Multi-detector Row CT Urography Research Articles

Urinary Bladder Neoplastic Masses Findings through Multidetector-Row CT Urography

AbstractBackground: Urinary bladder carcinoma is one of the most common tumors among the lower urinary tract, it is the seventh common malignancy and widely distributed in devel-oped countries.Aim of Study: To elucidate the diagnostic potential and additive imaging data obtained with Multi-Detector Computed Tomography (MDCT) in early detection and characterization of urinary bladder neoplastic masses by comparing the result of the study with the conventional cystoscopy results.Patients and Methods: This prospective descriptive study was conducted on forty patients, 36 was men and 4 women. The patients referred to Radio-Diagnosis Department, Ain Shams University Hospitals, Radio-Diagnosis Department in a period 6 months of data collection for suspicious bladder mass(es) after clinical assessment of patient or for further characterization of indeterminate bladder neoplastic mass lesion previously depicted on other radiological investigation as ultrasound examination.Results: A statistically significant difference was found between positive and negative cystoscopic biopsy results for malignancy in relation to presence CT features of malignancy.Conclusion: MDCT urography is useful for examination of patients especially when the CC is contraindicated such as hemorrhage, perforation, difficult to doing it or unsatisfactory in interpretation, and as a complementary technique in the evaluation of areas difficult to evaluate with CC, especially with the MDCT results satisfactory in finding lesions smaller than 5mm. MDCT urography gives us an opportunity for early detection bladder tumors because its reliability and accuracy and our results support that.

Auto-Initialized Cascaded Level Set (AI-CALS) Segmentation of Bladder Lesions on Multidetector Row CT Urography

To develop a computerized system for segmentation of bladder lesions on computed tomography urography (CTU) scans for detection and characterization of bladder cancer. We have developed an auto-initialized cascaded level set method to perform bladder lesion segmentation. The segmentation performance was evaluated on a preliminary dataset including 28 CTU scans from 28 patients collected retrospectively with institutional review board approval. The bladders were partially filled with intravenous contrast material. The lesions were located fully or partially within the contrast-enhanced area or in the non-contrast-enhanced area of the bladder. An experienced abdominal radiologist marked 28 lesions (14 malignant and 14 benign) with bounding boxes that served as input to the automated segmentation system and assigned a difficulty rating on a scale of 1 to 5 (5 = most subtle) to each lesion. The contours from automated segmentation were compared to three-dimensional contours manually drawn by the radiologist. Three performance metric measures were used for comparison. In addition, the automated segmentation quality was assessed by an expert panel of two experienced radiologists, who provided quality ratings of the contours on a scale from 1 to 10 (10 = excellent). The average volume intersection ratio, the average absolute volume error, and the average distance measure were 67.2 ± 16.9%, 27.3 ± 26.9%, and 2.89 ± 1.69 mm, respectively. Of the 28 segmentations, 18 were given quality ratings of 8 or above. The average rating was 7.9 ± 1.5. The average quality ratings for lesions with difficulty ratings of 1, 2, 3, and 4 were 8.8 ± 0.9, 7.9 ± 1.8, 7.4 ± 0.9, and 6.6 ± 1.5, respectively. Our preliminary study demonstrates the feasibility of using the three-dimensional level set method for segmenting bladder lesions in CTU scans.

Clinical Significance of Bladder Urothelial Thickening and Enhancement Revealed on MDCT Urography After Transurethral Resection of Tumor

To assess multidetector-row computed tomographic (MDCT) urography for detection of recurrence of bladder tumor after transurethral resection (TUR), and to assess significance of the MDCT findings like urothelial enhancement or thickening as a recurrence. A total of 216 MDCT urography examinations were performed for 100 patients undergoing follow-up after TURs were reviewed by 2 radiologists, according to MDCT findings (urothelial enhancement or thickening) and location (TUR site or distant sites of transitional cell carcinoma). Multidetector-row CT urography was confirmed by cystoscopy and urine cytologic examination. Analyses of per-MDCT urography and per-lesion basis were performed, assessing receiver operating characteristic analysis for combining excretory phases to noncontrast and portal venous phases. Fifty-two MDCT findings were positive, and 164 MDCT findings were negative. Of the 52 positive MDCT urography, 19 were true positive 33 were false positive. Of the 60 separate lesions, 25 lesions were true positive. Both urothelial enhancement and thickening were revealed in 19 lesions, urothelial enhancement in 4 lesions, and urothelial thickenings in 2 lesions. Nineteen lesions were revealed in TUR site, and 6 lesions were revealed in distant site of transitional cell carcinoma. For MDCT urography combining excretory phases to noncontrast and portal venous phases, a substantial agreement between radiologists was revealed (area under the curve; 0.910 ± 0.035, 0.749 ± 0.055; 8.3%; kappa score of 0.65). Multidetector-row CT urography has efficacy in detecting recurrence of bladder tumor in patients undergoing follow-up after TUR.

Utility of CT Scan in Detection of Melamine - Associated Urinary Stones

To detail the utility of CT scan in detection of urinary stones induced by melamine tainted formula. A total of 1062 children fed with melamine-contaminated infant formula were screened for urinary stones in our institute from September through December 2008. Ultrasonography of the urinary tract system was performed in all these children. If the children with suspected stones or severe obstruction were presented after ultrasound examination, the multi-detector row CT urographic examination was advocated subsequently. Ultrasound examination in combination with multi-detector row CT urography could increase the diagnostic rate from 3.4% (36/1062) by ultrasound examination alone to 4.6% (49/1062). The specificity and sensitivity of the multi-detector row CT urographic examination is higher than ultrasonography.

Tumor Characteristics of Urothelial Carcinoma on Multidetector Computerized Tomography Urography

We investigated the relationship between tumor characteristics of urothelial carcinoma and detectability on multidetector computerized tomography urography. We retrospectively reviewed all adult consecutive patients with hematuria who underwent multidetector computerized tomography urography during a 23-month period at our hospital. Patients with a final diagnosis of urothelial carcinoma verified by histological examination of surgical specimens were included in the study. The presence and location of urothelial carcinomas on multidetector computerized tomography urography without knowledge of final diagnosis were recorded. Tumor characteristics (location, size, histological classification and stage) were recorded based mainly on histological findings. The association between tumor characteristics and urothelial carcinoma detectability on multidetector computerized tomography urography was analyzed. A total of 70 patients who underwent multidetector computerized tomography urography had 87 verified urothelial carcinomas. Of these carcinomas 6 (6.9%) were undetectable by multidetector computerized tomography urography, including 5 ureteral and 1 bladder urothelial carcinoma. Size of detectable and nondetectable tumors on multidetector computerized tomography urography differed significantly (3.05 +/- 1.79 vs 0.65 +/- 0.99 cm, respectively, p = 0.001). Tumor location (p = 0.009), tumor size 1 cm or larger (p = 0.003) and noncarcinoma in situ tumors (p = 0.001) were significantly associated with multidetector computerized tomography urography detectability. Conversely organ confined disease had no association with multidetector computerized tomography urography detectability. Multivariate analyses showed that noncarcinoma in situ tumor was a significant predictor of multidetector computerized tomography urography detectability (p = 0.001). Multidetector computerized tomography urography is useful for detecting nearly all urothelial carcinomas in adults with hematuria. Careful assessment by multidetector computerized tomography urography is needed to detect small (less than 1 cm) or ureteral urothelial carcinomas. It remains a challenge to detect carcinoma in situ tumors by multidetector computerized tomography urography. Thus, negative results of urothelial carcinomas on multidetector computerized tomography urography do not exclude the presence of carcinoma in situ tumors.

Accuracy and intermediate dose of furosemide injection to improve multidetector row CT urography

Objective: Evaluate the usefulness of intermediate dose furosemide to improve visualization of the intrarenal collecting system and ureter using multidetector row computed tomography urography (MDCTU).

Genitourinary Imaging With Noncontrast Computerized Tomography—Are We Missing Duplex Ureters?

Noncontrast computerized tomography has replaced excretory urography as the first line diagnostic tool for evaluating nephrolithiasis at many centers. We evaluated the ability of noncontrast computerized tomography to detect ureteral duplication to determine how frequently these anomalies are under diagnosed. Computerized tomography images of 14 patients with known ureteral duplication who had previously undergone noncontrast and contrast enhanced computerized tomography and 5 control patients with normal ureteral anatomy were interpreted by 2 blinded radiologists who specialize in genitourinary imaging. The sensitivity of axial computerized tomography with contrast material, axial computerized tomography without contrast material and coronal computerized tomography without contrast material was 96%, 59% and 65%, respectively. The negative predictive value of axial computerized tomography with contrast material, axial computerized tomography without contrast material and coronal computerized tomography without contrast material was 95%, 65% and 67%, respectively. The accuracy of axial computerized tomography with contrast medium was significantly higher than that of noncontrast axial or noncontrast coronal computerized tomography (each p <0.01). Duplicated ureters, which represent a challenge to the endourologist, are under diagnosed on noncontrast computerized tomography. Urologists and radiologists should be aware of this limitation and contrast studies should be done when anatomical anomalies are suspected.

Accuracy of intermediate dose of furosemide injection to improve multidetector row CT urography

Objective Evaluate the usefulness of intermediate dose furosemide to improve visualization of the intrarenal collecting system and ureter using MDCTU. Materials and methods Two groups of 100 patients without urinary tract disease or major abdominal pathology underwent MDCTU. Group I (various abdominal indications) was performed without any additional preparation and Group II (suspicion of urinary tract disease) 10 min after injection of furosemide (20 mg). MIP images of the excretory phase were post-processed. Maximal short-axis diameter of the pelvis and ureter were measured on axial images for all phases. Visualization of the collecting system wall and the identification of the whole ureter were assessed. Results Mean pelvic diameter before contrast was (7.4 mm, S.D. ± 2.7; 13.4 mm, S.D. ± 4.1), on cortico-medullary phase (8.4 mm, S.D. ± 4.2; 14.3 mm, S.D. ± 4), on nephrographic phase (8.1 mm, S.D. ± 2.5; 14.8 mm, S.D. ± 4) and on excretory phase (9.7 mm, S.D. ± 3.4; 14.9 mm, S.D. ± 4.5), respectively, for Groups I and II. Intrarenal collecting system wall was clearly identified on both corticomedullary and nephrographic phases in 91% of Group II against 20% of Group I. Opacification of the entire ureter was excellent on excretory phase in 96% of Group II against 13% of Group I. The difference between the mean values for the two groups was statistically significant for all phases ( p < 10 −9). Conclusion Intermediate-dose furosemide (20 mg) before MDCTU is a very simple add-on for accurate depiction of pelvicalyceal details and collecting system wall without artefacts. The procedure is associated with a constant and complete visualisation of the entire urete.

Multi–Detector Row CT Urography of Normal Urinary Collecting System: Furosemide versus Saline as Adjunct to Contrast Medium

Multi–Detector Row CT Urography of Normal Urinary Collecting System: Furosemide versus Saline as Adjunct to Contrast Medium

Multi-Detector row CT urography on a 16-row CT scanner in the evaluation of urothelial tumors

The purpose of this study was to assess the role of multi-detector row CT urography (MDCTU), on a 16-row CT scanner in the evaluation of patients with painless hematuria, with emphasis placed in the detection of urothelial tumors. We retrospectively reviewed the MDCT urographies of 75 patients, referred for painless hematuria. The CT protocol included unenhanced images, obtained with a detector configuration of 16x1.5 mm and pitch of 1.2, nephrographic and excretory-phase images, obtained with a detector collimation of 16x0.75 mm and pitch of 1.2. Axial and coronal reformatted images were evaluated. Three-dimensional reformation of the excretory-phase images was performed using the volume-rendering technique. The standard of reference included clinical and imaging follow-up, cystoscopic, surgical and histologic findings. In 55 (73%) of 75 patients, the cause of hematuria was identified on MDCTU; the most common cause was urothelial cancer, including seven tumors with a diameter equal or smaller than 0.5 cm in diameter. Sixteen-row MDCTU provided satisfactory results in the investigation of patients with painless hematuria. The main advantage of the technique is its ability to detect uroepithelial malignancies.

Comparison of CT Urography and Intravenous Urography in Patients with Hematuria

Purpose: We wanted to compare CT urography (CTU) with using multi-detector row CT (MDCT) and intravenous urography (IVU) for diagnosing the causes of hematuria. Materials and Methods: From January 2003 to March 2004, IVU and CTU were obtained in 48 patients. We evaluated the causes of hematuria in 34 of 48 patients. The IVU images were obtained by the conventional method. The CTU images were routinely obtained before intravenous contrast injection, and at 2 and 5 minutes after intravenous contrast injection. In case of delayed excretion of contrast by the kidneys, the delayed CT scans were obtained at 120 minutes after contrast injection. All the CT images, including the axial and 3D coronal reformatted CTUs with using software as well as conventional IVU images, were reviewed by two radiologists working in consensus. We decided if urinary stone existed or not and we looked for the indirect signs such as hydronephrosis or delayed excretion, etc. We also observed if it was possible to determine the mass, ureteral stricture and enhancement of the ureteral wall, etc. We calculated sensitivity, specificity, positive predictive value and negative predictive value for each modality to diagnose urinary stone. We compared the detection rate according to the phases of CTU. Results: We confirmed the presence of urinary tract stones in 27 of 34 patients who had undergone both IVU and CTU. We diagnosed ureteritis in 1, transitional cell carcinoma in 5 and acute pyelonephritis in 1 of the remaining 7 patients. The urinary stones were detected in fifteen patients on both IVU and CTU (15/27, 55.6%). We detected the urinary stones on CTU, but not IVU, in twelve patients (12/27, 44.5%). The sensitivity to detect the urinary stones was 100% (27/27) on CTU and 55.6% (12/27) on IVU respectively. The specificity was 100% (7/7) on IVU and CTU, respectively. The positive predictive value was 100% (15/15) on IVU and 100% (27/27) on CTU, respectively. The negative predictive value was 36.8% (7/19) on IVU and 100% (7/7) on CTU. Precontrast CTU demonstrated the urinary stones in all 27 patients (100%, 27/27). On the other hands, urinary stones were detected in 19 patients (19/27, 70.4%) and 8 patients (8/27, 29.6%) at 2 and 5 minutes on CTU, respectively. Conclusion: CTU is superior to IVU to diagnose the causes of hematuria such as urinary tract stone or extrarenal lesion. Precontrast CTU is the most useful modality for the detection of the urinary tract stone of the other enhanced CTUs.

Multidetector-row CT urography in clinical practice

Multidetector-row CT urography in clinical practice