Differentials

Question 1

Abnormal Renal Activity on MDP

Answer 1

Chemo, XRT, Antibiotics, Pyelo, ATN, RVT, Obstruction

Question 2

MDP Accumulation in Tumors

Answer 2

OSA Mets, NB, Breast, Meningioma, Lung, Mucinous Liver Mets, Malignant Effusions & Ascites

Question 3

Abnormal Stomach Activity on MDP

Answer 3

Free TcO4 ( check thyroid),HPT (check lungs )

Question 4

Breast Activity on MDP

Answer 4

Cancer, XRT, Mastitis, Bx

Question 5

Soft Tissue Activity on MPD

Answer 5

Breast or Lung Ca, Malignant Effusions & Ascites (Benign effusion causes attenuation), Brain & Heart Infarcts, Fibrothorax, XRT Pneumonitis
Diffuse = Venous or Lymphatic Obstruction, Soft Tissue Neoplasm, Crush or Thermal Injury, Surgery, XRT

Question 6

Muscle Activity on MDP

Answer 6

Over Use, MO/Hematoma, Ischemia, Compartment Syn, Rhabdomyolysis, Electrical Injury, Fe Dextran Injection

Question 7

Hepatic Uptake on MDP

Answer 7

Focal = Mets (Colon, Breast, Ovary), Hepatoma, Cholangiocarcinoma
Diffuse = Aluminum Contamination, Hepatic Necrosis, Colloid Formation during Preparation

Question 8

Spleen Uptake on MDP

Answer 8

SS, Thalassemia, Hemosiderosis, Hematoma, Infarct

Question 9

Lung Uptake on MDP

Answer 9

Mets, Metastatic Ca+, Fibrothorax, Malignant Effusion, Lung Cancer, XRT, Alveolar Microlithiasis

Question 10

Superscan

Answer 10

Mets, HPT, Pagets, SS/Thal, Leuk/Lymph

Question 11

Cold Defect on MDP

Answer 11

Tumor (RCC, Thyroid, Myeloma, Chordoma), Hemangioma, Osteomyelitis (High Pressure), AVN, XR, Attenuation (Metal, BaSO4)

Question 12

Increased RAIU

Answer 12

Graves, TMG, Early Hashimotos, Recoverying Dequivains, Iodine Rebound, Exogenous TSH

Question 13

Decreased RAIU

Answer 13

Hypothyroid, IV Contrast, Meds (PTU, Lugols, T3, T4), Subacute Thyroiditis, Late Hashimotos, Ectopic Thyroid Hormone (Synthroid, Struma Ovarii)

Question 14

Hot Thyroid Nodule

Answer 14

Adenoma, Adenomatous Hyperplasia, Very Rarely Cancer

Question 15

Cold Thyroid Nodule

Answer 15

Colloid Cyst, Nonfunctional Adenoma, Carcinoma, Abscess, Hemorrhage, Mets, Lymphoma, Parathyroid Adenoma

Question 16

Hot Liver Lesion on SC

Answer 16

FNH, Regenerating Nodule, Budd Chiari (Caudate Lobe), SVC Obstruction

Question 17

Cold Liver Lesion on SC

Answer 17

Mets, Adenoma, Abscess, Cyst, Hepatoma, Hemangioma

Question 18

Delayed Biliary-Bowel Transit HIDA

Answer 18

Obstruction (Partial, Total), Meds (Narcotics), Ascending Cholangitis

Question 19

Persistent Nephrogram

Answer 19

ATN, Obstruction, RVT, RAS (MAG3)

Question 20

False Positive ACEI Renogram

Answer 20

Dehydration, ACE Induced Hypotension

Question 21

Panda Sign

Answer 21

Sarcoid, Sjogrens, AIDS, XRT

Question 22

Diffuse Lung on Gallium

Answer 22

Sarcoid, PCP, Pneumoconioses, Active IPF, Drugs (Bleomycin), Pneumonia, XRT, HP ?miliary mets?

Question 23

Kidney > 24 hr on Gallium

Answer 23

Obstruction, Neoplasm, Pyelo, Vasculitis, ATN, Lymphoma

Question 24

Lung > 24 hr on In-111 WBC

Answer 24

Atelectasis, CHF, Pneumonia, ARDS, Emboli

Question 25

Bowel Activity on In-111 WBC

Answer 25

IBD, PMC, Diverticulitis, Ischemic Bowel, CMV

Question 26

V/Q – Whole Lung Mismatch

Answer 26

Large PE (Unusual), Tumor, Swyer James, Hypoplastic or Stenotic PA, Prior Shunt for CHD, Fibrosing Mediastinitis

Question 27

V/Q – Patchy NSGM Perfusion

Answer 27

COPD/Asthma, Tumor Microemboli, CHF, Vasculitis, Fat Emboli, Radio Pharmaceutical Problem

Question 28

Abnormally High LVEF

Answer 28

IHSS & Hypertrophic CM, Hyper-thyroidism, Regurg (AI/MR/VSD)

Question 29

Technical Screw Ups

Answer 29

Venous Extravasation (Lymphatic Uptake), Arterial Injection (Glove Like), “Hot Spots” Lungs (Syringe Drawback), Hot Liver on MDP (Al or Colloid), Fuzzy Pictures (Off Photopeak)