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RT 124 SPRINGWEEK 1 – Part 1CHEST & ABD

A “Self Study” Review

Rev Spring 2010

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RT 124 - WEEK 1 (Part 2)is the Lecture Presentation for:

Chest II AP: SUPINE, SEMI-UPRIGHT – UPRIGHT

R & L DECUBITUSLATERAL – PT ON GURNEY OR IN W/C

ABDOMENAP SUPINE, UPRIGHT, LLD

RT 124 – Wk 1 – Part 1 Lecture on web can be reviewed for basic CHEST & ABD anatomy.

3A quick review of CHESTDedicated Chest Unit

• X-ray machine designed to perform routine chest imaging– tube has fixed alignment with

imaging plate (IP)

– when tube moves, IP moves

– Non-CR has film unit• includes stationary grid• magazine to hold unexposed

film• direct hook-up to processor

[or magazine for exposed film]

• ID flasher on unit

Digital Chest Unit

4Body Habitus

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6CASSETTES W/ GRID CAPS

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9Grids

• Allow primary radiation to reach the image receptor (IR)

• Absorb most scattered radiation

• Primary disadvantage of grid use – Grid lines on film

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11CR GRIDS

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CHEST

ANATOMY REVIEW

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Chest Anatomy• Thoracic cavity

(chest)– Surrounded by

boney thorax– Separated from

abdomen by diaphragm

• Muscular partition• Dome shaped• Lungs drape over

diaphragm

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Bony Thorax

• ENCLOSE THE ORGANS– STERNUM (breast bone)– 12 PAIR OF RIBS– 12 THORACIC

VERTEBRA

• ATTACH UPPER EXTREMITY– 2 CLAVICLES– 2 SCAPULA

AnteriorPosterior

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Thoracic Cavity• Sections of the thoracic cavity

– Pleural portion (lungs)– Mediastinum (between lungs)

– Pericardial portion (heart)

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Respiratory System

1. Lungs – Lobes

• Right 3 lobes• Left 2

lobes

– Terminology• Apex• Hilum• Base• Costophrenic angles

A A

H H

B B

C

C

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Bronchial Tree2. Bronchi

– Air tubes leading into the lung

– Right more vertical than left

– Branching structure• Primary 2ndary

teritiary...

– Only primary visible on PA projection

P

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Trachea3.Trachea

– In mediastinum– Passageway for air

to/from lungs– Approx. 4½" Long– Air visible on images

T

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Circulatory System1. Heart

– 4 Chambered pump

2. Great blood vessels– Aorta– Vena cava– Pulmonary Artery

• Not seen on image

A

VC

VC

PA

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Miscellaneous• Mediastinum

contents– Trachea– Major vessels– Esophagus– Lymphatics– Heart– Thymus

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Chest Examinations• Most common projections

– PA in an erect position– Right to left lateral in an erect position

• Less common projections– AP -- erect or recumbent position– Lateral decubitus

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Routine PA & L Lateral1. Erect position

– Diaphragm moves more inferior– Demonstrates air-fluid levels– Prevents blood pooling in gr. vessels

2. 72" Sid– magnification of heart

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Routine PA & L Lateral (cont.)

3. Breath held on inspiration– Expands lung fields– depresses

diaphragm– Provides contrast

(air vs. tissue)

4. Film (adult)14X17 lengthwise

(may be crosswise on broad chested male)

inspiration expiration

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Routine PA & L Lateral (cont.)

5. Technical factors– High kVp (>100)

• long scale contrast

– High mA & short time• reduces motion

– AEC– Grid

• decrease scatter on image

25PA Projection

(erect anterior position)• Patient

– Standing -- weight on both feet

– Anterior chest against IP– MS plane perpendicular

to IP & floor– Chin raised– Posterior of hands on

hips or machine “hug”– Shoulders depressed &

rotated forward

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PA Projection (cont.)

• X-ray beam– CR

• to film• in MS plane at T 7

• Collimation (very little)

– Full length of film– To lateral edges of

patient

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PA Projection (cont.)

• Film evaluation– Complete anatomy shown

• apices (chin elevated)

• base (both costophrenic angles)

• scapulae out of lungs (shoulder rotation)

• respiration (10 posterior ribs)

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PA Projection (cont.)

• Minimal rotation– Symmetry of SC

joints– MS plane to

lateral ribs = distance

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PA Projection (cont.)

• Technique– Vertebra seen through

heart (kVp)– "Good" density

• Other– no film artifacts– no motion (blur)

30PA Chest Anatomy

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Radiographic Anatomy -- PA

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Erect Left Lateral Chest• Patient

– Standing with weight on both feet

– L side against film holder– Chin raised– Arms elevated &

immobilized– Align MS plane

• parallel to the film to the floor

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Left Lateral Chest (cont.)

• X-ray beam– CR

to film• in midaxillary plane at

level of T7

(slightly lower than T7 ok)

– Collimation• full length of film• to anterior & posterior

surfaces of patient

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Abdomen Anatomy• Abdominopelvic

cavity– Abdomen

• diaphragm to pelvic inlet

– Pelvic cavity• pelvic inlet to floor

muscles of the cavity

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Abdomen Anatomy (cont.)

• Abdomen– Divisions

• 4 Quadrants (clinical)

• 9 Regions (anatomic)

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Abdomen Anatomy (cont.)

• Boney anatomy– lower ribs & T11-T12– lumbar spine (5)– sacrum & coccyx– innominate (2)

• iliac portion• ischial portion• pubic portion

– femur• head & neck• trochanters

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Abdomen Anatomy (cont.)

• Topographic (positioning) landmarks– Iliac crest (level of L4-5)

– Anterior superior iliac spine (ASIS)

– Greater trochanter of femur

– Pubic symphysis

Symphysis Pubis

GreaterTrochanter

LumbarVertebra

IliacCrest

ASIS

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Abdomen Anatomy (cont.)

• Major muscles (radiographically)– Diaphragm– R and L psoas muscles

39Major Abdominal Organs

stomach

large bowel

spleen

small bowel• duodenum• jejunum• ileum

liver (triangular)gall bladder

pancreas

40Urinary Organs & Major Vessels

aorta

kidney

ureter

vena cava

urinary bladder

urethra

adrenal glandadrenal glandadrenal glandadrenal gland

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Abdominal Radiography• Patient preparation

– KUB & acute abdomen• Remove radiopaque clothing & gown• Otherwise "as is“

• Breathing instructions– Expose after patient exhales– "Take deep breath, blow it all out, stop breathing"– Watch patient while giving instructions

– Contrast media exams• Dietary & bowel preps usually required

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Abdominal Radiography (cont.)

• Exposure factors (non contrast media)– Medium kVp -- 70-80

• adequate penetration• moderate contrast

– Short exposure time• decrease involuntary motion on image

– Enough mAs for sufficient density• Film markers• Radiation protection

– Check for pregnancy on all women– Gonadal shielding (???)

• Collimation– to film edge top & bottom– to patient width on sides

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Abdomen • AP projection, supine position

– KUB, flat plate, plain film, scout film

• Patient position -- Supine on table with– pillow for head– support sponge for knees– arms at but away from

sides– legs extended, internally

rotatedMidsagittal plane• perpendicular to table• parallel to table length

– R & L ASIS level– Shoulders level

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Abdominal Radiography (cont.)

• Film & centering– 14X17 cassette

lengthwise in table bucky

– Center of film at level of iliac crests

– CR to center of film passing through the MS plane at level of iliac crests

• adjust to include pubic symphysis at lower edge of film

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Abdominal Radiography (cont.)

• Film evaluation– No rotation

• symmetry of pelvis & spine

– Complete anatomy with no motion

• vertebral column in center of image

• symphysis pubis at bottom of image

• kidneys, liver, spleen at top of image

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Abdominal Radiography (cont.)

– density & contrast adequate to see

• Psoas muscles• lumbar transverse

processes• ribs• kidney & liver margins

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Other Abdominal Projections/Positions

– AP projection in an erect position

• CR 2" above iliac crests in MS plane

– AP or PA projection in a lateral decubitus position

• CR 2" above iliac crests in MS plane

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Abdominal Radiography (cont.)

– Lateral in a recumbent or erect position

• Seldom done due to level of radiation

• lack of significant diagnostic information