ABR IR/DR flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

TIPS target pressure gradient

The portosystemic pressure gradient after TIPS creation should be reduced to less than 12 mmHg, ideally 8 to 10 mmHg, to lower variceal rebleeding risk.

Y-90 lung shunt threshold

A lung shunt fraction greater than 20 percent (or 30 percent in some dose models) generally contraindicates radioembolization because of radiation pneumonitis risk.

Bosniak I cyst

A simple renal cyst with water attenuation, imperceptible wall, and no septa, calcification, or enhancement; it requires no further imaging or intervention.

LI-RADS LR-5 criteria

In an at-risk patient, a lesion 10 mm or larger with arterial phase hyperenhancement plus washout, capsule, or threshold growth is categorized LR-5, indicating definite hepatocellular carcinoma.

Adrenal adenoma HU cutoff

An adrenal incidentaloma measuring 10 HU or less on unenhanced CT is consistent with a lipid-rich adenoma and generally requires no further workup.

Silhouette sign right middle lobe

Loss of the right heart border on frontal chest radiograph indicates disease in the right middle lobe, which is anatomically adjacent to the right heart border.

Salter-Harris type I

A physeal fracture through the growth plate alone that may be radiographically occult; diagnosis may require clinical tenderness or MRI.

Ovarian torsion Doppler findings

Torsion typically shows an enlarged edematous ovary with peripherally displaced follicles and decreased or absent venous and arterial flow, though Doppler can be normal early.

PTC coagulation thresholds

Before percutaneous transhepatic cholangiography, correct INR above 1.5 and platelets below 50,000, and administer prophylactic antibiotics to reduce cholangitis risk.

Uterine artery embolization endpoint

UAE targets fibroid-related bleeding and bulk symptoms by embolizing bilateral uterine arteries; ovarian failure and nontarget embolization are recognized complications.

Internal jugular vein anatomy

The internal jugular vein lies lateral to the carotid artery within the carotid sheath; ultrasound guidance reduces arterial puncture and pneumothorax during central line placement.

Contrast nephropathy eGFR threshold

Risk of contrast-induced nephropathy increases substantially when eGFR is below 30 mL/min/1.73 m2; use the lowest contrast volume and avoid repeat dosing.

Pulmonary AVM embolization

Embolization of the feeding artery with coils or vascular plugs is preferred for pulmonary arteriovenous malformations; asymptomatic lesions with feeding arteries under 2 to 3 mm may be observed.

Lung biopsy pneumothorax risk

Pneumothorax risk after percutaneous lung biopsy is highest with small, deep nodules and underlying emphysema; a post-biopsy expiratory chest radiograph is standard.

ACR TI-RADS points

ACR TI-RADS assigns points for composition, echogenicity, shape, margin, and echogenic foci; total points and nodule size determine FNA and follow-up thresholds.

Chronic PE CT features

Chronic pulmonary embolism shows eccentric, web-like, or calcified filling defects with obtuse angles to the vessel wall and associated vessel narrowing or mosaic perfusion.

Acute PE CT appearance

Acute pulmonary embolism appears as a central filling defect outlined by contrast with acute angles to the vessel wall, often with vessel expansion.

Fat-containing renal mass

Macroscopic fat in a renal mass suggests angiomyolipoma; large or symptomatic lesions carry hemorrhage risk, and lipid-poor AML can mimic renal cell carcinoma.

Metformin and iodinated contrast

Current ACR guidance does not require withholding metformin in patients with normal renal function; withhold only if renal function is impaired or acute kidney injury develops.

Anaphylactoid contrast premedication

Premedication with corticosteroids and antihistamines is indicated for prior allergic-type contrast reactions, not for renal protection alone.

TIPS encephalopathy rate

Post-TIPS hepatic encephalopathy occurs in roughly 20 to 30 percent of patients and is typically managed with lactulose and lactulose-sparing strategies.

Coaxial biopsy technique

A coaxial needle system allows multiple tissue passes through a single pleural or capsular puncture, reducing repeated traversal and procedure time.

Bosniak IIF follow-up

A Bosniak IIF renal cyst has minimal enhancement or thickened septa and requires follow-up imaging to assess for progression rather than immediate surgery.

Bosniak IV cyst

A Bosniak IV renal lesion shows enhancing nodular components and is considered malignant, warranting surgical resection.

Adrenal washout study

For adrenal masses above 10 HU on unenhanced CT, delayed contrast-enhanced washout imaging can confirm adenoma using absolute and relative washout thresholds.

Silhouette sign lingula

Loss of the left heart border on frontal chest radiograph indicates lingular disease, as the lingula lies adjacent to the left heart border.

Salter-Harris type II

A physeal fracture extending through the growth plate and metaphysis, the most common type, often with a visible metaphyseal corner fragment.

Pulmonary nodule biopsy indications

Percutaneous biopsy is used to establish tissue diagnosis of indeterminate pulmonary nodules, especially when malignancy probability is intermediate or high and surgery is not immediate.

Thyroid nodule FNA threshold

ACR TI-RADS uses total points and size thresholds for FNA, such as 2.5 cm for TR4 nodules and 1.5 cm for TR5 nodules.

HCC washout definition

Washout is visually assessed hypoenhancement in the portal venous or delayed phase relative to the liver, a key LI-RADS major feature for hepatocellular carcinoma.

Cavoatrial junction tip

Central venous catheter tips should terminate at the cavoatrial junction, confirmed on post-procedure chest radiograph, to reduce arrhythmia and thrombosis risk.

Mosaic perfusion chronic PE

Mosaic attenuation on CT in chronic pulmonary embolism reflects heterogeneous lung perfusion due to chronic vascular obstruction and small-vessel disease.