Most common: Detection and follow-up of Skeletal metastatic disease.Evaluation of bone and joint infections as osteomyelitis and septic arthritis.Assessing of hardware prosthesis infection or loosening.Detection of radio-graphically occult injury (e.g. stress fractures and shin splint.Evaluation of primary bone tumors either malignant as osteosarcoma and Ewing sarcoma or benign as osteoid osteoma. Less common: Metabolic bone disease including the hyper-parathyroidism, osteomalacia and renal osteodystrophy, for detection of skeletal complications rather than diagnosis.Paget’s disease, to evaluate the osteoblastic activity before initiating therapy.Evaluation of avascular(osteonecrosis) that commonly occurs in the femoral head.Evaluation of malignant (necrotizing) otitis externa.Evaluation of temporo-mandibular joint disorders.
Cancer patients for metastatic work-up.Patients with suspected bone infection.patients of hardware prosthesis presenting with pain.Patients presenting with bony pain and occult radiographic findings.Patients with primary malignant bone tumors to evaluate skip lesions and metastatic deposits. Patients presenting with metabolic bone disorders to evaluate skeletal complications (e.g., pseudo fractures).Patients with Paget’s disease before initiating treatment.Patients suspected of petrous bone invasion in malignant otistis externa. Patients presenting with asymmetrical growth of the temopro-mandibular joints.
Pregnancy.Lactation (stopped for 24 hours)
Other anatomical imaging modalities (e.g. CT, MRI or X-ray).Other scintigraphic imaging as 18F-NaF, 18F-FDG, 131I, 67Ga.
The patient should drink about 1-2 litres of water between the time of injection of radiotracer till the time of delayed imaging (unless there is a contra-indication).The patient should empty the bladder before the study
IV canula is inserted.For adults, the dose of 99Tc-MDP radio-active tracer is ~13-30mCi. For children, the dose is adjusted according to their weight. If only delayed imaging is required, the radio-active tracer (99Tc-MDP) will be injected after insertion of the IV cannula and the patient will wait for about 2-4 hours then a whole-body skeletal imaging will be acquired using the Gamma camera while the patient lying on his back.If early images are required to assess specific site (e.g., hip pain, knee prosthesis), the patient will lie on his back on the gamma camera bed, early dynamic and blood pool images will be acquired simultaneously and/or within 10 minutes after 99Tc-MDP injection, after which the patient will stay in the waiting area for 2-4 hours drinking the required amount of water then he will acquire the delayed whole body skeletal imaging as previously described.Sometimes additional Spot views are required for better delineation of lesions. This will require few minutes.Sometimes SPECT/CT images are added for better localization of certain lesions.
The examination is done on state-of-the-art Gamma Camera machines (produced by Philips and GE) at Mohandeseen, Heliopolis and New Cairo branches.
Patients should stay away from children (less than 12 years of age) and pregnant ladies, for at least 24 hours starting after injection of the radiotracer.