40 Questions
What factors can affect the quality of a bone scan?
Factors that impair renal function
How does Fluorine-18 sodium fluoride exchange in the bone?
It exchanges for a hydroxyl ion on the surface of the hydroxyapatite matrix and migrates into the crystalline matrix of bone
What are the two main components of bone?
Inorganic mineral phase of crystals bound to protein, largely collagen
What is the main difference between technetium-99m diphosphonate and fluorine-18 sodium fluoride for bone scanning?
Fluorine-18 sodium fluoride offers better spatial resolution and sensitivity compared to technetium-99m diphosphonate
What is the purpose of voiding before imaging in bone scans?
To prevent bladder activity from obscuring pelvic lesions
What is the process responsible for remodeling bone?
Osteoclasts resorbing old bone and osteoblasts putting down new bone
Where is increased activity commonly seen in older patients with arthritis in a bone scan?
In the knees
What are the two main parts of the anatomical skeleton?
Axial and appendicular portions
Which diseases may accelerate the bone turnover process?
Fractures, infections, bone tumors, or metastases
What are bone-seeking radiopharmaceuticals commonly used for skeletal imaging?
Technetium-labeled diphosphonates and fluorine-18 sodium fluoride
What can cause false-negative scans on a 99mTc-diphosphonate bone scan in the early stages?
Cases where the blood supply to the bone is disrupted
How is septic arthritis characterized on bone scans?
Increased activity in all phases
What imaging techniques can be used to evaluate osteomyelitis?
Planar 99mTc-MDP scans, SPECT/CT, labeled leukocytes, and 18F-FDG CT
What is the characteristic appearance of hypertrophic pulmonary osteoarthropathy on bone scans?
Distinct parallel lines of activity along the cortex of the affected bones
What can diffuse increased activity throughout the skeleton indicate in metabolic bone diseases?
Primary and secondary hyperparathyroidism
What imaging techniques are useful for identifying hidden hip and knee fractures?
MRI
How long does the acute phase of a bone scan last after a fracture?
3 to 4 weeks
What type of fractures can be recognized by their location in consecutive ribs?
Rib fractures
What imaging technique can provide early diagnosis and treatment options for stress injuries?
Three-phase bone scans
What imaging technique is more specific for identifying the causes of prosthesis failure, including infection?
CT and MRI
What imaging techniques are commonly used to differentiate normal marrow from leukocyte accumulation in cases of suspected infected joint replacements?
99mTc-sulfur colloid scans and 111In-WBC imaging
What is the most widely used method for accurately determining Bone Mineral Density (BMD)?
Dual x-ray absorptiometry (DXA or DEXA)
How is BMD expressed in terms of T-scores and Z-scores?
BMD is expressed in absolute terms and relative terms as T-scores and Z-scores.
When should screening for osteoporosis begin in women and men without risk factors?
Age 65 in women and age 70 in men
What tool provides a 10-year risk of hip and global fractures for assessing fracture risk?
WHO fracture risk assessment tool (FRAX)
What are some common indications for bone scanning?
Detection and monitoring of skeletal metastases, differentiation between osteomyelitis and cellulitis, determining bone viability, assessing difficult fractures, evaluating prosthetic joint infections or loosening, determining biopsy sites, evaluating bone pain with normal or inconclusive radiographs, and assessing the significance of incidental skeletal findings.
How do bone scans compare to radiography in detecting metastatic lesions?
Bone scans are more sensitive than radiography in detecting metastatic lesions, with a lower false-negative rate.
What is the role of radionuclide bone scans in imaging primary bone tumors?
Radionuclide bone scans have a limited role in imaging primary bone tumors, but they can incidentally detect these tumors in patients with regional bone pain or inconclusive X-ray results.
How do benign osseous neoplasms typically appear on bone scans?
Benign osseous neoplasms have variable appearances on bone scans, with most malignant lesions being hyperemic and most benign lesions initially accumulating little radiopharmaceutical.
What factors can cause soft-tissue activity on bone scans?
Contamination from radioactive urine or injection, soft-tissue neoplasms or metastases (particularly in the liver), and calcification in certain tumors.
What is the typical dose range for Strontium-89 (89Sr) therapy?
40 to 60 μCi/kg (1.5 to 2.2 MBq/kg) up to 4 mCi (148 MBq)
How is Strontium-89 (89Sr) chloride primarily excreted from the body?
Through urine
What is the typical interval between repeated doses of Strontium-89 (89Sr) therapy?
3 to 4 months
When does pain relief typically become apparent after administering Strontium-89 (89Sr) therapy?
Within 1 to 3 weeks
What are two other successful beta-emitting radiopharmaceuticals mentioned in the text?
Rhenium-186 hydroxyethylene diphosphonate (HEDP or etidronate) and samarium-153 (153Sm) ethylenediaminetetra methylene phosphonic (EDTMP) acid or 153Sm lexidronam (Quadramet)
What is the physical half-life of Rhenium-186?
90 hours
What is the soft-tissue range of Samarium-153 lexidronam (Quadramet)?
0.6 mm
Why are alpha-emitting radionuclides like Radium-223 (223Ra) preferred over beta-emitters for treating bone metastases?
Alpha-particles deposit a larger amount of energy in a shorter range, minimizing damage to adjacent bone marrow and normal structures.
What is the primary elimination route for Radium-223 (223Ra) after administration?
Fecal excretion
How many intravenous doses are included in the treatment course of Radium-223 (223Ra)?
Six
Learn about the use of 99mTc-sulfur colloid scans and 111In-WBC imaging in differentiating normal marrow from leukocyte accumulation, as well as the interpretation of Bone Mineral Density (BMD) measurements by physicians.
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