Biomedical Diagnostics Two

Lesson One- Basics

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x-rayTransmission through the body

Gamma ray emission from within the body

Ultrasound echoes

Nuclear magnetic resonance induction

Basic Basic Imaging Imaging PrinciplesPrinciples

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Basic Imaging Principles

What does the human body look like on the inside?What does the human body look like on the inside?Invasive Techniques:Invasive Techniques: Operation Operation EndoscopeEndoscopeNoninvasive Techniques:Noninvasive Techniques: Magnetic Resonance Imaging (MRI) Magnetic Resonance Imaging (MRI) Ultrasound ImagingUltrasound Imaging x-rayx-ray Computed Tomography (CT)Computed Tomography (CT) Nuclear MedicineNuclear Medicine Functional Magnetic Resonance Imaging (fMRI)Functional Magnetic Resonance Imaging (fMRI) Positron Emission Tomography (PET)Positron Emission Tomography (PET)

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Basic Imaging Principles

What do Images look like, and why?Image reconstruction: the process of creating an

image from measurement of signals.Image quality determined by: Portray of the true spatial distribution of the

physical parameters. Resolution Noise Contrast Geometric Distortion Artifacts

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Projection Images:The creation of a two-dimensional image “shadow” of the three dimensional body. X-ray are transmitted through a patient, creating a radiograph.

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The three standard orientations of slice (or tomographic) images

Axial, Transaxial, Transverse

CoronalFrontal Sagittal

Oblique Slice: an orientation not corresponding to one of the Standard slice orientation.

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Computed Tomography

MMagnetic RResonance IImaging

PPositron EEmission TTomography

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Computed Tomography (CT-Computed Tomography (CT-scan)scan)The x-rays are collimated (restricted in their geometric

spread) to travel within an approximate 2-D “Fan beam” Type of CT scan: single-slice CT, helical CT, multislice CT

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Nuclear MedicineImaging of gamma rays emitted by radionuclides substance bounded to biochemically active drugs. Example iodine to study thyroid function.

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Ultrasound ImagingUltrasound ImagingUses electric-to-acoustic transducers to generate repetitive bursts of high-frequency sound.Time-of-return: give information about locationIntensity: give information about the strength of a reflector

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Magnetic Resonance Imaging Magnetic Resonance Imaging (MRI)(MRI)- Hydrogen nucleus align itself with an external Magnetic

field- Radio frequency pulse cause hydrogen atoms to tip a way from the direction of the external magnetic field.- When excitation pulse end, hydrogen nucleus realign itself with the magnetic field and realize a radio-frequency.

Ultrasonography

Obstetrics

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CRL: Crown Rump Length

Earliest detection at 4-5 weeks

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11-12 week fetus shows division of hemispheres and choroid plexus

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Fetal Spine

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Liver/Lung Interface

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Study of intracranial features including the cerebellum and corpus callosum.

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Umbilical Cord

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3D imaging of placenta

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3D Imaging of eyeball sockets at 12 weeks

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Diagnosis of fetal malformation. Hydrocephalus Anencephaly Myelomeningocoele Achondroplasia, Spina bifida, Cleft lips/ palate and Congenital cardiac abnormalities

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placenta previa diabetes, fetal hydrops, Rh isoimmunization and severe intrauterine growth

retardation

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Breast Imaging:Normal Breast

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Breast Cyst

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Multiple cysts

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Fibroadenoma Breast

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Breast Mass Invading the duct

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HISTORY:71 year old woman recently noticed a left breast lump. DIAGNOSIS:Intracystic papillary carcinoma HISTORY:71 year old woman recently noticed a left breast lump. DIAGNOSIS:

Intracystic papillary carcinoma

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Gallbladder US The gallbladder

demonstrates tiny gallstones. There was mild tenderness over the gallbladder. However, there is no evidence of wall thickening or pericholecystic fluid. There was no ultrasound evidence of acute cholecystitis.

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Gall Bladder US

Stone within the distal portion of the common bile duct. 

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Roundworm in the liver

A typical double-line echo pattern representing an Ascaris worm extends from the right lobe into the porta hepatis