RADIOLOGY

Editors: Jennifer Huang, MD and Anthony Micetich, MD
Reviewed by: Reza Imani, MD

Please note: the radiology chapter of the Vanderbilt Housestaff Handbook includes many images that are not viewable in the online version of the handbook. Please refer to the physical handbook for review of images. The online version of the handbook makes note of missing images.

Common Radiology Exams by Suspected Diagnosis

Musculoskeletal

Suspected diagnosis	Radiology exam
Fracture	X-rays CT (extremity) without contrast
Soft tissue infection	CT (extremity) with contrast MRI (extremity) with and without contrast
Osteomyelitis	X-ray (extremity) MRI (extremity) with and without contrast)
Bone or soft tissue tumors	MRI (extremity) with and without contrast)
DVT	Ultrasound doppler (extremity) venous (laterality)

Chest

Suspected diagnosis	Radiology exam
Pulmonary embolism	CT angiogram chest pulmonary embolism with contrast (CTPA)
Lung mass, metastases	CT chest with contrast
Pulmonary nodule	CT chest without contrast
Pneumothorax	X-ray chest portable (or 2 view), specify upright
Acute aortic syndrome	CT angiogram aorta with and without contrast

Abdomen/Pelvic

Suspected diagnosis	Radiology exam
Cholecystitis	Ultrasound abdomen limited (specify cholecystitis)
Pancreatitis	CT abdomen pelvis with contrast
Appendicitis	CT abdomen pelvis with contrast
Bowel obstruction	X-ray abdomen 1 view CT abdomen pelvis with contrast
HCC	CT abdomen with contrast, specify HCC in comments MRI abdomen with contrast, specify HCC in comments
Crohn's/IBD	CT abdomen pelvis enterography with contrast

Neurologic

Suspected diagnosis	Radiology exam
Brain mass/metastases	MRI brain with and without IV contrast
Stroke	MRI brain without contrast
Multiple sclerosis	MRI brain with and without contrast
Aneurysm or vascular injury	CT angiogram head and neck with and without contrast
Dural venous sinus thrombosis	CT venogram head
Intracranial hemorrhage	CT head without contrast
Spine trauma	CT (C/T/L) spine without contrast MRI spine without contrast
Spine tumor, infection, post-op	MRI (C/T/L) spine with and without contrast

Urogenital

Suspected diagnosis	Radiology exam
Testicular torsion	Ultrasound scrotal with complete doppler
Ovarian torsion	Ultrasound pelvic transvaginal
Ectopic pregnancy	Ultrasound pelvic transvaginal
Kidney stones	Ultrasound renal CT abdomen and pelvis without contrast
Pyelonephritis	Ultrasound renal CT abdomen and pelvis with contrast

See ACR appropriateness criteria for additional Information.
https://www.acr.org/Clinical-Resources/ACR-Appropriateness-Criteria

Basic Abdominal X-ray Interpretation

Often referred to as a KUB or GUAB film.

As with chest radiographs, use a systematic approach. Here are some important reminders:

Positioning

Supine films poorly evaluate for free air, but are fine for evaluating bowel gas pattern and tube positioning
Upright (preferred) or left lateral decubitus are more sensitive for free air

Lines/Tubes

Enteric tubes come in two general types at VUH:
NG/Suction (one radiopaque line)
Dobhoff/Feeding (two radiopaque lines with an opaque tip)
Enteric tubes should course midline inferior to the carina before taking a smooth rightward curve below the diaphragm and past the GE junction
Ideally, the tip and terminal sidehole of an NG tube should be below and oriented away from the GEJ
If post-pyloric placement is desired, the tube should terminate right of midline and resemble the "C-loop" of the duodenum
NGT radiograph will not include the lower abdomen or upper chest, so cannot fully evaluate bowel gas pattern. If the NGT is in the patient but not seen on the film, confirm that it is not coiled in the oropharynx, esophagus, or airway (confirm with CXR if necessary)

Bowel

Small bowel should be <3 cm, Large <6 cm, Cecum <9 cm; however a normal abdominal plain film cannot rule out obstruction
Presence of air in the rectum generally favors ileus rather than obstruction
Some seek to quantify stool burden by abdominal plain film, but this is insensitive and without objective thresholds

Pathologic Gas

Look for lucency adjacent to straight, opaque structures including the diaphragm, liver, and falciform (football sign) - Subdiaphragmatic - Outlines the serosal border of bowel (Rigler sign) - Bowel wall shouldn't have gas (pneumatosis) - Liver gas can be pneumobilia (prior ERCP/stent) or portal venous gas (from ischemic bowel)

Please refer to physical handbook page 525 for images of Rigler's (double wall) sign and Football sign

Stones and Bones

Kidney stones (Low dose CT Kidney Stone protocol is the preferred imaging modality for surveillance)
Incidental rib fractures, spine compression deformities, pelvic/hip fractures
Ingested foreign bodies
Surgical clips, embolic coils

Masses and Soft Tissue

The paucity of bowel gas or abnormal contour of intraluminal bowel gas can suggest a soft tissue mass in the abdomen, though this is better evaluated on CT
Kidney margins may be faintly visible, which is normal

Bladder

Foley projecting in right location?

Please refer to physical handbook page 525 for image of abdominal X-ray with Dobhoff placement

Basic Abdomen and Pelvis CT Interpretation

Structured search pattern and frequent windowing are important for evaluation of various structures and organs in the abdomen and pelvis.

Soft tissue window: for evaluation of solid organ and soft tissue structures
Bone windows: to identify fractures or osseous lesions
Lung windows: to evaluate lung bases. Also helpful for identifying intraperitoneal free air in the abdomen and pelvis.

Example of Routine CT Abdomen Pelvis Search Pattern and Dictation Template:

Lower Chest

Lung bases: consolidation, aspiration, atelectasis
Pleural effusion, pneumothorax
Pericardial effusion

Liver

Assess morphology, enhancement, masses, abscesses, vascular abnormalities, trauma

Please refer to physical handbook page 526 for associated liver image.

Liver trauma: laceration, hematoma, hemorrhage - Laceration: irregular linear/branching areas of hypoattenuation - Hematoma: intermediate to hyperdense collection between liver parenchyma and capsule - Vascular injury - Active hemorrhage: typically hyperdense compared to normal parenchyma

Gallbladder and Biliary Tract

Evaluate for dense gallstones, surrounding fat stranding or fluid, dilated biliary ducts

Pancreas

Assess morphology, enhancement, lesions, ductal dilation, peripancreatic fluid or stranding.

Please refer to physical handbook page 526 for associated pancreas image.

Pancreatitis: two subtypes (interstitial edematous and necrotizing) - Parenchymal enlargement, alterations in attenuation, indistinct margins, surrounding fat stranding, lack of parenchymal enhancement suggests necrosis

Spleen

Size, enhancement, trauma

Adrenal Glands

Morphology, masses

Kidneys and Ureters

Renal size, morphology, enhancement, masses, hydronephrosis, hydroureter, renal or ureteral stones.

Urolithiasis: distal obstructing ureteral calculus with upstream hydronephrosis

Please refer to physical handbook page 526 for associated urolithiasis images.

Pyelonephritis: wedge-like regions of parenchymal swelling and reduced enhancement relative to normal parenchyma - Complications: renal or perinephric abscess, renal papillary necrosis, emphysematous pyelonephritis (look for bubbly or linear streaks of gas, fluid collections with air-fluid levels)

Please refer to physical handbook page 527 for associated pyelonephritis image.

Urinary Bladder

Not well assessed when decompressed. Assess for wall thickening, masses, intraluminal debris, periserosal fat stranding.

Gastrointestinal Tract

Morphology of distal esophagus and stomach, bowel caliber, wall thickness, masses, mural enhancement, stool burden, appendix

Bowel obstruction: Dilated gas or fluid-filled loops of bowel (3-6-9 cm rule for upper limit of normal size for small bowel, colon, and cecum diameter), air-fluid levels, fecal matter in small bowel loops, transition point between dilated and collapsed loops of bowel

Please refer to physical handbook page 527 for associated bowel obstruction image.

Bowel perforation: assess for free air, pneumatosis, portal venous gas

Pneumatosis intestinalis: Intramural bowel gas. Linear lucencies or rounded bubbly collections. - Can be life-threatening secondary to ischemia, obstruction, enteritis/colitis, organ transplantation - Can also be incidental and secondary to benign etiology, making clinical context crucial

Please refer to physical handbook page 527 for associated pneumatosis intestinalis image.

Diverticulitis: Pericolonic fat stranding, segmental bowel wall thickening, mural hyperenhancement. - Complicated diverticulitis: perforation (free air and fluid), abscess formation, fistula formation (usually a chronic complication)

Appendicitis: - Base of appendix located between the ileocecal valve and apex of the cecum - Location of the tip of the appendix and length of the appendix are variable - Appendiceal dilatation (classically >6mm outer diameter), wall thickening and enhancement, intraluminal fluid, periappendiceal fat stranding, adjacent cecal thickening

Peritoneum

Free air, free fluid, fluid collections, peritoneal or omental nodularity/implants - Small volume of peritoneal fluid may be physiologic in female pts, particularly around menses - Fluid is generally hypodense. Hyperdense fluid may suggest hemoperitoneum, especially in context of trauma

Vasculature

Suboptimally assessed without intravenous contrast, best assessed with CT angiography - Portal, splenic, superior mesenteric veins: evaluate patency - IVC: contrast mixing in IVC can appear similar to a hypodense filling defect - Abdominal aorta (Please refer to physical handbook page 528 for associated AAA image): - Abdominal aortic aneurysm: focal dilatation >3 cm in maximum transverse diameter - Ruptured AAA: retroperitoneal hemorrhage adjacent to aneurysm, blood extending into perirenal or pararenal spaces or psoas muscles. High attenuation crescent representing acute hematoma within mural thrombus or aneurysm wall suggests impending rupture - Visceral arteries (celiac, splenic, common hepatic, renal, SMA, IMA) - Iliac, pelvic, and femoral arteries and veins

Lymph Nodes

Throughout the abdomen and pelvis. Evaluate size (general guideline is <10mm short axis), morphology, enhancement. - Lower chest, upper abdomen (gastrohepatic ligament, celiac, portocaval, porta hepatis), retroperitoneum, mesentery, pelvis (inguinal, mesorectal, sidewall)

Reproductive Organs

Generally not well evaluated with CT, can be used as an adjunct to imaging with ultrasound or MRI

Ovarian torsion: enlarged ovary, ovary shifted medially, twisted ovarian pedicle in the adnexa, adnexal fat stranding, underlying ovarian mass

Pelvic inflammatory disease: tubular adnexal "mass", fallopian tube thickening, uterosacral ligament thickening, complex pelvic free fluid, pelvic fat stranding or haziness

Abdominal Wall

Hernias, hematomas, solid or cystic masses, skin/soft tissue infection

Musculoskeletal

Important to assess using bone windows - Fractures - Destructive osseous lesions - Degenerative changes

Additional Resources for Abdomen and Pelvis CT Interpretation:

https://radiopaedia.org/cases/how-to-read-a-ct-of-the-abdomen-and-pelvis?lang=us
https://pubs.rsna.org/doi/10.1148/rg.210129

Gastrointestinal Fluoroscopy

Though plain film radiography and CT are crucial diagnostic tools, they are limited by their ability to only capture images at one point in time. Fluoroscopy allows for dynamic and functional imaging, which is often invaluable in evaluating gastrointestinal pathologies.

Esophagram

The exact technique varies by radiologist and the study indication; generally, the patient swallows several contrast boluses as images are obtained of the pharynx, esophagus, and proximal stomach
Potentially much more sensitive than CT for the evaluation of perforation or fistula; however, in the emergent setting a CT chest/abdomen with an appropriately timed water-soluble oral contrast bolus may suffice
Inpatient exams for indications other than perforation are nearly always appropriately deferred to the outpatient setting

Upper GI

Imaging is obtained of the esophagus, stomach, and duodenum to the ligament of Treitz; no imaging of the jejunum or ileum is obtained
Often utilized for evaluation of esophageal hernias, post-operative complications, and gastric outlet obstruction

Small Bowel Follow Through

Essentially this is an Upper GI with additional serial images obtained to follow the contrast bolus until it reaches the cecum
If obstruction is of concern, a version of this exam can be performed (Non-Fluoro SBFT) on the floor; after a period of gastric decompression via NGT the patient is instructed to drink 150-300 mL of water-soluble contrast while several serial abdominal radiographs are obtained until contrast reaches the cecum or the exam is aborted

Contrast Enemas

Often called barium enema, which is a misnomer since barium is rarely used
Typically performed to evaluate suitability of distal bowel for ostomy reversal

Dobhoff Tube Placement

A common misconception is that there is direct visualization of the tube during the placement; in the fluoroscopy suite the radiologists are placing tubes in the exact same manner as on the floor
The benefit is purely logistical since radiologists can take an immediate spot fluoro image to evaluate the tube position rather than needing to wait for an image to be obtained and interpreted
There is no safety benefit and a request for fluoro guided placement should not be considered to be above routine priority

Basic Chest X-ray Interpretation

Always use a systematic approach. It doesn't matter what the approach is, just be consistent. Below is one example of a search pattern.

Systematic Approach

Assess quality: AP vs. PA; upright vs. supine; patient positioning; Is the whole chest included?
Lines/tubes/drains/devices: What lines are present and are they in the expected locations? ET tube, central lines, NG tube/Dobhoff, Pacemaker, valve replacements
Airway: Is the trachea midline?
Mediastinum: Is it widened (masses, aortic injury, lymphadenopathy)?
Cardiac: Is the heart enlarged (cardiothoracic ratio (maximal horizontal cardiac diameter/maximal horizontal thoracic diameter [inner edge ribs]) on PA CXR should be about 0.4-0.5)
Pleural space: Is there a pneumothorax? Pleural effusion?
Rest of image: Look for soft tissue changes—foreign bodies, subcutaneous air. Look for bone abnormalities—fractures, masses. Look for abdominal pathology—air under the diaphragm, position of tubes

Please refer to physical handbook page 530 for chest X-ray images with landmark identification table.

Additional Resources for Chest X-ray Interpretation

https://radiologyassistant.nl/chest/chest-x-ray/basic-interpretation
Felson's Principles of Chest Roentgenology: a programed text. Available electronically on Eskind Biomedical Library.
https://radiopaedia.org/articles/chest-radiograph-assessment-using-abcdefghi?lang=us

Basic Non-Contrast Head CT Interpretation

Imaging exam of choice for pts with acute CNS symptoms or traumatic head injury.

High sensitivity for detection of neurosurgical emergencies (acute intracranial hemorrhage, mass effect, territorial infarct, brain herniation, or hydrocephalus).

Mnemonic for framework of quick Head CT review: Blood Can Be Very Bad

Blood

Appearance of blood varies by timing: - Acute blood is hyperdense (bright white) - Subacute (~1 week) blood becomes isodense to brain parenchyma - Chronic (>2 weeks) blood is hypodense (dark)

Epidural Hemorrhage (extra-axial)

Bleeding between dura mater and skull
Does not cross skull sutures, expands inwards toward the brain parenchyma. Lentiform shape
Often preceded by history of trauma, injury to middle meningeal artery (look for associated scalp injury, skull fracture)

Please refer to physical handbook page 531 for associated epidural hemorrhage image.

Subdural Hemorrhage (extra-axial)

Bleeding between dura and arachnoid mater
Does cross skull sutures
Crescent shape
Typically secondary to trauma with injury to bridging cortical veins
Subacute subdural hemorrhage can be difficult to identify as it tends to resemble grey matter

Please refer to physical handbook page 531 for associated subdural hemorrhage image.

Subarachnoid Hemorrhage (extra-axial)

Bleeding into subarachnoid space between arachnoid and pia mater
Most apparent around the circle of Willis or in the Sylvian fissure
CT sensitivity highly dependent on the amount of blood and time since hemorrhage
Most commonly secondary to trauma or spontaneously from aneurysmal rupture

Please refer to physical handbook page 532 for associated subarachnoid hemorrhage image.

Intraventricular Hemorrhage (extra-axial)

Blood within ventricular system
Can be primary (blood in ventricles with minimal parenchymal blood) or more commonly secondary (secondary extension of parenchymal or subarachnoid bleed into ventricles)
Tends to pool dependently, best seen in the occipital horns of the lateral ventricles

Please refer to physical handbook page 532 for associated intraventricular hemorrhage image.

Intraparenchymal Hemorrhage (intra-axial)

Can be spontaneous (no underlying lesion – hypertensive or amyloid-related hemorrhage) or due to an underlying lesion (tumor, vascular malformation, or cerebral venous thrombosis)
Traumatic intraparenchymal bleeding often is ipsilateral or directly contralateral to the site of injury (coup-contrecoup mechanism)
Spontaneous bleeding related to uncontrolled hypertension classically occurs in the deep grey matter structures (like basal ganglia and thalamus)

Please refer to physical handbook page 533 for associated intraparenchymal hemorrhage image.

Cisterns

Subarachnoid or basal cisterns = compartments within the subarachnoid space where CSF pools between arachnoid and pia mater. Contains vasculature and cranial nerves
Assess for hemorrhage (subarachnoid), effacement, and asymmetry
Multiple, with major cisterns including:
Sylvian cisterns: between frontal and temporal lobes
Suprasellar cistern: above the sella turcica, under the hypothalamus
Quadrigeminal cistern: between the tectum, splenium of the corpus callosum and the superior cerebellum
Prepontine cistern: anterior to the pons, posterior to the clivus
Cisterna magna

Brain

Please refer to physical handbook page 533 for associated brain image.

Gross evaluation of parenchymal structure, identification of major parenchymal abnormalities
Symmetry of bilateral sulci and gyri, sulcal effacement
Parenchymal attenuation:
Acute blood, calcification, IV contrast = hyperdense
Air, fat, ischemia, edema = hypodense
Grey-white matter differentiation: compare to the contralateral side. Loss of grey-white matter differentiation is an early sign of ischemic insult
Midline shift: evaluate the midline structures (falx cerebri, septum pellucidum) for mass effect

Edema

Cytotoxic edema: result of ischemia or infarction. Affects grey and white matter
Vasogenic edema: Usually related to a lesion (tumor or abscess). Blood-brain barrier disrupted. Affects mainly white matter with preserved grey-white matter differentiation

Herniation

Shifts of cerebral tissue from normal location into adjacent space
Secondary to a change in intracranial volume and increase in intracranial pressure (edema, tumor, hemorrhage)

Masses

Better assessed with intravenous contrast
Look for associated hemorrhage, edema, calcification, mass effect

Ventricles

Intraventricular hemorrhage (described above)
Be aware that dense choroid plexus calcifications may resemble acute intraventricular hemorrhage
Asymmetry
Hydrocephalus: important to determine if it is obstructive or communicating to identify the underlying cause
Temporal horns tend to dilate first in the setting of hydrocephalus
Ventricular effacement: thinning of ventricles; can be secondary to cerebral edema, space occupying lesion, hemorrhage

Please refer to physical handbook page 534 for associated ventricle images.

Bones

Important to evaluate bony structures with dedicated bone windows
Fractures of the calvarium and skull base may be subtle. Use signs of superficial soft tissue injury as a clue for underlying fractures
Presence of gas (pneumocephalus), blood, and opacification of sinuses may also hint at underlying fracture

Additional Resources for Head CT Interpretation:

https://radiopaedia.org/articles/ct-head-an-approach?lang=us
https://radiologyassistant.nl/neuroradiology
https://litfl.com/ct-head-interpretation/

Consults for Radiology Procedures

Radiology Procedures are performed by 3 separate consult services depending on the procedure requested.

These pagers are covered 24/7, often by the same person for up to a week at a time (home call, not night float), so kindly reserve overnight pages for true urgent/emergent indications and save non-emergent communications until the morning.

Consult Service	Vascular IR	CT/US Procedures	Fluoro/Neuro/MSK fluoroscopy
EPIC Order	"Inpt Consult to Interventional Radiology"	"Inpt Consult for Adult Image-Guided Procedures (CT/US)"	Call 20878 (Fluoroscopy) for scheduling & orders
Contact # (weekdays)	#20840 (MD desk)	#20120 (MD desk)	#20878 (Fluoro techs)
Contact # (nights & weekends)	Pager only	Pager only	#37185 (ER reading room)
Service Pager	835-5105	835-0770	N/A
Procedure Requested	• Active bleeding → Embolizations • Cholecystostomy • PTC (biliary drains) • Nephrostomy • Tunneled lines • Dialysis interventions • G-tube placement • IVC Filter • Drain repositioning	• Abscess drainage • Biopsies • Paracentesis • Thoracentesis	• Dobhoff tube placements • Lumbar punctures • Joint injections/aspirations • Esophograms • Upper GI Series • Small bowel follow-through • Contrast enemas

*Generally requires failed bedside/Inpt medicine procedures service attempt

Specific Procedural Questions

Pre-Procedure

(Contact consult services for case-specific requirements, guidelines below):

NPO @ MN prior to procedure if sedation is to be used (majority of cases). Local only cases do not require pt to be NPO (see IR or CT/US procedures consult note for details)
Labs required within 1 month of procedure or sooner if there is a clinical situation that can affect those lab values. Think Warfarin and INR, for example:
INR <1.5 for most procedures
Platelets >50K

Anticoagulation

Google "SIR anticoagulation guidelines 2019"
VUMC IR guidelines based on SIR 2019 guidelines are included at end of section

Inpatient Biopsies for Malignancy

Inpt biopsies are lowest priority on the CT/US procedures service given resource availability and will more than likely get bumped. We recommend that these get scheduled outpatient. - Place an outpatient consult to image guided procedures at time of discharge/through discharge tab in EPIC to facilitate outpt biopsies

Drain Management

Best to discuss directly with service that placed the drain (IR vs. CT/US vs. surgery) - Flush with 10 mL sterile saline q shift while inpt (flush into drain towards the pt and then place back to gravity or accordion suction bag)

If drain output decreases, either:

The collection (e.g. abscess) has been drained
The drain is clogged, malfunctioning, or mispositioned
Start with making sure there are no kinks in the drain, the 3 way is not clogged, and that the accordion drain is functioning
Next, ensure the drain flushes appropriately. What this means is: you can flush the drain with 10 ml of saline and when you place back to gravity/accordion drainage bag you get back what you flushed in. There should be no leakage around the drain at the skin at baseline or during flushing
If the drain is functioning, and there is still no output, obtain a CT w/ IV contrast to evaluate the collection and ongoing need for drainage
If the collection remains, and drain is appropriately positioned within the drain, it is likely clogged/malfunctioning. First ensure proper suction/3-way direction. If this is not the issue, you can consider instilling tPA into the catheter for 2 hours
- Would avoid in the setting of therapeutic anticoagulation given increased risk of bleeding unless discussed with procedural service
- Epic order: Alteplase (TPA) injection/infusion options → percutaneous drainage → 2mg or 4mg
If this doesn't improve output in 48 hours, consider repositioning drain (VIR consult)

Additional References

Labs and Anticoagulation for CT/US and Vascular IR Procedures

Based on 2019 SIR Consensus Guidelines. JVIR 2019; 1168-1184. The length of time anticoagulation is held may differ from these guidelines in certain clinical circumstances at the discretion of the proceduralist. Generally, may resume anticoagulation 24 hours after the procedure. More details about re-initiation of anticoagulation can be found in the SIR guidelines.

Low Risk Procedures

Screening Coagulation Laboratory Tests

PT/INR, platelet count, Hgb not routinely needed

Suggested Laboratory Thresholds for Most Patients

INR: correct to <3.0
Platelets: transfuse if <20,000

Suggested Laboratory Thresholds in Patients with Chronic Liver Disease

INR: n/a
Platelets: transfuse if <20,000
Fibrinogen: cryoprecipitate if <100

List Low Risk Procedures

Vascular: - Central venous catheter non-tunneled/tunneled line placement, removal and exchanges (e.g. port) - Dialysis access interventions (e.g. shuntograms) - IVC filter placement and retrieval - Laser ablation and phlebectomy - Lymphangiogram - Sclerotherapy for venous malformation - Transjugular liver biopsy - Venography and select venous interventions (e.g. adrenal vein sampling)

Nonvascular: - Superficial abscess drainage - Catheter exchanges (e.g., biliary, nephrostomy, abscess) - FNA/superficial biopsy - Gastrostomy and GJ exchanges - Appendicular skeleton bone biopsy, joint injections, peripheral nerve blocks - Thoracentesis - Paracentesis - Tunneled drainage catheter placement

Anticoagulation Management for Low Risk Procedures:

Medication	Recommendation
Heparin (unfractionated)	Do not withhold
LMWH (therapeutic)	Do not withhold
LMWH (prophylactic)	Do not withhold
Fondaparinux (Arixtra)	Do not withhold
Edoxaban (Savaysa)	Do not withhold
Rivaroxaban (Xarelto)	Do not withhold
Apixaban (Eliquis)	Do not withhold
Argatroban	Do not withhold
Bivalirudin (Angiomax)	Do not withhold
Dabigatran (Pradaxa)	Do not withhold

Antiplatelet Management for Low Risk Procedures:

Medication	Recommendation
Aspirin (81 or 325 mg)	Do not withhold
Clopidogrel (Plavix)	Do not withhold
Prasugrel (Effient)	Do not withhold
Ticagrelor (Brilinta)	Do not withhold
Cangrelor (Kengreal)	Do not withhold

NSAID Management for Low Risk Procedures:

Type	Recommendation
Short-Acting: Ibuprofen, Diclofenac, Ketoprofen, Indomethacin	Do not withhold
Intermediate-Acting: Ibuprofen, Diclofenac, Ketoprofen, Indomethacin	Do not withhold
Long-Acting: Meloxicam	Do not withhold

Glycoprotein IIb/IIIa Inhibitor Management for Low Risk Procedures:

Type	Recommendation
Long-Acting: Abciximab (ReoPro)	Withhold 24 hours
Short-Acting: Eptifibatide (Integrilin), Tirofiban (Aggrastat)	Withhold 4 hours

High Risk Procedures

Screening Coagulation Laboratory Tests

PT/INR, platelet count, Hgb

Suggested Laboratory Thresholds for Most Patients

INR: correct to <1.8 (<1.5 if neuro procedure)
Platelets: transfuse if <50,000

Suggested Laboratory Thresholds in Patients with Chronic Liver Disease

INR: <2.5 (<1.5 if neuro procedure)
Platelets: transfuse if <30,000
Fibrinogen: cryoprecipitate if <100

List of High Risk Procedures:

Vascular: - Angiography and arterial interventions (e.g. chemoembolization, renal embolization, uterine embolization) - BRTO/BATO - Catheter directed thrombolysis (e.g. DVT, PE, portal vein) - Complex IVC filter removal - Lymphangiogram with thoracic duct embolization - Portal vein interventions - Pulmnonary artery malformation embolization - Transjugular intrahepatic portosystemic shunt (TIPS)

Non-Vascular: - Ablations (e.g., cryoablation, microwave ablation, radiofrequency ablation) - Deep abscess drainage - Biliary interventions (new placement e.g. cholecystostomy) - Deep non-organ biopsy (e.g., retroperitoneal, pelvic, intra-abdominal) - New Gastrostomy and GJ tube placement - Axial skeleton biopsy, bone marrow biopsy - Neuro: epidural injection, facet block, LP, myelogram, vertebral biopsy - Solid organ biopsy (e.g. liver, kidney, lung) - Spine procedures - Urinary tract interventions (nephrostomy tube placement, ureteral dilation)

Anticoagulation Management for High Risk Procedures:

Medication	Recommendation
Warfarin (Coumadin)	Withhold 5 days, goal INR <1.8. Bridging per PCP/Cardiology)
Heparin (unfractionated)	Withhold IV for 4 hours, Withhold SQ for 6 hours
LMWH (therapeutic)	Withhold for 24 hours
LMWH (prophylactic)	Withhold for 12 hours
Rivaroxaban (Xarelto)	Withhold: 2 days (if CrCl≥30), 3 days (CrCl<30)
Edoxaban (Savaysa)	Withhold 2 days
Fondaparinux (Arixtra)	Withhold: 2 days (if CrCl≥50), 3 days (if CrCl<50)
Apixaban (Eliquis)	Withhold: 2 days (if CrCl≥50), 3 days (if CrCl<50)
Argatroban	Withhold for 2 hours
Bivalirudin (Angiomax)	Withhold for 2 hours
Dabigatran (Pradaxa)	Withhold: 2 days (if CrCl≥50), 3 days (if CrCl<50)

Antiplatelet Agent Management for High Risk Procedures:

Medication	Recommendation
Aspirin (81 or 325 mg)	81mg: Do not withhold; 325mg: Withhold 5 days unless angiography or neuro procedure
Clopidogrel (Plavix)	Withhold 5 days unless angiography/embolization
Prasugrel (Effient)	Withhold 7 days
Ticagrelor (Brilinta)	Withhold 5 days
Cangrelor (Kengreal)	Avoid; if emergent withhold 1 hour

NSAID Management for High Risk Procedures:

Type	Recommendation
Short-Acting: Ibuprofen, Diclofenac, Ketoprofen, Indomethacin	No recommendation
Intermediate-Acting: Ibuprofen, Diclofenac, Ketoprofen, Indomethacin	No recommendation
Long-Acting: Meloxicam	No recommendation

Glycoprotein IIb/IIIa Inhibitor Management for High Risk Procedures

Type	Recommendation
Long-Acting: Abciximab (ReoPro)	Withhold 24 hours
Short-Acting: Eptifibatide (Integrilin), Tirofiban (Aggrastat)	Withhold 4 hours

Contrast Allergies or Extravasation

See ACR contrast manual for additional Information
https://www.acr.org/Clinical-Resources/Contrast-Manual

Examples of Premedication Regimens

Methylprednisolone 32mg PO 12, 2 hrs prior ± Benadryl 50mg PO 1 hr prior OR
Prednisone 50mg PO 13, 7, 1 hr prior ± Benadryl 50mg PO 1 hr prior OR
Hydrocortisone 200mg IV 5 hrs and 1 hr and Benadryl 50mg IV 1 hr prior

Regimen by Problem

Hives/diffuse erythema: Can observe - If associated with hypotension or respiratory distress, considered anaphylaxis. Treat with IVF, epinephrine, and supplemental O2 - If only skin findings but severe and/or progressive, can give Benadryl 50mg PO, IV or IM

Laryngeal edema (inspiratory stridor): epinephrine

Bronchospasm: beta-2 agonist inhaler 2 puffs x3, epinephrine if not responsive or severe

Hypotension with tachycardia: IVF, epinephrine, supplemental O2

Hypotension with bradycardia: IVF, atropine if refractory, supplemental O2

Contrast extravasation: elevate arm (heart level), cool compress, remove rings; consider surgical consultation for decreased perfusion, sensation, strength, active ROM, or increasing pain