Pearls and Pitfalls of CT and MR Urography :What Residents Must Know know

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1 Pearls and Pitfalls of CT and MR Urography :What Residents Must Know know Poster No.: C-0507 Congress: ECR 2014 Type: Educational Exhibit Authors: R. M. S. V. Vadapalli, A. Roychowdhury, P. Kaila, A. S Vadapalli ; Hyderabad/IN, Worcester, MA/US, Decatur/US, 4 Pune, Maharastra/IN Keywords: Neoplasia, Inflammation, Pathology, Radiation safety, Imaging sequences, Diagnostic procedure, CT, MR, CT-High Resolution, Urinary Tract / Bladder, Kidney, Abdomen DOI: /ecr2014/C-0507 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 76

2 Learning objectives CTU Page 2 of 76

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4 Fig. 1: CT Urography with 3D VR of excretory phase showing Urteric obstruction on Left due to VUJ TCC 1. highlight the basic concepts of CT and MR Urographic Techniques with outlines of the protocol and discuss the precise Clinical indications of each or Combined (Combo Urography) in Clinical Uroradiological Imaging practice.2. Discuss the Pearls and Pitfalls of these techniques in calculus disease, Obstructive uropathy, Painless haematuria evaluation as well as in Renal mass lesions and Uro thelial neoplasms. 3. Surgeon friendly Visualization techniques like 3D MIP. Volume rendering, shaded Surface Display (SSD) and Virtual Uretero cystoscopy and their role are showcased with examples in Common and Uncommon pathologies including variants and anomalies. MRU Page 4 of 76

5 Fig. 2: MR urography of Distal ureteric Obstruction Page 5 of 76

6 Background CT urography, has emerged as the initial Imaging Technique ahead of conventional intravenous urography; Clinical experience has now clearly demonstrated that CTUrography is the test of choice for Diagnosis of Urological Diseases, including urolithiasis, renal masses, urinary tract infection, trauma, and obstructive uropathy. CT urography provides a detailed depiction of the anatomy of urinary tract(kub) kidneys, intra renal collecting systems, ureters, and bladder-with symptom specific protocols like Painless haematuria, renal colic and flank pain with haematuria to be evaluated comprehensively. Un enhanced CT urography: Single Scan Page 6 of 76

7 Fig. 3: Non enhanced CTU with calculus in Distal ureter Curved reformat Page 7 of 76

8 Cortico medullary Phase Scan Cortico medullary Phase sec Nephro graphic sec Fig. 4: CT urography Corticomedullary phase -Horse shoe Kidney Page 8 of 76

9 Fig. 5: Bear Paw sign CM phase of CTU The bear's paw sign is seen in xanthogranulomatous pyelonephritis and refers to the cross-sectional appearance of the kidney which is said to resemble the paw of a bear. The renal pelvis is contracted whereas the calyces are dilated, mimicking the toe-pads of the paw. Cortico medullary phase images. The images are acquired sec following the start of i.v. contrast injection. The contrast is still in the arteries and the renal cortex.nephrographic Phase(70-100sec):also passed through the kidney and into the renal vein. Page 9 of 76

10 Excretory Phase CT Urography Fig. 6: TCC renal Pelvis(excretory Phase CTU) Excretory phase images. Five minutes following contrast injection, the contrast has passed through the kidneys to the renal pelvis, ureters and the bladder Page 10 of 76

11 MR Urography Magnetic resonance (MR) urography comprises an evolving group of techniques with the potential for allowing optimal non invasive evaluation of many abnormalities of the urinary tract. MR urography is clinically useful in the evaluation of suspected urinary tract obstruction, hematuria, and congenital anomalies, as well as surgically altered anatomy, and can be particularly beneficial in pediatric or pregnant patients or when ionizing radiation is to be avoided. Paediatric uropathies: MR urography include preoperative anatomic imaging for the assessment of vascular anatomy, evaluation of duplex systems, and distinction between pelvicalyceal dilatation and cystic disease Functional data that can be obtained with MR urography include renal transit time, differential renal function, and estimated GFR The most common MR urographic techniques for displaying the urinary tract can be divided into two categories: 1.Static-fluid MR urography. Static-fluid MR urography makes use of heavily T2weighted sequences to image the urinary tract as a static collection of fluid, can be repeated sequentially (cine MR urography) to better demonstrate the ureters in their entirety and to confirm the presence of fixed stenoses, and is most successful in patients with dilated or obstructed collecting systems. 2.Excretory MR urography Excretory MR urography is performed during the excretory phase of enhancement after the intravenous administration of gadolinium-based contrast material; thus, the patient must have sufficient renal function to allow the excretion and even distribution of the contrast material. Diuretic administration is an important adjunct to excretory MR urography, which can better demonstrate nondilated systems. Page 11 of 76

12 3.Dynamic Contrast enhanced MRI For Characterization of renal masses or functional Imaging Page 12 of 76

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14 Fig. 7: MR urography: TCC Bladder and VUJ with Obstructive hydronephrosis Page 14 of 76

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16 Fig. 8: MR Urography of Calculus Hydronephrosis Fig. 9: Excretory MR urography Follow the Pre administrative Check lists(serum Cr/e GFR),Comprehensive MR contrast guidelines and Policies to prevent NSF in all Patients especially high risk Page 16 of 76

17 Findings and procedure details Excretory Phase CT urography Excretory phase images are obtained min after administration of Intravenous contrast medium to evaluate the urothelium., collecting systems, ureters, and bladder which depends on opacification and distension. Fig. 10: CT urography calculus Hydronephrosis(excretory phase 3D MIP) furosemide is a useful adjunct to CT urography. The intravenous administration of 10 mg of furosemide 2-3 minutes prior to the administration of intravenous contrast material has been reported as substantially improving middle and distal ureteral opacification Page 17 of 76

18 Fig. 11: CTU vesical calculi Page 18 of 76

19 Fig. 12: CTU 3D VR Vesical calculi Page 19 of 76

20 Fig. 13: CTU Vesical calculi 3D Volume rendering Page 20 of 76

21 Split Bolus technique (Two Scan. Three Phase 1.unenhanced CT scan fractionated dose of contrast material (30-50 ml, 300 mg of iodine per milli liter) is administered followed by a delay of 8-10 minutes before the remaining ( ml) contrast material is given 2. subsequent scan, obtained 100 seconds after the second dose of contrast material, contains excretory information from the first dose and nephrographic information from the second dose 3.When the split-bolus technique is used, parameters that include the volume, concentration, and timing of contrast material; the number and timing of CT scan acquisitions; and ancillary maneuvers or supplemental measures need to be optimized Fig. 14: Retroaortic renal vein Page 21 of 76

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23 Fig. 15: CTU Calculus Hydronephrosis Three scan Protocol(ALARA) Radiation Dose reduction techniques :ALARA Principle,Auto MAS,ASIR (Adaptive Statistical iterative reconstruction),tube Current Modulation are used. 1.For the unenhanced scan, the abdomen and pelvis are imaged by using a maximum collimation of 2.5 mm. 2. The kidneys are imaged during the nephrographic phase, 100 seconds after intravenous administration of 100 ml of Iodinated isoosmolar Non ionic contrast medium at a rate of 3 ml/sec by using a maximum collimation of 2.5 mm. 3. The abdomen and pelvis are scanned during the excretory phase, minutes after contrast medium injection, by using a maximum collimation of 1.0 mm Fig. 16: Parapelvic cortical Cyst Page 23 of 76

24 Fig. 17: Parapelvic cortical Cyst with calcifications Page 24 of 76

25 Fig. 18: Parapelvic cortical Cyst on CTU excretory phase with contrast fluid levels indicating communication with PUJ Page 25 of 76

26 Fig. 19: CT urography 3D Volume rendered Excretory phase image of Para- pelvic cortical Cyst Low Dose CT urography : Pearls Page 26 of 76

27 1.Use of a low-tube-voltage technique drastically reduces the radiation dose because the dose is proportional to the square of the tube voltage. 2.Decreasing tube voltage decreases the radiation transmitted and increases image noise (from 120KVp to 80 KVp) 3.The increased image noise can be reduced with adaptive noise reduction filters. 4.Iodine attenuation increases as tube voltage decreases because the energy in the xray beam moves closer to the k-absorption edge of iodine 5.Low-tube-voltage techniques may examinations such as CT urography. be useful during contrast-enhanced CT 6. Radiation Dose reduction techniques :ALARA Principle,Auto MAS,ASIR (Adaptive Statistical iterative reconstruction),tube Current Modulation are used. 7.Mean dose delivered by Conventional IVU exam with Nephrographic excretory phases, Nephro tomography, Oblique views and Post void Images i 8.The effective radiation dose at MDCT urography also depends on the scan parameters, the number of scans, and the sex of the patient s about 9 9.The effective dose for one MDCT urography session is msv.7 msv ranges from 5-15 msv (Nawfel et al.). 10.Effective Dose The estimated effective dose for scans obtained at 120 kvp was 7.00 ± 0.59 msv (range, msv). 11.For scans obtained at 80 kvp, the estimated effective dose was 2.90 ± 0.20 msv (range, msv). 12. Dual Energy CT in future offers Virtual non contrast Imaging,Dose reduction,evaluation of stone composition. Dual Energy CT is the future for Low dose urography especially stone disease and management. Ref:Low-Dose MDCT Urography: Feasibility Study of Low-Tube-Voltage Technique and Adaptive Noise Reduction Filter Yumi Yanaga et al. Page 27 of 76

28 American Journal of Roentgenology :3, W220-W229 Fig. 20: CT urography Indications and Protocols Page 28 of 76

29 Fig. 21: CTU in Calculus disease Page 29 of 76

30 Fig. 22: CT urography in calculus disease -3D visualization Page 30 of 76

31 Fig. 23: CT urography in calculus Disease Visualization of calculi Page 31 of 76

32 Fig. 24: CTU in Papillary necrosis Page 32 of 76

33 Fig. 25: CTU renal colic -3D visualization and Absent ureteric jet Page 33 of 76

34 Fig. 26: Combo urography(ctu+mru) and MRU in Calculus obstruction Page 34 of 76

35 Fig. 27: CT Urography in Acute Distal ureteric calculus obstruction with Periureteric Leak and contrast extravasation Page 35 of 76

36 Fig. 28: CTU in Congenital Anomalies :Ectopic Pelvic kidney and PUJ obstruction Page 36 of 76

37 Fig. 29: CTU Horse shoe Kidney Page 37 of 76

38 Fig. 30: Horse shoe kidney with papillary RCC from isthumus Page 38 of 76

39 Fig. 31: CT urography in Retrocaval ureter Page 39 of 76

40 Fig. 32: Left Ovarian vein Syndrome and Circumaortic renal vein Page 40 of 76

41 Fig. 33: CTU in Invasions: Pelvic endometriosis and Xantho-granulomatous Pyelonephritis Page 41 of 76

42 Fig. 34: CTU in Genito-urinary Tuberculosis and thimble bladder Page 42 of 76

43 Fig. 35: CT and MR urography of Ureteric obstruction due to Invasion by recto sigmoid colonic carcinoma and Mass effect by Non Hodgkin's Lymphoma(NHL) Page 43 of 76

44 Fig. 36: TCC CTU and MRU signs Page 44 of 76

45 Fig. 37: Transitional cell carcinoma Pelvis and PUJ References: Department of radiology UMASS Roy chowduary co author Page 45 of 76

46 Fig. 38: Multifocal Bladder and distal Ureteric TCC Page 46 of 76

47 Fig. 39: Ureteric TCC Page 47 of 76

48 Fig. 40: MR Urography of Ureteric Obstruction: Direct Invasion by Carcinoma cervix and Metastatic Krukenberg's tumours Page 48 of 76

49 Fig. 41: MRU of TCC Page 49 of 76

50 Fig. 42: CT Urography TCC Page 50 of 76

51 Fig. 43: MR urography TCC Page 51 of 76

52 Fig. 44: CTU and MRU of TCC Page 52 of 76

53 Fig. 45: CTU in Benign renal lesions: Angiomyolipoma and Renal cysts Page 53 of 76

54 Fig. 46: CTU in RCC Page 54 of 76

55 Fig. 47: Bilateral Perirenal Fibrosis :Perirenal Rind sign Images for this section: Page 55 of 76

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57 Fig. 1: CT Urography with 3D VR of excretory phase showing Urteric obstruction on Left due to VUJ TCC Page 57 of 76

58 Fig. 2: MR urography of Distal ureteric Obstruction Page 58 of 76

59 Fig. 3: Non enhanced CTU with calculus in Distal ureter Curved reformat Page 59 of 76

60 Fig. 4: CT urography Corticomedullary phase -Horse shoe Kidney Page 60 of 76

61 Fig. 5: Bear Paw sign CM phase of CTU The bear's paw sign is seen in xanthogranulomatous pyelonephritis and refers to the cross-sectional appearance of the kidney which is said to resemble the paw of a bear. The renal pelvis is contracted whereas the calyces are dilated, mimicking the toe-pads of the paw. Page 61 of 76

62 Fig. 6: TCC renal Pelvis(excretory Phase CTU) Page 62 of 76

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64 Fig. 7: MR urography: TCC Bladder and VUJ with Obstructive hydronephrosis Fig. 10: CT urography calculus Hydronephrosis(excretory phase 3D MIP) Page 64 of 76

65 Fig. 23: CT urography in calculus Disease Visualization of calculi Page 65 of 76

66 Fig. 32: Left Ovarian vein Syndrome and Circumaortic renal vein Page 66 of 76

67 Fig. 31: CT urography in Retrocaval ureter Page 67 of 76

68 Fig. 33: CTU in Invasions: Pelvic endometriosis and Xantho-granulomatous Pyelonephritis Page 68 of 76

69 Fig. 40: MR Urography of Ureteric Obstruction: Direct Invasion by Carcinoma cervix and Metastatic Krukenberg's tumours Page 69 of 76

70 Fig. 47: Bilateral Perirenal Fibrosis :Perirenal Rind sign Page 70 of 76

71 Fig. 37: Transitional cell carcinoma Pelvis and PUJ Page 71 of 76

72 Conclusion Take Home Points for CT Urography -Use tailor made Symptom and Disease specific protocols with ALARA Approach. -Substitute Multi phasic exams with Low KVp (80KVp) protocols with other Dose reduction techniques to reduce radiation dose. -Follow the Iodinated Contrast Administration Guidelines and Policies to Prevent CIN(Contrast Induced Nephropathy) in high Risk Patients(diabetes, Myeloma, uncontrolled Hypertension,Previous history of renal disease, Age >60 years), nephrologist Consultation in decision making before administration of Contrast in Patients with renal Dysfunction /Haemo Dialysis and Using other drugs like Metformin for Diabetes, NSAIDS or COX 2 Agents) -Serum Cr estimation should be done in all high risk patients -Have a Premedication Policy in Place to prevent Contrast induced Reactions, Contrast extravasation by Pre administrative Check lists (e. g:acr manual describes the 4 Hs a. History b. Hydration c. Have equipment and expertise ready d. Heads up Take Home Points :MR Urography 1.Non contrast: Use it as a safe alternative in all Patients where CT urography poses a risk or in combination with an un enhanced CT urography in calculus disease or in Pain less haematuria, in Paediatric Patients, Pregnant Patients. 2.Screening for impaired renal function (to Prevent NSF). Patients with the conditions below are at risk for impaired renal function and must have a serum Creatinine with estimated GFR (egfr) checked prior to administration of IV GBCA: Age > 60 years old Diabetes Mellitus (insulin-dependent, oral hypoglycemic or diet-controlled) Page 72 of 76

73 History of renal disease (includes renal insufficiency or failure, solitary kidney, renal transplant, renal tumor) Other conditions as deemed appropriate 3.Identify risk factors for AKI, including recent surgery, severe infection, severe trauma and nephrotoxic drugs Whenever possible, MR with IV GBCA should be avoided in patients on dialysis or with AKI or CKD stage 4 or 5 (egfr <30 ml/min/1.73m2). 4.Check List for Contra Indications for MRI exam it self (Pacemakers, intra cranial Aneurysmal clips, Cochlear Implants, Ferro magnetic foreign bodies in Vital locations e.g Ocular) Conclusion :This Exhibit offers the Resident an overview of Pearls and Pitfalls of CT and MR Urography in Clinical UroradioIogy practice. Personal information Rammohan Vadapalli.MD Senior Consultant radiologist Vijaya Diagnostics and research Hyderabad AP,India rammohanvsv@yahoo.com References Low-Dose MDCT Urography: Feasibility Study of Low-Tube-Voltage Technique and Adaptive Noise Reduction Filter Yumi Yanaga et al. American Journal of Roentgenology :3, W220-W229 Page 73 of 76

74 Coakley FV, Yeh BM. Invited commentary. RadioGraphics 2003; 23: [commentary on: Joffe SA, Servaes S, Okon S, Horowitz M. Multi-detector row CT urography in the evaluation of hematuria. RadioGraphics 2003; 23: ]. Vrtiska TJ, King BF, LeRoy AJ, Hattery RR, McCollough CH, Quam JP. CT urography: analysis of techniques and comparison with IVU (abstr). Radiology 2000; 217(P):225 Joffe SA, Servaes S, Okon S, Horowitz M. Multi-detector row CT urography in the evaluation of hematuria. RadioGraphics 2003; 23: Retrocaval Ureter :Two case reports M.Y.Keiy et al. Ghana Med J December; 45(4): Dreyfuss W. Anomaly simulating a retrocaval ureter. J Urol. 1959;82:630. [PubMed] Lerman I, Lerman S, Lerman F. Retrocaval ureter: Report of a case. J Med Soc N J. 1956;53:74. [PubMed] Heslin JE, Mamonas C. Retrocaval ureter: Report of four cases and review of literature. J Urol. 1951;65: [PubMed) Lynch HT, Taylor RJ, Lynch JF, et al. Multiple primary cancer, including transitional cell carcinoma of the upper uroepithelial tract in a multigeneration HNPCC family: molecular genetic, diagnostic, and management implications. Am J Gastroenterol 2003; 98: Images for this section: Page 74 of 76

75 Fig. 48: References Page 75 of 76

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