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Ch. 1 The Human Body: An Orientation
Marieb - Human Anatomy & Physiology 11th Edition
Marieb, Hoehn11th EditionHuman Anatomy & PhysiologyISBN: 9780136874034Not the one you use?Change textbook
All textbooksMarieb, Hoehn 11th EditionCh. 1 The Human Body: An OrientationProblem 25
Chapter 1, Problem 25

A man is behaving abnormally, and his physician suspects that he has a brain tumor. Which of the following medical imaging techniques would best localize the tumor in the man’s brain (and why)?
Conventional X-ray
DSA
PET
Ultrasound
MRI

Verified step by step guidance
1
Step 1: Understand the goal of the imaging technique, which is to localize a brain tumor accurately within the brain's soft tissue structures.
Step 2: Review the characteristics of each imaging method: Conventional X-ray is good for bones but poor for soft tissues like the brain; DSA (Digital Subtraction Angiography) visualizes blood vessels but not detailed brain tissue; PET (Positron Emission Tomography) shows metabolic activity but has lower spatial resolution; Ultrasound is limited in penetrating the skull and thus not effective for brain imaging.
Step 3: Recognize that MRI (Magnetic Resonance Imaging) provides high-resolution images of soft tissues, including detailed brain anatomy, making it excellent for detecting and localizing tumors.
Step 4: Consider the principle behind MRI, which uses strong magnetic fields and radio waves to generate detailed images of soft tissues without ionizing radiation, allowing clear differentiation between normal and abnormal brain tissue.
Step 5: Conclude that MRI is the best choice for localizing a brain tumor because it combines high spatial resolution with excellent soft tissue contrast, enabling precise identification of tumor location.

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Medical Imaging Techniques

Medical imaging techniques are tools used to visualize the internal structures of the body. Each method, such as X-ray, DSA, PET, ultrasound, and MRI, has unique principles and applications, affecting their ability to detect and localize abnormalities like brain tumors.
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Magnetic Resonance Imaging (MRI)

MRI uses strong magnetic fields and radio waves to produce detailed images of soft tissues, including the brain. It provides high-resolution, contrast-rich images that help accurately localize brain tumors without exposure to ionizing radiation.
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Limitations of Other Imaging Modalities for Brain Tumors

Conventional X-rays have poor soft tissue contrast, DSA visualizes blood vessels but not tumors directly, PET shows metabolic activity but with lower spatial resolution, and ultrasound is limited by the skull’s density. These limitations make MRI the preferred choice for brain tumor localization.
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Aiden has been suffering agonizing pain with each breath and has been informed by the physician that he has pleurisy.

a. Specifically, what membranes are involved in this condition?

b. What is their usual role in the body?

c. Explain why Aiden's condition is so painful.

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