Last Week Topics

Question 1

Thyroid nodule management algorithm

Answer 1

Note: If first FNA indeterminate, wait 6-12 weeks and repeat (to avoid false positives from reactive changes caused by first FNA)

Question 3

Thyroid nodules greater than ___ in size are clinically significant and require further evaluation

Answer 3

Thyroid nodules greater than 1 cm in size are clinically significant and require further evaluation

Question 4

If a biopsy result for thyroid mass returns as medullary thyroid cancer, the next step is. . .

Answer 4

. . . MEN2 testing

If MEN2 testing is positive, urine metanephrines should be run to screen for pheochromocytoma. If present, this cancer takes precidence and should be dealt with prior to the medullary carcinoma.

Question 5

If a patient’s FNAB results are nondiagnostic, the next step is to. . .

Answer 5

. . . try FNAB again!

Repeat biopsy will obtain an adequate specimen the second time in 50% of cases

If this second biopsy failed, the surgery is recommended.

Question 6

Routine tests performed in a patient with a thyroid nodule who is clinically euthyroid

Answer 6

TSH and FNA biopsy

Question 7

Adrenocortical carcinoma

Answer 7

• Poor prognosis
• No biochemical markers to detect malignancy – criteria for cancer based on imaging findings
  
  • < 4 cm, can monitor, low risk malignancy
  • > 4 cm, higher risk malignancy, remove by open adrenalectomy

Question 8

Any adrenal incidentaloma ____ needs an evaluation – unless it is ___.

Answer 8

Any adrenal incidentaloma > 1 cm needs an evaluation – unless it is an obvious myelolipoma (fatty on imaging).

Question 10

You should NEVER biopsy a patient with an adrenal mass without ruling out. . .

Answer 10

. . . pheochromocytoma

Question 11

When you have an adrenal mass and you are not sure whether or not it is a pheochromocytoma after CT and metanephrines, what can you do?

Answer 11

I-131 metaiodobenzylguanidine scan

Used for confirmation or evaluation of nonlocalized pheochromoctyomia. Has specificity of 90-100% for pheos, but is not entirely sensitive.

Question 12

Types of focal liver lesion

Answer 12

• Hemangioma (benign)
• Focal nodular hyperplasia (benign)
• Hepatic adenoma (potentially malignant)
• Hepatocellular carcinoma (malignant)
• Cholangiocarcinoma (malignant)
• Metastasis from distant site (malignant)

Question 13

Liver hemangioma

Answer 13

• Most common benign liver tumor
• Typically asymptomatic, may cause vague abdominal pain, nausea, loss of apetite
• “Light bulb sign” is classical. Marked hyperintensity of the lesion relative to the surroundings with early filling of the rim and late filling of the central mass.
• Biopsy is contraindicated – highly vascular
• Surgical resection or embolization may be indicated for palliation of symptoms

Question 14

Focal nodular hyperplasia

Answer 14

• Benign liver tumor common in women in their 40’s-50’s
• Mostly asymptomatic
• “Central scar” appearance on CT
• May require biopsy to differentiate from hepatic adenoma

Question 15

Nodular regenerative hyperplasia

Answer 15

• Focal regeneration in the liver
• Thought to be related to obstructed blood flow in liver regions resulting in injury and subsequent regeneration
• Common in those over age 80
• No treatment necessary

Question 19

Triple phase CT scan

Answer 19

CT scan with IV contrast that acquires images at 30 seconds (arterial), 60 seconds (portal-venous), and 90 seconds (equilibrium)

Alows for better characterization of liver lesions

Question 20

Subtypes of hepatic adenoma

Answer 20

• Inflammatory:
  
  • High risk for bleeding, low risk for malignant transformation
• HNF-1 mutated:
  
  • No risk for bleeding or malignant transformation – benign
• Beta-catenin activated:
  
  • High risk for malignant transformation when > 5 cm in size

Question 21

CT scan has a reduced detection rate of hepatocellular carcinomas in patients with . . .

Answer 21

. . . cirrhotic livers

Cirrhosis makes it difficult to visualize the interior of the liver as well as you would otherwise

Question 22

Management of a new diagnosis of hepatic adenoma

Answer 22

• If on an OCP or taking anabolic steroids, STOP these medications
• If < 5 cm in size, risk of rupture and malignant transformation is low. These can be safely observed and managed expectantly.
  
  • Pregnancy is not contraindicated for women with <5 cm adenomas
• If > 5 cm in size, patient should be considered for tumor resection or ablation to reduce bleeding and malignant transformation risks

Question 23

Major risk factors for hepatocellular carcinoma

Answer 23

• Untreated hepatitis B virus (most important of all)
• Cirrhosis:
  
  • Fatty liver
  • Alcohol use disorder
  • Chronic untreated hepatitis C virus
  • Other etiologies of cirrhosis (less than the above three)

Question 25

Differentiating FNH from hepatic adenomas

Answer 25

Best test for this is radiolabeled sulfur colloid scintigraphy

This isotope is taken up by Kupffer cells in FNH, but not by adenomas.

This can be super helpful as the demographics affected by FNH and hepatic adenomas (middle aged, pre-menopausal women) are the same.

Question 26

Hemochromatosis on MRI

Answer 26

Increased liver density on CT, decreased signal on MRI

Question 27

Quick MRI trick to identify a hemangioma

Answer 27

They are one of the only lesions in the abdomen that exhibits the T2 shine phenomenon: Bright on DWI, bright on ADC

Question 28

Fat in an adrenal adenoma vs a myelolipoma

Answer 28

A myelolipoma is mostly fat, and so it will be fat attenuation on CT

Fat in a benign adrenal adenoma is mostly microscopic, so you cannot tell on CT. But, on MRI it will have reduced signal on in/out of phase imaging.

Question 29

Finding the parotid on CT

Answer 29

The parotid is quite fatty, and is slightly hypoattenuating on MRI. It is just medial to the pinna.

Question 30

How can you tell whether a renal cyst is simple or hemorrhagic?

Answer 30

Simple: T1 dark, T2 bright

Hemorrhagic (Extravasated blood): T1 bright, T2 gray

Question 31

Liver hemangiomas are *highly* __ on ultrasound

Answer 31

Liver hemangiomas are *highly*​ **hyperechoic** on ultrasound

Question 32

What is going on in this image?

Answer 32

Cobblestoning This is pulmonary alveolar proteinosis May be acquired, secondary, or genetic. Acquired is most common and involves anti-GM-CSF antibodies. Biopsy is the gold standard for dx.

Question 33

If you see a *simple* cyst on breast ultrasound. . .

Answer 33

. . . **it is benign and doesn't need a biopsy**

Question 34

Hill-Sachs deformity

Answer 34

Imprinting on the lateral aspect of the humeral head Results from anterior shoulder dislocation and banging of the humeral head against other parts of the bony scapula

Question 35

Signs of elbow fracture

Answer 35

Posterior: See fat pad at all Anterior: Sail sign

Question 36

Which types of femur fracture at higher risk for avacular necrosis?

Answer 36

Femoral neck fx, because the blood supply runs through here

Question 37

Scaphoid blood supply

Answer 37

Enters distally, flows proximally So, in scaphoid fx the proximal scaphoid is at risk for avascular necrosis

Question 38

Talonavicular joint

Answer 38

Question 39

Benign bone features

Answer 39

Did it have time to grow? Is the transition zone narrow?

Question 40

Typical metastatic disease staging scans

Answer 40

CT chest/abd/pelv + bone scan OR FDG PET CT

Question 41

If there is difference vs no difference between stress and rest nuclear heart scan

Answer 41

Difference: Cath lab! Save that myocardium None: No cath lab. That heart is dead and not coming back.

Question 42

Fatigue, anemia, guiac positive stool, but no evidence of acute bleed What test do you use to find it?

Answer 42

Tc99 blood cell/sulfur colloid scan

Question 43

When to f/u in 6 weeks for ovarian cyst

Answer 43

Abnormal features \> 5 cm

Question 44

Cogwheel sign

Answer 44

Nodular appearance of thickened

Question 45

Risk factors for ovarian torsion

Answer 45

Enlarged ovaries by any etiology (including ovarian hyperstimulation syndrome) Pregnancy Adhesions

Question 46

PCOS morphology on US

Answer 46

\> 20 follicles and/or \> 10 cc

Question 47

Ovarian torsion

Answer 47

Note: The presence of flow does NOT rule out torsion. Venous flow is more important than arterial flow.

Question 48

Endometriosis on US

Answer 48

Question 49

Fibroids on US

Answer 49

Often hypoechoic, cystic If there is anechoic material in the center, it is a degenerating fibroid

Question 50

Indications for OB ultrasound

Answer 50

During fetal survey, we are also assessing for previa. If previa is present, we will re-assess in the 3rd trimester to see if it is still there.

Question 51

Implantation bleed

Answer 51

Very common Bleed when trophoblast is implanting Not concerning. May consider serial bHCG until \> 2000, then re-image.

Question 52

Signs of 1st trimester abortion on US

Answer 52

Question 53

Subchorionic hematoma

Answer 53

Very common. Accounts for 20% of intrapartum bleeding Can tell its age based on US charactersitics.

Question 54

Placenta previa on US

Answer 54

Question 55

Air bronchograms are seen in. . .

Answer 55

. . . **any condition where pathology localizes to the alveolar space and spares the bronchi** Pneumonia, ARDS, pulmonary edema, pulmonary hemorrhage, and sometimes cancer. But, NOT fibrosis or empyhsematous change.

Question 56

In left lateral decubitus, which side is down?

Answer 56

The left The named side is the one that is down

Question 57

How can you tell if hydronephrosis is acute or chronic on ultrasound?

Answer 57

In chronic hydronephrosis, the renal cortex becomes thinner A normal cortex should be 7-10 mm, and a normal parenchyma should be 15-20 mm. Note the definition of cortical thickness here as C, while parenchymal thickness (P) includes the cortex and the calyces.

Question 58

Stopping metformin for CT contrast: 2 days before or 2 days after?

Answer 58

2 days after AND only restart creatinine is at patient baseline

Question 59

Preferred study to diagnose osteoporosis in patients with degenerative disc disease

Answer 59

Quantitative CT (QTC) scan

Question 60

Features of Charcot joint

Answer 60

Question 61

When to order an MRI in addition to x-ray for a patient with diabetc foot disease and soft tissue swelling

Answer 61

Always If there is soft tissue swelling, *always* Ulcer or not. Neuropathic foot disease or not. *Always*. They are VERY high risk.

Question 62

What determines whether someone gets hip hemiarthroplasty vs total hip arthroplasty?

Answer 62

Basically whether or not the acetabulum was injured and if there is any significant osteoarthritis If the acetabulum looks good enough, there is no need to replace it.

Question 63

Knee lipohemarthrosis indicates. . .

Answer 63

. . . ***some* intraarticular fracture** Most of the time it will be tibial plateau fracture, but NOT ALWAYS.