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2012 DUAL-ENERGY VERSUS CONVENTIONAL COMPUTED TOMOGRAPHY IN DETERMINING STONE COMPOSITION
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THE JOURNAL OF UROLOGY姞
of 5-15cm. If the stone was place in the proximal ureter additional scanning was done until the stone was seen. The demographic data, stone localization, the rate of spontenous stone passage, the length of scanning, the estimated radiation doses in mSv units were analyzed. RESULTS: The mean patient age was 41.5(23-68) The mean stone size was 5.5mm. Sixteen patients had lower ureteral stone, 1 patient had mid-ureteral stone and 3 patients had upper ureteral stone. Spontenous passage was seen in 10 patients and 10 ureterorenoscopies were performed for the removal of the stone. Mean radiation exposure in the first and the control CT’s were 7.46 (4.11-10.26) ve 1.15 (070-2.73) mSv respectively. Mean length of scanning in the control CT was 115mm. Overall, there was a %84 reduction in radiation exposure. (Graphic 1) In patients who didn’t have spontenous passage, all stones were detected with the low dose protocol. CONCLUSIONS: The low dose protocol utilizing multi-detector flash CT is an efficient method and decreases radiation exposure for the follow-up of ureteral stone disease.
Vol. 189, No. 4S, Supplement, Wednesday, May 8, 2013
5 and 7 mm stones (p ⫽ 0.01). False negatives for 3 mm stones occured 0.5%, 0.5%, 1.1%, 1.1%, 4.4%, 3.8%, 5.5% at 140, 70, 50, 30, 15, 7.5, and 5 mAs. CONCLUSIONS: Both low and conventional-dose CT scans demonstrate excellent sensitivity and specificity for the detection of uric acid ureteral stones. Detection of 3 mm uric acid stones is compromised at extremely low-dose (⬍ 30 mAs) settings. To maximize uric acid stone detection sensitivity and specificity, a low-dose 30 mAs protocol should be utilized. Uric acid stone detection appears to be decreased compared to the more dense calcium oxalate stones particularly with smaller stone sizes. mAs 5 7.5
Sensitivity 0.7
Significance ⬍0.01
Specificity 0.94
Significance 0.89
0.83
0.01
0.91
0.93
15
0.83
0.01
0.88
0.60
30
0.93
0.47
0.89
0.75
50
0.96
0.91
0.91
0.93
70
0.97
0.63
0.92
0.76
140 0.97 Reference 0.92 Reference Sensitivity and specificity of uric acid stone detection at varying low dose and conventional dose computed tomography with significance of difference in comparison to reference conventional dose.
Source of Funding: None
2012 DUAL-ENERGY VERSUS CONVENTIONAL COMPUTED TOMOGRAPHY IN DETERMINING STONE COMPOSITION Eric Wisenbaugh*, Robert Paden, Alvin Silva, Mitchell Humphreys, Phoenix, AZ Source of Funding: None
2011 DETECTION OF URIC ACID STONES USING LOW AND CONVENTIONAL-DOSE COMPUTED TOMOGRAPHY Caroline Wallner*, Gene Huang, Steven Engebretsen, David Culpepper, Christopher Chung, Andrew Mai, Caleb Ng, Jonathan Creech, Gaudencio Olgin, Jason Smith, D. Duane Baldwin, Loma Linda, CA INTRODUCTION AND OBJECTIVES: Non-contrast computed tomography (CT) is the gold standard for evaluating urinary calculi, but exposes the patient to significant radiation exposure. Although lowdose CT protocols have been shown to have excellent detection for dense calcium oxalate ureteral stones, the ability of low-dose CT to diagnose less dense uric acid stones has not been well characterized. The purpose of this study is to determine the sensitivity and specificity of low-dose CT for detection of uric acid ureteral stones. METHODS: Twenty-seven, 3-7 mm uric acid stones were obtained from a reference laboratory and prospectively placed into 14 ureters arranged in 50 random configurations (523 total scanned stones). The intact urinary tracts were placed into a male cadaver (BMI 27.1 kg/m2) and CT imaging was performed at conventional dose 140 milliampere-second (mAs) and low dose 70, 50, 30, 15, 7.5, and 5 mAs settings, while holding all other imaging parameters constant. CT images were reviewed in a blinded fashion by a single radiologist and stone detection was reported. Sensitivity and specificity were compared between different settings. RESULTS: Overall sensitivity and specificity were 89 and 91%, respectively. Imaging using 140, 70, 50, 30, 15, 7.5, and 5 mAs settings resulted in 97%, 97%, 96%, 93%, 83%, 83% and 70% sensitivity, and 92%, 92%, 91%, 89%, 88%, 91% and 94% specificity, respectively. False negatives were more frequent among 3 mm stones compared to
INTRODUCTION AND OBJECTIVES: The successful treatment of urolithiasis can be largely dependent on stone composition, yet there is no reliable method of composition determination with conventional imaging. While uric acid stones can be differentiated from calcium stones on the basis of Hounsfield-Units (HU), accurately differentiating other subtypes remains elusive. Dual-energy computed tomography (DECT) is a promising imaging modality that has the potential to improve our current ability to determine different stone phenotypes and compositions. Our goal was to compare the accuracy between conventional single-energy and dual-energy CT in predicting stone composition. METHODS: A total of 32 renal stones with known composition were placed in a phantom water bath and scanned using fast-switched kV DECT at 80 and 140kV (GE Discovery 750 HD, Milwaukee, WI. Images were viewed on a processing workstation capable of displaying pixel values for monochromatic images from 40 to 140 KeV. Stones were composed of uric acid, cystine, struvite, and calcium oxalate. A region of interest (ROI) was encircled on each stone and a spectral curve was created demonstrating the change of HU across the KeV spectrum. Sample curves were compared to curves of known materials from the National Institute of Standards and Technology to determine the best fit for each stone. Composition using single-energy CT was determined by measuring the HU for a ROI at 120KeV and comparing them to known HU values attained from the literature. RESULTS: Included were 29 stones large enough to allow a ROI that fit completely within the stone. Of these, single-energy measurements accurately identified 12 of 29 stones of all composition (44%), while the DECT spectral curves correctly identified 20 (74%). When analyzed by stone type, single-energy vs. DECT correctly identified 12 vs. 12 of the twelve uric acid stones, 0 vs. 3 of the six struvite stones, 0 vs. 3 of the five cystine stones and 0 vs. 2 of the four calcium oxalate stones, respectively. When classified simply as uric acid vs. non-uric acid stones, single-energy CT could accurately differentiate only 3 of 15 non-uric acid stones (20%), compared to 14 of 15 (93%) for DECT. CONCLUSIONS: Dual-energy CT appears to be superior to conventional CT in differentiating stone composition, and is particularly
Vol. 189, No. 4S, Supplement, Wednesday, May 8, 2013
accurate in detecting uric acid vs. non-uric acid stones. This may serve as an important adjuvant modality that could guide important treatment decisions for kidney stone patients. Source of Funding: None
2013 CT UROGRAPHY FOR HAEMATURIA: INCIDENTAL DETECTION OF EXTRAURINARY TUMOURS Abdullah Zreik*, Ishita Basu, Suzanne Langley, Raj Nigam, Guildford, United Kingdom INTRODUCTION AND OBJECTIVES: Ultrasound of the renal tract is commonly used as a first line imaging investigation for patients with haematuria. With the development of rapid multi-slice Computed Tomography (CT), this modality is now replacing ultrasound in several centres as the initial investigation of haematuria. One argument for CT as a sole primary radiological investigation is that it allows for the incidental diagnosis of clinically significant non urological pathology and malignancies. The purpose of this study was to describe the incidence and types of non-urological tumours found on CT imaging in a prospective cohort of patients attending the haematuria clinic. METHODS: A new protocol for investigating haematuria was implemented at our institution in 2009 with the aim of reducing referral to treatment time. The new Haematuria Pathway replaced intravenous urography and ultrasound with a multi-slice CT urogram on the same day as a flexible cystoscopy in a one-stop service. The results of CT imaging were recorded prospectively and all suspicious tumours, urological and non-urological, were noted. The non-urological tumours confirmed histopathologically were recorded and categorised as: gynaecological, colorectal, hepatopancreatobiliary, adrenal and lower respiratory. RESULTS: 1608 patients with a median age of 66 years (range 27 to 89) were investigated for haematuria from January 2009 to September 2012. Male to female patient ratio was 2:1. 31% of patients had microscopic and 69% macroscopic haematuria. 346 patients (21.5%) were identified with urological tumours. 4.7% were found to have upper tract tumours and 16.8% had bladder tumours. 46 patients (2.9%) were found to have non-urological tumours: gynaecological (0.7%), colorectal (1.3%), hepatopancreatobiliary (0.4%), adrenal (0.3%) and respiratory (0.2%). CONCLUSIONS: The incidence of non-urological tumours found on CT imaging to investigate haematuria was 2.9%. This rate is higher than previously reported. Although there are other advantages for the use of CT as the primary imaging modality for haematuria, this large prospective study reports a relatively limited use as an indirect screener for non-urological malignancies. Source of Funding: None
2014 CAN CT (COMPUTED TOMOGRAPHY) VIRTUAL CYSTOSCOPY WITH INTRA VESICAL DILUTE CONTRAST MEDIA REPLACE SURVEILLANCE CYSTOSCOPY? Uttam Mete*, abizer kapadia, anupam lal, niranjan khandelwal, Nandita Kakkar, Arupkumar Mandal, Chandigarh, India INTRODUCTION AND OBJECTIVES: To determine the value of Computed tomography (CT) Virtual Cystoscopy by intravesical instillation of dilute contrast medium, for the detection of bladder tumour in patients undergoing conventional cystoscopy for Transitional Cell Carcinoma (TCC) of the Urinary Bladder. METHODS: In this prospective study a total of twenty (20) patients, comprising of 18 males and two females, with carcinoma of the urinary bladder were enrolled. After performing non-enhanced scan, 250 to 300 ml of dilute contrast(10 ml of 76% urogaffin contrast in 500 ml of normal saline, 2% solution) was instilled into the bladder. Helical volume scanning of the contrast medium filled baldder was done in both supine and prone positions. Three-dimensional images
THE JOURNAL OF UROLOGY姞
e827
were reconstructed with visualization gray scale software to study the axial images. Data was downloaded into a work station equipped with navigation software. Bladder mucosal surface was delineated using contrast medium and by adjusting the threshold HU manually using standard visualization software. The lumen was displayed without any pixel defects by optimizing the threshold at 300 to 450 HU based on smoothing pixel defects visually. The number, size, location and morphological features of the lesions were noted on transverse and virtual images. Each lesion was characterized as polypoidal, sessile, focal septae or irregular wall thickening. Data acquired by virtual CT Cystoscopy and conventional cystoscopy were compared. RESULTS: The conventional cystoscopy had detected 17 lesions in 14 patients (70 %). CT virtual cystoscopy detected fifteen lesions in 12patients (60%) and fifteen out of 17 lesions (88.24%). Seven lesions (58.3 %) were papillary and 5 (41.6 %) were sessile. (25 %) patients had multiple lesion and (75 %) had a single lesion. The mean lesion size was 2.8 cm. ( smallest 0.9 cm & largest 5.5cm). Two lesion with ⬍1cm. were missed. The probable reason of not achieving 100 % sensitivity was the lesion size. The specificity, positive predictive value, negative predictive value and accuracy of CT cystoscopy were 100%, 100%, 75% & 90% respectively. CONCLUSIONS: Detection rate of bladder lesion with vitual CT cystoscopy approaches conventional cystoscopy . It obviates operation theatre visit, physical & psychological trauma and might detect enlarged pelvic lymph nodes. In situations where conventional cystoscopy cannot be applied CT virtual cystoscopy can be of clinical benefit. CT machine with proper approved software for navigation and an experienced radiologist are the prerequisite for CT cystoscopy. Source of Funding: None
2015 REPEAT IMAGING IS UNNECESSARY WHEN URETERS ARE INCOMPLETELY OPACIFIED ON COMPUTED TOMOGRAPHY UROGRAPHY Jason Woo*, Lejla Aganovic, Fiona Cassidy-Hughes, Christian Welch, A. Karim Kader, San Diego, CA INTRODUCTION AND OBJECTIVES: Computed tomography urography (CTU) has become the preferred imaging modality for hematuria evaluation and for surveillance of the upper urinary tract for urothelial malignancies. Ureteral segments are frequently nonopacified because of ureteral peristalsis, anatomical variations, and differences in contrast excretion. Incompletely evaluated ureters are concerning for missed urothelial malignancies. There are no reports of the clinical significance of nonopacified ureteral segments nor recommendations about how to deal with this increasingly common clinical scenario. We investigate the clinical significance of incompletely opacified ureters on CTU and whether repeat imaging offers increased diagnostic yield. METHODS: 1000 consecutive CTUs performed at the San Diego VA hospital from 2006 to 2010 were reviewed. If a nonopacified segment was seen, a repeat scan through that ureteral segment was performed during the same CT study. All CTUs were reviewed by two attending radiologists. Presence of mass, hydroureter or ureteral wall thickening was recorded. Follow up urinary tract imaging and urologic evaluations were reviewed for development of new upper tract malignancies. RESULTS: The primary indications were gross hematuria, microscopic hematuria or upper tract evaluation in patients with known urothelial malignancies. 536 of 1000 (53.6%) CTUs had at least one nonopacified segment of ureter after initial scan. 231 patients (23.1%) had complete opacification after repeat scan. 305 (30.5%) had at least one segment that was never completely opacified. On repeat scans, there were no cases of newly discovered ureteral tumors in a previously nonopacified segment of ureter. In the nonopacified group, all cases of pathologically confirmed ureteral tumors (15/15) had associated findings of hydroureter, ureteral wall thickening or an obvious mass. No patients with nonopacified ureteral segments and otherwise normal CTU developed upper tract malignancies in the 2-6 year period of follow up.
THE JOURNAL OF UROLOGY姞
of 5-15cm. If the stone was place in the proximal ureter additional scanning was done until the stone was seen. The demographic data, stone localization, the rate of spontenous stone passage, the length of scanning, the estimated radiation doses in mSv units were analyzed. RESULTS: The mean patient age was 41.5(23-68) The mean stone size was 5.5mm. Sixteen patients had lower ureteral stone, 1 patient had mid-ureteral stone and 3 patients had upper ureteral stone. Spontenous passage was seen in 10 patients and 10 ureterorenoscopies were performed for the removal of the stone. Mean radiation exposure in the first and the control CT’s were 7.46 (4.11-10.26) ve 1.15 (070-2.73) mSv respectively. Mean length of scanning in the control CT was 115mm. Overall, there was a %84 reduction in radiation exposure. (Graphic 1) In patients who didn’t have spontenous passage, all stones were detected with the low dose protocol. CONCLUSIONS: The low dose protocol utilizing multi-detector flash CT is an efficient method and decreases radiation exposure for the follow-up of ureteral stone disease.
Vol. 189, No. 4S, Supplement, Wednesday, May 8, 2013
5 and 7 mm stones (p ⫽ 0.01). False negatives for 3 mm stones occured 0.5%, 0.5%, 1.1%, 1.1%, 4.4%, 3.8%, 5.5% at 140, 70, 50, 30, 15, 7.5, and 5 mAs. CONCLUSIONS: Both low and conventional-dose CT scans demonstrate excellent sensitivity and specificity for the detection of uric acid ureteral stones. Detection of 3 mm uric acid stones is compromised at extremely low-dose (⬍ 30 mAs) settings. To maximize uric acid stone detection sensitivity and specificity, a low-dose 30 mAs protocol should be utilized. Uric acid stone detection appears to be decreased compared to the more dense calcium oxalate stones particularly with smaller stone sizes. mAs 5 7.5
Sensitivity 0.7
Significance ⬍0.01
Specificity 0.94
Significance 0.89
0.83
0.01
0.91
0.93
15
0.83
0.01
0.88
0.60
30
0.93
0.47
0.89
0.75
50
0.96
0.91
0.91
0.93
70
0.97
0.63
0.92
0.76
140 0.97 Reference 0.92 Reference Sensitivity and specificity of uric acid stone detection at varying low dose and conventional dose computed tomography with significance of difference in comparison to reference conventional dose.
Source of Funding: None
2012 DUAL-ENERGY VERSUS CONVENTIONAL COMPUTED TOMOGRAPHY IN DETERMINING STONE COMPOSITION Eric Wisenbaugh*, Robert Paden, Alvin Silva, Mitchell Humphreys, Phoenix, AZ Source of Funding: None
2011 DETECTION OF URIC ACID STONES USING LOW AND CONVENTIONAL-DOSE COMPUTED TOMOGRAPHY Caroline Wallner*, Gene Huang, Steven Engebretsen, David Culpepper, Christopher Chung, Andrew Mai, Caleb Ng, Jonathan Creech, Gaudencio Olgin, Jason Smith, D. Duane Baldwin, Loma Linda, CA INTRODUCTION AND OBJECTIVES: Non-contrast computed tomography (CT) is the gold standard for evaluating urinary calculi, but exposes the patient to significant radiation exposure. Although lowdose CT protocols have been shown to have excellent detection for dense calcium oxalate ureteral stones, the ability of low-dose CT to diagnose less dense uric acid stones has not been well characterized. The purpose of this study is to determine the sensitivity and specificity of low-dose CT for detection of uric acid ureteral stones. METHODS: Twenty-seven, 3-7 mm uric acid stones were obtained from a reference laboratory and prospectively placed into 14 ureters arranged in 50 random configurations (523 total scanned stones). The intact urinary tracts were placed into a male cadaver (BMI 27.1 kg/m2) and CT imaging was performed at conventional dose 140 milliampere-second (mAs) and low dose 70, 50, 30, 15, 7.5, and 5 mAs settings, while holding all other imaging parameters constant. CT images were reviewed in a blinded fashion by a single radiologist and stone detection was reported. Sensitivity and specificity were compared between different settings. RESULTS: Overall sensitivity and specificity were 89 and 91%, respectively. Imaging using 140, 70, 50, 30, 15, 7.5, and 5 mAs settings resulted in 97%, 97%, 96%, 93%, 83%, 83% and 70% sensitivity, and 92%, 92%, 91%, 89%, 88%, 91% and 94% specificity, respectively. False negatives were more frequent among 3 mm stones compared to
INTRODUCTION AND OBJECTIVES: The successful treatment of urolithiasis can be largely dependent on stone composition, yet there is no reliable method of composition determination with conventional imaging. While uric acid stones can be differentiated from calcium stones on the basis of Hounsfield-Units (HU), accurately differentiating other subtypes remains elusive. Dual-energy computed tomography (DECT) is a promising imaging modality that has the potential to improve our current ability to determine different stone phenotypes and compositions. Our goal was to compare the accuracy between conventional single-energy and dual-energy CT in predicting stone composition. METHODS: A total of 32 renal stones with known composition were placed in a phantom water bath and scanned using fast-switched kV DECT at 80 and 140kV (GE Discovery 750 HD, Milwaukee, WI. Images were viewed on a processing workstation capable of displaying pixel values for monochromatic images from 40 to 140 KeV. Stones were composed of uric acid, cystine, struvite, and calcium oxalate. A region of interest (ROI) was encircled on each stone and a spectral curve was created demonstrating the change of HU across the KeV spectrum. Sample curves were compared to curves of known materials from the National Institute of Standards and Technology to determine the best fit for each stone. Composition using single-energy CT was determined by measuring the HU for a ROI at 120KeV and comparing them to known HU values attained from the literature. RESULTS: Included were 29 stones large enough to allow a ROI that fit completely within the stone. Of these, single-energy measurements accurately identified 12 of 29 stones of all composition (44%), while the DECT spectral curves correctly identified 20 (74%). When analyzed by stone type, single-energy vs. DECT correctly identified 12 vs. 12 of the twelve uric acid stones, 0 vs. 3 of the six struvite stones, 0 vs. 3 of the five cystine stones and 0 vs. 2 of the four calcium oxalate stones, respectively. When classified simply as uric acid vs. non-uric acid stones, single-energy CT could accurately differentiate only 3 of 15 non-uric acid stones (20%), compared to 14 of 15 (93%) for DECT. CONCLUSIONS: Dual-energy CT appears to be superior to conventional CT in differentiating stone composition, and is particularly
Vol. 189, No. 4S, Supplement, Wednesday, May 8, 2013
accurate in detecting uric acid vs. non-uric acid stones. This may serve as an important adjuvant modality that could guide important treatment decisions for kidney stone patients. Source of Funding: None
2013 CT UROGRAPHY FOR HAEMATURIA: INCIDENTAL DETECTION OF EXTRAURINARY TUMOURS Abdullah Zreik*, Ishita Basu, Suzanne Langley, Raj Nigam, Guildford, United Kingdom INTRODUCTION AND OBJECTIVES: Ultrasound of the renal tract is commonly used as a first line imaging investigation for patients with haematuria. With the development of rapid multi-slice Computed Tomography (CT), this modality is now replacing ultrasound in several centres as the initial investigation of haematuria. One argument for CT as a sole primary radiological investigation is that it allows for the incidental diagnosis of clinically significant non urological pathology and malignancies. The purpose of this study was to describe the incidence and types of non-urological tumours found on CT imaging in a prospective cohort of patients attending the haematuria clinic. METHODS: A new protocol for investigating haematuria was implemented at our institution in 2009 with the aim of reducing referral to treatment time. The new Haematuria Pathway replaced intravenous urography and ultrasound with a multi-slice CT urogram on the same day as a flexible cystoscopy in a one-stop service. The results of CT imaging were recorded prospectively and all suspicious tumours, urological and non-urological, were noted. The non-urological tumours confirmed histopathologically were recorded and categorised as: gynaecological, colorectal, hepatopancreatobiliary, adrenal and lower respiratory. RESULTS: 1608 patients with a median age of 66 years (range 27 to 89) were investigated for haematuria from January 2009 to September 2012. Male to female patient ratio was 2:1. 31% of patients had microscopic and 69% macroscopic haematuria. 346 patients (21.5%) were identified with urological tumours. 4.7% were found to have upper tract tumours and 16.8% had bladder tumours. 46 patients (2.9%) were found to have non-urological tumours: gynaecological (0.7%), colorectal (1.3%), hepatopancreatobiliary (0.4%), adrenal (0.3%) and respiratory (0.2%). CONCLUSIONS: The incidence of non-urological tumours found on CT imaging to investigate haematuria was 2.9%. This rate is higher than previously reported. Although there are other advantages for the use of CT as the primary imaging modality for haematuria, this large prospective study reports a relatively limited use as an indirect screener for non-urological malignancies. Source of Funding: None
2014 CAN CT (COMPUTED TOMOGRAPHY) VIRTUAL CYSTOSCOPY WITH INTRA VESICAL DILUTE CONTRAST MEDIA REPLACE SURVEILLANCE CYSTOSCOPY? Uttam Mete*, abizer kapadia, anupam lal, niranjan khandelwal, Nandita Kakkar, Arupkumar Mandal, Chandigarh, India INTRODUCTION AND OBJECTIVES: To determine the value of Computed tomography (CT) Virtual Cystoscopy by intravesical instillation of dilute contrast medium, for the detection of bladder tumour in patients undergoing conventional cystoscopy for Transitional Cell Carcinoma (TCC) of the Urinary Bladder. METHODS: In this prospective study a total of twenty (20) patients, comprising of 18 males and two females, with carcinoma of the urinary bladder were enrolled. After performing non-enhanced scan, 250 to 300 ml of dilute contrast(10 ml of 76% urogaffin contrast in 500 ml of normal saline, 2% solution) was instilled into the bladder. Helical volume scanning of the contrast medium filled baldder was done in both supine and prone positions. Three-dimensional images
THE JOURNAL OF UROLOGY姞
e827
were reconstructed with visualization gray scale software to study the axial images. Data was downloaded into a work station equipped with navigation software. Bladder mucosal surface was delineated using contrast medium and by adjusting the threshold HU manually using standard visualization software. The lumen was displayed without any pixel defects by optimizing the threshold at 300 to 450 HU based on smoothing pixel defects visually. The number, size, location and morphological features of the lesions were noted on transverse and virtual images. Each lesion was characterized as polypoidal, sessile, focal septae or irregular wall thickening. Data acquired by virtual CT Cystoscopy and conventional cystoscopy were compared. RESULTS: The conventional cystoscopy had detected 17 lesions in 14 patients (70 %). CT virtual cystoscopy detected fifteen lesions in 12patients (60%) and fifteen out of 17 lesions (88.24%). Seven lesions (58.3 %) were papillary and 5 (41.6 %) were sessile. (25 %) patients had multiple lesion and (75 %) had a single lesion. The mean lesion size was 2.8 cm. ( smallest 0.9 cm & largest 5.5cm). Two lesion with ⬍1cm. were missed. The probable reason of not achieving 100 % sensitivity was the lesion size. The specificity, positive predictive value, negative predictive value and accuracy of CT cystoscopy were 100%, 100%, 75% & 90% respectively. CONCLUSIONS: Detection rate of bladder lesion with vitual CT cystoscopy approaches conventional cystoscopy . It obviates operation theatre visit, physical & psychological trauma and might detect enlarged pelvic lymph nodes. In situations where conventional cystoscopy cannot be applied CT virtual cystoscopy can be of clinical benefit. CT machine with proper approved software for navigation and an experienced radiologist are the prerequisite for CT cystoscopy. Source of Funding: None
2015 REPEAT IMAGING IS UNNECESSARY WHEN URETERS ARE INCOMPLETELY OPACIFIED ON COMPUTED TOMOGRAPHY UROGRAPHY Jason Woo*, Lejla Aganovic, Fiona Cassidy-Hughes, Christian Welch, A. Karim Kader, San Diego, CA INTRODUCTION AND OBJECTIVES: Computed tomography urography (CTU) has become the preferred imaging modality for hematuria evaluation and for surveillance of the upper urinary tract for urothelial malignancies. Ureteral segments are frequently nonopacified because of ureteral peristalsis, anatomical variations, and differences in contrast excretion. Incompletely evaluated ureters are concerning for missed urothelial malignancies. There are no reports of the clinical significance of nonopacified ureteral segments nor recommendations about how to deal with this increasingly common clinical scenario. We investigate the clinical significance of incompletely opacified ureters on CTU and whether repeat imaging offers increased diagnostic yield. METHODS: 1000 consecutive CTUs performed at the San Diego VA hospital from 2006 to 2010 were reviewed. If a nonopacified segment was seen, a repeat scan through that ureteral segment was performed during the same CT study. All CTUs were reviewed by two attending radiologists. Presence of mass, hydroureter or ureteral wall thickening was recorded. Follow up urinary tract imaging and urologic evaluations were reviewed for development of new upper tract malignancies. RESULTS: The primary indications were gross hematuria, microscopic hematuria or upper tract evaluation in patients with known urothelial malignancies. 536 of 1000 (53.6%) CTUs had at least one nonopacified segment of ureter after initial scan. 231 patients (23.1%) had complete opacification after repeat scan. 305 (30.5%) had at least one segment that was never completely opacified. On repeat scans, there were no cases of newly discovered ureteral tumors in a previously nonopacified segment of ureter. In the nonopacified group, all cases of pathologically confirmed ureteral tumors (15/15) had associated findings of hydroureter, ureteral wall thickening or an obvious mass. No patients with nonopacified ureteral segments and otherwise normal CTU developed upper tract malignancies in the 2-6 year period of follow up.