Untitled Quiz

Imaging Modalities

• Imaging modalities are techniques used to visualize internal body structures.
• Different modalities offer various advantages and disadvantages.
• Different types of imaging modalities include ultrasound, fluoroscopy, computed radiography, computed tomography, magnetic resonance imaging, nuclear medicine, bone densitometry, PET scan, SPECT scan, and radiation therapy.

Ultrasound

• Ultrasound, also known as sonography, uses sound waves to create images of internal structures.
• It is a noninvasive, safe procedure that does not use radiation.
• It provides real-time images of soft tissues, making it useful for examining pregnant women and their unborn babies.
• Ultrasound is widely available, easy to use, and less expensive than other imaging methods.

Disadvantages of Ultrasound

• Difficult to image large patients and structures obscured by air or gas (eg, lungs, bowel).
• Limited ability to penetrate bone.
• Images only show the outer surface of bony structures.

Fluoroscopy

• Fluoroscopy is a medical imaging procedure that uses X-rays to create images of internal organs in real time.
• It allows visualization of organ movements.
• Used in diagnostic and interventional procedures.
• Types of Fluoroscopy include barium swallow, barium enema, and angiography.
• Angiography involves identifying and diagnosing narrowing or blockages in arteries.

Advantages of Fluoroscopy

• Allows observation of movement and function of internal organs.
• Provides real-time images, allowing for better visualization of anatomical structures in motion.
• Guides procedures like surgeries, catheter placements, and biopsies.

Disadvantages of Fluoroscopy

• Higher radiation doses compared to other imaging modalities.
• Exposure poses a risk of developing cancer later in life.
• Some procedures may be uncomfortable.

Computed Radiography

• Computed radiography (CR) uses a phosphor imaging plate to create a digital image.
• It's a bridge between analog and digital radiography.
• CR is widely available, and offers a low upfront investment.
• Effective for smaller or low-volume clinics.

Advantages of Computed Radiography

• Low upfront investment.
• High compatibility with wide range of traditional systems.
• The same plate can be used again and again.
• Images are stored and manipulated electronically.

Disadvantages of Computed Radiography

• Long time to view images.
• Risk of overexposure.
• High maintenance requirements.
• Risk of damage from improper handling or abuse.

Digital Radiography

• Digital radiography (DR) utilizes digital detectors to create images directly from X-rays.
• Advantages include improved image quality and ease of use.
• It can reduce radiation exposure to patients and staff due to reduced retakes.
• Fast processing and storage.

Advantages of Digital Radiography

• Higher image quality, more reliable images, reduced retakes, and faster processing.
• Cost savings due to elimination of chemicals and darkroom operations.
• Easy-to-use software for adjustment of brightness, contrast, and magnification (zoom, pan).

Disadvantages of Digital Radiography

• High initial investment in equipment such as computers, servers, and storage devices.
• Need for more storage space.
• Risk of intentional manipulation of images.
• Radiographic film gives a greater resolution compared to digital imaging.

Computed Tomography Scan

• A CT scan produces detailed cross-sectional images of the body using X-rays.
• CT scans show internal structures that are difficult to see with standard X-rays.
• They are commonly used to diagnose injury, cardiovascular disease, and strokes.

Advantages of Computed Tomography Scan

• Rapid image acquisition.
• Specific information, detailed image output.
• Allows imaging of a small or large portion of the body in a single examination.

Disadvantages of Computed Tomography Scan

• Concerns about exposure to ionizing radiation.
• Potential for allergic reactions or other side effects due to contrast agents.

Magnetic Resonance Imaging

• MRI uses a large magnet and radio waves to produce detailed images of body structures.
• No ionizing radiation is used.
• Provides high contrast images of soft tissues, unlike X-rays, better distinguishing between muscle, fat, water etc
• Can be used for imaging any part of the body (e.g., head, abdomen, joints, etc.).

Advantages of Magnetic Resonance Imaging

• Creates detailed images of soft tissues (muscle, fat, water etc.), distinguishing between tissues.
• Enables imaging from all sides of the body, useful in detecting cancers, other illnesses, and injuries.
• Non-invasive procedure, doesn't use ionizing radiation.

Disadvantages of Magnetic Resonance Imaging

• Might create loud knocking noises.
• Prone to peripheral nerve and muscle stimulation (twitching sensation).
• Long MRI scans may cause heating.
• May require the removal of metal objects from patients.

Nuclear Medicine

• Nuclear medicine uses radioactive materials to examine organ function and structure.
• Used in diagnosis and treatment of diseases.
• Radiotracers are small amounts of radioactive compound bound with a molecule that tends to collect in places where abnormal processes are occurring such as tumors.

Advantages of Nuclear Medicine

• The absorption rate of the radiotracer shows the activity level of different organs and tissues.
• Diagnoses disease processes early in progression, allowing for effective treatment options.
• Assist in guiding therapeutic interventions, like killing or shrinking tumors.

Disadvantages of Nuclear Medicine

• Higher radiation doses compared with other imaging modalities.
• Potential side effects from radioactive materials.
• Some procedures are time-consuming, more complicated.

Bone Densitometry or Dual-energy X-ray Absorptiometry

• Measures bone mineral density.
• Uses a small dose of X-ray to produce pictures of the inside of the body, typically the lower or lumbar spine and hips.
• Widely used for diagnosing osteoporosis (low bone density).
• It is commonly used for diagnosing bone fractures and to evaluate bone loss.

Advantages of Bone Densitometry

• Straightforward procedure.
• Rapid and quick scan.
• Noninvasive technique providing peace of mind for staff and patients.

Disadvantages of Bone Densitometry

• Some central DXA devices are more expensive than the standard DXA models
• It is not useful in patients suffering from spinal deformities etc.
• Other imaging modalities like CT scans may be more appropriate for some patients, especially those with spinal abnormalities.

PET Scan

• Positron emission tomography (PET) scans utilize radioactive tracers that are absorbed differently by organs and tissues in the body, allowing doctors to visualize those processes in motion.
• Images of the body's internal workings; not just structures.
• Helps in cancer diagnosis and treatment planning.

Advantages of PET Scan

• Provides detailed images of organ and tissue function (different tissue/organs uptake different amounts of radioactive compound).
• Very helpful in detecting tumors that may not be visible using other modalities.
• Shows the response to treatment and helps in treatment planning.

Disadvantages of PET Scan

• Higher radiation exposure compared to traditional X-rays.
• Relatively expensive and not as widely available as X-rays, CT and other imaging methods.
• Radionuclides decay quickly, requiring their production close to the examining location.

SPECT Scan

• Single-photon emission computed tomography (SPECT) is a nuclear imaging modality.
• Evaluates organ perfusion and function.
• Helps evaluate the workings of the heart, brain etc.
• A SPECT scan can identify areas of abnormality while viewing tissue function.

Advantages

• Allows evaluation of both organ perfusion and function.
• Relatively less expensive than a PET scan.
• Good sensitivity for myocardial viability.
• Can be used alongside other imaging devices.

Disadvantages

• Lower spatial resolution than other methods.
• Higher cost compared to some other methods such as echocardiography.

Radiation Therapy

• Radiation therapy uses high-energy radiation to damage or destroy cancer cells.
• It can be used externally or internally (through the insertion of radioactive material).
• The type of treatment depends on factors such as the type and size of the tumor, and patient health history.

Advantages of Radiation Therapy

• Cure certain small tumors when used alone.
• Shrinks tumors before surgery, making them easier to operate on.
• Preserves body organs, such as the breasts if tumors are in the chest area.
• May trigger an immune response to aid in killing cancerous cells.

Disadvantages of Radiation Therapy

• May damage healthy tissues in the area of treatment.
• Possibility of secondary cancer.
• Some procedures are time-consuming and inconvenient.