Ct mri urography

ct mri urography

1. CT AND MRI UROGRAPHY DR. DEV LAKHERA

2. UROGRAPHY DEFINITION Urography is a radiologic technique used for the evaluation of the genitourinary system: specifically, the kidneys, ureters and bladder.

3. UROGRAPHIC TECHNIQUES INTRAVENOUS UROGRAPHY COMPUTERIZED TOMOGRAPHIC UROGRAPHY MAGNETIC RESONANCE UROGRAPHY

4. CT urography Hybrid CTU CT Urography

5. Hybrid CT urography CT and IVU are done together. Adv :- no reformatting needed Disadv :- Imaging at different location

6. CTU Protocol –Three phase protocol Unenhanced phase Nephrographic phase after 90-100 secs Pyelographic phase after 12-15 minutes 4 Phase protocol (5 min and 7.5 min)

7. Contrast media Omnipaque (100-150 ml non ionic contrast media at a rate of 2-4 ml/second)

8. Split Bolus MDCT Urography with Synchronous Nephrographic and Excretory Phase Enhancement Unenhanced Phase Nephro-pyelographic phase : 30 ml of nonionic contrast material is infused and after 10 min another 100 ml of contrast is injected ADV: Assess tract with low radiation exposure.

9. Image post processing techniques

10. Multiplanar Reformation (MPR)

11. Maximum Intensity Projection (MIP) Projecting the voxel with the highest attenuation value on every view throughout the volume onto a 2D image

12. Volume rendering technique (VRT)

13. Indication of CT Urography To evaluate patients with hematuria Calculi Renal / Urothelial tumors Congenital anomalies.

14. Renal calculi Presence, size and location of urinary tract calculi Exclude extraurinary pathologies that may mimic calculi

15. Renal Tumors Enhancement : Nephrographic phase Location : Renal cell carcinoma is frequently located at the periphery or near the cortico-medullary junction of the kidney as it originates in the renal cortex tumors with nephron sparing surgery

16. CT urogram (volume rendering ) Axial CECT

17. UROTHELIAL CARCINOMA Excretory phase CTU shows a soft-Tissue attenuation mass in upper left kidney with associated calyceal distortion

18. Coronal reformatted image MIPimage

19. Papillary necrosis

20. Ureteric injury

21. Congenital anomalies Retrocaval ureter Ureteral duplication Crossed fused kidneys Ectopic kidneys

22. Fused low lying ectopic kidney

23. Maximum intensity projection curved planar reformation excretory phase CT urogram

24. Advantages of IVU over CT urography Better spatial resolution Lesser radiation dose Cheaper

25. Ct urography: Advantages Multidetector CT : Thin slices in single breath hold allow optimal anatomic information Isotropic MPR reconstruction Better contrast resolution

26. Image improvement techniques Compression Saline Infusion Diuretic Administration Patient Positioning

27. 34 year old lady with pain Left side of abdomen, and hydronephrosis on USG

28. MR Urography urinary tract obstruction Hematuria congenital anomalies surgically altered anatomy beneficial in pediatric or pregnant patients or when ionizing radiation is to be avoided

29. Principle urine have very long T2-relaxation time heavily T2-weighted pulse sequence generate images with high signal intensity from static fluid

30. Sequences Without contrast administration : Heavily T2-weighted static-fluid MR urograms Half fourier acquisition single-shot turbo spin-echo(HASTE sequence) With contrast administration with excretory T1-weighted sequences (excretory MRU)

31. Static fluid MR Urogram demonstrates the collecting system, ureters and bladder

32. Coronal static-fluid MR urogram shows obstruction of the right distal ureter in a patient with prostrate cancer

33. Coronal single-shot fast spin-echo image shows a metastatic lymph node

34. Excretory urography Gadolinium shortens the T1 relaxation time of the urine, allowing the urine to initially appear bright on T1-weighted image Dose: 0.1 mmol /kg

35. Effect of gadolinium excretion on T2- weighted MR urographic techniques

36. static-fluid MR urography MIP excretory urography after gadolinium

37. Advantages MRU has better contrast resolution than CT urography without radiation exposure and IV contrast administration

38. Disadvantages over CT Urography Longer examination times than for CT urography Decreased spatial resolution Inability to reliably depict calcifications and calculi

39. THANK YOU