M1: Intro to Med Imaging Flashcards by Adams Bruce Al-os

Produced by focusing a beam of high energy electrons onto a tungsten target. Electromagnetic radiation.

X-ray

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Person who Discovered Xray

Wilhelm Rontgen

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In Xray: Tissue of high density. High atomic numbers. Lighter grey or white.

Dense/Opaque (Greater Attenuation)

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In Xray: Darker than tissues of higher density.

Lucent (Lesses Attenuation)

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Plain Radiographs: Black in color. Lungs, bowel & stomach.

Air/Gas

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Plain Radiographs: Off white in color.

Bone

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Plain Radiographs: Light grey. Solid organs, heart, blood vessels, muscles & fluid filled organs such as bladder.

Soft tissues/water

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Plain Radiographs: Bright white in color.

Contrast material/metal

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Plain Radiographs: Dark grey in color. Subcutaneous tissue layer.

Fat

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Cassettes are inserted in the laser reader. ADC produces an image.

Computed radiography

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Detector screen containing silicon detectors. Produce electrical signal when exposed to x-rays.

Digital radiography

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Advantages of digital over conventional radiography: _______ of areas of interest.

Magnification

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Advantages of digital over conventional radiography: Alteration of _______.

Density

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Advantages of digital over conventional radiography: Measurement of ________ & _______.

Distances & Angles.

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Large computer storage facility. Images form different modalities are stored. Allows instant recall and display of patients’ imaging study. Easy accessibility for other hospital facilities.

Picturing & Archiving System (PACS)

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Constant stream of X-rays. Angiography and interventional radiology. Contrast studies on the GI tract. Guidance of therapeutic injections and arthrograms. Screening in theater.

Fluoroscopy

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Computer removes unwanted information from a radiographic image.

Digital Subtraction Angiography

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High atomic number. Strongly absorbs x-rays. Used in GI tract studies, CT scan, DSA & Arthrography. For enhancements.

Barium & Iodine (contrast materials)

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Cross sectional imaging with the use of x-rays. Rotating gantry on one side and a set of detectors on the other side. Images are analyzed by computers. Accurate display of cross-sectional anatomy, differentiation of organs and pathology.

CT scan

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CT scan has sensitivity to the presence of specific materials such as

Fat & Calcium

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Density measurement of water in CT scan

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Differentiation of normal blood vessels from abnormal masses. To make an abnormality more apparent. To demonstrate the vascular nature of a mass and thus aid in characterization.

Intravenous contrast

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Differentiation of normal enhancing bowel loops from abnormal masses or fluid collections. Diagnosis of perforation of the GI tract & of leaking surgical anastomoses.

Oral Contrast

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Example of Lab procedure that uses an Oral contrast

CT Enterography

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Detailed examination of the pelvis and distal large bowel

Rectal Contrast

CT scan: High Attenuation

High density

CT scan: Low attenuation

Low density

CT scan: Low density color

Black

CT scan: High density color

Light grey or white

Alteration of grey-scale settings. Image information can be manipulated to display various tissue of the body.

CT scan: Windows

Helical/Spiral CT scanners. Tube and detectors rotate as the patient passes through on the scanning table.

Multidetector Row CT scan (MDCT)

Number of row scanner in MDCT

16-320

Advantages of MDCT vs Conventional CT: Increase _______ of examination.

Increase

Advantages of MDCT vs Conventional CT: ________ examination at optimal levels of IV contrast concentration.

Rapid

Advantages of MDCT vs Conventional CT: Continues volumetric nature of data allows ______ high quality 3D and _________ reconstruction.

Accurate. Multiplanar.

For CT Enterography. Brain perfusion scanning. Planning of fracture repair in complex areas: acetabulum, foot & ankle, distal radius and carpus. Display of complex anatomy for planning of cranial and facial reconstruction surgery.

Multidetector CT (MDCT)

Disadvantages of MDCT: Ionizing _______.

Radiation

Disadvantages of MDCT: Hazard of IV ____________.

Contrast material

Disadvantages of MDCT: Lack of ________ of equipment.

Portability

Disadvantages of MDCT: Relatively High _______.

Cost

High frequency sound waves. For abdominal pathology.

Ultrasound

Basic component of an Ultrasound

Piezoelectric crystals

Reflected sound waves

Echoes

Varying sound wave reflection

Ethnogenicity

Ultrasound: Reflect more sound waves

Hyperechoic

Ultrasound: Hyperechoic color

White or Light grey

Ultrasound: Reflect less sound waves

Hypoechoic

Ultrasound: Hypoechoic color

Dark grey

Ultrasound: Black in color

Anechoic

Tissues distally receive more sound waves.

Ultrasound Acoustic Enhancement

In Ultrasound Acoustic Enhancement, what organs appear lighter.

Distal to gallbladder: urinary bladder or simple cyst.

Reverse effect. Darker.

Ultrasound Acoustic Shadowing

In Acoustic Shadowing, these appears darker.

Gas containing bowel, Gallstone, Renal stones & Breast malignancy "GGRB"

For the quantitation of blood flow. Confirm blood flow within organs (ex.testis to exclude torsion). Assess the vascularity of tumors.

Doppler Ultrasound

Doppler Ultz: Color of blood flowing away from the transducer.

Blue (Vein)

Doppler Ultz: Color of blood flowing towards the transducer.

Red (Artery)

Application of Ultrasound

Solid organs, Urinary tract, Breast, OB Gyn, Musculo & Small organs "SUBO MiSs"

Applications of Doppler Ultrasound

Vascular CS & Echocardiography "VE"

Disadvantages of Ultrasound: ________ dependent.

Operator

Disadvantages of Ultrasound: cannot penetrate _____ or ______.

Gas or bone.

Disadvantages of Ultrasound: _________ may obscure structures deep in the abdomen, such as the pancreas or renal arteries.

Bowel gas

Uses magnetic properties of spinning hydrogen atoms to produce images. Strong external magnetic field.

Magnetic Resonance Imaging

Magnetic strength

Tesla

MR signals depend on: ______ & _______ imaging.m

Tissue & Structural

MR signals depend on: number of hydrogen atoms present in tissue

Proton density

MR signals depend on: chemical environment of the hydrogen atom

Free water or bound by Fat

MR signals depend on: Flow

Blood vessels or CSF

MR signals depend on: ______ susceptibility.

Magnetic

MR signals depend on: ____ & ____ relaxation time.

T1 & T2

MRI Tissue Contrast Imaging: Color of increased water in T1 relaxation (edema, tumor, infarction, inflammation, infection hemorrhage ; hyperacute/chronic)

Dark

MRI Tissue Contrast Imaging: Color of increased water in T2 relaxation (edema, tumor, infarction, inflammation, infection hemorrhage ; hyperacute/chronic)

Bright

MRI Tissue Contrast Imaging: Color of low proton density, calcification, flow void in T1 & T2 relaxation.

Dark

MRI Tissue Contrast Imaging: Color of protein-rich fluid, fat, subcutaneous hemorrhage, melanin, slowly flowing blood, paramagnetic substances and laminar necrosis of cerebral infarction in T1 Relaxation.

Bright

MRI Tissue Contrast Imaging: Color of Methemoglobin (extracellular) in subacute hemorrhage in T2 Relaxation

Bright

MRI Tissue Contrast Imaging: Color of protein-rich fluid & paramagnetic substances in T2 Relaxation.

Dark

Ability to image tissues in various ways by manipulating the various electromagnetic fields it is able to generate. Spin echo, Gradient-recalled echo, Inversion recovery, Diffusion and Perfusion weighted imaging.

MRI: Pulse Sequences

For arterial anatomy & pathology. 3D. Arteries of the brain, renal & peripheral arteries.

Magnetic Resonance Angiography (MRA)

For venous sinuses of the brain.

Magnetic Resonance Venography (MRV)

In MRA & MRV: blood can appear as Black

Flow void

In MRA & MRV: blood can appear as White

Increased signal

Contrast MRI material, A Paramagnetic substance that causes T1 shortening leads to increased signal on T1-weighted images. This is highly toxic if unbound.

Gadolinium

Other name for Gadolinium

Diethylenetriamine Pentaacetic Acid (DTPA)

Indication for Contrast Material MRI in the Brain: Meningitis & Encephalitis.

Inflammation

Indication for Contrast Material MRI in the Brain: Primary metastasis

Tumors

Indication for Contrast Material MRI in the Brain: Recurrence after treatment

Tumor residua

Indication for Contrast Material MRI in the Spine: ________ to differentiate fibrosis to disc protrusion.

Post operative

Indication for Contrast Material MRI in the Spine: Discitis & Epidural abscess

Infection

Indication for Contrast Material MRI in the Spine: Primary metastasis

Tumor

Indicated for soft tissue tumors & Arhrography (Musculoskeletal System) and Characterization of tumors in liver, kidney & pancreas.

Contrast Material MRI

Imaging modality of choice for most brain and spine disorders.

MRI

MRI Advantages: Excellent soft tissue _____ & ______.

Contrast & Characterization

MRI Advantages: Lack of ______ from adjacent bones.

Artifact

MRI Advantages: _______ capabilities.

Multiplanar

MRI Advantages: Lack of ionizing _______.

Radiation

MRI Disadvantages: Examination takes _____.

Time

MRI Disadvantages: young children and infants usually require ________.

Anesthesia

MRI Disadvantages: Patients experiencing pain may require ________.

IV pain relief

MRI Disadvantages: Abdominal examination, ___________ may be required.

Antispasmodic

MRI Disadvantages: Safety issues r/t ___________ with the patient.

Ferromagnetic materials

MRI Disadvantages: High ________ noise levels. Use _______.

Auditory. Earplugs.

MRI Disadvantages: Fear of narrow space

Claustrophobia

MRI Disadvantages: Contrast reactions to _________. Allergy & ______ systemic fibrosis.

Gadolinium. Nephrogenic.

Acoustic Shadowing: near surface or skin

Linear

Acoustic Shadowing: deep organs like pancreas

Convex

Acoustic Shadowing: Transvaginal & Transrectal

Endocavitary

Imaging study for breast tissues. Detect Breast abnormalities.

Mammography

Two Basic forms of Mammography

Screening & Diagnostic

Used to check for breast CA after a lump or other sign or symptom of the disease has been found.

Diagnostic Mammography

Used to look for CA in women with NO symptoms & history of breast surgery. Goal is to detect small cancer in breast tissue.

Screening Mammography

Age at which Mammography must be started annually.

40 y/o

Recommended age for Mammography: with BRCA1 & 2 mutation carriers.

By age 30 but not before age 25

Recommended age for Mammography: Women with mother or sister with premenopausal breast CA and Women with 20% lifetime risk for Breast CA on family history: by age ____ but not before age ___. Or ___ years earlier than the age of diagnosis of the youngest affected relative.

30. 25. 10.

Recommended age for Mammography: Women with histories of mantle radiation received between ages ____ & ____. Beginning ____ years after the radiation therapy but not before age ____.

10 & 30. 8. 25.

Recommended age for Mammography: Women with biopsy-proven lobular neoplasia, ADH, DCIS, invasive breast CA, or ovarian cancer is _________.

Regardless of age

Mammography Findings: goes undetected & elude diagnosis.

False Negatives

Mammography Findings: may look like cancer. Biopsy done=non cancerous.

False Positives

Use of gamma radiation to form images following the injection of various radiopharmaceuticals.

Nuclear Med: Scintigraphy

An example of Radiopharmaceuticals

Radionuclide

Most commonly used for oncology. Isotope is attached to a biological compound to form a radiophramaceutical. Hot spot.

Positron Emission Tomography (PET)

In PET scan: 2-deoxyglucose labeled with the positron emitter fluorine-18.

FDG

PET scan Application: tumor staging, assessment of tumor response to therapy, differentiate benign fro, malignant masses and detect tumor recurrence.

Oncology

PET scan Application: non invasive assessment of myocardial viability in patients with coronary arterial disease.

Cardiac

PET scan Application: characterization of dementia disorders & localization of seizure focus in epilepsy.

CNS

Advantages of Scintigraphy: High ________.

Sensitivity

Advantages of Scintigraphy: _______ info is provided as well as _______ information.

Functional. Anatomical.

Disadvantages of Scintigraphy: Use of Ionizing _______.

Radiation

Disadvantages of Scintigraphy: ______ of equipment.

Cost

Disadvantages of Scintigraphy: Extra ______ in handling radioactive materials.

Care

Main disadvantage of Scintigraphy.

Nonspecificity

May reduce the nonspecificity of Scintigraphy

Combining Scintigraphy with CT or MRI

In MRI: Same for bones.

T1 & T2 Relaxation

Diagnostic procedure of choice for Bone

CT scan

Diagnostic procedure of choice for spine, brain, musculo & cardio

MRI

Diagnostic procedure of choice for abdomen

Ultrasound