A patient presents with right hypochondrium pain. Which of the following investigations should be done:
**Core Concept**
The patient's presentation of right hypochondrium pain is suggestive of gallbladder pathology, such as cholecystitis or gallstones. This condition often involves inflammation of the gallbladder, which can be caused by gallstones obstructing the cystic duct.
**Why the Correct Answer is Right**
The correct investigation for suspected gallbladder pathology is ultrasound of the gallbladder. This is because ultrasound is a non-invasive, cost-effective, and highly sensitive imaging modality for detecting gallstones and gallbladder inflammation. It can also evaluate the bile ducts and liver for any complications.
**Why Each Wrong Option is Incorrect**
* **Option A:** CT scan of the abdomen is not the first-line investigation for suspected gallbladder pathology. While it can be used for further evaluation or in cases of unclear diagnosis, ultrasound is preferred due to its non-invasive nature and lower radiation exposure.
* **Option B:** MRI of the abdomen is not typically used for gallbladder pathology. It may be used in cases of unclear diagnosis or when other imaging modalities are inconclusive, but it is not the preferred initial investigation.
* **Option D:** ERCP (Endoscopic Retrograde Cholangiopancreatography) is an invasive procedure that is usually reserved for therapeutic purposes, such as removing bile duct stones or stenting obstructed bile ducts. It is not a first-line diagnostic investigation for suspected gallbladder pathology.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that ultrasound is the first-line imaging modality for suspected gallbladder pathology due to its non-invasive nature, low cost, and high sensitivity for detecting gallstones and gallbladder inflammation.
**Correct Answer:** C. Ultrasound of the gallbladder.