Download MBBS Anatomy PPT 12 Principles Of Radiology Notes

Radiology

--- Content provided by FirstRanker.com ---

? Means Science of radioactive substances and high energy radiations.

? Is a branch of medicine concerned with use of radiant energy or radioactive

material in the diagnosis and treatment of diseases.

--- Content provided by FirstRanker.com ---

Discovery of X Rays by...

WC Roentgen

--- Content provided by FirstRanker.com ---

In the year...

1895

Classification of radiological procedures

--- Content provided by FirstRanker.com ---

? Diagnostic radiology
? Interventional radiology
? Computed tomography (CT)
? Magnetic resonance imaging (MRI)

--- Content provided by FirstRanker.com ---

? Ultrasonography (USG)
? Mammography
? Interventional radiology

X ray generator

--- Content provided by FirstRanker.com ---

Diagnostic radiology

? Plain radiography

--- Content provided by FirstRanker.com ---

? Fluoroscopy
? Observing moving body structures

--- Content provided by FirstRanker.com ---

Plain radiography

? A/k/a X Rays/ Skiagrams/ Radiographs
? Radiosensitive film

--- Content provided by FirstRanker.com ---

? Negative- black and white
? Farther the structure ? image is magnified but borders are less sharp.
? Only 2D representation.
? For skeletal system and internal organs.
? Not much use in soft tissue injuries and abnormalities eg. tendon, ligament

--- Content provided by FirstRanker.com ---

etc.

Fundamental principles for radiography

--- Content provided by FirstRanker.com ---

? Radio-opacity

? Positioning

? Different body tissues have different

--- Content provided by FirstRanker.com ---

capacity to block or absorb X Rays

depending on density of structure.

--- Content provided by FirstRanker.com ---

Positioning

A P View

Lateral View

--- Content provided by FirstRanker.com ---

P A View

Radiological features of skeletal system

--- Content provided by FirstRanker.com ---

General features of long bone

? Compact bone-- thick , homogenous calcified

band

--- Content provided by FirstRanker.com ---

? Nutrient canal-- oblique radiolucent line

passing through compact bone

--- Content provided by FirstRanker.com ---

? Cancellous bone? network with spaces , clear

at ends of shaft.

? In young-- uncalcified epiphyseal plate-

--- Content provided by FirstRanker.com ---

irregular radiolucent band.

? Metaphysis? calcified epiphyseal plate and

--- Content provided by FirstRanker.com ---

new bone near it.


General features of Joints

--- Content provided by FirstRanker.com ---

? Articular disc-- not visible.

? Joint space? interval between epiphyseal areas of

adjacent bones.

--- Content provided by FirstRanker.com ---

Skeletal maturity

? Based on ossification centres and their fusion.

--- Content provided by FirstRanker.com ---

? Varies in sexes, race, geographical location and nutritional status.

Fluoroscopy

? Real time observation of moving organs.

--- Content provided by FirstRanker.com ---

? Image is created by striking X rays on a fluorescent screen coated with

phosphor and recorded electronically.

? High radiation exposure and low resolution of image.

--- Content provided by FirstRanker.com ---

Role of contrasts

? To differentiate structures of same density.
? Barium contrasts for diagnosis of abnormal constrictions and growths

--- Content provided by FirstRanker.com ---

of gut tube.

? Intravenous pyelogram

--- Content provided by FirstRanker.com ---

? Hysterosalpingography


Iodinated contrasts for
? arteriograms,

--- Content provided by FirstRanker.com ---

? venograms,
? myelograms.

Digital subtraction angiograms

--- Content provided by FirstRanker.com ---

Vascular interventions

? Peripheral vascular disease? Balloon angioplasty
? Percutaneous Transluminal Coronary Angioplasty
? Stent placement

--- Content provided by FirstRanker.com ---

Prevent Avascularity

? Blood clot dissolving drugs are pushed into the artery through a

--- Content provided by FirstRanker.com ---

catheter.

Vascular interventions

? Aneurysms- Coils, Stents

--- Content provided by FirstRanker.com ---

? Haemorrhage- Embolisation- eg. gelfoam

? Varicose veins :RF Ablation

--- Content provided by FirstRanker.com ---

? Thrombectomy ? pulmonary embolus

Non-Vascular interventions

? Drainage of pus/fluids from thorax or abdomen.

--- Content provided by FirstRanker.com ---

? Insert feeding tubes- gastrostomy, jejunostomy

? Uterine fibroids, heavy bleeding (DUB): PVA, glue, Gelfoam

--- Content provided by FirstRanker.com ---

? Renal and Gall stones fragmentation followed by drainage.

? Tumour ablation RF

? Pressure relief from cancer masses.

--- Content provided by FirstRanker.com ---

Computerized Axial Tomography (CT Scan)
? Principle: construction of cross sectional image by passing Xrays in multiple

--- Content provided by FirstRanker.com ---

directions along a 36 degree arc.

? 3mm -1cm slice

? Patient can not move

--- Content provided by FirstRanker.com ---

? High radiation

? Uses :

--- Content provided by FirstRanker.com ---

? Trauma- fractures, clots,

? Rupture of vessel in brain.

Magnetic Resonance Imaging (MRI)

--- Content provided by FirstRanker.com ---

? Alignment of polarised molecules in the body when placed in strong

magnetic field.

? Subjected to radio waves- alignment is displaced (depends on

--- Content provided by FirstRanker.com ---

chemical environment).

? When returning to aligned position the energy emitted is detected.

--- Content provided by FirstRanker.com ---

? Series of images is collected by computer application.

Magnetic Resonance Imaging (MRI)

? Subjected to radio waves- alignment is displaced (depends on

--- Content provided by FirstRanker.com ---

chemical environment).

? When returning to aligned position the energy emitted is detected.
? Series of images is collected by computer application.

--- Content provided by FirstRanker.com ---

Drawbacks
? Pacemakers, stents etc. contraindicated

? Patient movement degrade quality of image,

--- Content provided by FirstRanker.com ---

Ultrasonography

--- Content provided by FirstRanker.com ---

? Short bursts of high frequency

sound waves.

? Uses:

--- Content provided by FirstRanker.com ---

? Evaluation of organs such as

kidney, pancreas, GB, spleen etc.

? Obstetrics

--- Content provided by FirstRanker.com ---

? Heart
? Needle biopsy
? Drainage tube insertion
? Doppler studies

--- Content provided by FirstRanker.com ---

Mammography

? Parallel-plate compression

? evens out the thickness of breast tissue

--- Content provided by FirstRanker.com ---

? increase image quality

? reducing amount of x-rays to penetrate,

--- Content provided by FirstRanker.com ---

? decreasing the amount of scattered

? holding the structure to prevent motion

blur.

--- Content provided by FirstRanker.com ---

Positron emission tomography
(PET) scan

Some ques..

--- Content provided by FirstRanker.com ---

1. Ultrasonography works on principle of....

piezoelectric effect

--- Content provided by FirstRanker.com ---

2. X rays are electromagnetic radiation of ......... wavelength
Short
An area on a scan has an associated measurement of 900HU, it is most
likely to be composed of

--- Content provided by FirstRanker.com ---

A. Bone

B. Fat

C. Air

--- Content provided by FirstRanker.com ---

D. Water