, 4.1-6.7]) and a STONE score <6 reduced the likelihood of ureteral stones (sensitivity 0.94, specificity 0.43, LR 0.15 [95% CI, 0.10-0.22]). Standard-dose (sensitivity 0.96, specificity 0.94, LR+ 16 [95% CI, 11-23], LR- 0.05 [95% CI, 0.03-0.07]) and low-dose computed tomography (CT) scanning (sensitivity 0.93, specificity 0.94, LR+ 17 [95% CI, 8.8-31], LR- 0.08 [95% CI, 0.03-0.19]) were the most useful imaging techniques for identifying patients with or without ureteral stones.

Conclusions

Individual signs, symptoms, or the presence of microscopic hematuria do not substantially impact the likelihood of ureteral stones in patients with clinically suspected renal colic. The STONE score at high and low thresholds and a modified STONE score at a high threshold may sufficiently guide physicians' decisions to obtain imaging. Low-dose, non-contrast CT imaging provides superior diagnostic accuracy compared with all other imaging index tests that are comparable with standard CT imaging. Limitations of the evidence include methodological shortcomings and considerable heterogeneity of the included studies.

The Role of Radiological Imaging in the Diagnosis and Treatment of Urolithiasis: A Narrative Review

The incidence and prevalence of urolithiasis have been increasing worldwide for the last several decades. This increase could be attributed to many factors, including missed cases of small stones, a sedentary lifestyle, a high BMI, a lack of physical activity, and poor dietary intake. In addition, the increased incidence of co-morbidities such as diabetes, dyslipidemia, infections, and multiple urinary tract surgeries could contribute significantly to the formation of urolithiasis. Radiology has a major role in diagnosing a variety of these stone types and can be used in planning management approaches, either as guidance or as a direct therapeutic method for stones. Because of the availability, safety, cost, and effectiveness of radiological imaging nowadays, urolithiasis is rarely missed; furthermore, the availability of radiological treatment options decreases the need for surgical intervention for urolithiasis, which minimizes hospital stay and surgical-related complications. This review aims to scope and analyze the role of radiological imaging modalities in reaching a diagnosis and planning treatment options for urolithiasis in different circumstances. Information was gathered from relevant peer-reviewed publications in PubMed and thereafter refined and summarized to provide a comprehensive review. The selected indexing terms included "radiological imaging modality," "treatment of urolithiasis," and "diagnosis of urolithiasis," among others.

Optimization of urolithiasis treatment and diagnosis in the Turkestan region

The article aims to identify the main problems in treating urological pathologies by analyzing scientific literature from this field and developing recommendations. The quantitative excretion of uric acid, urine volume, and pH are essential in the formation of uric acid stones. The most important risk factor for uric acid nephrolithiasis is the acidic reaction of urine, which is a prerequisite for the formation of urinary stones. When urine is alkalized, the pH should be 6-6.5. Drugs alkalize urine, and one should titrate using urine pH indicator paper until the level is stable. This study found that the spread of genitourinary diseases is increasing. This situation can be improved by monitoring and assessing epidemiological processes, preventing urological pathology, and optimizing medical care organization in the context of health care reform.

Computed Tomography Image Features under Convolutional Neural Network Algorithm in Analysis of Inflammatory Factor Level and Prognosis of Patients with Hepatitis B Virus-Associated Acute-on-Chronic Liver Failure

This study aimed to explore the application value of three-dimensional (3D) convolutional neural networks (3D-CNN)-based computed tomography (CT) image intelligent segmentation model in the identification of lesions of patients with hepatitis B virus-associated acute-on-chronic liver failure (HBV-ACLF). A total of 30 patients with HBV-ACLF, 30 patients with chronic HBV hospitalized in hospital, and 30 healthy volunteers were selected as subjects. Liver function and serum inflammatory factors were measured in each group, and the 3D-CNN algorithm model was applied to CT imaging. The results showed that the levels of interleukin (IL)-6, IL-26, and IL-37 in the HBV-ACLF group were the highest, which were 128.43 ± 45.16 pg/mL, 1237.47 ± 536.22 pg/mL, and 50.83 ± 7.62 pg/mL, respectively. Total bilirubin (TBIL) (P=0.035) and IL-26 (P=0.013) were independent predictors that affected the prognosis of HBV-ACLF patients. The results of lesion segmentation showed that the Dice coefficient of 3D-CNN low-density focus and enhanced focus segmentation was the highest (0.821 ± 0.07 and 0.773 ± 0.071), and the marked area was close to the area manually drawn by the doctor. 3D CNN was superior to other algorithms in the number of nodular lesions detected (533), sensitivity (97.5%), and missed detection rate (0.52%) (P < 0.05). In short, IL-26 may become a useful biomarker in the treatment of HBV-ACLF. The 3D-CNN model improved the segmentation performance of lesions in CT images of HBV-ACLF patients, which provided a reference for the diagnosis and prognosis of HBV-ACLF.

Can obstructive urolithiasis be safely excluded on contrast CT? A retrospective analysis of contrast-enhanced and noncontrast CT

PURPOSE

The aim of this study was to determine if contrast-enhanced CT can safely exclude obstructive urolithiasis in patients with flank plain. We performed a retrospective cohort analysis to compare the negative predictive values of contrast-enhanced and non-contrast CTs for the detection of obstructing urolithiasis.

METHODS

Through report analysis, we identified all non-contrast and contrast-enhanced CT examinations of the abdomen and pelvis performed on adult patients in the emergency department at a single, multi-site academic medical institution in 2017 with an indication of flank pain. The prevalence of obstructive urolithiasis in each group was calculated. We subsequently analyzed 200 consecutive studies from each of these groups (reported negative for obstructive urolithiasis) for negative predictive value calculation. Follow up abdominal imaging within 7 days from original presentation was used as a reference standard for analysis.

RESULTS

In the noncontrast group, 1 study out of 200 was false negative (negative predictive value = 99.5%). In the contrast-enhanced group, there were no false negatives (negative predictive value = 100%). The prevalence of obstructive urolithiasis was 44.0% (351/797) in the noncontrast group and 18.7% (86/459) in the contrast-enhanced group.

CONCLUSION

Our results suggest that contrast-enhanced CT can safely exclude obstructing ureteral calculi in the setting of acute flank pain. This finding is of clinical relevance given the inherent benefit of IV contrast in diagnosing abdominopelvic pathology.

The use of computed tomography as the first imaging modality in patients with renal colic and microscopic haematuria

OBJECTIVE

We aimed to evaluate the use of computed tomography (CT) as the first imaging modality in patients with renal colic and microscopic haematuria.

METHODOLOGY

The patients that presented to the emergency service of six health centers with renal colic between January 2017 and January 2018 and were found to have microscopic hematuria on urinalysis were retrospectively evaluated. Only patients for whom non-contrast CT was used as the first imaging modality were included in the study. Patients were divided into two groups according to the stone presence (stone +, stone -) and the groups were compared in terms of demographics and clinical characteristics of patients.

RESULTS

A total of 834 patients were included in the study and 711 (85.3%) were diagnosed with urolithiasis. CT also revealed additional pathology in 26 (3.1%) patients. The male patients had a significantly higher rate of stones than female patients (89.5% vs 75.2%; P < .001) and the BMI values were also significantly higher in the male patients compared with the females (27.0 ± 2.1 vs 25.0 ± 4.0, P < .001). Right renal colic was more common in female patients and the rate of left renal colic was significantly higher in male patients. The male patients diagnosed with stone disease required treatment at a higher rate than the female patients (P = .005).

CONCLUSIONS

Because of its high sensitivity and specificity values in the diagnosis of stone disease, easy applicability and fast results, CT can be safely used as the first imaging modality for the diagnosis of renal colic and microscopic haematuria.

Prevalence of microhematuria in renal colic and urolithiasis: a systematic review and meta-analysis

BACKGROUND

This systematic review and meta-analysis aims to investigate the prevalence of microhematuria in patients presenting with suspected acute renal colic and/or confirmed urolithiasis at the emergency department.

METHODS

A comprehensive literature search was conducted to find relevant data on prevalence of microhematuria in patients with suspected acute renal colic and/or confirmed urolithiasis. Data from each study regarding study design, patient characteristics and prevalence of microhematuria were retrieved. A random effect-model was used for the pooled analyses.

RESULTS

Forty-nine articles including 15'860 patients were selected through the literature search. The pooled microhematuria prevalence was 77% (95%CI: 73-80%) and 84% (95%CI: 80-87%) for suspected acute renal colic and confirmed urolithiasis, respectively. This proportion was much higher when the dipstick was used as diagnostic test (80 and 90% for acute renal colic and urolithiasis, respectively) compared to the microscopic urinalysis (74 and 78% for acute renal colic and urolithiasis, respectively).

CONCLUSIONS

This meta-analysis revealed a high prevalence of microhematuria in patients with acute renal colic (77%), including those with confirmed urolithiasis (84%). Intending this prevalence as sensitivity, we reached moderate values, which make microhematuria alone a poor diagnostic test for acute renal colic or urolithiasis. Microhematuria could possibly still important to assess the risk in patients with renal colic.