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Flashcards in SP6:Skeletal System Scintigraphy Deck (41)
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Which of the following is a malignant bone disease?
(a)Paget’s disease

(b) Ewing’s sarcoma
(c) Osteomyelitis
(d) Osteoid osteoma


(b) Ewing’s sarcoma is a type of cancer most often found in children and young adults and is more common in males than females. Paget’s disease is a chronic bone disease involving enlarged and deformed bones. Osteomyelitis is an infection of the bone or bone marrow. Osteoid osteoma is a benign bone tumor that is common in the appendicular skeleton. Osteoid osteoma demonstrates tracer uptake on blood pool images during a bone scan as opposed to most benign osseous neoplasms.


A three-phase bone scan is often done to differentiate
(a)Osteoporosis vs. cellulitis

(b) Osteomyelitis vs. diskitis
(c) Osteomyelitis vs. cellulitis
(d) Osteoporosis vs. septic arthritis


(c) Cellulitis often demonstrates as diffuse increased activity on early images, and activity decreases on delayed images. Osteomyelitis shows increased uptake in bone on early images which continues to increase on delayed images.


The presence of gastric and thyroid activity on a bone scan signals the presence of:
(a)Metastatic disease

(b) Free pertechnetate
(c) Radionuclide impurity
(d) Reducing agent


(b) Free pertechnetate may be due to poor tagging of phosphates, or too much time may have elapsed between radiopharmaceutical preparation and injection.


What is the purpose of a reducing agent in a 99mTc diphosphonate kit?
(a)To oxidize technetium

(b) To lower the valence state of technetium
(c) To improve the tag efficiency
(d) Both (b) and (c)
(e) (a), (b), and (c)


(d) Stannous chloride reduces the valence state of technetium, thereby improving the tag efficiency.


What is the dose of 99mTc MDP most often prescribed for a planar bone scan?
(a)1–3 mCi

(b) 5–10 mCi
(c) 20–30 mCi
(d) 30–35 mCi


(c) Planar bone scans can be performed using 10-30 mCi of 99mTc phosphates and phosphonates; higher doses may be indicated in obese patients and calculated based on weight (300-350 uCi/kg).


Which of the following is least likely to cause an artifact on bone scan?
(a)Snap on trousers

(b) Colostomy bag
(c) Skin contaminated by urine
(d) Injection site


(b) Since most of the injected dose will leave the body via the urinary tract, the skin contaminated by urine is a common problem. Metal on clothing will cause an attenuation artifact. If there is even a small amount of extravasation of the dose during injection, there will be a hot artifact at the injection site. A colostomy bag is the least likely to cause an artifact on bone scans.


What is not an indication for a bone scan?
(a)Metastatic disease

(b) Osteoporosis
(c) Cellulitis
(d) Avascular necrosis


(b) Bone mineral density, which is decreased in osteoporosis, can be evaluated using quantitative CT (QCT), dual photon absorptiometry (DPA), and dual x-ray absorptiometry (DXA). Detection and follow-up of metastases and differentiation of osteomyelitis and cellulitis are common indications for bone scanning. It is also used for evaluating avascular necrosis.


The presence of free pertechnetate on a bone scan may be the result of:
(a)The use of a radiopharmaceutical which was prepared too long ago

(b) Introduction of air into the kit vial while adding technetium
(c) Increased blood flow to bones
(d) Both (a) and (b)
(e) (a), (b), and (c)


(d) Free pertechnetate demonstrate as gastric, salivary, and thyroid activity on bone scans may be the result of administering a dose from a kit that has been prepared more than 4 h prior to injection. Additionally, if air has been introduced into the reaction vial during labeling, there may be a poor technetium-phosphate tag.


What is the purpose of hydration and voiding after an injection for a bone scan?
(a)To block the uptake of unlabeled technetium by the stomach

(b) To reduce the possibility of urine contamination
(c) To obtain a superscan
(d) To reduce the radiation dose to the bladder


(d) Hydration and frequent voiding after administration of a diphosphonate radiopharmaceutical reduce the radiation dose to the bladder since the radiopharmaceuticals are excreted through the urinary bladder. Patients should void immediately before imaging so that bladder activity does not obscure visualization of the pelvis.


What could be the cause of generalized, diffuse activity in the abdomen on a bone scan?
(a)Free pertechnetate

(b) Malignant ascites
(c) Pacemaker
(d) Bone cyst


(b) Malignant ascites may be seen as diffusely increased activity on bone scans. Malignant pleural effusion may be similarly seen in the chest.


What timing protocol best describes a four-phase bone scan?
(a)During injection, immediately following injection, 2-4 h, and 18-24 h

(b) During injection, 2-4 h, 24 h, and 48 h
(c) During injection, immediately following injection, 2-4 h, and 6 h
(d) None of the above


(a) The fourth phase of imaging is usually completed approximately 24 h following injection; therefore, choices (b) and (c) are incorrect. This protocol may be necessary in patients with renal failure because soft tissue activity may persist.


A focal hot spot near the left femur shows up on a bone scan. What is/are the best way/ways to proceed?
(a)Change to pinhole collimator and image.

(b) Perform SPECT imaging.
(c) Have the patient remove clothing of that area.
(d) Ask the patient to wash the skin in that area with soap and water
(e) (c) and (d).


(e) Focal hot spots on bone scans that appear to be in soft tissue, particularly on the medial aspect of the thighs, are often the result of radioactive contamination on clothing or skin from urine. Patients should remove clothing and wash the skin to remove the possible contamination.


A bone scan showing relatively uniformly increased skeletal uptake of radiopharmaceutical with almost absent renal and bladder activity is usually referred to as a:
(a)Flare phenomenon

(b) Superscan
(c) Renal failure
(d) Suprascan


(b) Decreased renal activity, together with diffusely increased bone uptake, especially in the axial skeleton, is often referred to as a superscan. This is most often seen where there is diffuse metastatic involvement in the skeleton but may also be due to certain metabolic conditions. The flare phenomenon refers to the apparent worsening of bone metastases in the months following chemotherapy, which is actually due to increased uptake resulting from healing. Patients in renal failure often show overall increased soft tissue uptake.


The glove phenomenon is usually the result of:
(a)Reactive arthritis

(b) Intravenous injection
(c) Antecubital injection
(d) Arterial injection
(e) Subcutaneous injection


(d) The glove phenomenon is markedly increased activity in the distal extremity and is due to an arterial injection.


What are common sites of bony metastasis?

(b) Spine
(c) Ribs
(d) All of the above


(d) Prostate, lung, and breast cancers often metastasize to the bone, most commonly in the bones of the thorax, spine, and pelvis.


What is the purpose of a stannous ion in a diphosphonate kit?
(a)Acts as a reducing agent

(b) Acts as an oxidizing agent
(c) Provides a stabilizing force
(d) Maintains particle size


(a) 99mTc, following elution form an alumina column generator, exists primarily in the valence state +7. Stannous ions reduce the valence state, usually to +4, and this improves the tag efficiency.


The appendicular skeleton includes the following bones, except:
(a)The femurs

(b) The skull
(c) The phalanges
(d) The radius


(b) The appendicular skeleton refers to the appendages (which includes the femurs, phalanges, and the radius; choices (a), (c), and (d)) and the bones of the pelvis and shoulder girdles. The skull, spine, most bones of the thorax, and some pelvic bones comprise the axial skeleton.


The axial skeleton contains:
(a)The ribs

(b) The skull
(c) The vertebral column
(d) The pelvis
(e) All of the above
(f) (a), (b), and (c) only


(f) The skull, spine, most bones of the thorax, and some pelvic bones comprise the axial skeleton.


By what mechanism do diphosphonates localize in the bone?
(a)Capillary blockade

(b) Active transport
(c) Ion exchange
(d) Phagocytosis


(c) It is believed that ions in the tracer exchange with those in the bone crystal, hydroxyapatite. Uptake appears to be related to osteogenic activity and skeletal blood perfusion.


Which of the following describes a pediatric bone scan?
(a)Increased uptake in long bones

(b) Decreased uptake along epiphyseal plates
(c) Increased uptake along epiphyseal plates
(d) Overall decreased uptake in the bone


(c) Pediatric bone scans show intense uptake in the area of the epiphyses, because the cartilaginous epiphyseal plates are the sites of longitudinal bone growth. When bone growth stops, the cartilage is replaced by bone.


The first phase of a three-phase bone scan is best performed by:
(a)Bolus injection followed by dynamic 2-s images for 60 s

(b) Bolus injection followed by dynamic 20-s images for 2 min
(c) Bolus injection followed by a static 500-600-K count image
(d) Bolus injection followed by dynamic 1-s images for 30 s


(a) A three-phase bone scan is begun by administration of a bolus injection followed by imaging every 1-3 s, for at least 1 min. Choice (d) is incorrect because the dynamic images are not performed for a sufficient length of time.


What pharmaceuticals may be used for bone marrow imaging:
(a)99mTc albumin colloid

(b) 99mTc sulfur colloid
(c) 99mTc PYP
(d) (a) and (b)
(e) All of the above


(d) Bone marrow scans are commonly performed using 99mTc sulfur or albumin colloid because the marrow contains reticuloendothelial cells which localize the colloid by phagocytosis.


What is often used in imaging-suspected avascular necrosis of the hip?
(a)SPECT imaging

(b) PET imaging
(c) Pinhole collimation
(d) Diverging collimation
(e) Both (a) and (c)


(e) SPECT is useful for evaluating avascular necrosis. Pediatric cases may especially benefit from pinhole collimation because the epiphysis is small and there is nearby activity from the bladder and the acetabulum.


Splenic uptake on a bone scan is often associated with
(a)Liver failure

(b) Sickle cell disease
(c) Splenic abscess
(d) Paget’s disease


(b) Patients with sickle cell anemia often have splenic uptake on bone scans due to splenic infarcts. The radiopharmaceutical localizes in the spleen following infarct due to revascularization; if infarcts are repetitive, there may be mineral deposits which also cause uptake.


The bone is made of:
(a)Hydrogen peroxide

(b) Hydroxyapatite mineral
(c) Collagen
(d) (a) and (b) only
(e) (b) and (c) only


(e) Bone’s osseous tissue contains calcium phosphate in the form of hydroxyapatite. Collagen provides some elasticity.


Osteoblastic activity refers to:
(a)Bone marrow biopsy

(b) Destruction and reabsorption of the bone
(c) Bone compression
(d) New bone formation


(d) Osteoblasts are cells that create collagen and strengthen bone; therefore, osteoblastic activity refers to formation of new bone.


Osteoclastic activity refers to:
(a)Bone marrow biopsy

(b) Destruction and reabsorption of the bone
(c) Bone compression
(d) New bone formation


(b) Osteoclasts are cells that destroy mineral tissue as part of a process called bone turnover. Therefore, osteoclastic activity refers to destruction and reabsorption of bone.


The function of the skeleton is:
(a)To provide support

(b) To protect organs
(c) Production of blood cells
(d) All of the above
(e) (a) and (b) only


(d) The skeleton provides support and protection for organs, and the bone marrow is the site of production of leukocytes and erythrocytes.


Which group shows the highest rate of primary bone tumors?
(a)The elderly

(b) Children
(c) Males
(d) Females


(b) A large number of bone tumors develop in the first decades of life, for example, Ewing’s tumor, osteosarcoma, and chondroblastoma. Many also occur in young adulthood, e.g., giant-cell tumors and primary bone lymphoma.


The radiation dose from a bone scan is highest to the:
(a)Bone marrow

(b) Chest
(c) Bladder
(d) Brain


(c) Since radiopharmaceuticals used for bone scanning are excreted in urine, the bladder receives the highest radiation dose. Hydration and frequent voiding reduce the radiation dose to the bladder.


When performing a bolus injection for a three-phase bone scan, why would the tourniquet be released and injection delayed for 1 min?
(a)To minimize pain during injection

(b) To reduce transient hyperemia resulting from vasodilation
(c) To double check the dynamic sequence settings
(d) To obtain a better bolus


(b) When performing a three-phase bone scan of the upper extremities, the technologist should obtain venous access and then release the tourniquet and delay injection slightly to avoid increased uptake on the injected side.


What is an advantage of spot planar imaging over whole body imaging for a bone scan?

(b) Decreased patient to detector distance.
(c) Less film is used.
(d) No need for COR correction.


(b) The technologist can position the patient directly adjacent to the detector head during spot planar imaging.


Which of the following would be a reason not to inject in the right antecubital fossa?
(a)The patient has had blood drawn from the back of the right hand that same day.

(b) The patient was injected on the right for a previous bone scan.
(c) There is a suspicion of osseous abnormality in the right distal humerus.
(d) The patient is left handed.


(c) It is important to check the patient’s history and the referring physician’s suspicions before injection, to ensure that areas of potential interest are not obscured by extravasation of the radiopharmaceutical.


The preparation for a bone scan is:
(a)NPO from midnight.

(b) Cleansing enema.
(c) The patient must be off thyroid medication for 4 weeks.
(d) None of the above.
(e) (a) and (b) only.
(f) All of the above.


(d) Being NPO, taking a cleansing enema, or refraining from taking thyroid medication will have no effect on bone scan images.


Metastases usually affect the axial skeleton before the appendicular skeleton.



(a) The most common sites for bony metastases are the spine, thorax, and pelvis.

The advantage(s) of bone scanning over plain radiography is:
(a)The bone must lose only a minimum of calcium content before lesions are visible on bone scintigraphy.

(b) Time.
(c) Efficient for multifocal trauma such as child abuse.
(d) All of the above.
(e) (a) and (c) only.


(e) Bone lesions are undetectable on radiographs until 30% or more of the bone’s calcium content is lost; lesions can be seen on bone scans even when there is a slight loss of calcium. When there is suspicion of multifocal trauma, a bone scan can more efficiently survey the whole body, than can conventional radiography.


The mechanism of localization for bone marrow scanning is:
(a)Active transport

(b) Ion exchange
(c) Phagocytosis
(d) Capillary blockade


(c) Radiolabeled sulfure or albumin colloid particles are phagocytized by the reticuloedothelial cells in the bone marrow.


A large amount of diffuse soft tissue activity present on a bone scan at 4 h frequently represents:
(a)Increased cardiac output

(b) Renal insufficiency
(c) Metastatic disease
(d) Infection


(b) There are many reasons for soft tissue activity on bone scans. Of the choices listed, renal insufficiency is the most likely cause, although there can be diffuse soft tissue in the abdomen or chest in cases of metastatic ascites and metastatic pleural effusion.


What imaging agent can be used to image the skeleton as well as myocardial infarction?
(a)99mTc MDP

(b) 99mTc HDP
(c) 99mTc PYP
(d) 201Tl chloride


(c) 99mTc pyrophosphate can be used for bone scintigraphy, myocardial infarction, and blood pool imaging.


Rib fracture often show up as:
(a)Multiple focal hot spots located in consecutive ribs

(b) A linear distribution along the long axis of the rib
(c) Diffuse activity in the chest cavity
(d) Cold spots


(a) Rib fractures are often found in consecutive ribs. Bone metastasis is more likely to appear as linear uptake along the rib.


The cold defect in the left proximal humerus on Fig. 1 (Cold spot bordered by increased uptake) is most likely the result of:

(b) Pacemaker
(c) A bandage around the left upper arm
(d) Surgically implanted metal
(e) Motion


(d) The cold spot in the left proximal humerus, which is bordered by increased uptake, is most likely the result of surgically implanted metal. The cold area in the distal humerus is the result of shielding.