Nuclear medicine in general practice Dr Reza Garzan MD, FRACP, - PowerPoint PPT Presentation

Nuclear medicine in general practice Dr Reza Garzan MD, FRACP, FAANMS

• Myocardial perfusion study • Bone scans in general practice • Thyroid scans in general practice

Gamma camera

Detection of gamma rays

Myocardial perfusion Imaging

How is it performed? Rest/Stress protocol : Radiopharmaceutical injected at rest and then post stress. Same day or two day protocol

Radiopharmaceuticals Tc-99m Sestamibi (MIBI) • Sestamibi (MIBI) : Lipophilic agent, diffuses from blood into the myocardial cell and is retained in mitochondria • Tc-99m : Short physical half life of 6hrs , good energy gamma rays ( better quality pictures)

Radiopharmaceuticals Thallium (TI-201): • Behaves physiologically much like K ion, and is transported across the myocardial cell membrane via Na-K ATPase • Long half life and low energy photons, so much less commonly used nowadays

Modes of stress • Exercise • Pharmacologic • Vasodilator ( Adenosine, Dipyridamole) : Dilate the coronary arteries, but the stenosed vessels are not able to dilate as much as normal coronary arteries are able to. Contraindicated in asthma and severe COPD. • Dobutamine : Sympathomimetic

ACCF/ASNC/ACR/AHA/ASE/SCCT/SCMR/SNM 2009 Appropriate Use Criteria for Cardiac Radionuclide Imaging J Am Coll Cardiol . 2009;53(23):2201-2229. doi:10.1016/j.jacc.2009.02.013

Ischemic cascade

What information do we get from MPS? • Perfusion (rest and stress) • Wall motion (rest and stress), systolic function, LVEF • Symptoms • If exercise, exercise capacity • ECG changes

Cardiac planes

• 67-year-old-man, with episodes of chest pain at rest

• 74- year-old, with DM and exertional chest and throat pain, unable to complete exercise stress test

• Moderate to large amount of reversible ischemia in LAD territory

Small MI in distal LAD territory

Prognostic value of normal ( low -risk) and moderately to severely abnormal (high-risk) myocardial perfusion SPECT in estimating annual rates of cardiac death and nonfatal myocardial infarction

• Bone Scans

• Radiotracer injected, ( Tc-99m HDP) • Early phase images immediately ( presence or absence of hyperaemia/normal or abnormal vascularity) • Delayed phase images in about 3-4 hrs ( osteoblastic activity)

Common applications of bone scans in general practice • Stress fractures • Sports injuries • Suspected fractures with normal x-ray • Arthritis/assessment of facet joint arthropathy • Osteomyelitis • Staging and restaging of prostate, breast and lung cancers • Metabolic bone disease e.g. Paget’s disease • Assessment of painful THR and TKR

Normal whole body bone scan

Case 1 • 50 year old female, pain in bilateral hands , history of fall 4 days back on outstretched hands. Xray : normal

Blood flow and blood pool images

Delayed images

SPECT/CT

• Fracture of bilateral trapezium

Case 2 • 76 year-old female, active walker, pain in the left foot since 3/52, ? Stress Fx

Blood flow and blood pool images

Blood pool images

SPECT/CT

• Active arthritis of tarsometatarsal joint

Case 3 • 85-year-old female, Chronic ulcer in the left foot, close to 1 st MTP joint.

Blood pool images

Delayed images

SPECT/CT

• Osteomyelitis of the distal left 1 st metatarsal bone

Case 4 • 47 -year-old male, right 2 nd metatarsal pain after a long walk

Blood flow and blood pool images

Delayed images

SPECT/CT

• Stress fracture of distal right 2 nd metatarsal

Case 5 • 52 year old female, with back pain for investigation

Delayed SPECT/CT images

• Intensely increased radiotracer uptake in the left L5/S1 facet joint, consistent with left L5/S1 facet joint arthropathy • Can be useful for investigation of cervical facet joint arthropathy too.

Case 6 • 68-year-old man with right foot and heel pain after long walk.

• Right Achilles tendon enthesopathy

Thyroid scans • Thyrotoxicosis • Assessment of thyroid nodules

Radiopharmaceutical : Tc-99m Pertechnatate ( TcO4)

• 69 year-old man presenting with thyrotoxicosis

• Hot autonomous functioning nodule

• 65 year-old female, presenting with thyrotoxicosis

• Graves’ disease • Positive TSH receptor antibodies can confirm the diagnosis

• 30-year-old female presenting with post- partum hyperthyroidism

Thank you!