X Ray Ultrasound CT Scan Nuclear MedicineNucle

Endoscopy

Imaging Source

X Ray (outside) Ultrasound waves (Outside)

X-Rays(outside)

Gamma Ray from Radioisotopes (inside)

Light source from outside guided into the body(non-bundled fibre)

Physis and concept

Attenuation and transmission of X ray , exposure of film

Reflection at boundaries with different acoustic impedance

Attenuation and transmission of X ray , Collected by a number of sensor and computer processing

Radioactive decay, radioactive half life and biological half life, gamma rate imaged by senor

Total internal reflection, refraction

Remark Gel to reduce loss at air/skin interface

Nuclear Cow produces Technicium

Advantages Low Cost(100)Not/ invasive

Low cost(500)Non-invasive, safeNo radiation used(good for fetus examination)Real Time movement of organ-easily accessible/portable- comfortable to patient/no pain

SpeedCan scan images for bone and CartilageNon-invasive-form 3D image

-Functional organ visualization-(kidney)-Help define space occupied bu tumor-

Non-ionizing, see texture and colour-direct observation, can do biopsy/tissue sample at the same time, no need to make large surgical cut to look inside;

Drawback Do not image all organ and tissue well (good for lung, bad for-ionizing- not behind bones

Cannot see area around lung(air inside reflects ultrasound)/behind bones/behind air filled organs(bowel)-image not clear-small field of vision vs CT

High CostIonizing radiation(higher dosage than X-Ray)

Poor Anatomical DefinitionSignificant ionizing radiation dosage

Invasive-May cause infection/complication, perforation, longer time,need anaesthesia/fasting-only for area with natural opening to outside or need incision(walls of cavity, hollow organs)-can see surface only, small field of vision

Good for Bones fetus Brain tumor Kidney function Stomach, Colon, Cannot be used for

Image behind bone (=> not for brain or organ behind bones)

Cannot see beyond air filled space(most sound energy reflected at tisse/air boundary backwards)

Inside brain or inside solid tissue(liver)

Common use Broken Bones/chest/TB/Cancer/dental

Fetus(=>non-ionizing)Heart- real time, soft tissue among soft tissueKidney(water filled cf lung – gas filled, large intestine)

-blood clot-Brain(=Xray not good resolution, ultrasound cannot penetrate)-emergency room(quick full imaging)

-Kideny-Adominal region-brain

Colon cancer screening

Invasive – possible infection