| IV Contrast |
| General guidelines for renal function |
Young, healthy patients can generally receive IV contrast without renal function testing. Point-of-care creatinine testing is done for:
| ● |
Age > 65 |
| ● |
Diabetes |
| ● |
Known renal insufficiency |
Cr <1.7
(or GFR >60) |
Administer contrast (usually Omnipaque 350 mgI/mL). |
Cr 1.7-2.0
(or GFR 30-60) | The decision to administer contrast in these higher-risk patients is typically made through discussion between the radiology and referring attendings. Contrast (Visipaque 320 mgI/mL, usually at a reduced dose) may be administered if essential for diagnosis. Recommend IV fluids ± Mucomyst to reduce the risk of contrast-induced nephropathy. |
Cr >2.0
(or GFR <30) | Avoid contrast unless life-threatening scenario where contrast is essential for clinical decision-making. |
Trauma patient
(unknown GFR) | Visipaque 320 mgI/mL |
| Pediatric patient | Visipaque 320 mgI/mL |
● One kidney
● PE study
● Cardiac CTA
| Visipaque 320 mgI/mL |
Among the commonly used iodinated IV contrast agents, Visipaque 320 mgI/mL has much lower osmolality than Omnipaque 350 mgI/mL (290 mOsmol/kg versus 884 mOsmol/kg), and thus carries a lower risk of contrast nephropathy.
|
| Contrast phases |
| Arterial |
| ● Pulmonary arterial |
|
Bolus tracking
with ROI trigger in
main pulmonary artery |
● Early arterial
|
Evaluate vasculature
|
ROI trigger in ascending aorta: |
| ● |
Aorta CTA |
|
ROI trigger in abdominal aorta: |
| ● |
GI bleeding protocol |
| ● |
Mesenteric ischemia protocol |
| ● |
Trauma abdominal CTA protocol |
| ● |
Lower extremity run-off CTA |
|
25-30 sec
or bolus tracking
with ROI trigger
in aorta |
● Late arterial
● Corticomedullary
● Pancreatic
● Hepatic arterial
|
Evaluate for arterially enhancing masses (e.g. hypervascular malignancies) |
35-45 sec |
| Venous |
| ● Chest venous |
|
40 sec |
● Portal venous
● Nephrographic |
General venous phase used for most abdominal scans |
60 sec |
| ● IVC |
|
90 or 120 sec |
| ● Lower extremity veins |
|
120 sec |
| Delayed |
| ● Urinary collecting system (excretory phase) |
5 min |
| ● Cholangiocarcinoma |
10-20 min |
| ● Adrenal washout evaluation |
15 min |
|
KRISTIN PORTER, MD, PHD PAMELA JOHNSON, MD