1st

Generator is a device used to extract the metastable isotope

Technetium generator.. from molybdenum 99 generate 99m technetium

Rubidium generator.. from 82Stronicor to 82rubidio

Gallium generator.. from 68Germanium to 68Galium

Copper generator.. from 62zinc to 62copper

Krypton generator.. from 82Rb to 81m krypton

Yttrium generator.. from 90Sr to 90 Ytrium

Rhenium generator.. from 188W to 188 Rhenium

Generator uses unique equilibrium between long-lived parent radionuclide and short lived radioactive daughter

2nd step is separation of parent and daughter radionuclide to use daughter radionuclide in radiopharmaceutical

Parent here is 99Molybdenum to active daughter 99technetium

Scintigraphy, or gamma scan, is a diagnostic test in nuclear medicine

Dynamic scintigraphy is taking of pictures frequently after administration of radiopharmaceutical, to visualize the visualize targeted metabolic processes

I.e. in kidney/urinary tract visualization, also in bones scans (osteomyelitis)

Or planar scintigraphy, 2D nuclear medicine imaging procedure, created by accumulation of counts, gives rough idea about metabolic function, but no good visualization

PET/CT 1500$

SPECT/CT 800$

MRI 800$

CT 500$

SPECT 250$

WHOLE BODY SCINTIGRAPHY 150$

DENSITOMETRY 70$

X-RAY 20$

Bone scans show osteogenesis, generally most frequently used scintigraphy method

Indicated for joint, muscle, bone diseases, bone infections, bone metabolism disorders

3 major phases:

Flow phase: dynamic imaging is performed, the visualized blood flow should be prompt and symmetrical to the area of interest, if the flow is asymmetrical it indicates pathology, for example inflammation or infection

Blood pool phase: characterizes blood pool accumulation in soft tissue or bone/ the lack thereof

Delayed phase: starts 2-4 hours after initial injection, activity usually seen largely through osseous structures and soft tissue activity predominantly cleared through kidney.. should be compared to”normal” pictures of clearing

Acute infective disease of the bone

Tuberculosis of bone

Noninfective inflammations of the bone

Transient synovitis of hip

Acute pyogenic arthritis

Osteoarthritis

Rheumatoid arthritis

Ankylosing spondylitis

Reiter syndrome

MPI-myocardial perfusion scintigraphy

Consists of stress and rest phases, patients should stop beta blockers in advance

Most often used 99technetium-sestamibi or -tetrofosim

Treatment of joint diseases using radionuclides that are applied to the joint cavity.

Indications are: rheumatoid arthritis, inflammatory joint disease, persistent effusion of joint, hemarthrosis in patients with hemophilia

RF in colloidal form tightly binds to synovial membrane, phagocytoses by macrophages into superficial layers of synovium resulting in coagulation necrosis and subsequent fibrotic changes of synovial surface

90-Ytrium silicate used in hip and knee

186 renium colloid used in shoulder and elbows

169-Erbium colloid used in wrists, small joints

Radium-223

Is largely in skeleton, directly incorporated in places with increased boneturnover, subsequently killing the tumor cells by breaking of DNA

Fluodeoxyglucose

A ventilation–perfusion (VQ) scan is a nuclear medicine scan that uses RF to examine airflow (ventilation) and blood flow (perfusion) in the lungs

The aim of the scan is to look for evidence of any blood clot in the lungs, called pulmonary embolism

V/Q scan is performed in 2 steps

1. For ventilation, inhalation of xenon-133, then pictures to visualize airflow in lungs

2. For perfusion, radiopharmaceutical injected, then pictures are taken to visualize blood flow in lungs

   If no blockage is present lung perfusion should be distributed uniformly, in case of blockage perfusion defects can be seen peripherally to the obstruction

the conscientious, explicit and judicious use of current best evidence in making decisions about the care of individual patients

Basically: make personalized decision on best treatment of individual patient in respective of results from prior performed tests, labs, anamnesis etc.

With dosimeters, these measure ionizing radiation doses

Can function on thermoluminiscent basis, via ionizing chamber, or as scintillation detectors (I.e. foot-hand detector)

Terrestrial radiation, internal/body radiation, space

Main sources of natural radiation in SK are ground radon and thoron

Cameras produce one complete image

Scanners produce multiple layers of pictures of varying trans sections which can be combined to form one final picture

Scanners don’t show the whole object but gradually shows layers

Single Photon Emission Computed Tomography

Procedure:

• Production of isotope by nuclear reactor, generator, or cyclotron

• Isotope has a longer half-life (hours-days)

• Injection of RF, which stay in the bloodstream rather than being absorbed by the surrounding tissue

• Rotating camera (planar camera is used)

Radioactive isotopes used: Iodine-123, Iodine-131, Technetium 99m, Thallium-201, Xenon-133

Indications: info about blood flow, cerebrovascular diseases, dementia, epilepsy, bone disorders, tumors

A Bq is defined as activity or quantity of radioactive material in which one nucleus decays per second.

A very small unit, radioactivity is usually given in megaberquerel MBq

The Sievert (Sv) is the SI unit for ionizing radiation dose, measuring the amount of energy absorbed in a human's body per unit mass (J/kg)

Is a measure of external and internal biological exposure to radiation

Distance

Time

Barrier,

+tagging of radiation areas, usage of dosimeter by staff, wearing protective gear

Generally effective dose in normal population 1mSv/year

In workers max. 100mSv per 5years, without exceeding 50mSv in a year

Pregnant women and children max 1mSv

Volunteers max. 5mSv

Deterministic effects are negative, unwanted, harmful effects that occur upon exposure to radiation, these effects are dose dependent

for example acute radiation sickness, radiodermatitis

Single photon emission computerized tomography vs. positron emission tomography

• SPECT is less sensitive than PET but less expensive

• PET uses positron-emitting radioisotopes, SPECT uses gamma-emitting radioisotopes

Both allow for visualization of morphology and function

Diagnosis: 123-I (for thyroid imaging-examination)

Treatment: 131-I (for hyperthyroidism – emits beta particles)

Radioactive iodine treatment (for thyroid carcinoma) - swallow a radioactive substance that travels through the blood and kills the cancer cells

Radioisotopes are radioactive isotopes of an element. They are atoms that contain an unstable combination of neutrons and protons, or excess energy in their nucleus

Therefore they emit energy when undergoing changes to a more stable form

Each radioisotope has a characteristic disintegration or semi-life period. Energy may be liberated mostly in the form of alpha (helium nuclei), beta, (electrons or positrons), or gamma (electromagnetic energy) rays

Radiopharmaceuticals are pharmacological agents used in diagnosis and treatment

Consist of radionuclide tracer element and a pharmaceutical carrier element

-capacity of mapping the physiologic and metabolic function to give information of the organs in a non-invasive way. Can be administered IV, intradermally, via mouth, by inhalation placed inside body cavities. The radioactive signal they emit is traced with cameras and computers.

An ideal radiopharmaceutical must:

Easily available

Short effective half-life

Particle emission

Decay by electron capture or isometric transition

High Target-to-Nontarget activity ratio

Radionuclides are produced by 3 main methods: 1)Cyclotron 2)Generator 3)Nuclear reactor

EF=EDV-ESV/EDV

normal 55-70%

Can be measured via echocardiogram, cardiac catheterization, MRI,CT, nuclear medicine scan

Natural: terrestrial, body/internal and space radiation (in sk radon and thoron)

Artificial sources of radiation: occupational, industrial, consumer, medical like x-ray scanners at airports, combustible fumes, televisions, fluorescent lamps, smoke detectors

In patients with ischemia we can potentially see impaired perfusion at rest, but most often normal MPI at rest, with noticeable impairment upon exertion (stress)

Upon exposure to radiation the energy is absorbed in matter, exciting the atoms with few effects

• Chemical: fission molecules, free radicals (indirect effect)

• Biochemical effect: macromolecular changes (direct effect) causes metabolic disorders, biochemical changes.

• Biological effect: cell -> tissue -> organ damage

Deterministic effect, dose dependent on radiation, higher dose causes more significant side effects, like acute radiation sickness, radiodermatitis

Stochastic effect, dose independent, exposure to radiation can randomly cause genetic changes & malignant tumors

Superscan is an imaging appearence on a TC-99m diphosphate bone scan which demonstrates markedly increased skeletal radioisotope uptake relative to soft tissues in association with absent or faint renal activity (absent kidney sign)

Appareance can result fron a range of factors:

• Diffuse metastattic diseases (prostatic carcinoma, breast cancer, lymphoma)

• Metabolic bone disease (renal osteodystrophy, hypoparathyroidism)

• Myelofibrosis

• Paget´s diseases

A method used to find out the stage of cancer (amount or spread of cancer in the body) using tests that are done before surgery. These include physical exams, imaging tests, laboratory tests (such as blood tests), and biopsies.

TNM principle, first Tumor(size etc), second lymph node involvement, third metastases

Diagnostic-

• Pure gamma ray emitter – 141 keV

• Reduced radiation burden: no particle emissions and short enough T1/2. Suitable for labeling and clinical applications;

• High target/background ratio for radio-labeled compounds

• Readily available: Mo-99 / Tc-99m generator

• Quality control can be performed onside

Therapeutic-

Corpuscular beta/alfa radiation emitter with short ray fly

Medium T1/2 – days, good radiotoxic effect.

Low accumulation in nontarget tissue

Suitable for labeling and clinical applications

Gamma emission is useful for imaging but problem for radiation burden of environment.

Created in 1957 by anger, for the first time made mapping of distribution of radioactivity in the whole body possible

Gamma camara converts photos emitted by the radionuclide in the patient into a light pulse and later into a voltage signal which is used to form an image

It’s made up of three parts:

1. Collimator: acts as a filter which absorbs the oblique radiation rays

2. Scintillation crystal (NaI+thalium): convert the photons into visible light

3. Photomultiplier tubes (PTM): detect the light flashes and convert them into electrical signals

Finally computer sums up the counts to produce a 2D image

Indication: function of thyroid, parathyroid, salivary gland, kidneys, heart, lungs

PET is an imaging method which detects the metabolism within the body tissues using positron-emitting radioisotopes (3D image). The radioactive isotope decays in the body and produces positrons which interact with the surrounding electrons. ANNIHILATION occurs resulting in release of 2 photons which are detected.

YES! monitor metabolism by tracer method, use of isotopes for the study of biological systems

They all create radiopharmaceutical drugs.

Cyclotron produces energy by acceleration of protons, produced nuclei have an excess positive charge-neutron deficit

Nuclear reactor produce nuclei having deficiency of positive charge- deficit of proton

Radionuclear generator: they are devices for preparation of short-term emitters directly at the examination site. Used to extract the metastable isotope. Mother elements decay into daughter products of very short half-life

As low as reasonable achievable

Contraindicated in every examination by radiation which dose not have diagnostic benefits.

• prefer diagnostic methods without radiation: MRI, SONO

• Selection of sensitive and specific methods- the right choice of method

• Do not repeat the examination unless a change of status can be expected. Good quality testing to avoid its repetition

• Use all technical means to reduce exposure

• Avascular necrosis of bone;

• Osteochondrosis;

• Traumatic and sports injuries of bone;

• Periarticular rheumatism syndromes;

• Muscular and musculotendinous rheumatism syndromes;

• Metabolic diseases of bone;

• Benign and primary malignant bone tumors;

• Metastatic bone tumors;

• Tumorous conditions of bone.

Most frequent scintigraphy method, gives images of metabolic activity of skeleton, commonly utilizes 99-technetium, which mimics metabolic processes in bone (technetium methylene diphosphate)

Bone scan modes include whole body scintigraphy, 3 phase planar bone scintigraphy (dynamic scintigraphy), plantar spot scintigraphy, SPECT and SPECT/CT.

General indications: diseases of bone, joint, muscle, and musculotendinous unit, bone infections, bone metabolism

Radiopharmaceuticals are a group of pharmaceutical drugs that have radioactivity and can be used as diagnostics and therapeutic agents.

Contrast media is the substance used to enhance the contrast of an image, hence, making an image more detailed and apparent.

It is one of the essential prerequisites for maintaining health protection. It serves to check the effectiveness of protection against ionizing radiation and allows to uncover extraordinary events.

Types of monitoring:

• Staff

• Workplace monitoring

• Monitoring of discharges and waste

• Patient monitoring

• Documentation

Protection against deterministic effects of ionizing radiation is to avoid reaching the threshold dose. This requires the establishment of strict limits for tissue doses.

Avoid deterministic effects and minimize chance for stochastic effects

It is the medical specialization which makes use of open radionuclides on diagnostical and therapeutically management of disease

Basic detection method is via gamma camera, developed by angerin 1957.

The collimator directs the gamma-rays photons to a scintillation crystal (Nal), which converts their energy into visible light.

Dependent on impact, it releases electrons from the photocathode. These are multiplied by the dynode system. 

Finally they are captured on the anode as an electronic pulse, which is further processes by an electronic device.

Hybrid imaging methods yield a combined picture of morphology and function

• Improvement in lesion detection on both CT and PET or SPECT images

• Improvement in the localization of foci of uptake resulting in better differentiation of physiological from pathologic uptake

• Precise localization of the malignant foci, for example, in the skeleton vs soft tissue or liver vs adjacent bowel or node

• Confirmation of small, subtle, or unusual lesions excluding the need of further procedures

• Have the potential to provide important information to guide the biopsy of a mass to active regions of the tumor and to provide better maps than CT alone to modulate field and dose of radiation therapy

Group of pharmaceutical drugs containing radioactive isotopes

They are made up of 2 components: radionuclide (as a TRACER) + carrier molecule. They have the capacity of mapping the physiologic and metabolic function to give information of the organs in a non-invasive way. Can be administered IV, intradermally, via mouth, by inhalation placed inside body cavities. The radioactive signal they emit is traced with cameras and computers

Also gamma scan, are diagnostic imaging methods in nuclear medicine

We have:

Static scintigraphy

Whole body scintigraphy

Dynamic scintigraphy

Sequential scintigraphy

Dynamic scintigraphy is many planar pictures are taken in a given period of time (sequential snapshots). For example, it may be used to visualize RF accumulation and excretion in the urinary tract.

Sequential scintigraphy is Few planar images are taken every few hours to evaluate long-term dynamic events.

In cyclotron we produce isotope by acceleration of positive charge (protons).

• Fluorine 18 (used in PET for bone and tumors imaging)

• Among these classical radionuclides are: 18F, 13N, 11C and 15O. These four PET radionuclides are also commonly referred to as “standard” radionuclides in literature and are mostly produced using low energy medical cyclotrons

Nuclear reactors produce proton deficit.

Fission occurs in a nuclear reactor where neutrons are used to bombard fission nuclides such as uranium-235 (235U) or plutonium-239 (239Pu).

Fission results in the splitting of the large nucleus into smaller fission fragments along with the release of gamma radiation and high energy neutrons

It is an area of pharmacology, that investigates and describes the distribution of drugs in the body, from their administration to the excretion

RF is administered by blood

RF begins process of accumulation

Accumulation of RF is completed (the biggest amount of Rf is retained in the target apparatus

Elimination of Rf

Can be administered:

• Intravenously

• Intradermally

• Via mouth

• By inhalation placed inside body cavities

It shows OSTEOGENESIS (development and formation of bone)

Bone scan is the most frequent scintigraphy method, because they have many indications. 

General indications: diseases of bone, joint, muscle, and musculotendinous unit, bone infections, bone metabolism.

Commonly used: techmetium methilene disphosphate and hydroxyle ethilne diphosphate.

Flow phase

• 2-to-5 second images are obtained for 60 seconds after injection

• demonstrates perfusion

• characterizes blood flow to a particular area

Blood pool phase

• obtained 5 minutes after injection

• demonstrates the blood pool (balance between plasma and interstitium), not the blood flow

• inflammation causes capillary dilatation and increased blood flow

• If the study is going to be a triphasic bone scan, a third phase is added.

Delayed phase 

• obtained 2-4 hours later

• urinary excretion has decreased the amount of the radionuclide in soft tissue

• mechanism of uptake is not known with certainty, although it has been proposed that the radiotracer attaches to hydroxyapatite crystals (chemisorption)

• degree of uptake depends on blood flow and rate of new bone formation

Myocardial perfusion scintigraphy: non-invasive imaging test that shows how well blood flows throw and perfuses the heart muscle.

SPECT MPI: depicts (detects) only the territory supplied by most severe stenosis and region with less reduced flow seems to be normal.

Takes a longer time, high radiation dose, only qualitative information.

PET MPI: allows absolute quantification of perfusion and it appears to be useful in patients with balanced disease.

It’s more accurate, faster stress-rest study (1h), less radiation dose to the patient and staff, QUANTITATIVE assessment of myocardial blood flow, appears to be useful in patients with balance diseases

1. Chest X-ray: we always have to carry it out first. Can detect cancer, infection or air collecting in the space around a lung, which can cause the lung to collapse. They can also show chronic lung conditions, such as emphysema or cystic fibrosis, as well as complications related to these conditions.

2. V/Q Scan

3. Pulmonary CT angiography

A ventilation–perfusion (VQ) scan is a nuclear medicine scan that uses RF to examine airflow (ventilation) and blood flow (perfusion) in the lungs.

The aim of the scan is to look for evidence of any blood clot in the lungs, called pulmonary embolism.

The basic principle of the perfusion scintigraphy is based on an intravenous injection of technetium 99m Tc labelled macro aggregated albumin particles. A pulmonary embolism will block a small fraction of pulmonary capillaries and thereby enable scintigraphic assessment of lung perfusion at the tissue level

Typical shape of lung perfusion defect is triangular, RF is not distributed peripherally to blockage of vessel

VQ mismatch is the combination of good lung ventilation + poor lung perfusion

• Causes: chronic obstructive pulmonary disease (COPD), asthma, pneumonia, lung cancer, fibrosis, atelectasis

Reversed VQ mismatch is bad ventilation + good perfusion

VQ match is good ventilation + good perfusion, bad ventilation + bad perfusion

LV EF is percentage of blood ejected from LV with each contraction, It is basic function parameter of LV

Ejection fraction (EF): % of end diastolic volume (EDV) that is ejected by a ventricle during systole (EF=EDV-ESV/EDV)

Normal range: 55-70%,

Heart failure (HF): <40%

• 99mTc-methylene-diphosphonate (MDP) or hydroxyl ethylene diphosphonate (HEDP) is useful in a broad spectrum of diseases of the bone

• Bone infections can additionally be imaged using 111In(99mTc)-leucocytes

• 99mTc-phosphate in the process of new bone formation

• Bone metabolism- 47Ca Calcium, 32P Phosphorous, 18F Fluorine

Quality assurance (QA): preventing mistakes and defects in manufactured products and avoiding problems when delivering products or services (results of imaging) to customers

Quality control (QC): is used to describe the fifth phase of the DMAIC model:

Define, Measure, Analyze, Improve, Control.

DMAIC is a data-driven quality strategy used to improve processes.

PREPARING PHASE

1. Indication of examination -> Physician with diagnostic problem -> Demand letter for actual diagnostic problem

2. Patient (PT) preparing -> Nurse and NM staff -> Information to the PT

3. Patient admission & data control -> Office staff/Tec & physician -> Quality control (QC) patients data – explanation of the method

IMAGING PHASE:

1. RF Preparing -> Pharmacologist -> QC radiopharmacon (RF)

2. RF application -> NM physician & Nurse -> Quality assurance (QA) + identification of RF

3. Detection -> Technician (Tec) -> QA – gamma camera (physicist)

4. Data analysis -> Physicist/Tec -> QA – steps of examination

INTERPRETATION PHASE

1. Reporting -> Physician specialized NM -> Double reading + seminars NM

2. Administration -> Office staff -> Clinical seminar, case report, comparative study (NM specialist)

3. Interpretation + PT-Management -> Physician -> Feedback cooperation with NM specialist

1. Indication of examination -> Physician with diagnostic problem -> Demand letter for actual diagnostic problem

2. Patient (PT) preparing -> Nurse and NM staff -> Information to the PT

3. Patient admission & data control -> Office staff/Tec & physician -> Quality control (QC) patient’s data – explanation of method. Contrast media (CM)ßFarmacy, EA (external agencies)

4. CM application -> Nurse & Tec -> Allergy prevention

5. Detection -> Technician (Tec) -> QA – X-ray, CT, MRI technology

6. Data analysis -> Physicist/Tec -> QA – steps of examination (EA)

7. Reporting -> Physician specialized NM -> Double reading + seminars NM

8. Administration -> Office staff -> Clinical seminar, case report, comparative study (NM specialist)

9. Interpretation + PT-Management -> Physician -> Feedback cooperation with NM specialist