Renografin-60 Dosage

Excretion Urography

Appropriate preparation of the patient is desirable for optimal results. In adults and older children, a laxative the night before the examination, a low residue diet the day before, and low liquid intake for 12 hours prior to the procedure may be used to clear the gastrointestinal tract and to induce a partial dehydration which is believed to increase the urinary concentration of the contrast medium. Preparatory partial dehydration is not recommended in infants, young children, the elderly, or azotemic patients (especially those with polyuria, oliguria, diabetes, advanced vascular disease, or preexisting dehydration). The undesirable dehydration in these patients may be accentuated by the osmotic diuretic action of the medium.

In uremic patients partial dehydration is not necessary and maintenance of adequate fluid intake is particularly desirable.

Cerebral Angiography

Appropriate preparation of the patient is indicated, including suitable premedication. The average single dose for adults is 10 mL, repeated as indicated. Children require less in proportion to weight.

Either the percutaneous or operative method of administration may be used. For visualization of the cerebral vessels, the contrast medium is injected into the common carotid artery; for angiography of the vessels in the posterior fossa or the occipital lobes, the medium is injected into the vertebral artery. Since the medium is given by rapid injection, the patient should be watched for untoward reactions. Unless general anesthesia is used, patients should be warned that the medium may provoke movement and that they may feel transient pain, flushing, or burning during the injection.

A scout film should be made routinely before the contrast medium is injected. Serial films begun while the last few mL are being injected should permit visualization of the arterial, intermediate, and venous phases.

Peripheral Arteriography

Appropriate preparation of the patient is indicated, including suitable premedication. For visualization of an entire extremity, a single dose of 20 to 40 mL is suggested; for the upper or lower half of the extremity only, 10 to 20 mL is usually sufficient.

Injection is made into the femoral or subclavian artery by the percutaneous or operative method. Because the contrast agent is given by rapid injection, flushing of the skin may occur. Patients not under general anesthesia may experience nausea and vomiting or a transient feeling of warmth. Vascular spasm is not likely to occur.

A scout film should be made routinely before administering the contrast medium. Radiograms of the upper half of the extremity are taken while the last few mL are being injected, followed by radiograms of the lower half of the extremity a few seconds later.

Venography

For visualization of veins in the upper extremities, a single dose of 10 mL per extremity is suggested. For veins in the lower extremities, doses of 20 to 40 mL per extremity are suggested. In exceptional circumstances, larger doses may be necessary; visualization of the iliac vein, extensive varicosities or large veins may require 50 mL or more. Total doses up to 100 mL per lower extremity have been used safely.

For visualization of an upper extremity, the medium may be given by percutaneous injection into any convenient superficial vein of the forearm or hand. For the visualization of a lower extremity it should be injected into a superficial vein on the lateral side of the foot. The medium is injected rapidly; patients should be observed for untoward reactions.

Radiograms are taken when injection is completed; sufficient time should be allowed to permit diffusion of the contrast medium.

Operative and Postoperative Cholangiography

Operative cholangiography is performed as soon as the gallbladder and ducts have been exposed surgically. The usual dose is 10 mL but as much as 25 mL may be needed, depending on the caliber of the ducts. If desired, the contrast agent may be diluted 1:1 with Sodium Chloride Injection USP under strict aseptic procedures.

The contrast medium is instilled slowly through the stump of the cystic duct or directly into the choledochal lumen. Following surgical exploration of the ductal system, repeat studies may be performed before closure of the abdomen, using the same dose as before.

Postoperatively, the ductal system may be examined by injection of the contrast agent through an in-place T-tube. “T-tube cholangiography” is usually performed eight to ten days after operation; the usual dose is the same as for operative cholangiography.

For each procedure, films are taken immediately after instillation of the medium and are read immediately. Additional films are then taken if necessary.

Percutaneous Transhepatic Cholangiography

Facilities for emergency surgery should be available whenever this examination is performed. Appropriate premedication of the patient is recommended; drugs which are likely to cause spasm, such as morphine, should be avoided.

Depending on the caliber of the biliary tree, a dose of 20 to 40 mL is generally sufficient to opacify the entire ductal system. The contrast agent may be diluted 1:1 with Sodium Chloride Injection USP, if desired, under strict aseptic procedures.

Injection is made into a biliary duct by the percutaneous transhepatic method. Before the dose is administered, as much bile as possible is aspirated. The medium is then slowly injected into the duct under very slight pressure. If a duct is not located promptly, successive small doses of 1 to 2 mL are injected into the liver as the needle is gradually withdrawn, until a duct is visualized by x-ray. If no duct can be located after three or four attempts, the procedure is abandoned.

Serial films are taken rapidly during and after injection of the medium into the biliary ducts. Repositioning of the patient, if necessary, should be done with care.

In hepatocellular disease, the biliary ducts are generally not enlarged and cannot successfully be opacified by this method. Thus, in the presence of long-standing jaundice, failure to obtain a successful percutaneous transhepatic cholangiogram by a person experienced in the technique is generally considered to be strongly suggestive of nonobstructive or hepatocellular-type jaundice.

Splenoportography

Prior gastrointestinal x-ray examination should include particular attention to the lower esophageal area. A hematologic survey, including prothrombin time and platelet count, should be performed. The patient should have no food for several hours and should be mildly sedated. Splenoportography is usually performed under local anesthesia.

Approximately 20 to 25 mL of the contrast agent is usually adequate. The dose is injected rapidly, following radiologic location and percutaneous puncture of the spleen.

Preliminary films are taken to locate the spleen before the injection is begun. Rapid serial films are then started simultaneously with injection of the dose. Serial films are necessary since the entire portal system cannot be captured on a single film and also because of individual variations in portal circulation time.

Arthrography

The amount of contrast agent required is dependent on the size of the joint to be injected. For an adult, the following doses are generally suitable: knee-5 to 15 mL; shoulder or hip-5 to 10 mL; other joints-1 to 4 mL. Dosage for children should be suitably reduced.

The injection site should be prepared aseptically. Excessive synovial fluid should be aspirated to minimize pain and to reduce intra-articular dilution of the contrast agent. If indicated, the agent may be administered under local anesthesia. After injection of the medium, the joint should be manipulated gently in order to spread the medium throughout the joint space. In some instances, double contrast arthrography, injecting both air and contrast medium, has been of value.

Films are taken from several angles; stereoscopic films may be advantageous.

When the contrast agent is used to opacify a joint space, much of the agent may be aspirated at the end of the procedure.

Discography

No prior preparation of the patient is required, although administration of an analgesic or sedative 20 minutes before the procedure may be helpful. Discography is performed under local anesthesia using the usual aseptic precautions.

Dosage is generally determined by the amount of contrast agent which can easily be injected into the disk without force. A cervical disk will normally accept up to 0.5 mL and a lumbar disk 1 or 2 mL. The amount may vary, and injection should be discontinued when resistance is felt. The rate of injection may influence the amount which can be injected. To reduce the probability of extravasation and to minimize unnecessary pain, injection should be made slowly and not more than 2 mL should be injected into any one disk.

A two-needle technique may be used to administer the contrast medium, with a large-gauge needle to locate the disk and a small-gauge needle within the larger one to puncture the disk and administer the medium. The correct position of the two needles is established radiologically before the medium is injected.

Spot roentgenograms should be taken anteroposteriorly, obliquely, and laterally as soon as disks have been injected.

When the contrast agent is used for discography, it need not be aspirated at the end of the procedure.

Computed Tomography