64层螺旋CT尿路成像与静脉尿路造影对照分析

目的探讨64层螺旋CT尿路成像(CTU)与静脉尿路造影(IVU)对泌尿系病变的应用价值。方法 130例临床疑诊泌尿系病变的患者,先进行IVU,再行64层螺旋CT尿路成像检查,通过工作站进行多种后处理,比较两者结果。结果 IVU诊断正常3例,诊断泌尿系结石95例,其中肾结石50例,输尿管结石44例,膀胱结石1例,输尿管外压病变2例,泌尿系畸形6例,肿瘤7例,感染性病变1例。CTU诊断正常2例,诊断泌尿系结石106例,其中肾结石60例,输尿管结石45例,膀胱结石1例,外压病变4例,泌尿系畸形9例,肿瘤20例,感染性病变17例。对于泌尿系结石、畸形的诊断两种方法无统计学差异(P>0.05),对于泌尿系肿瘤、感染的诊断两者有统计学差异(P<0.05)。结论 64层螺旋CT通过多种后处理方法,既可全景显示泌尿系的形态结构,也可观察局部病变细节,对泌尿系各种疾病的诊断有重要的临床价值;而对于泌尿系单纯结石性梗阻亦可采用IVU。     

Improved pelvicalyceal visualization with multidetector computed tomography urography; comparison with helical computed tomography

Our aim was to compare the quality of pelvicalyceal visualization on computed tomography (CT) urography using a small intravenous contrast material dose, hydration, and high-resolution multidetector CT (MDCT) with that of conventional helical CT. The test (MDCT) group (49 consecutive patients, 98 kidneys) was scanned 5 min following an intravenous bolus of 30 ml of iodinated contrast material. The control (helical CT) group (50 consecutive patients, 95 kidneys) was scanned 5 min following injection of 120–150 ml of intravenous contrast material. Enhancement and quality of calyceal detail were measured using a five-scale grading system (1 for no detail, 5 for cupped calyces). Calyceal attenuation was substantial in both groups (more than 220 Hounsfield units, HU) but less in the test group compared with the control group (mean 475 and 920 HU, respectively), p<0.0001. In the test group, the calyceal attenuation was less than 500 HU in the majority of cases (65/98 kidneys), while the opposite was true for the control group, where calyceal attenuation was more than 750 HU in 50/95 kidneys (p<0.001). The quality of calyceal detail was 3.4/5 in the test group compared with 1.8/5 in the control group (p<0.0001). The combination of hydration, low-contrast dose, and the high image resolution achieved with MDCT significantly improves calyceal visualization in CT urography.     

Multidetector-row computed tomography (MDCT) in patients with a history of previous urothelial cancer or painless macroscopic haematuria

The sensitivity and specificity of MDCT for depiction and localization of urothelial carcinoma (UC) was determined retrospectively. Axial and coronal four-row MDCT of the urinary tract (unenhanced, contrast-enhanced nephrographic, CT urography) was independently reviewed for UC by a radiologist (R1) and a urologist (R2), without other patient information, in 27 patients (22 male, five female; age, 72 ± 11 years) with previous UC and/or painless macroscopic haematuria. Urinary tract segments included bladder, right and left upper, middle, and lower caliceal groups, renal pelvis, uretero-pelvic junction, upper, middle, and lower ureter. MDCT findings were corroborated by surgery, other invasive procedures, and 1-year follow-up, including MDCT, intravenous urography, and cystoscopy. Receiver-operating characteristic analysis was undertaken and the the area under the curve (AUC) calculated. Eighteen of 27 patients had evidence of UC (pTa, n = 3; pT1-pT3, n = 15; TNM 2002). Tumor was correctly located by both R1 and R2 in 17 patients (sensitivity, 94%; 95% confidence interval, 84–100%) and ruled out in seven (specificity, 78%; 95% confidence interval, 51–100%), with complete agreement. Each detected ten of 11 upper urinary tracts affected by UC. For 35 urinary tract segments with UC and 308 without, the AUC was 0.910 ± 0.035 (R1) and 0.74 ± 0.055 (R2), z = 2.4772, Bonferroni-corrected P = 0.022. MDCT depicts urinary tracts affected by UC with high sensitivity and substantial agreement between readers with different training. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Magnetic resonance urography vs computed tomography urography in the evaluation of patients with haematuria

Purpose

This study was done to evaluate by direct comparison the image quality of magnetic resonance urography (MRU) and computed tomography urography (CTU) and to assess the diagnostic confidence of the two techniques in detecting urothelial malignancy in patients with haematuria

Materials and methods

Thirty-five patients with haematuria underwent both CTU and MRU. Two different investigators evaluated calyceal, renal pelvis, ureteral and bladder visibility. Their diagnostic confidence in detecting urothelial malignancy with the two procedures was assessed. A Wilcoxon matched-pairs test was performed to compare results. Inter-reader agreement was calculated by weighted kappa (WK) statistic. Patient history (further examinations, cystoscopy and histological specimens) was considered as reference standard to calculate receiver operating characteristic (ROC) curves of diagnostic confidence.

Results

CTU provided better visibility of urothelial structures (p<0.01) and allowed for greater diagnostic confidence (ROC area 0.994 vs. 0.938) than MRU, with a good inter-reader agreement (WK=0.62). Nevertheless, in obstructive patients with impaired excretory function, MRU, thanks to the static-fluid technique, offered better visualisation than CTU.

Conclusions

There is a potential role for MRU in urinary tract imaging, but as diagnostic confidence in detecting urothelial malignancy is poorer than in CTU, it might be stareserved for patients at low risk for malignancy and for evaluating obstructed patients.     

Unenhanced helical computed tomography vs intravenous urography in patients with acute flank pain: accuracy and economic impact in a randomized prospective trial

Unenhanced helical computed tomography (UHCT) has evolved into a well-accepted alternative to intravenous urography (IVU) in patients with acute flank pain and suspected ureterolithiasis. The purpose of our randomized prospective study was to analyse the diagnostic accuracy of UHCT vs IVU in the normal clinical setting with special interest on economic impact, applied radiation dose and time savings in patient management. A total of 122 consecutive patients with acute flank pain suggestive of urolithiasis were randomized for UHCT (n=59) or IVU (n=63). Patient management (time, contrast media), costs and radiation dose were analysed. The films were independently interpreted by four radiologists, unaware of previous findings, clinical history and clinical outcome. Alternative diagnoses if present were assessed. Direct costs of UHCT and IVU are nearly identical (310/309 Euro). Indirect costs are much lower for UHCT because it saves examination time and when performed immediately initial abdominal plain film (KUB) and sonography are not necessary. Time delay between access to the emergency room and start of the imaging procedure was 32 h 7 min for UHCT and 36 h 55 min for IVU. The UHCT took an average in-room time of 23 min vs 1 h 21 min for IVU. Mild to moderate adverse reactions for contrast material were seen in 3 (5%) patients. The UHCT was safe, as no contrast material was needed. The mean applied radiation dose was 3.3 mSv for IVU and 6.5 mSv for UHCT. Alternative diagnoses were identified in 4 (7%) UHCT patients and 3 (5%) IVU patients. Sensitivity and specificity of UHCT and IVU was 94.1 and 94.2%, and 85.2 and 90.4%, respectively. In patients with suspected renal colic KUB and US may be the least expensive and most easily accessable modalities; however, if needed and available, UHCT can be considered a better alternative than IVU because it has a higher diagnostic accuracy and a better economic impact since it is more effective, faster, less expensive and less risky than IVU. In addition, it also has the capability of detecting various additional renal and extrarenal pathologies. An erratum to this article is available at .     

Comparison of nephrographic with excretory phase helical computed tomography for detecting and characterizing renal masses.

OBJECTIVE: A retrospective study was performed to compare nephrographic phase (NP) with excretory phase (EP) renal helical computed tomographic (CT) images with respect to detection of renal masses 10 mm or more in diameter, and reviewer confidence in mass characterization. METHODS: Two reviewers evaluated 39 renal helical CT examinations. All masses measuring 10 mm or more in maximal diameter were classified as simple cysts, complex cysts, solid lesions, or indeterminate lesions. Reviewers graded their confidence in the characterization of the masses and decided whether the NP or EP contrast-enhanced images were superior. RESULTS: The 2 reviewers confidently characterized 71 (reviewer 1) and 65 (reviewer 2) of 72 detected masses 10 mm or more in diameter on NP images and 70 (reviewer 1) and 67 (reviewer 2) of 71 detected masses on EP images. There was strong agreement between the 2 sets of images in respect to the characterization of renal masses (kappa = 1.00 and 0.86). Only one mass (a focus of acute pyelonephritis) was not detected by either reviewer on EP images. Collecting system artifact degraded the quality of the EP image in images from only 1 patient. CONCLUSION: Although EP images are often aesthetically inferior to NP images, use of EP images results in a similar rate of detection and confidence in characterization of renal masses measuring 10 mm or more in diameter.     

3D excretory MR urography: improved image quality with intravenous saline and diuretic administration

PURPOSE: To assess the effect of diuretic administration on the image quality of excretory magnetic resonance urography (MRU) obtained following intravenous hydration, and to determine whether intravenous hydration alone is sufficient to produce diagnostic quality studies of nondilated upper tracts. MATERIALS AND METHODS: A total of 22 patients with nondilated upper tracts were evaluated with contrast-enhanced MRU. All patients received 250 mL of saline intravenously immediately prior to the examination. A total of 11 patients received 10-20 mg furosemide in addition to saline. Imaging was performed with a three-dimensional (3D) and two-dimensional (2D) breathhold spoiled gradient-echo sequences. Excretory MRU images were acquired five minutes after the administration of 0.1 mmol/kg gadolinium and were independently reviewed by two radiologists, who were blinded to the MRU technique. Readers evaluated the calyces, renal pelvis, and ureters qualitatively for degree of opacification, distention, and artifacts on a four-point scale. Statistical analysis was performed using a permutation test. RESULTS: There was no significant disagreement between the two readers (P=0.14). Furosemide resulted in significant improvement in calyceal and renal pelvis distention (P<0.005), and significant artifact reduction in all upper tract segments (P<0.001) compared to the effect of saline alone. CONCLUSION: Intravenous furosemide significantly improves the image quality of excretory MRU studies obtained following intravenous hydration. Intravenous saline alone is insufficient to produce diagnostic quality studies of the non-dilated upper tracts.     

MDCT urography: experience with a bi-phasic excretory phase examination protocol

The benefit of multidetector computed tomographic urography (MDCTU) for visualising early and late excretory phase (EP) upper urinary tract (UUT) opacification has been studied. UUT opacification was retrospectively evaluated in 45 bi-phasic four-row MDCTU examinations. The UUT was divided into intrarenal collecting system (IRCS), proximal, middle and distal ureter. Two independent readers rated opacification: 1, none; 2, partial; 3, complete. Numbers of segments and percentages of UUTs at each score were calculated for each EP and two EPs combined. Results of a single EP and of combined EPs were compared by Wilcoxon matched-pairs signed-ranks. IRCS and proximal ureter were at least partially opacified in each EP in >95%. The middle ureter was at least partially opacified in the early and late EP in 85% and 93%, respectively. The distal ureter was opacified in 65% (49/75) in the early EP and in 78% (59/75) in the late EP. Combining two EPs, non-opacified distal segments decreased to 9% (7/75). Significant improvement between a single EP and combining two EPs were found for the middle and distal ureter (P < 0.03). Bi-phasic MDCTU substantially improved opacification of the middle and distal ureter. IRCS and proximal ureter are reliably opacified with one EP.     

Comparison of quality of urinary bladder filling in CT urography with different doses of furosemide in the work-up of patients with macroscopic hematuria

IntroductionThe protocol for preparation of computed tomography urography (CTU) examinations at our hospital was changed in 2013 to improve the quality of urinary bladder filling in the excretory phase. The aim of this study was to evaluate the quality of urinary bladder filling on CTU after different doses of furosemide were administered to patients with macroscopic hematuria.MethodsThe cohort was 215 patients who underwent elective CTU due to macroscopic hematuria between 2014 and 2018. 5 mg furosemide were administrated to 100 patients, 2.5 mg to 100 patients and 0 mg to 15 patients. Contrast medium layered bladders were excluded, leaving 193 patients: 92, 89 and 12 in each group. Urinary bladder volume was calculated in corticomedullary (CMP) and excretory phase (EP). Bladder distension was classified as satisfactory or not. Attenuation of bladder content in EP was noted.ResultsAverage volume in EP was 370 ± 224 ml (28–1052) after 5 mg furosemide, 274 ± 120 ml (43–628) after 2.5 mg and 180 ± 104 ml (53–351) after 0 mg. 85% of the bladders were satisfactory distended after 5 mg, 80% after 2.5 mg and 58% after 0 mg. Average attenuation was 266 ± 89 HU (103–524) after 5 mg, 362 ± 156 HU (118–948) after 2.5 mg and 761 ± 331 HU (347–1206) after 0 mg. The differences in volume and attenuation were significant.Conclusion5 mg furosemide is preferred rather than 2.5 mg in preparation for CTU examinations of patients with macroscopic hematuria. There was no difference between the doses concerning rate of satisfactory bladder distension, but the higher dose resulted in larger bladder volume and more suitable attenuation of bladder content.Implications for practiceDevelopment of CTU-image quality could improve bladder cancer diagnostics.     

Comparison of computed tomographic urography,magnetic resonance urography and the combination of diffusion weighted imaging in diagnosis of upper urinary tract cancer

Purpose

To evaluate the performance of computed tomographic urography (CTU), static-fluid magnetic resonance urography (static-fluid MRU) and combinations of CTU, static-fluid MRU and diffusion weighted imaging (DWI) in the diagnosis of upper urinary tract cancer.

Material and Methods

Between January 2010 and June 2011, patients with suspected UUT cancer underwent CTU, static-fluid MRU and DWI (b = 1000 s/mm ²) within a 1-week period. The diagnostic performances of CTU, static-fluid MRU and combinations of CTU, static-fluid MRU and DWI for upper urinary tract cancer were prospectively evaluated. The ureteroscopic and histopathologic findings were compared with the imaging findings.

Results

Compared to static-fluid MRU alone (sensitivity: 76/75%, reader 1/reader 2), combining DWI with MRI can increase the sensitivity (sensitivity: 84/84%, p = 0.031/p = 0.016) of upper urinary tract cancer diagnosis. CTU had greater sensitivity (95/94%) and accuracy (92/91%) than both static-fluid MRU (sensitivity: p < 0.001/p < 0.001 and accuracy: 83/81%, p = 0.001/p < 0.001) and static-fluid MRU with DWI (sensitivity: p = 0.023/p = 0.039 and accuracy: 87/85%, p = 0.042/p = 0.049) for the diagnosis of upper urinary tract cancers. Compared with CTU alone, CTU with DWI did not significantly increase sensitivity, specificity or accuracy. However, the diagnostic confidence was improved when the combined technique was used (p = 0.031/p = 0.024). Moreover, there was no significant change in sensitivity, specificity, accuracy or diagnostic confidence when static-fluid MRU was used in combination with CTU and DWI.

Conclusion

Although there is a potential role for static-fluid MRU and static-fluid MRU with DWI in urinary tract imaging, CTU is still the better choice for the diagnosis of upper urinary tract cancer. Combining DWI with CTU can help improve confidence in upper urinary tract cancer diagnoses.     

Limited cone-beam computed tomography imaging of the middle ear: a comparison with multislice helical computed tomography

Purpose: To determine the applicability of cone-beam computed tomography (CBCT) in otological imaging, and to compare its accuracy with the routinely used multislice helical CT (MSCT) for imaging of the middle- and inner-ear areas.

Material and Methods: Thirteen unoperated human cadaver temporal bones were imaged with CBCT and MSCT. Sixteen landmarks of the middle and adjacent inner ear were evaluated and compared for their conspicuity according to a modified Likert scale. Total scores and scores for subgroups including landmarks of specific clinical interest were also compared.

Results: No significant differences were found between the imaging techniques or subgroups when scores of individual structures were compared. While the middle ear itself was visible in all cases with CBCT, parts of the inner ear were “cut off” in four cases due to the limited field of view. For the same reason, the evaluation of the whole mastoid was not possible with CBCT. The cochlear and vestibular aqueducts were not visualized in either CT techniques. The contrast-to-noise ratio was more than 50% lower in CBCT than in MSCT, but still adequate for diagnostic task.

Conclusion: CBCT proved to be at least as accurate as routinely used MSCT in revealing the clinically and surgically important middle-ear structures. The results show that high-quality imaging of the middle ear is possible with the current CBCT device.     

Combined magnetic resonance urography and targeted helical CT in patients with renal colic: a new approach to reduce delivered dose

PURPOSE: To determine whether magnetic resonance urography (MRU), obtained before helical computed tomography (CT) in patients with acute renal colic, can help delimit the obstructed area to be subsequently examined by a targeted CT scan, thus reducing the dose of radiation. MATERIALS AND METHODS: Patients (51) with symptoms of acute renal colic underwent MRU and a total urinary tract helical CT. CT images from the 5 cm below the level of ureteral obstruction as demonstrated by MRU were selected out. Combined interpretation of MRU and selected CT images constituted protocol A. Protocol B consisted of the entire unenhanced helical CT of the urinary tract. The two protocols were compared regarding the following points: 1) sensitivity in diagnosing the presence of obstructing urinary stones, and 2) the delivered radiation dose. RESULTS: Protocol A and protocol B had, respectively, 98% and 100% sensitivity in demonstrating ureteral stone as a cause of renal colic. Estimated average dose calculated from phantom study was 0.52 mSv for protocol A and 2.83 mSv for protocol B. Therefore, the effective radiation dose was 5.4 times lower in protocol A compared to protocol B. CONCLUSION: Combined MRU and short helical CT has a high sensitivity in detecting ureteral calculi with a reduced radiation dose.     

Randomized prospective comparison of non-contrast enhanced helical computed tomography and intravenous urography in the diagnosis of acute ureteric colic

Non-contrast enhanced helical CT has become an accepted technique for evaluating acute ureteric colic. The results of a randomized prospective comparison of the accuracy, cost and radiation dose of CT and intravenous urography (IVU) are presented. All patients presenting to the Emergency Department with symptoms and signs suggestive of ureteric colic over a 16-month period (n = 242) were randomized to CT or IVU. Follow up was obtained for 228 patients (94%), with 14 patients (6%) lost to follow up. One hundred and twenty-three patients (54%) underwent CT and 105 (46%) had an IVU. At follow up the sensitivity and specificity of CT were each 100%, while those of IVU were 99% and 100%, respectively. Computed tomography demonstrated seven of 26 (27%) potential alternative diagnoses, whereas IVU suggested one of 23 (4%). Estimates of the average effective dose were calculated for CT (4.95 mSv) and IVU (1.48 mSv, 95% confidence interval (CI) 0.7-2.27). Radiation dose and intravenous contrast material safety are discussed and the relative costs are considered. Computed tomography is as accurate as IVU in the diagnosis of acute ureteric colic. It confers certain major diagnostic benefits, and is a fast, well-tolerated technique. Its accompanying higher effective radiation dose is recognized.     

Evaluation of the vascular pattern of hepatocellular carcinoma with dynamic computed tomography and its use in identifying optimal temporal windows for helical computed tomography

The aim of this work was to study the vascularization of hepatocellular carcinoma (HCC) by means of dynamic CT and to demonstrate the existence of optimal temporal windows for visualization of HCC in order to develop new protocols for helical CT of the liver. We studied, by means of dynamic CT, 42 histologically proved HCCs in 30 patients after injecting contrast medium (100 ml, 3 ml/s). We performed a time–density analysis of the aorta, liver, portal vein, spleen and lesion. We identified three temporal curves of attenuation of the neoplastic tissue. Curve 1 was three-phasic: hyperattenuation, isoattenuation and hypoattenuation; curve 2 was two-phasic: hyperattenuation and isoattenuation; curve 3 was two-phasic: isoattenuation and hypoattenuation. Thirty-two lesions were homogeneous (curve 1 in 22 cases, 68.7 %; curve 2 in 7 cases, 21.8 %; curve 3 in 3 cases, 9.4 %), whereas 10 lesions were non-homogeneous. Two optimal temporal windows were identified: the first, with predominantly hyperattenuating lesions (range 29–65 s, 90.4 % sensitivity); the second, with predominantly hypoattenuating lesions (range 132.1–360 s, 76.1 %). There is an interposed time range of reduced visualization (range 62–127 s, 54.7 %) in which lesions are isoattenuating. Combined CT study during the first and second temporal windows improves the detection of HCCs especially for homogeneous and small lesions. The intermediate isoattenuation time range does not increase lesion detection rate. Received: 22 March 1996; Revision received 3 September 1996; Accepted 21 March 1997     

80kVp条件下低剂量对比剂分次团注双期CTU的应用研究

目的 研究80 kVp联合迭代重建技术的条件下,使用低剂量碘对比剂行分次团注双期CT尿路成像(CTU)检查的可行性.方法 60例血尿待查患者分为2组(80 kVp组、120 kVp组各30例),行全泌尿系平扫及分2次团注对比剂后行肾实质-分泌期CTU扫描.2次团注对比剂的方案为:80 kVp组35 mL和60 mL;120 kVp组50 mL和70 mL.2组CTU重建方法为:80 kVp组自适应统计迭代重建(30％ASiR);120 kVp组滤波反投影(FBP).2名读片者对CTU重建图像进行独立盲法读片,对图像质量进行主观评分,测量图像噪声、集合系统各段CT值,计算对比噪声比(CNR).记录、计算所有病例CTU有效剂量(ED)及体型特异性剂量评估值(SSDE).对2组图像质量主观评分、噪声、CT值、CNR、ED及SSDE使用非参数秩和检验进行比较,以P<0.05为差异有统计学意义.结果 80 kVp组与120 kVp组图像质量主观评分差异无统计学意义(Z=-1.791,P=0.073).80 kVp组图像噪声高于120 kVp组,差异有统计学意义(Z=-6.299,P<0.001).80 kVp组S6段(膀胱)CT值高于120 kVp组(Z=-2.466,P=0.014),余2组CTU各尿路分段CT值差异均无统计学意义(Z=-1.204～-0.163,P=0.228～0.871);2组CTU各尿路分段CNR差异均无统计学意义(Z=-1.818～-0.202,P=0.069～0.840).80 kVp组ED和SSDE低于120 kVp组,差异有统计学意义(Z=-6.655～-6.653,P<0.001).结论 80 kVp联合迭代重建技术的条件下,使用低剂量碘对比剂行分次团注双期CTU检查是可行的,可明显降低辐射剂量,且图像质量满足临床诊断要求.     

Implementation of helical computed tomography in magnetic resonance imaging

PURPOSE: To provide a rapid sequence for volumetric imaging of large fields of view. MATERIALS AND METHODS: The volumetric imaging principles of x-ray helical computed tomograpy (CT) were implemented here on an MRI scanner. However, using the advantages offered by MRI, spiral trajectories in K-space were incorporated to make the helical scan more efficient. Thus, data acquisition and interpolations were conducted in K-space and images reconstructed by gridding and applying the inverse Fourier transform. The rapid spiral helical (RASH) imaging method was evaluated by computer simulations, by scanning phantoms and an in vitro heart, and by comparison to conventional multislice interleaved spirals (MSIS) imaging. RESULTS: A significant time saving (61.4% to 85.9%) relative to MSIS was achieved without significant degradation in image quality. Volume assessment and in-plane resolution by RASH were almost identical to the MSIS pulse sequence. The corresponding increase in effective slice width was estimated to range (for the values studied here) from 1.31 to 2.5 according to the selection of the helical pitch and the slice thickness used for imaging. CONCLUSION: The suggested method offers the advantages provided by x-ray helical CT and can be useful in MRI volumetric scanning of large objects.     

MSCT尿路造影技术的临床应用价值

目的探讨MSCT尿路造影技术的临床应用价值。方法回顾性分析有临床症状并行CT尿路造影的病例50例,通过常规平扫、动脉期、静脉期、延迟期扫描将所获得的数据进行MPR、MIP、CPR及VR三维重建。然后对获得的影像进行分析。结果所有病例均可成功重建出双肾、输尿管和膀胱的三维图像,能够通过旋转、放大等清晰显示全尿路及其局部细微结构、形态、走形及与周围组织的关系。结论通过MSCT对全尿路的适当扫描,对采集的数据进行各种三维重建,能够大大提高病灶检出的阳性率和诊断率。     

A prospective comparative study of non-contrast helical computed tomography and intravenous urogram for the assessment of renal colic

Objective: To compare noncontrast helical computed tomography (NCHCT) and intravenous urography (IVU) for diagnosis of urinary calculi in evaluation of renal colic. Materials and methods: A 4-month prospective paired study compared NCHCT and IVU in patients being evaluated for renal colic. Each patient was studied with NCHCT followed by an IVU. An IVU was regarded as positive if any of the following were identified: delayed filling, hydronephrosis, hydroureter, ureteral calculus, or extravasation of contrast. A NCHCT was regarded as positive if any of the following were identified: hydronephrosis, hydroureter, ureteral calculus, or perinephric or ureteral inflammatory change. The sensitivity (Se), specificity (Sp), positive predictive value (PPV), and negative predictive value (NPV) were reported using the clinical outcome as the gold standard, by either observation of passage or retrieval of calculus. Bladder distention was noted on NCHCT relative to the level of the acetabulum. The charts were also reviewed retrospectively for the results of urinalysis. Results: One hundred sixty-eight patients had both examinations interpreted. Nineteen positive NCHCT and IVU studies were eliminated due to lack of observation or retrieval of calculus, leaving 149 studies for interpretation. NCHCT had Se 0.98, Sp 0.95, PPV 0.98, and NPV 0.95. IVU had Se 0.83, Sp 0.95, PPV 0.97, and NPV 0.67. In 13/168 (8 %) cases, and in 9/37 (24 %) negative cases, NCHCT offered an alternative diagnosis. Ureterovesical junction (UVJ) calculus was identified on 84 NCHCT scans, with near-even distribution between well, partially, and poorly distended bladder. No UVJ calculus was identified on IVU that was not present on NCHCT. Absence of hematuria was found in 26 % of patients with proven urolithiasis. Conclusion: NCHCT is superior to IVU for the evaluation of renal colic. NCHCT identifies significant pathology in 24 % of cases negative for ureteral obstruction/calculus. Bladder distention does not play an important role in detection of UVJ calculus. Hematuria is not universally present in patients with painful urolithiasis.