Diagnostic value of renal parenchymal density difference on unenhanced helical computed tomography scan in acutely obstructing ureteral stone disease. Commentary (original) (raw)
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Urology, 2004
Objectives. To evaluate the diagnostic value of the renal parenchymal density difference, detected using unenhanced helical computed tomography, as a secondary sign of acute obstruction due to a ureteral stone. Methods. Fifty-five patients with acute flank pain, in whom a ureteral stone was detected on the symptomatic side using unenhanced helical computed tomography, and 22 control subjects with no urinary stone disease were included in this prospective study. Computed tomography was performed, starting from the upper poles of the kidneys down to the base of the urinary bladder. The renal parenchymal density was measured in the upper, middle, and lower portions of each kidney, and a mean value was calculated. The difference between the mean values of the two kidneys was used to predict the presence of an acutely obstructing ureteral stone. Results. In 49 patients with a ureteral stone (89.1%), the difference between the parenchymal densities of the obstructed and nonobstructed kidneys was 5 Hounsfield units (HU) or greater and was lower on the obstructed side. In the remaining 6 patients (10.9%), the density difference was less than 5 HU but was still lower on the obstructed side. All subjects in the control group had a density difference of less than 5 HU. A renal parenchymal density difference of 5.0 HU or greater had 89.1% sensitivity, 100% specificity, 100% positive predictive value, 85.7% negative predictive value, and 93.4% accuracy in predicting the presence of an acute obstructing ureteral stone. Conclusions. These data suggest that the renal parenchymal density difference may be a valuable secondary sign of acute obstructing ureteral stone disease. UROLOGY 64: 223-227, 2004.
Chang Gung medical journal
The purpose of this study was to determine the usefulness and optimal cutoff point of decreased renal parenchymal density (DRD) for diagnosis of ureteral stone disease (USD) in emergent patients with acute flank pain. A total of 85 emergency patients with acute flank pain who underwent unenhanced helical computed tomography (UHCT) were prospectively included in this study as the study group. An additional 30 patients with no USD undergoing UHCT were retrospectively included as the control group. The mean parenchymal density difference between both kidneys of the control group was compared to that of the study group. Within the study group, the DRD of patients with USD and with no USD was compared. The sensitivities and specificities of DRD for diagnosis of USD in a range of possible optimal cutoff points were analyzed. There was a statistically significant difference in DRD between the study and control groups (p < 0.0001). In the study group, the DRD of patients with USD was sig...
BMC medical imaging, 2004
BACKGROUND: To determine accuracy of ultrasound (US) kidney, ureter and bladder (KUB) compared to un-enhanced helical CT (UHCT) in patients with renal failure in the diagnosis of stone and obstruction. METHODS: This is a case controlled study conducted in the period from June 2000 to July 2003 at a university hospital. All patients had both US and UHCT scan. Patients with serum creatinine >/= 1.8 mg/dl were included in the study. Only direct visualization of stone was considered as confirmatory. In both the studies, UHCT and US, presence of stone and obstruction were noted. The relevant biochemicals, radiological and clinical records of all the patients were analyzed. Data was analyzed using commercially available software. RESULTS: During the period of study 864 patients had UHCT for evaluation of the urinary tract in patients presenting with flank pain. Out of these 34 patients had both UHCT and US done within a span of one day and had serum creatinine of >/=1.8 mg/dl. Mean ...
Accuracy of Sonography for Detection of Renal Stone Comparison with Non-Enhanced Computed Tomography
Introduction: Renal or ureteric calculi are a common incidental finding on abdominal imaging. In most cases no definite cause is identified and the natural cumulative recurrence rate is reported to be 14% at 1 year, 35% at 5 years and 52% at 10 years. Many factors, including race, diet, occupation and water hardness have been implicated in stone formation. In most cases a definite cause is not identified but certain predisposing factors are recognized. Non enhanced helical computed tomography (CT) has become the primary imaging modality for evaluating acute flank pain and suspected renal stone disease. Ultrasound has an important role in the diagnosis and management of urinary tract stones but it has its limitations. The safety and ease of the ultrasound examination are unsurpassable, but its accuracy is modest. Reported sensitivities range from 37 to 64% for calculus detection and 74 to 85% for the detection of acute obstruction. Depending on its composition, a renal stone can be either sound transmitting or so reflective that only its near surface is seen as echogenic cap. Objectives: To determine the sensitivity and specificity of ultrasonography (US) for detecting parenchymal and renal pelvis calculi and to establish the accuracy of US for determining the size and number of calculi, and to find the correlation between the accuracy of sonography with stone size. Patients & method: This is a prospective study conducted from October 2015 to May 2016. Fifty patients (23 men and 27 women) with a mean age of 40 years (range, 19–69 years) selected from Consultant Clinic of Urology of Baghdad Teaching Hospital who had acute flank pain, hematuria or dysuria, and suspected renal stone. Ultrasound was performed by using Philips HD 11 EX equipped with (3.5 MHz) Convex Transducer with High Resolution Monitor and a Thermal Page Printer, Real Time B-Mode Gray Scale and the Examination consist of either dedicated Renal or Abdominal imaging. Non-Enhanced CT scans were performed with (4-chnannel multidetector spiral CT unit [ Toshiba Aquilion , model TSX-101A ] , 5.0 mm slices with 1.0 pitch , 5.0 mm collimation , 120 kv , (200-360) m As this was changed by the operator according to the patient size. Results: Of the 50 patients, 36 (72 %) had a total 105 renal stones identified on Nonenhanced CT scans. Mean stone size (long axis) was 4.5 mm ± 0.5 with a range of (1.1 – 25 mm), Of these 36 patients, 20 (55 %) had multiple renal stones with mean stone size 3.8 mm ± 0.3 (size range 1.4 – 25 mm). Ultrasound demonstrate 50 of 105 renal stones identified on CT images, 16 stones in the Small size group (0.0-3.0mm), 19 stones in the Medium size group (3.1-7.0mm) and 15 stones in Large size group (>7.0mm). Conclusion: US is of limited value for detecting renal stones.CT is the gold standard for assessing the size, number, and location of renal stones.
BMJ (Clinical research ed.), 2014
To derive and validate an objective clinical prediction rule for the presence of uncomplicated ureteral stones in patients eligible for computed tomography (CT). We hypothesized that patients with a high probability of ureteral stones would have a low probability of acutely important alternative findings. Retrospective observational derivation cohort; prospective observational validation cohort. Urban tertiary care emergency department and suburban freestanding community emergency department. Adults undergoing non-contrast CT for suspected uncomplicated kidney stone. The derivation cohort comprised a random selection of patients undergoing CT between April 2005 and November 2010 (1040 patients); the validation cohort included consecutive prospectively enrolled patients from May 2011 to January 2013 (491 patients). In the derivation phase a priori factors potentially related to symptomatic ureteral stone were derived from the medical record blinded to the dictated CT report, which wa...
International Journal of Radiology and Diagnostic Imaging, 2021
The purpose of this study was to determine the frequency of secondary signs associated with ureteral stones and their relationships with stone size in unenhanced computed tomography (CT) scans. Methods: Patients aged 18 and over, who underwent non-contrast tomography in the stone protocol, due to suspected urinary system stones, were included in our study. Tomography images of 324 patients meeting these criteria were retrospectively evaluated. Results: The study included 187 males (57.7%). Ureteral stones were observed in 63.9% of the patients with hydronephrosis, 62.7% of the patients with hydroureter, 36.1% of the patients with perinephric fat stranding, 32.5 % of the patients with tissue rim sign. Ureteral stones were categorized into two groups according to their size as ≤4 mm and >4 mm. There was a significant difference between the groups concerning the presence of hydronephrosis (p = 0.009). There was no significant difference considering other findings. Conclusıon: The frequency of secondary findings in ureteral stones is high. Especially hydronephrosis, the most common secondary clue, is more common in calculi larger than 4 mm in diameter. Secondary findings may be useful when it is challenging to distinguish ureteral stones from extra-uretic calcifications.
Stone formation in the urinary tract affects about 5-10% of the population in industrialized countries and ureteric colic accounts for approximately 0.6% of total ED visits. Objective: To compare the diagnostic accuracy of STONE score and CHOKAI score in predicting the probability of ureteral stones in patients presenting with flank pain by taking CT Scan as a gold standard in emergency department. Study Design: This was a Cross Sectional study. Subject and Methods: After including the patients in study, patients were divided in to two groups through lottery method. Patients in Group A were subjected to STONE score and patients in Group B were subjected to CHOKAI score. Patients having STONE score >8 were labeled as having ureteral stones. While for CHOKAI score, a score of >6 were used to label the ureteral stones. All the study patients underwent CT scanning for confirmation of diagnosis of ureteral stones. RESULTS: As per findings on Chokai Score, 64 (18.23%) patients had ureteric stones. As per findings on stone score, 40 (11.36%) patients had ureteric stones. As per findings on CT Scan, 80 (22.79%) were dignosed for ureteric stones. As per diagnostic accuracy of chokai score, sensitivity was 44.44%, specificity was 48.57%, PPV was 18.23%, NPV was 77.21% and accuracy was 47.72%. As per diagnostic accuracy of stone score, sensitivity was 33.33%, specificity was 46.56%, PPV was 11.40%, NPV was 77.21% and accuracy was 44.30%. CONLCUSION: As per our results, we have come to the conclusion that the use of the STONE clinical score validates patients as low, moderate, and high risk for ureteral stone.
Journal of Experimental and Clinical Medicine, 2012
Uzun süren üreteral obstrüksiyonun böbrek fonksiyon kaybına neden olduğu iyi bilinmektedir. Üriner sistem taşına bağlı herhangi bir obstrüksiyonun kontrastsız çok kesitli bilgisayarlı tomografi (KÇKBT) ile belirlenmesi tedavi zamanlaması hakkında karar vermek açısından çok önemlidir. Çalişmamızda deneysel hidronefroz oluşturulan ratlarda renal parankim dansitesinde meydana gelen değişiklikler KÇKBT ile değerlendirildi. Bu çalışmada sol üreterlerinde total veya parsiyel obstrüksiyon oluşturulmuş Spraque-Dawley ratların böbrek parankim dansiteleri deneyin 1.,3. ve 30. günlerinde KÇKBT ile değerlendirilerek, sham ve kontrol grubu ratların böbrek parankim dansiteleri ile karşılaştırıldı. Parsiyel üreteral obstrüksiyon oluşturulmuş ratların böbrek parankim dansiteleri ile kontrol grubunun böbrek parankim dansiteleri arasında anlamlı bir fark olmadığı saptandı. Bununla birlikte total üreteral obstrüksiyon oluşturulmuş ratların böbrek parankim dansitelerinin karşı taraf böbrekleri ve kontrol grubu ile karşılaştırıldığında anlamlı olarak azaldığı saptandı. Böbrek üst, orta ve alt segmentlerinin ortalama dansite değerleri benzerdi. Elde edilen bu bulguların insanlarda üreter obstrüksiyonun sonuçlarının değerlendirilmesinde yararlı olabileceğini düşünmekteyiz. KÇKBT değerlendirilmesinde renal parankim dansitesinin azalması renal parankimal hasarın bir göstergesi olabilir.
Urology, 2015
Non-enhanced CT exams were acquired using a 64-channel spiral CT scanner (Sensation-64 or Definition-64, Siemens Healthcare, Forchheim, Germany) with 64 x 0.6 collimation, a pitch of 1.2, 120 kVp, and quality reference mAs of 240. In addition a modulated tube current (CARE Dose) was applied to lower radiation exposure. 1 For the stone quantification, reconstructions of 2 mm slice thickness at 2 mm increments were used with a B40 (medium sharp) reconstruction algorithm.