2. UROGRAPHY DEFINITION
Urography is a radiologic technique used for the evaluation of the
genitourinary system: specifically, the kidneys, ureters and bladder.
9. 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.
14. Indication of CT Urography
To evaluate patients with hematuria
Calculi
Renal / Urothelial tumors
Congenital anomalies.
15. Renal calculi
Presence, size and location of urinary
tract calculi
Exclude extraurinary pathologies that
may mimic calculi
16.
17. 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
31. 34 year old lady with pain Left side of abdomen, and
hydronephrosis on USG
32. 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
33. Principle
urine have very long T2-relaxation time
heavily T2-weighted pulse sequence generate images with high signal intensity
from static fluid
34. 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)
41. 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
44. Advantages
MRU has better contrast resolution than CT urography
without radiation exposure and IV contrast administration
45. Disadvantages over CT Urography
Longer examination times than for CT urography
Decreased spatial resolution
Inability to reliably depict calcifications and calculi
IVU IS THE MOST COMMONLY USED TECHIQUE , CT urography is a developing diagnostic imaging technique is progressively replacing the ivu in western contries
, ROLE OF MR IN UROGRPAHY IS STILL BEING ESTABLISHED
Two sets of
Solution: table top with insertable grid and cassette and ceiling mounted xray tube , Scanned projection radiographic
(100-150 ml non ionic contrast media at a rate of 2-4 ml/second) //Nephrogenic phase is after the cortico-medullary phase (50 seconds) –dye has reached the distal part of collecting duct( renal vasculature) // To evaluate urothelium from the pelvicalyceal system to the bladder // avoided due to radiation risks
Unenhanced CT scans used for the evaluation of calculi, renal parenchymal calcifications, precontrast attenuation measurements// nephrographic phase is Neoplasm inflammatory diseases
(Iohexol) 300mg/min
(A) Coronal MPR image demonstrating only a small segment of the left ureter in its mid portion (B) Curved multiplanar reformation displaying a left ureteric
calculus, the consequent hydronephrosis and the entire dilated ureter proximal to it in a single image regardless of opacificaion
area of interest can be obscured the by high density material, such as bone, calcium, and oral contrast medium.---Better detect pulmonary nodules, vessels
MINip areas of emphysema
all attenuation values within a voxel are used to obtain the final image Entire volume of data and displays anatomic structures with different levels of attenuation //with bone editing///angiography , large airway abnormality
Symptomatic indications include hematuria,
Secondary signs obstructive urinary calculi of Hydronephrosis, hydroureter, ipsilateral renal enlargement. Calculi in unusual positions such as in calyceal divertculae
VRT image (B) displaying the
same
Enhance ment of more than 20 HU// Require information about its location near the collecting system. ….
Contrast-enhanced axial CT scan: (A) showing an enhancing mass in the upper and mid pole of the right kidney. CT urogram using volume rendering (B) showing distortion of the calyces by the mass lesion
CT urogram using MIP technique (C) showing splaying, distortion of the calyces on the right side –right renal cell carcinoma
excretory IVU shows compression of the upper left renal infundibulum
Papillary necrosis. Coronal (A) and sagittal (B) MIP images of the left kidney demonstrate a filling defect in the superiormost calyx (arrow) secondary to sloughing of the papilla into the calyx.
Axial CT scan of the pelvis in the excretory phase demonstrates extravasation of contrast
3D volume-rendered image of the study shows the exact location of the ureteric injury
ureteric compression but also the IVC
low lying ectopic kidney with fusion of both kidneys
Volume rendered image in the excretory phase
Duplicated collecting system with an ureterocele///dilated left upper pole and ureter (arrows) and ureterocele
Projectional imaging technique The patient's body habitus, state of bowel preparation, and renal excretion rate are factors contributing directly to the visible radiographic contrast, and can lead to sub-optimal image quality,
Cross section radiography, projection radiography. compromised by variables like bowel preparation, renal function and radiographic factors. three-dimensional view of the renal morphology
Furosemide: prone position achieved higher opacification of the mid and distal ureters.
a) Scout film KUB area shows no radio-opaque calculus. b) 30 minutes prone IVU film showing hydronephrosis with proximal hydroureter Left side. c) CTU Coronal MIP image clearly showing calculus within Left ureter.
ionizing radiation or iodinated contrast material is to be avoided.
treats the urinary tract as a static column of fluid--high signal intensity from static fluid in the collecting whereas lower signal intensity from parenchymal tissue is suppressed. ..Diuretic administration…. extremely fast and are performed in one breathhold
Static-fluid MR urography does not require the excretion of contrast material and is therefore useful for
Prostate cancer metastatis to lymph nodes
A, Coronal T2-weighted MR image shows low-signal intensity filling defect ( Arrow ) in right renal pelvis. B, T2-weighted static-fluid MR urograph confirms presence of filling defect (Arrowhead ) in renal pelvis
A, Unenhanced CT urographic scan through pelvis shows thickened postpar tum uterus ( arrow).B,Pyelographic phase CT urographic scan shows multiple filling defects (
Arrowhead ) due to blood clots in bladder.
C, Coronal reformation of pyelographic phase CT urographic scan shows absence of contrast excretion from right renal collecting system ( arrow).D,Coronal T2weighted static-fluid MR urograph shows filling defects (arrowhead) suggestive of blood clots in pelvicaliceal system of kidney.
Coronal MIP image from excretory MR urographic data
The T2 shortening effect of gadolinium prevents successful application of static-fluid MR urography during the excretory phase after the intravenous administration of gadolinium-based
Static fluid mru shows the presence of urine rather than excretory function
