Dr. Zbigniew Serafin, MD, PhD serafin@cm.umk · evacuated -path for the e s to travel through – x-ray tube insert external energy source to accelerate the e-s – generator X-rays

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Day 1

Dr. Zbigniew Serafin, MD, PhD

serafin@cm.umk.pl

The coursework of Radiology and Diagnostic Imaging includes 90 hours of tutorials and seminars. Tutorials

and seminars are prepared in a week cycle. The course is divided into Core Radiology on 4th year and Organ-

Based Radiology on 5th year. Core Radiology ends with a credit with grade. Organ-Based Radiology curriculum

ends with a final test exam. The final test will be timed in the schedule of the session.

Basic textbooks:

Gibson R: Essential Medical Imaging. Cambridge University Press, 2009.

Weissleder R: Primer of Diagnostic Imaging. 4th ed, Mosby Elsevier, 2007.

Moeller T.B., Reif E.: Pocket Atlas of Sectional Anatomy, Computed Tomography and Magnetic

Resonance Imaging, Vol. 1-3. Thieme Verlag, 2007.

Additional textbooks:

Daffner R: Clinical Radiology. Lippincott Williams & Wilkins, 2007.

Vilensky J: Medical Imaging of Normal and Pathologic Anatomy. WB Saunders Company, 2010.

Suetens P: Fundamentals of Medical Imaging, Cambridge University Press, 2009.

2

Requirements and crediting

1. The classes are obligatory. In the case of the illness a sick leave has to be delivered. Other absences due to

important reason must be documented. In the case of the absence the respective topics have to be credited.

Students presenting with unjustified and uncredited absences will not be credited and allowed for the final

exam.

2. Each Student is obliged to come for the classes on time. Delayed Students can enter the class only if the

time of delaying does not exceed 15 minutes from the moment the classes have been started.

3. Students are obliged to prepare the respective part of the material for each classes. Topics are listed in

Syllabus. The knowledge and the activity of each Student will be noted. In the case of a negative note the

Student has to pass the respective topics till the end of the course.

4. Students are obligated to clean up after themselves. Eating, drinking, and using mobile phones during the

labs are prohibited. Any accidents, injuries and other emergencies must be immediately reported to the

Tutor.

5. Students are obliged to follow ethical rules as well as the rules of deontology, especially when attending live

cases.

6. Students are obliged to observe copyright and respect the right of intellectual property of electronic

publications as well as printed collections (published works, master’s and bachelor’s dissertations, course

books etc.) 3

Interim test

The test consists of multiple choice questions (only

one answer correct).

Students who failed the test are obliged to retake

the test.

The final scores of are not changeable.

The scores of the retake will be confirmed by a

signature in the Student Book as positive score but

not as the mean of these two.

In the case of an absence at the test a sick leave has

to be submitted to the examiner within three days

after the test.

The test will be assessed according to the following

scores:

Note Score

Unsatisfactory (2) < 60%

Satisfactory (3) 60-64%

Fairly Good (3,5) 65-69

Good (4) 70-79

Very Good (4,5) 80-89

Excellent (5) ≥ 90% 4

Plan of classes

seminars + exercises = 30 h

8:00 – 12:30

1. Monday – radiography.

2. Tuesday – computed tomography.

3. Wednesday – magnetic resonance imaging.

4. Thursday – ultrasonography.

5. Friday – management in radiology, TEST.

5

Aims of classes

to provide basic knowledge on:

physical and technical principles of medical imaging,

cross-sectional anatomy,

indications and contraindications imaging,

radiation safety.

6

7

Diagnostic imaging

radiography

fluoroscopy

invasive angiography

CT

MRI

ultrasound

nuclear imaging (scintigraphy, PET, SPECT)

coronarography, ventriculography, electrophysiology,

echocardiography

molecular imaging

optical iamging

interventional radiology

8

organ-based approach

modality-based approach

9

neuroimaging

cardiovascular imaging

MSK imaging

GI imaging

respiratory imaging

uroimaging

radiography

CT

MRI

ultrasound

nuclear imaging

interventional

10

1895 – invention of X-rays by W.K. Roentgen

1895 – first X-ray of the human

1896 – first radiation in juries

1896 – Becquerel discovers radioactivity

1905 – the first English book on Chest Radiography is published

1918 – Eastman introduces radiographic film

1934 – Joliot and Curie discover artificial radionuclides

1950's – development of the image intensifier and X-ray television

1956 – medical use of ultrasound starts in Poland.

1962 – emission reconstruction tomography (later SPECT and PET)

1972 – invention of CT by Hounsfield at EMI

1977 – first human MRI images.

1980's – Fuji develops CR technology.

1984 – MRI cleared for commercial use by FDA

11

November 8, 1895 Roentgen’s experimental apparatus (Crookes tube) that led to the discovery of the new radiation. Roentgen demonstrated that the radiation was not due to charged particles, but due to an as yet unknown source, hence “x” radiation or “x-rays.”

http://www.learningradiology.com 12

13 http://www.learningradiology.com

Bertha Roentgen (1895) „Über eine neue Art von Strahlen”

14

Radiation

emission or emission and propagation of energy in the form of particles or waves.

Ionizing radiation

radiation having sufficient energy to ionize an atom

15

Interaction of X-rays with matter = sources of attenuation

The attenuation that results due to the interaction between penetrating radiation and matter is not a simple process. A single interaction event between a primary x-ray photon and a particle of matter does not usually result in the photon changing to some other form of energy and effectively disappearing. Several interaction events are usually involved and the total attenuation is the sum of the attenuation due to different types of interactions.

These interactions include the photoelectric effect, scattering, and pair production

16

Photoelectric absorption of x-rays occurs when the x-ray photon is absorbed, resulting in the ejection of electrons from the outer shell of the atom, and hence the ionization of the atom. Subsequently, the ionized atom returns to the neutral state with the emission of an x-ray characteristic of the atom. This subsequent emission of lower energy photons is generally absorbed and does not contribute to (or hinder) the image making process. Photoelectron absorption is the dominant process for x-ray absorption up to energies of about 500 KeV. Photoelectron absorption is also dominant for atoms of high atomic numbers.

Photoelectric effect is a low-energy phenomenon and is the most important for image acquisition and radiation safety

17

Compton scattering occurs when the incident x-ray photon is deflected from its original path by an interaction with an electron. The electron gains energy and is ejected from its orbital position. The x-ray photon loses energy due to the interaction but continues to travel through the material along an altered path. Since the scattered x-ray photon has less energy, it, therefore, has a longer wavelength than the incident photon. The event is also known as incoherent scattering because the photon energy change resulting from an interaction is not always orderly and consistent.

Compton scattering is the most probable interaction of gamma rays and high energy X-rays with atoms in living beings. The phenomenon responds for the image noise and health hazard related to imaging.

18

Thomson scattering (Rayleigh, coherent, or classical scattering), occurs when the x-ray photon interacts with the whole atom so that the photon is scattered with no change in internal energy to the scattering atom, nor to the x-ray photon. Thomson scattering is never more than a minor contributor to the absorption coefficient. The scattering occurs without the loss of energy. Scattering is mainly in the forward direction.

Thomson scattering is related to 5-10% of all tissue interactions with X-rays.

19

Pair production can occur when the x-ray photon energy is greater than 1.02 MeV, but really only becomes significant at energies around 10 MeV. Pair production occurs when an electron and positron are created with the annihilation of the x-ray photon. Positrons are very short lived and disappear (positron annihilation) with the formation of two photons of 0.51 MeV energy. Pair production is of particular importance when high-energy photons pass through materials of a high atomic number.

Pair production is used in PET imaging.

20

Basic X-ray production

electron source – cathode

target – anode

evacuated path for the e-s to travel through – x-ray tube insert

external energy source to accelerate the e-s – generator

X-rays are produced when energetic electrons strike a metal target. The X-ray source consists of an evacuated tube containing a cathode, from which the electrons are emitted, and an anode, which supports the target material where the X-rays are produced. Only about 1 per cent of the energy used is emitted as X-rays – the remainder is dissipated as heat in the anode. In most systems the anode is rotated so that the electrons strike only a small portion at any one time and the rest of the anode can cool. The X-rays are emitted from the tube via a radio-translucent exit window.

21

Electron interactions with the anode produce:

1. Heat – the kinetic energy (KE) of the electron deposits its energy in the form of heat (~99%)

2. X-rays production

Bremsstrahlung

– continuous energy spectrum

characteristic X-rays – discrete energies

22

Each part of the X-ray tube is essential to create the environment necessary to produce x-rays via:

Bremsstrahlung

Characteristic x-rays

The potential difference (kVp), tube current (mA), and exposure time (s) are selectable parameters to determine the x-ray spectrum characteristics (quality and quantity of x-ray photons

23 23

X-ray tube filtration:

absorbs low-energy x-rays

inherent filtration - glass or metal insert at x-ray tube window

added filtration (Al, Cu, plastic, Mo, Rh)

reduces patient dose

increases x-ray beam quality

24

X-ray tube collimation:

collimators adjust size and shape of x-ray beam

reduces patient dose

improves image contrast

25

Other elements of X-ray tube:

HF generator – converts AC to DC and increases the voltage

operator console – exposure time settings

phototimers – AEC system

Bucky grid

patient’s table

detector

80 kW generator can produce 800 mA at 100 kVp

26

Other elements of X-ray tube:

HF generator – converts AC to DC and increases the voltage

operator console – exposure time settings

phototimers – AEC system

Bucky grid

patient’s table

detector

27

Other elements of X-ray tube:

HF generator – converts AC to DC and increases the voltage

operator console – exposure time settings

phototimers – AEC system

Bucky grid

patient’s table

detector (casette)

28

Limitations of film-screen radiography:

limited dynamic range (only about two orders of magnitude)

difficult multiplication of the image

waiting time for the result

limited processing capabilities

need for additional personnel

environmental pollution

QA monitoring is time consuming

29

Digital radiography:

Computed Radiography (CR)

phosphor-based storage plate

chemical storage (oxidation of Eu)

laser scanning, light erasure

Digital Radiography (DR)

flat-panel detectors

Csl scintillator and photo-diodes

better dynamic range, quantum efficiency

Charge Coupled Device (CCD)

phosphor screen, fiberoptic cables, CCD sensor

good sensitivity, low noise

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31

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What can we imagine on plain films?

skeleton

high-density foreign bodies

calcifications

tubular structures

EXERCISE

33

What can we imagine on plain films?

skeleton

high-density foreign bodies

calcifications

tubular structures

34

What can we imagine on plain films?

skeleton

high-density foreign bodies

calcifications

tubular structures

35

What can we imagine on plain films?

skeleton

high-density foreign bodies

calcifications

tubular structures

36

What can we imagine on plain films?

skeleton

high-density foreign bodies

calcifications

tubular structures

37

congenital

trauma

inflammation

neoplasms

cardiovascular

38

congenital

trauma

inflammation

neoplasms

cardiovascular

39

congenital

trauma

inflammation

neoplasms

cardiovascular

40

congenital

trauma

inflammation

neoplasms

cardiovascular

41

congenital

trauma

inflammation

neoplasms

cardiovascular

42

CNS

skeleton

cardiovascular

respiratory

GI

urinary

reproductive

43

CNS

skeleton

cardiovascular

respiratory

GI

urinary

reproductive

44

CNS

skeleton

cardiovascular

respiratory

GI

urinary

reproductive

45

CNS

skeleton

cardiovascular

respiratory

GI

urinary

reproductive

46

CNS

skeleton

cardiovascular

respiratory

GI

urinary

reproductive

47

CNS

skeleton

cardiovascular

respiratory

GI

urinary

reproductive

48

CNS

skeleton

cardiovascular

respiratory

GI

urinary

reproductive

49

???

infertility

neoplasms

cataracts (progressive lens opacity)

heritable mutations

marrow stimulation / depletion

contrast media

50

???

pregnancy

ataxia teleangiectasia

Bloom syndrome

clinically unstable patient

obesity

lacking indications!!!

51

???

infertility

neoplasms

cataracts (progressive lens opacity)

heritable mutations

marrow stimulation / depletion

contrast media

52

???

infertility

neoplasms

cataracts (progressive lens opacity)

heritable mutations

marrow stimulation / depletion

contrast media

53

54

Any substance that renders an organ or structure more visible than is possible without its addition. CM allows visualization of structures that can not be seen well or at all under normal circumstances

55

Contrast media is needed because:

Soft tissue has a low absorption / interaction ratio

Absorption is dependent on

• atomic number

• atomic density

• electron density

• part thickness

• K-shell binding energy (K-edge)

Negative CM

air

oxygen

carbon dioxide

Positive CM

barium

iodine

56

Non-water-soluble CM

absorbed – oily &/or viscous (Lipiodol)

not absorbed – inert (Barium)

Water-soluble

non-injectible – oral

injectible – intravenous

Direct application

barium studies

angiography

Water-soluble

non-injectible – oral

injectible – intravenous

57

Adverse reactions:

anaphylactoid • urticaria • facial / laryngeal edema • bronchospasm • circulatory collapse

non-anaphylactoid • nausea / vomiting • cardiac arrhythmia • pulmonary edema • seizure • renal failure

delayed • fever, chills, rush • nausea, vomiting • headache

DEATH:

1/40.000 – 1/200.000 patients

58

Clinical applications:

vascular imaging

inflammation

neoplasms

GI tract imaging

urinary tract imaging

trauma

„tissue differentiation”

59 http://www.learningradiology.com

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Flat-panel detector

Clinical applications:

GI tract imaging intraoperative image-guidance evacuation of foreign bodies differentiation of pulmonary nodules ERCP --------------------

62 http://www.learningradiology.com

Whose that hand? (1896) lime / mercury / petroleum

63

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Digital Subtracted Angiography (DSA)

66

Digital Subtracted Angiography (DSA)

67

Digital Subtracted Angiography (DSA)

69

70

Clinical applications:

vascular imaging

• arteriography

• venography

• lymphography ?

(endovascular procedures – interventional radiology)

71

arteriography

vascular malformations

atherosclerosis

embolism

trauma

neoplasms

fistulae

72

arteriography

vascular malformations

atherosclerosis

embolism

trauma

neoplasms

fistulae

73

arteriography

vascular malformations

atherosclerosis

embolism

trauma

neoplasms

fistulae

74

arteriography

vascular malformations

atherosclerosis

embolism

trauma

neoplasms

fistulae

75

arteriography

vascular malformations

atherosclerosis

embolism

trauma

neoplasms

fistulae

76

arteriography

vascular malformations

atherosclerosis

embolism

trauma

neoplasms

fistulae

77

venography

deep vein thrombosis

pulmonary embolism

vascular malformations

vein insufficiency

78

venography

deep vein thrombosis

pulmonary embolism

vascular malformations

vein insufficiency

79

venography

deep vein thrombosis

pulmonary embolism

vascular malformations

vein insufficiency

80

venography

deep vein thrombosis

pulmonary embolism

vascular malformations

vein insufficiency

81

phlebography

lymphatic edema

metastases

82

previous severe reaction to contrast media

impaired blood clotting factors

inability to undergo surgical procedure

impaired renal function ?

83

puncture site

infection hematoma nerve injury (brachial plexus)

arteriography

vasospasm dissection, stenosis, occlusion perforation, hemorrhage release of atheroma, embolism stroke, AKI, mesenteric ischemia, limb ischemia DEATH

venography

phlebitis, thrombophlebitis dislodging a clot, embolism

contrast media

84

1

2

3

85

1

2 3

86

6

4

3

2 1

5

87

5

4

3

2

1

88

1 2

89

1

2

4

3

90

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