Nuclear Medicine Contest

Prepared by: Dr Majid Al-Homiedan Dr Yasser Al-Ghamdi

NUCLEAR MEDICINE CONTEST

1

•Which radiopharmaceutical commonly used for cystography? •What is the advantage over MCUG? •What is the difference between direct and indirect cystography? •How is reflux graded with radiopharmaceutical cystography?

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Which radiopharmaceutical commonly used for cystography? What is the advantage over MCUG? What is the difference between direct and indirect cystography? How is reflux graded with radiopharmaceutical cystography?

 99mTc

DTPA and 99mTc Sulfur colloid.

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More sensitive in detection of VUR and 50 to 200 times less radiation to the gonads.

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Direct: cathetrization and instillation of tracer inside the bladder, indirect: performed after routine renography.

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Mild reflux: confined to the ureter, moderate: reaches the pelvicalyceal system, severe: distorted collecting system and dilated tortuous ureters.

2

•Describe the scintigraphic findings? •Give the diagnosis? •What treatment options are appropriate for this patient? •What would you expect the radioactive iodine uptake would be?

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Describe the scintigraphic findings? Give the diagnosis? What treatment options are apropriate for this patient? What would you expect the radioactive iodine uptake would be?

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Hot nodule in the right thyroid lobe with supression of the remaining gland.

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Toxic autonomous thyroid nodule.

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Surgery and radioactive iodine 131I , therapy with PTU or methimazole sometimes is used as initial treatment.

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May be moderately elevated, but its often in the normal range. Normal 24 hours uptake is 10% to 30%.

3

•What is the radiopharmaceutical and mechanism of distribution? •What are the most common causes of acute testicular pain? •What is the mechanism of testicular torsion? •What are the imagining findings and diagnosis in this case?

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What What What What

is the radiopharmaceutical and mechanism of distribution? are the most common causes of acute testicular pain? is the mechanism of testicular torsion? are the imagining findings and diagnosis in this case?

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99mTc pertechnetate, initial blood flow and distributes in the extracellular fluid space.

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Acute epidydimitis, testicular torsion, torsion of the testicular appendage.

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Developmental anomalies of testicular decent and attachment predisposes to spermatic cord torsion, the most common anomaly is the bell-clapper testis.

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Decreased blood flow to the left testicle and photopenic on delayed image consistent with acute testicular torsion.

4

•Describe the bone scan findings? •Name two non-osseous systems that should be evaluated on bone scan? •Describe any other finding? •What term can applied to this case?

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Describe the bone scan findings? Name two non-osseous systems that should be evaluated on bone scan Describe any other finding? What term can applied to this case?

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Increased radiotracer uptake in large majority of visualized bones, especially the appendicular skeleton with focal areas of increased uptake in femur and tibia bilaterally.

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Soft tissues and genitourinary system.

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Faint activity in the kidneys, little soft tissue activity seen.

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Superscan secondary to Osteomalacia.

5

Describe the findings? Provide the differential diagnosis? What is the likely diagnosis in this case ? Discuss the pathogenesis?

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Describe the findings? Provide the differential diagnosis? What is the likely diagnosis in this case ? Discuss the pathogenesis?

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Three phase study, abnormal increased blood flow and blood pool of the distal right upper extremity, the delayed phase shows increased activity in the bones in the same distribution, with striking increase in periarticular activity.

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Reflex sympathetic dystrophy syndrome, disuse of limb of new onset.

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Reflex sympathetic dystrophy syndrome (Sudek’s atrophy).

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Neurogenic origin with loss of sympathetic autonomic tone is the generally accepted explanation, although not firmly established.

6

•Describe the bone scan findings? •Provide the differential diagnosis? •What are the phases of this disease? •The patient may experience clinical symptoms related to another organ system, discuss the mechanism?

•Describe the bone scan findings? •Provide the differential diagnosis? •What are the phases of this disease? •The patient may experience clinical symptoms related to another organ system, discuss the mechanism?

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Abnormal high uptake in the left femur which appears widened and bowed, increased uptake is seen in the pelvis and left first metatarsal are also seen.

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Paget’s disease, fibrous dysplasia, chronic osteomyelitis and primary bone tumors in particular osteosarcoma.

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Lytic, sclerotic and mixed.

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High output congestive heart failure, once believed to be sue to arteriovenous malformation in the bone lesion, now hyperemia and increased blood flow to the lesion and not shunting.

7

•Describe the findings? •What other imaging study should be ordered? •What is the diagnosis and most likely common cause for this scan? •Mention other causes of this condition?

•Describe the findings? •What other imaging study should be ordered? •What is the diagnosis and most likely common cause for this scan? •Mention other causes of this condition?

General increased activity in the long bones with pericorticalstriping along the medial and lateral aspects of lower extremities (railroad tracking) characteristic. Chest x-ray Hypertrophic pulmonary osteoarthropathy, bronchogenic cancer of the lung. Mesothelioma, pulmonary mets, bronchiectasis, mediastinal disease (hodgkin’s), lung abscess, asthma, cystic fibrosis, CCHD, bacterial endocarditis,r egional enteritis, UC and congenital billiary atresia.

This is the chest x-ray of the patient

8

•Describe the difference between Grave’s disease and euthyroid scan appearance? •What is the appropriate therapy for Grave’s disease? •What are the usual administered doses of 131I uptake, 123I scan and Grave’s disease therapy? •What are the short term and long term side effects of 131I therapy?

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Describe the difference between Grave’s disease and euthyroid scan appearance? What is the appropriate therapy for Grave’s disease? What are the usual administered doses of 131I uptake, 123I scan and Grave’s disease therapy? What are the short term and long term side effects of 131I therapy?

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May be similar, with large goiter the scan often has plumper appearance with convex borders, the pyramidal lobe maybe seen.

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Surgery, seldom performed. PTU and methimazole sometimes used initially particularly in patients with severe disease who require cooling down, young children and pregnant patients. Most of the times treated with radioactive iodine after 6 to 12 months of antithyroid medication. Many patients are treated initially with 131I.

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131I

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Short term: exacerbation of hyperthyroidism, cardiac symptoms in elderly, very rare thyroid storm. Long term: hypothyroidism, there is no increased incidence of secondary cancers, reduction in fertility or congenital defects.

uptake (10 µCi), 123I scan and uptake (300 µCi), Grave’s disease therapy 131I (5 to 15 mCi).

9

•If the EEG is flat line, why is another study indicated? •What are the clinical findings of brain death? •List 2 different types of tracers with different mechanism that could be used in this study? •What are the scintigraphic findings and diagnosis?

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If the EEG is flat line, why is another study indicated? What are the clinical findings of brain death? List 2 different types of tracers with different mechanism that could be used in this study? What are the scintigraphic findings and diagnosis?

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A flat EEG can be caused by barbiturates, depressive drugs or hypothermia.

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Deep coma, no brain stem reflexes or spontaneous respiration, exclusion of reversible causes and the cause of the brain dysfunction must be diagnosed.

 99mTc

DTPA or Tc pertechnetate can be used as a brain flow study. However Tc HM-PAO and 99mTc ECD have the advantage of irreversible cellular binding on the first pass allowing for delayed images.

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No blood flow to the cerebral cortex. Brain blood flow study consistent with brain death.

10

•Name the radiophamaceutical used? •List methods for preparation of this radiopharmaceutical? •Describe the methodologies of radiolabling? •List the advantage and disadvantage of the different radiolabling?

•Name the radiophamaceutical used? •List methods for preparation of this radiopharmaceutical? •Describe the methodologies of radiolabeling? •List the advantage and disadvantage of the different radiolabeling?  99mTc-labled

RBCs.

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In-vivo, modified in-vivo and in-vitro methods.

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In-vivo: stannous pyrophosphate is adminstered IV and followed in 15 min by 99mTc pertechnetate. Modified in-vivo: 3 -5 mls of blood into syringe containing 99mTc pertechnetate and anticoagulant, incubated for 10 mins and agitated then infused. In-vitro: blood is withdrawn and placed in a closed vial containing stannous chloride and sodium hypochlorite to oxidize excess extracellular stannous, then adding 99mTc pertechnetate followed by 20 mins incubation before reinjection.

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The in-vivo method is simplest and least costly, but has the lowest labeling efficiency. The in-vitro kit method has the highest labeling efficiency but requires more time and cost.

THANK YOU