Question:
The Hounsfield unit (HU) is a measure used in which imaging modality?
The Hounsfield unit (HU) is a measure used in which imaging modality?
Show Hint
Hounsfield scale measures X-ray attenuation in one cross-sectional modality.
Updated On: Jun 24, 2026
- CT
- MRI
- PET
- USG
Show Solution
Verified By Collegedunia
The Correct Option is A
Solution and Explanation
Step 1: The Hounsfield scale, named after Godfrey Hounsfield, quantifies the X-ray attenuation of a tissue in computed tomography (CT).
Step 2: On this scale water is arbitrarily assigned a value of 0 HU and air is about -1000 HU, while dense bone reads several hundred to over a thousand HU. The HU value of each voxel determines its grey-scale brightness on the CT image.
Step 3: The other modalities use different physical principles and units. MRI relies on signal intensity from proton relaxation, PET measures radiotracer uptake, and ultrasound (USG) depends on reflected sound waves, so none of them is described by Hounsfield units.
Step 4: Therefore HU is a measure of CT attenuation.
Step 2: On this scale water is arbitrarily assigned a value of 0 HU and air is about -1000 HU, while dense bone reads several hundred to over a thousand HU. The HU value of each voxel determines its grey-scale brightness on the CT image.
Step 3: The other modalities use different physical principles and units. MRI relies on signal intensity from proton relaxation, PET measures radiotracer uptake, and ultrasound (USG) depends on reflected sound waves, so none of them is described by Hounsfield units.
Step 4: Therefore HU is a measure of CT attenuation.
Was this answer helpful?
0
0
Top NEET PG Radiology Questions
- The occipitomental view of an X-ray of the paranasal sinuses (PNS) is called?
- A cancer patient undergoes radiotherapy. Pick the true statement regarding radiosensitivity of tissues:
- Identify the condition in the X-ray given below.
- A chest radiograph obtained in a male with hypertension. What will be the diagnosis?
- Identify the radiological sign given below.
View More Questions
Top NEET PG Questions
- A patient hailing from Delhi presents with fever, arthralgia, and extensive petechial rash for 3 days. Lab investigations revealed a hemoglobin of 9 g/ dL, a white blood cell count of 9000 cells/mm3, a platelet count of 20000 cells/mm3, and a prolonged bleeding time. The clotting time was normal. What is the most likely diagnosis?
- Which of the following statements is true about Trichomonas vaginalis?
- A lady from West Rajasthan presented with an ulcer surrounded by erythema on the right leg. Microscopy of the biopsy from the edge of the ulcer showed organisms with dark staining nuclei and kinetoplast. What is the most likely causative agent?
- A child presents with a fever and a rash. Urine examination showed cells with owl's eye appearance. What is the most likely diagnosis?
- Infection with Clonorchis sinensis is associated with an increased risk of__?
View More Questions