Rationale use of unenhanced multi-detector CT (CT KUB) in evaluation of suspected renal colic

The proportion of computed tomography kidneys, ureters and bladder (CTKUB) scans that comply with scan extent protocol in an emergency department: a clinical audit and dose ramification study

INTRODUCTION

To assess computed tomography kidneys, ureters and bladder (CTKUB) scan extent protocol compliance and associated doses in the Emergency Department (ED) of an Australian tertiary hospital.

METHODS

A retrospective clinical audit of 150 consecutive ED CTKUB cases was completed. For each patient, scan extent compliance at the superior (kidneys) and inferior (pubic symphysis) borders, in reference to the protocol was recorded. Compliance and non-compliance (over-/under-scanning) was identified, described (superior/inferior), quantified (via IMPAX measurements) and recorded via a purpose-built audit tool. In addition, a PBU40 phantom was scanned to assess the percentage of dose (DLP) increase per centimetre of over-scanning to contextualise results.

RESULTS

A notable non-compliance with department protocol was noted. Eight cases (5.3%) demonstrated overall CT scan extent compliance. The remaining 142 cases (94.7%) demonstrated some form of non-compliance; superiorly, inferiorly or both. Analysing the 150 superior and 150 inferior data points independently, the most common non-compliance was over-scanning at the kidneys by 4 cm to5 cm (19 cases, ~10% extra DLP) beyond tolerance and over-scanning inferiorly at the pubic symphysis by 1 cm to 2 cm (29 cases, ~6.4% extra DLP). Estimated dose increases of up to 35% to 45% were found when clinical audit results were simulated using a PBU40.

CONCLUSIONS

Over-scanning is a predominant occurrence in CTKUB scans in this department. Reasons for over-scanning weren't investigated. It's anticipated this audit will lead to greater awareness of scan extent compliance and dose ramifications of non-compliance. The usage of more easily identified anatomical landmarks and a follow-up audit is suggested.

Predicting emergency interventions in patients with acute ureteral colic using acute renal colic scoring system in a Pakistani cohort

OBJECTIVE

To evaluate the acute renal colic score (ARC) in predicting the need of emergency intervention (EI) in patients with ureteric colic secondary to a ureteral stone.

PATIENT AND METHODS

In an emergency room (ER) of a university hospital, we conducted a prospective cohort study over a period of 6 months. ARC score was calculated using four parameters, i.e., serum creatinine, total white cell count (TLC), stone length and level. Primary outcome measure was EI, which was defined as the need of endourological intervention within 48 h of presentation. ARC was calculated for each patient against the two possible outcomes, i.e., EI vs. no EI. The need of intervention was based on patient-related clinical factors and the decision of the attending urologist.

RESULTS

The study included 132 patients. EI was performed in 85 patients (64.4%). URS was the most common intervention performed in 81 (95.3%) patients, followed by the a insertion of a double J stent in two (2.4%) patients for forniceal rupture and high TLC count and percutaneous nephrostomy in two (2.4%) patients for raised creatinine and TLC. All four variables in ARC score including serum creatinine (p < 0.001), TLC (p < 0.001), stone size (p < 0.001) and stone level (p < 0.001) were found to be significantly associated with need for EI. Using ROC the sensitivity and specificity of the score was 92.9% and 87.5%, respectively, with AUC of 0.93.

CONCLUSIONS

ARC score is highly sensitive and specific in determining the need of EI in patients with uncomplicated ureteric colic within 48 h of initial presentation.

The role of ultrasonography in detecting urinary tract calculi compared to CT scan

Objective

To evaluate the accuracy of ultrasonography (US) in measuring the urinary tract stone using non-contrast computed tomography (NCCT) as the standard reference.

Patients and methods

A total of 184 patients suspected with urolithiasis who had undergone NCCT and US radiologic investigation from 2015 to 2017 were enrolled in this study. The sensitivity, specificity, and stone size measured in US were validated by NCCT. Data of the stone size in US were classified into four groups (0–3.5, 3.6–5, 5.1–10, >10 mm) and then compared with NCCT data.

Results

In 184 patients, NCCT detected 276 (97.2%) stones, while US could identify 213 (75.5%) stones. Overall sensitivity and specificity of US were 75.4% and 16.7%, respectively. Detection rate of mid and distal ureteral stone was lower than that at other locations. The detection rate increased with the stone size. About 73% concordance was obtained for the stone size measured by US and NCCT (Pearson’s correlation coefficient was 0.841). Factors such as the stone size, amount of hydronephrosis, and weight affected the detection rate of the urinary tract stone using US (P<0.001, P=0.02, and P=0.01, respectively).

Conclusion

The stone size obtained by US was almost the same as that detected by NCCT; however, US is a limited imaging modality in detecting urinary tract stone, especially when used by an inexperienced radiologist, and in the case of smaller stone size, increased weight, and low grade of hydronephrosis.

Comparison of ureteric stone size, on bone window versus standard soft-tissue window settings, on multi-detector non-contrast computed tomography

Objective

To compare the difference in mean stone size, as measured on bone window vs standard soft-tissue window setting using multi-detector computed tomography (MDCT) in patients with a solitary ureteric stone.

Patients and methods

In all, 60 patients presenting to the emergency and outpatient departments of a University Hospital from May 2015 to October 2015 and fulfilling the inclusion criteria were included in the study. A 64-slice MDCT was used to assess the locations and size of the ureteric stones. A consultant radiologist independently analysed the MDCT scans of all the patients. The mean difference in stone size was calculated between both window settings in axial and coronal planes.

Results

The mean (SD) age of the patients was 37.13 (11.9) years. Males constituted ∼68% of the cohort and 32% were female. In all, 85% of the patients had left ureteric stones and 15% had right ureteric stones. The mean (SD) stone size, as measured on the soft-tissue window setting was 6.68 (2.01) mm, and on the bone window setting was 4.8 (1.9) mm. The mean (SD) difference in stone size between the two window settings was +1.85 (0.55) mm. The two means were compared using Student’s t-test, and the difference was found to be statistically significant (P < 0.05).

Conclusion

The stone size measured using the soft-tissue window setting on a MDCT is significantly different from the measurement on the bone window setting.

Management of alternative pathology detected using CT KUB in suspected ureteric colic

Acute flank pain is a common presentation to the emergency department (ED), and imaging studies play an important role in establishing an accurate diagnosis. Computed Tomography of Kidneys, Ureters, Bladder (CT KUB) has surpassed all other imaging modalities to become the gold standard in detection of ureteric calculi. The purpose of this study is to identify the range and management of alternative diagnoses established by CT KUB in patients with suspected ureteric colic. Two hundred and fifteen consecutive CT KUB examinations ordered in the ED of a tertiary-care centre for suspected ureteric colic were retrospectively reviewed. This comprised of 134 male (62.3%) and 81 female (37.7%) patients with a mean age of 53 years old. The positive detection rate for ureteric calculi in males was 43.3% compared to a lower rate for females of 29.6% (p < 0.05). Almost two-thirds of patients were discharged following CT KUB imaging, and admission rates were significantly higher in those with alternative radiological findings (p < 0.04) Alternative radiological findings occurred in 72 patients (33.5%), including 15 patients (7.0%) who had clinically important alternative pathology. The rate of clinically important alternative findings was significantly higher in males than females, 9.7% versus 2.5% respectively (p = 0.04). Surgical intervention was more common in patients with alternative radiological findings classified as gastrointestinal (18.2%) compared to non-gastrointestinal (3.6%), however this did not reach statistical significance (p = 0.07). In conclusion, significant alternative pathology was identified using CT KUB in 7% of patients with suspected ureteric colic. The low rates of detection of ureteric calculi and significant alternative pathology in female patients suggests a more thorough clinical assessment is warranted to improve their management, prior to ordering investigations with exposure to radiation.

Application of Ureteroscope in Emergency Treatment with Persistent Renal Colic Patients during Pregnancy

Background

Although the application of ureteroscopy in the treatment of ureteral calculi during pregnancy has been on the rise, for persistent renal colic patients without ultrasound-detected ureteral calculi, it may represent a clinical dilemma due to the potential risks for both mother and fetus.

Objective

The aim of the present study is to present our experience with the application of the ureteroscope in the emergency treatment of persistent renal colic patients during pregnancy.

Methods

From March 2009 to September 2014, a total of 117 pregnant women who received ureteroscopy for persistent renal colic were retrospectively analyzed. Patients were divided into three groups according to duration of the persistent renal colic: Group A (within 12 hours; 24 cases); Group B (12 to 24 hours; 76 cases); and Group C (more than 24 hours; 17 cases). The stone-free rate, complications, and other qualitative data were analyzed.

Results

Of the 117 patients, 31 patients who were found not to have renal or ureteral calculi received ureteroscopic double-J (DJ) stent insertion, whereas 86 patients who were found with ureteral calculi received ureteroscopic lithotripsy (URSL) and DJ stent insertion. Among them, 24 patients (27.9%) were found with ureteral calculi by ureteroscopy rather than ultrasound. In addition, 73 patients (84.9%) had complete fragmentation of calculi; 12 patients (10.3%) had a threatened abortion (the rates of threatened abortion in Groups A, B and C were 8.3% vs. 6.5% vs. 29.4%; Group C compared with Groups A and B, p<0.05), and one patient (1.2%) had urosepsis (in Group C). However, these complications were cured with conservative treatment, without postpartum infant and maternal complications.

Conclusion

For pregnant patients with persistent renal colic/ureteral calculi and hydronephrosis, ureteroscopic DJ stent insertion and URSL are effective and safe options when conservative treatment fails, even if no urinary calculi were found by ultrasound. At the same time, for patients with persistent renal colic during pregnancy, early application of ureteroscopy may reduce the risk of preterm birth.

In Vivo Evaluation of Chemical Composition of Eight Types of Urinary Calculi Using Spiral Computerized Tomography in a Chinese Population

BACKGROUND

This study was conducted to evaluate the chemical composition of eight types of urinary calculi using spiral computerized tomography (CT) in vivo.

METHODS

From October 2011 to February 2013, upper urinary tract calculi were obtained from 122 patients in the department of urinary surgery of the First Affiliated Hospital of Soochow University. All patients were scanned with a 64-detector row helical CT scanner using 6.50 mm collimation before ureterorenoscopy. Data from the preoperative spiral CT scans and postoperative chemical composition of urinary calculi were collected.

RESULTS

The chemical composition analysis indicates that there were five types of pure calculi and three types of mixed calculi, including 39 calcium oxalate calculi, 12 calcium phosphate calculi, 10 calcium carbonate calculi, 8 magnesium ammonium phosphate calculi, 6 carbonated apatite, 21 uric acid/ammonium urate calculi, 10 uric acid/calcium oxalate calculi, and 16 calcium oxalate/calcium phosphate calculi. There were significant differences in the mean CT values among the five types of pure calculi (P < 0.001). Furthermore, we also observed significant differences in the mean CT values among three types of mixed calculi (P < 0.001). Significant differences in the mean CT values were also found among eight types of urinary calculi (P < 0.001). However, no statistically significant difference was observed between the mean CT values of magnesium ammonium phosphate calculi and uric acid/calcium oxalate calculi (P = 0.262).

CONCLUSION

Our findings suggest that spiral CT could be a promising tool for determining the chemical composition of upper urinary tract calculi.