NCCPA Diagnostic Studies 3 — Questions and Answers
Question 1: A 35-year-old woman has a hemoglobin of 9 g/dL, MCV of 72 fL, low serum ferritin, and elevated TIBC. What is the most likely diagnosis?
- Anemia of chronic disease
- Iron deficiency anemia (Correct answer)
- Thalassemia trait
- Sideroblastic anemia
Correct answer: Iron deficiency anemia
Low ferritin with elevated TIBC and microcytic anemia is the classic pattern of iron deficiency anemia.
Question 2: Spirometry shows FEV1/FVC ratio of 0.60 with no significant bronchodilator response. Which pattern does this represent?
- Restrictive lung disease
- Obstructive lung disease (Correct answer)
- Mixed pattern
- Normal spirometry
Correct answer: Obstructive lung disease
An FEV1/FVC ratio below 0.70 indicates airflow obstruction; lack of bronchodilator response suggests fixed obstruction as in COPD.
Question 3: A patient with suspected pulmonary embolism has a Wells score of 7. What is the next appropriate step?
- D-dimer testing
- CT pulmonary angiography (Correct answer)
- Ventilation-perfusion scan
- Lower extremity ultrasound
Correct answer: CT pulmonary angiography
A Wells score ≥5 indicates high pre-test probability for PE; CT pulmonary angiography (CTPA) is the definitive diagnostic test.
Question 4: Which lab finding best differentiates prerenal azotemia from acute tubular necrosis?
- Elevated serum creatinine
- BUN:creatinine ratio > 20:1
- Fractional excretion of sodium < 1% (Correct answer)
- Urine specific gravity < 1.010
Correct answer: Fractional excretion of sodium < 1%
FeNa < 1% indicates the tubules are intact and avidly reabsorbing sodium, consistent with prerenal azotemia rather than ATN.
Question 5: A 50-year-old male has a PSA of 5.2 ng/mL. What is the most appropriate next step?
- Repeat PSA in 5 years
- Begin testosterone therapy
- Transrectal ultrasound-guided prostate biopsy (Correct answer)
- Start finasteride
Correct answer: Transrectal ultrasound-guided prostate biopsy
An elevated PSA (>4 ng/mL) warrants further evaluation with prostate biopsy to rule out prostate cancer.
Question 6: A chest X-ray shows a 'sail sign' in a pediatric patient. What does this indicate?
- Pleural effusion
- Thymic shadow (Correct answer)
- Pneumothorax
- Lobar consolidation
Correct answer: Thymic shadow
The 'sail sign' on chest X-ray in children represents a normal thymic shadow, which can be mistaken for pathology.
Question 7: Which ECG finding is most associated with hyperkalemia?
- Prolonged QT interval
- Peaked T waves (Correct answer)
- Delta waves
- ST depression in V4-V6
Correct answer: Peaked T waves
Peaked (tall, narrow, symmetric) T waves are the earliest ECG manifestation of hyperkalemia.
NCCPA Diagnostic Studies 3
A 35-year-old woman has a hemoglobin of 9 g/dL, MCV of 72 fL, low serum ferritin, and elevated TIBC.
What is the most likely diagnosis?