Correct Answer: D

Rationale: The correct answer is D: A HIDA scan. A HIDA scan is the most appropriate imaging study for investigating the likely cause in this case because the patient's symptoms (abdominal pain centered on the right side just under the ribcage, tenderness in the right upper quadrant) are suggestive of a possible gallbladder issue, such as cholecystitis or biliary colic. A HIDA scan is specifically used to evaluate the gallbladder and biliary system. A: Abdominal radiographs would not provide detailed information about the gallbladder or biliary system, and are not the best choice in this scenario. B: A CT scan of the abdomen with contrast can be helpful in some situations, but it may not provide the specific information needed to evaluate the gallbladder and biliary system. C: Right upper quadrant ultrasound is a good initial imaging study for evaluating gallbladder disease, but a HIDA scan is more specific for functional assessment of

Correct Answer: B

Rationale: The correct answer is B: Myelomeningocele. McEwen sign refers to the characteristic scalloping of the frontal bones due to pressure from the expanding brain in individuals with myelomeningocele. This sign is specific to myelomeningocele and is not associated with hydrocephalus (A), microcephaly (C), or encephalocele (D), which have different clinical manifestations and imaging findings. Myelomeningocele is a neural tube defect where the spinal cord and its coverings protrude through an opening in the spine, leading to neurological deficits and associated signs like McEwen sign.

Correct Answer: B

Rationale: The correct answer is B: FALSE. In mild preeclampsia, the mother may have symptoms such as mild hypertension, proteinuria, and swelling. This contradicts the statement that the mother has no complaints. Choice A is incorrect because it inaccurately states that the mother has no complaints. Choices C and D are not applicable as they do not provide any relevant information to address the question.

Correct Answer: C

Rationale: The correct answer is C: Multiple gestation. Preterm birth is more common in multiple gestation pregnancies due to the increased strain on the mother's uterus and cervix. This can lead to early labor and delivery. Social habits (choice A) and genetic factors (choice B) may play a role in preterm birth but are not highly associated. Chronic conditions (choice D) can also contribute to preterm birth, but multiple gestation is a stronger predictor.

Correct Answer: B

Rationale: The correct answer is B because the absence of any other abnormal findings suggests that Mr. Thornton is currently experiencing an anterior wall infarction. This is indicated by the localized area of myocardial necrosis due to prolonged ischemia. Option A is incorrect because ischemia would typically present with reversible changes rather than necrosis. Option C is incorrect as NSTEMI would show some abnormal findings. Option D is incorrect as STEMI would show more significant ECG changes and enzyme elevation. In summary, the absence of other abnormalities points towards an acute event like an anterior wall infarction.