Intravenous urography scrutiny is to show the nephritic cerebral mantle, calyceal size, and form, nephritic pelvic girdle, pyeloureteric junction. Ureteric drainage and the vesica, although presentation of the vesica may non necessitate. Contrast agent is administered intravenously, normally via the average cubital vena, and images of the kidney are obtained through assorted phases of contrast synthesis. Contrast agent can be seen about instantly after injection of contrast agent, shown as a ‘blush ‘ of contrast agent in the nephritic cerebral mantle and known as a ‘nephrogram ‘ . This shows glomerular filtration of the contrast agent, before it reaches the calyceal system. It is of import to see the nephritic lineations as alterations in the smooth lineation may bespeak presence of tumor, cyst or cortical scarring. It besides provides early information on nephritic size. It is possible to see visual aspects of nephritic bloom for some clip after injection and it is non ever considered necessary to demo the first bloom instantly after injection of contrast agent, since nephritic lineations can be assessed along with the calyceal systems at ulterior phases in the scrutiny. Around 5 proceedingss after injection the calyces should be seen to make full with contrast agent, which so passes down the ureters to make full the vesica. In some instances the calyces empty rapidly, forestalling equal presentation of the calyces and nephritic pelvic girdle. To antagonize this, external compaction of the umbilical part of the venters is required, which restricts the flow of excreted contrast down the ureters.
Therefore, retains contrast agent within the kidney for a longer period of clip to guarantee equal imagination of the roll uping systems. Compression is normally left in topographic point for around 5 proceedingss before an image of the kidneys is taken and it must be noted that inordinate and drawn-out compaction may do the calyces to look somewhat blunted and distended ( copying early hydronephrosis ) . It is recognised that compaction is applied routinely, frequently 5 proceedingss after injection, to guarantee that there is optimization of contrast build up in the calyces but there are contraindications for the of compaction which must be considered. Includes:
Known nephritic concretion
Recent abdominal surgery
Nephritic graft ( since the transplanted kidney will be located in the right iliac pit )
A scope of projections are for the IVU, in assorted combinations to show the system, and appropriate choice of this combination. Projections used are taken from the undermentioned list:
Cross renal, collimated to the kidneys and upper ureters
Oblique individual kidney
Bladder anteroposterior ( AP ) with caudal angle of about 15 grade to unclutter the vesica from the upper boundary line of symphysis pubic bone
In add-on to fast drainage, there may be other grounds for failure to show the cerebral mantle or calyces and these are related to pathology or overlying intestine gas and fecal matters. Additional or auxiliary techniques may be necessary to better visual image in these state of affairss. These include images on the opposite stage of suspended respiration to potentially alter the place of overlying visual aspects such as intestine gas, fecal matters radio-opacities. Second, zonography to clear images of intestine gas and fecal matters. Last, tomographyto provide more elaborate information after calyceal and nephritic pelvic girdle images suggest or can non except make fulling defects. Tomography and zonography should non be used routinely.
Once the calyceal system has been demonstrated it is necessary to supply information of the ureters and vesica, with grounds of ureteric drainage being particularly of import. Ideally a KUB scrutiny at this point, around 15-20 proceedingss after injection will demo nephritic lineations, calycine systems, nephritic pelvic girdle, ureteric length and some vesica information. If the usage of compaction has been necessary it must be released in order to let kidney drainage and, in pattern, the nephritic lineation is frequently sick defined as a consequence since the kidney responds to the remotion of compaction by vigorous elimination of urine and contrast. However, if the nephritic country has been adequately demonstrated antecedently, this may non be an issue. In any instance, whether the compaction has been applied or non, subdivisions of the ureters may non be seeable on the KUB, due to the fact that piss is transported down these constructions by vermiculation, the contraction of external musculus beds coercing fluid along its length. If the exposure is made at a point of contraction, parts of the ureters will be constricted and that part of the ureter will non be seeable on the image. This in itself does non truly present a job, if the ureter is obstructed so there should be other grounds to propose this, including distended or blunted calyces, hydronephrosis ( seen ab initio as delayed concentration of contrast agent and subsequently every bit distended as and club form calyces, distended ureters and failure of contrast to go through the obstructed country on prone KUB or oblique vesica images.
The prone KUB is peculiarly utile to demo the ureteric obstructor site, the kidney prevarication in the retroperitoneal venters upon the posterior abdominal wall and the ureters extend from the kidneys anteriorly until they about level with L4/L5 and so towards the vesica, which is situated in the anterior pelvic girdle. Therefore, in the supine patient, piss is traveling ‘uphill ‘ for the first subdivision of the ureter, turning the patient prone after sitting the patient vertical for 5 proceedingss to let urine drainage reverses this and allows the piss to pool ‘downhill ‘ towards the site of obstructor. Most series will include a control non-contrast KUB, cross nephritic position, KUB with contrast, and a post-micturition vesica projection. We must accept that at the minute it does look that a conventional or ideal IVU series may non be believed to be, and that the everyday IVU series varies dramatically in different imagination section. When radiotherapist command the series, that series will even change between radiotherapists in the same section. This fluctuation illustrates how hard it is to get a satisfactory decision on a everyday series and it is clear that this modus operandi must besides alter when pathology becomes evident. Some imagination section have already responded to the state of affairs by presenting standardization of the IVU through a set protocol, depicting a series that has been agreed between the radiotherapists as frequently happened in the early yearss of radiographer engagement in the Ba clyster. This means that protocols may still change between infirmaries, with some holding every bit few as three set images and others holding every bit many as seven or more. This issue must be governed by two rules: the demand to cut down the dosage to the patient to a degree every bit low as moderately accomplishable ( ALARA ) as stated in current ordinances and guidelines.
So, sing the scope of projections available, schemes to better visual image of cardinal countries and effects on pathology on visual aspects on the system, it is hard to show a set of instructions that are guaranteed to work every clip for every patient. The most of import is that, even if a set protocol is agreed, it is indispensable that radiographers transporting out IVU scrutinies must hold a thorough apprehension of the purposes of the scrutiny plus anatomy, physiology, pathology, and radiographic rules involved, in order to guarantee that those purposes are met. Indeed, some imaging section who consider and agree on set protocols do bring forth more than one protocol, one for the everyday class patient, plus others for nephritic gripes, hematuria, injury or follow up after old known presence of concretion.
Suggested Routine Technique
Control KUB on inspiration for appraisal of gross anatomy and presence of obvious pathology such as radiopaque concretion. Position the patient for a cross-renal image. Injection of the contrast agent. Cross nephritic 5 proceedingss after injection, to measure nephritic lineations and calyces and taken on arrested termination. If calyces are non good demonstrated, use compaction if this is non contraindicated and reiterate the cross nephritic 5 proceedingss tardily. If there is suspected pathology, or gas or fecal matters impair item, undertake zonography or imaging of the nephritic country. Fulcrum highs selected for this will change harmonizing to patient physique but three ‘cuts ‘ are normally taken from a scope between 7-11 cm.If compaction has non been applied, 15-20 minute KUB with contrast, taken on inspiration. If compaction has been applied, let go of compaction and undertake KUB after calyces have been adequately demonstrated. Collimated AP 15 grade caudal angle vesica image, taken after urination.
Preliminary movie ( Control ) , ( 35 x 43cm ) supine full A.P. venters to include lower boundary line of symphysis pubic bone and stop, to look into, abdominal readying, exposure values and for any calcifications overlying the nephritic piece of land countries.
Auxiliary movies to find place of any opacity.
Inspiration movie of nephritic countries for suspected concretion.
35 & A ; deg ; posterior oblique of the nephritic countries.
Contrast Media Injection
The average cubital vena is punctured with a 19 gage acerate leaf and the warmed ( 40*C ) contrast agent is injected quickly. Movies are so taken at intervals to show the whole of the nephritic piece of land.
End of Injection movie, ( 24 x 30cm ) A.P. of the nephritic countries to demo the nephrogram, i.e. the nephritic parenchyma opacified by the contrast medium in the nephritic tubules.
5 Minute movie, ( 24 x 30cm ) A.P. of the nephritic countries to find if elimination is symmetrical or if uptake is hapless and a farther dosage of contrast agent is required.
Compaction may be applied in some centres at this point to dilate the pelvicalyceal systems to show any filling defects and a movie taken at 10 proceedingss of the nephritic countries. Compaction should non be used in instances of suspected nephritic gripes, nephritic injury or after recent abdominal surgery.
15 Minute movie ( 35 x 43cm ) ( On release if compaction has been applied ) to show the pelvicalyceal systems and the ureters.
25 Minute movie ( 24 x 30cm ) 15 & A ; deg ; caudal angulation centered 5 centimeters above the upper boundary line of the symphysis pubic bone to show the distended vesica.
Post Micturition movie ( 24 x 30cm ) 15 & A ; deg ; caudal angulation centered 5 centimeters above the upper boundary line of the symphysis pubic bone to show the vesica emptying success, and the return of the antecedently distended lower terminals of ureters to normal.
Variations of Routine during the Examination on patient Condition
Failure to show the calyces, particularly easy to observe when one kidney appears as normal in comparing to a non-apparent kidney on the other side in the early phases of the scrutiny. This is due to inordinate piss, which dilutes the contrast agent, staying in the kidney. Often there is concentration of the contrast agent subsequently in the scrutiny but sometimes non for several hours. The cause of the hydronephrosis is impairment or obstructor of drainage at some point, from the pelviureteric junction down to the vesica, normally due to calculus or tumour. It can besides be caused by vesica mercantile establishment obstructor.
Blunted and distended calyces
Chronic hydronephrosis is likely to be accompanied by loss of nephritic cerebral mantle
Simple ‘s alteration involves guaranting that there are delayed images of the affected kidney, initiated at around 20 proceedingss after injection, to let for more contrast agent to blend with the piss and better image contrast over the calyces and pelvic girdle. Imaging may be utile, particularly if gas and fecal matters make visual image even more hard. If the other kidney appears to be working, the remainder of the everyday facet of the scrutiny may go on, with farther delayed images of the affected kidney being supplied at intervals. Micturition is delayed until equal presentation of both kidneys has been achieved, unless several hours base on balls and this is non possible.
Hydronephrosis will attest itself as a consequence obstructor, and the radiographer will therefore initiate alteration for hydronephrosis, followed by methods to demo the site of obstruction.these include to sitting the patient fot 5 proceedingss or 10-15 proceedingss if the hydronephrosis is sevre and so set abouting a prone KUB image. Leaning the patient with their caput up for 5-15 proceedingss and set abouting a cross-renal image in this place. When the suspected site of obstructor is at or near the vesicoureteric junction, where the lower ureter lies behind the contrast filled vesica. At post-micturion phase, set abouting a KUB image to demo contrast and urine staying in the ureter above the site of obstructor.
If the CT is unavailable verification or exclusion of concretion is indispensable and the acutely sick patient will show in the exigency state of affairs. It is possible to maintain radiation exposures to a lower limit and a limited series is possible, suggested as:
Administration of contrast agent
KUB 15 proceedingss after injection
Nephritic Graft Patients
Although RN1 is most suited for appraisal of map of the transplanted kidney, IVU may be still be used in Centres with limited or no entree to this installation, or if it is suspected that the kidney is being compressed by abdominal or pelvic pathology. Transplant patient will hold one working kidney, the transplanted one, attached to a short ureter and placed in the right iliac pit. This negates the usage of compaction and affects the projection taken. Full length KUB is non appropriate, nor is transverse nephritic placement, and images should be confined to the pelvic part. If cassettes are used a 30 Ten 40 centimeter cassette, placed transversally in the tabular array bucky are most appropriate, with centring as for an AP pelvic girdle projection and including the vesica and anterior superior iliac spinal column ( ASIS ) in collimation. The method is as follows:
A control image of the country is taken, as described above
Contrast agent is injected
5 proceedingss after injection, another image of the country is taken
A post-micturition image of the country is taken
Clearly, any pathology or nephritic failure in the transplanted kidney will impact this modus operandi in the same manner as the other effects.
Radiation Protection and the IVU
Protection is afforded as for the AP venters for the AP supine kidneys, ureters and B ; adder projection, the supine or oblique projection of nephritic lineations require arrangement of lead gum elastic over the lower venters. Since the border of collimation for cross-renal, oblique and KUB projections falls following to breast tissue in the grownup female, it is recommended that lead gum elastic is besides placed over the chests for these images. The upper venters can be protected during the oblique vesica projection.