INTRAVENOUS UROGRAPHY

PRESENTER : DR JUNED A ANSARI

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The Intravenous Urogram is the classic routine investigation of UroradiologyTechnically satisfactory IVU demonstrates clearly and completely both the renal parenchyma & the collecting system including the calyces, renal pelvis, ureters and the urinary bladder and gives an indication of their function

                                                     

                          

1937-Berger made several recommendations•Routine tomography•High dose of contrast agents•Ureteral compression

Introduction of excretory urography was done in 1929, by American urologist Moses Swick. He injected an organically-bound iodide compound—later named Uroselectan—into a vein, taking X-rays as the material cleared the body through the urinary tract.

Moses Swick

INDICATIONS:Persistent or frank haematuriaRenal or ureteric calculiUreteric strictures or fistulasComplex urinary tract infection

CONTRAINDICATIONS:No absolute contraindicationRelative contraindications•Renal & hepatic failure•Multiple myeloma•Pregnancy•Previous reaction to contrast media•H/o allergy•Infancy •Thyroid disease•Diabetes

PATIENT PREPARATIONPATIENT PREPARATION

Dehydration : Effective fluid restriction may produce a slightly detectable increase in urographic density but the nephrogram is uneffected, hence no longer considered applicable

Bowel preparation

Psychological preparation

Informed consent

EXPOSURE FACTORSEXPOSURE FACTORS

Kv(p) 66-70mA Sufficiently high to allow short exposure timesFilm/Screen combination Medium speed

Physiology of contrast excretion

I.V. injection Contrast media

Anion(I2)

Osmotically inert & non reabsorbable

Cation

Meglumine

Not reabsorbedby renal tubules

Sodium

Freely reabsorbed by renal tubules

Following bolus I.V. injection, very rapid plasma concentration is followed by rapid declineRapid mixing in vascular compartmentDiffusion into extravascular, extracellular spaceRenal excretion

Extrarenal routes for contrast excretion:

Hepatic

Small bowel

Sweat

saliva

Tears

Gastric juice

PROCEDUREPROCEDURE

Plain film of the abdomen (Scout film)•State of bowel preparation•Calcific density in the renal tract•Soft tissue masses•To observe the abdominal parieties•To check exposure factors & positioning

Oblique views

Contrast administration: bolus/infusion Dose: adults- 50ml of 350-370 strength water soluble contrast children-2-3ml/kg body wt.

                                                                                                                                                                                                                      

       

FILM SEQUENCEFILM SEQUENCE1-3 minutes Antero-posterior- film coned to the renal area

5 minutes Antero-posterior-film coned to the renal area

Apply ureteral compression

10 minutes Antero-posterior

Release compression

“Flush”, “X” or “Release view”- - full length view

Upright post void Antero-posterior

Nephrotomography-whenever anatomic information is obscured

Role of delayed films- rule of eight

Contraindications to ureteral compression:

Suspected or proven aortic aneurysm

Evidence of obstruction in early urogram films

Recent abdominal surgery

Severe hypertension

Abdominal pain on application of compression

Recent acute injury

Renal transplantation

Abdominal distension

WHAT TO LOOK FOR IN IVUWHAT TO LOOK FOR IN IVU

Size, shape, position and axis of kidneysExternal cortex and inner medullaCalyceal systemRenal pelvis and ureteropelvic junctionUreterUretero-vesical junctionUrinary bladderRelation of ureter to spine and psoas muscle

RADIATION DOSE FROM IVU1,465 mR/projection for males1,047 mR for femalesTotal dose to the gonads / exam-751 mR –males 577 mR-females

UROGRAPHIC INTERPRETATIONUROGRAPHIC INTERPRETATION

Nephrogram- Provides information regarding arterial perfusion of the kidney as well as the functional & structural integrity of the nephrons

•Vascular/ capillary/cortical nephrogram- due to distribution of contrast media in the cortical microvasculature

•Urographic/parenchymal nephrogram- due to entry of contrast in the proximal tubules

•Fading of contrast- continous flow of contrast in the tubules -reduced plasma conc. of C.M.

NEPHROGRAPHIC PATTERNS

Immediate Faint Persistent Nephrogram

Due to severe impairment of Glomerular filtration

•Proliferative/necrotising disorders

•Renal vein thrombosis

•Chronic severe ischaemia

Immediate Dense Persistent Nephrogram

Due to unimpaired glomerular filtration

•Acute tubular necrosis

•Acute renal failure

•Acute on chronic renal failure

•Acute hypotension

Increasingly Dense Nephrogram

•Acute obstruction . Acute Pyelonephritis

•Acute Hypotension . Multiple Myeloma

•Acute tubular necrosis . Renal vein thrombosis

•Acute glomerulonephritis .Amyloid, Acute papillary necrosis

Increasingly Dense Nephrogram

Rim Nephrogram

•Severe hydronephrosis

•Acute complete arterial occlusion

Striated Nephrogram

•Acute ureteric obstruction

•Infantile polycystic disease

•Medullary sponge kidney

•Acute pyelonephritis

Pyelogram

Value of compression

•In normally functioning kidneys, contrast is first seen in the calyces at 2 mins following bolus injection.

UretersUreters begin to transport opacified urine about 3 mins post injectionMaximum ureteral filling occurs between 5-10 minutes.

Bladder

MINUTE SEQUENCE IVP

Evaluation of renovascular hypertension

Minimum series includes films at 1,2,3 minutes, post injection

Criteria

•Delayed visualisation of contrast in the collecting system on the affected side

•Decreased renal size

•Delayed washout of contrast

•Notching of the proximal ureter

HIGH DOSE UROGRAPHY

Indicated for imaging the kidneys in patients with mild renal impairment

Prerequisites

.Adequate hydration

•Optimal metabolic & CVS condition

•Higher contrast medium dose

•Use of low osmolality agent

FINDINGS IN CRFReduced renal sizeParenchymal thinningNormal pevicalyceal anatomy

ADVERSE REACTIONS

Minor reactions- flushing,arm pain, nausea, vomiting, headache, rigors and mild urticaria.

Intermediate reactions-•More severe degrees of the above mentioned symptoms•Moderate degrees of hypotension and bronchospasm

Severe life threatening reactions-•Severe manifestations of above symptoms•Severe bronchospasm•Unconsciousness•Laryngeal oedema•Pulmonary oedema•Severe cardiac dysaarrythmias•Cardiac arrest•Cardiovascular and pulmonary collapse

Death

IVU findings in certain entitiesIVU findings in certain entities

Renal agenesis

U/L-Absent renal outline & U/L-Absent renal outline & pelvicalyceal system, pelvicalyceal system, 9999mmTcTc

DMSA most sensitiveDMSA most sensitive

B/L-Uncommon & B/L-Uncommon & incompatible with lifeincompatible with life

Renal Ectopia

Failure of complete ascent of the kidney to its normal position

IVU- abnormally placed kidneys

Pancake kidney

Crossed fused renal ectopia

Two complete pelvicalyceal systems on one side usually one above the other

Ureter from the lower renal pelvis crosses the midline and enters bladder normally

Horseshoe kidney

Kidneys placed lower than normal

Malrotation of pelvis

Lower pole calyces of both sides deviated towards midline

Ureters have characteristic vaselike curve

Pelvicalyectasis

Renal calculi

Duplex collecting system

Minor form – bifid renal pelvis

Ureteral duplication Incomplete – ureters fuse

in their course Complete – 2 ureters

open seperately in bladder, lower moiety inserted orthoptically & upper moiety ectopically

“Drooping lily” sign

Ureterocele

Contrast filled structure with a thin smooth radiolucent wall surrounded by contrast containing urine in the bladder- “Cobra’s head’ appearence

                            

            

Retrocaval ureter

The ureter may have a sickle, S or reverse J appearance before crossing behind and medial to the IVC.

The ureter descends medial to right lumbar pedicle.

Proximal ureter is dilated.

Congenital HydronephrosisDue to functional obstruction at the pelvi-ureteral junctionAetiology- cong. Bands, adhesions, neuro muscular inco-ordination, abberent vesselsAdvanced cases• large soft tissue mass replacing the renal parenchyma•No opacification of collecting systemLesser degrees of obstruction• Nephrogram- thin rim of renal substance outlining the kidney•Later films – crescent shaped opacities produced by dilated stretched tubules surrounding the enlarged non opacified calyx•Delayed films – slow filling of calyces & renal pelvisMild forms•“Wine glass appearance”Mildest form- minimal deviation from the normal appearance

Polycystic kidneys

Autosomal dominant Plain films- cyst calcification IVU- enlarged kidneys with

compression and displacement of calyces by intrarenal cyst

Autosomal recessive B/L symmetrical

enlargement of kidneys Streaky nephrogram Calyces maybe distorted

Medullary sponge kidney

Brush like linear striations in renal papillae

Enlargement of kidney

Renal calculi

Acute urinary obstruction

Increasingly dense “obstructive” nephrogram

Moderate kidney enlargement

Delayed calyceal opacification

Minimal to moderate pelvicalyectasis

Standing column of the ureter

Spontaneous pyelosinous extravasation

Chronic urinary obstruction

Kidney size -large(partial obstruction) -small(complete obst) Nephrogram density - normal or reduced Parenchymal thickness-

reduced Pyelogram-

Hydronephrosis Ureter-dilatation &

tortuosity -mucosal striations

Renal Vein Thrombosis

Enlarged kidney with faint or absent Nephrogram

Pelvicalyceal filling maybe absent or the PCS stretched & compressed by oedematous renal parenchyma

Rarely, increasingly dense nephrogram, sometimes wiyh striation

Later stages- Renal atrophy

Renal masses

Small SOL

Localised bulge with increased thickness of the renal substance

Deforms or displaces or distends a calyx

Medium sized lesions Localized or generalized

enlargement of the kidneys Displacement or distortion of renal

pelvis, ureter or adjacent structures

Malrotation

Very large lesions Non functioning kidneys Calycine spreading Visceral displacement

Renal tuberculosis

Early stage Irregularity or destruction of

one or more papillae

Later stage Calcification

Renal

Parenchymal

Punctate calcification

Calcification within caseous pyonephrosis

Proceeds to Tuberculous Autonephrectomy

Cavities- irregular, communicates

with the collecting system

Fibrosis- leading to obstruction

- Hydronephrosis, hydrocalicosis

Bladder wall-Thickened and trabeculated

- small capacity bladder

Concentration of contrast medium is poor in proportion to the degree of obstruction

Conclusion  

“A tailored urographic study allowing optimal visualization of

sequentially opacified portions of the urinary tract may provide

diagnostic detail in certain portions of the urinary system beyond the current capabilities of other imaging modalities. This can be accomplished only with good technique, an understanding of the limitations of the procedure, and adherence to basic rules of interpretation. The ability to correlate urographic findings with those from other imaging modalities will remain an important skill until an ideal "global" urinary tract imaging technique emerges.”