A nuclear medicine whole-body bone scan. The nuclear medicine whole-body bone scan is generally used in evaluations of various bone-related pathology, such as for bone pain, stress fracture, nonmalignant bone lesions, bone infections, or the spread of cancer to the bone.
The most common
radiopharmaceutical for bone scintigraphy is 99mTc with
methylene diphosphonate (MDP).[12] Other bone radiopharmaceuticals include 99mTc with HDP, HMDP and DPD.[13][14] MDP
adsorbs onto the crystalline
hydroxyapatite mineral of bone.[15] Mineralisation occurs at
osteoblasts, representing sites of bone growth, where MDP (and other diphosphates) "bind to the hydroxyapatite crystals in proportion to local blood flow and
osteoblastic activity and are therefore markers of bone turnover and bone perfusion".[16][17]
Note that the technique depends on the osteoblastic activity during remodelling and repair processes following initial osteolytic activity. This leads to a limitation of the applicability of this imaging technique with diseases not featuring this osteoblastic (reactive) activity, for example with
multiple myeloma. Scintigraphic images remain falsely negative for a long period of time and therefore have only limited diagnostic value. In these cases CT or MRI scans are preferred for diagnosis and staging.
Technique
In a typical bone scan technique, the patient is injected (usually into a vein in the arm or hand, occasionally the foot) with up to 740
MBq of
technetium-99m-MDP and then scanned with a
gamma camera, which captures planar
anterior and posterior or
single photon emission computed tomography (SPECT) images.[19][14] In order to view small lesions SPECT imaging technique may be preferred over planar scintigraphy.[20]
In a single phase protocol (skeletal imaging alone), which will primarily highlight osteoblasts, images are usually acquired 2–5 hours after the injection (after four hours 50–60% of the activity will be fixed to bones).[19][14][21] A two or three phase protocol utilises additional scans at different points after the injection to obtain additional diagnostic information. A dynamic (i.e. multiple acquired frames) study immediately after the injection captures
perfusion information.[21][22] A second phase "blood pool" image following the perfusion (if carried out in a three phase technique) can help to diagnose inflammatory conditions or problems of blood supply.[23]
Although bone scintigraphy generally refers to gamma camera imaging of 99mTc radiopharmaceuticals, imaging with
positron emission tomography (PET) scanners is also possible, using
fluorine-18sodium fluoride ([18F]NaF).
For
quantitative measurements, 99mTc-MDP has some advantages over [18F]NaF. MDP renal clearance is not affected by urine flow rate and simplified data analysis can be employed which assumes
steady state conditions. It has negligible tracer uptake in
red blood cells, therefore correction for plasma to whole blood ratios is not required unlike [18F]NaF. However, disadvantages include higher rates of protein binding (from 25% immediately after injection to 70% after 12 hours leading to the measurement of freely available MDP over time), and less
diffusibility due to higher
molecular weight than [18F]NaF, leading to lower
capillary permeability.[25]
There are several advantages of the PET technique, which are common to PET imaging in general, including improved
spatial resolution and more developed
attenuation correction techniques. Patient experience is improved as imaging can be started much more quickly following radiopharmaceutical injection (30–45 minutes, compared to 2–3 hours for MDP/HDP).[26][27] [18F]NaF PET is hampered by high demand for scanners, and limited tracer availability.[28][29]
References
^Bahk, Yong-Whee (2000). Combined scintigraphic and radiographic diagnosis of bone and joint diseases (2nd ed.). Berlin, Heidelberg: Springer. p. 3.
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^Livieratos, Lefteris (2012). "Basic Principles of SPECT and PET Imaging". In Fogelman, Ignac; Gnanasegaran, Gopinath; van der Wall, Hans (eds.). Radionuclide and Hybrid Bone Imaging. Berlin: Springer. p. 345.
doi:
10.1007/978-3-642-02400-9_12.
ISBN978-3-642-02399-6.
^Pecher, Charles (1941). "Biological Investigations with Radioactive Calcium and Strontium". Proceedings of the Society for Experimental Biology and Medicine. 46 (1): 86–91.
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^Fleming, William H.; McIlraith, James D.; Richard King, Capt. E. (October 1961). "Photoscanning of Bone Lesions Utilizing Strontium 85". Radiology. 77 (4): 635–636.
doi:
10.1148/77.4.635.
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^Subramanian, G.; McAfee, J. G. (April 1971). "A New Complex of 99mTc for Skeletal Imaging". Radiology. 99 (1): 192–196.
doi:
10.1148/99.1.192.
PMID5548678.
^Biersack, Hans-Jürgen; Freeman, Leonard M.; Zuckier, Lionel S.; Grünwald, Frank (2007). Clinical Nuclear Medicine. Berlin: Springer. p. 243.
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^
abcVan den Wyngaert, T.; Strobel, K.; Kampen, W. U.; Kuwert, T.; van der Bruggen, W.; Mohan, H. K.; Gnanasegaran, G.; Delgado-Bolton, R.; Weber, W. A.; Beheshti, M.; Langsteger, W.; Giammarile, F.; Mottaghy, F. M.; Paycha, F. (4 June 2016).
"The EANM practice guidelines for bone scintigraphy". European Journal of Nuclear Medicine and Molecular Imaging. 43 (9): 1723–1738.
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^Chopra, A (24 August 2009).
"99mTc-Methyl diphosphonate". Molecular Imaging and Contrast Agent Database. National Center for Biotechnology Information (US).
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^Brenner, Arnold I.; Koshy, June; Morey, Jose; Lin, Cheryl; DiPoce, Jason (January 2012). "The Bone Scan". Seminars in Nuclear Medicine. 42 (1): 11–26.
doi:
10.1053/j.semnuclmed.2011.07.005.
PMID22117809.
^
abDonohoe, Kevin J.; Brown, Manuel L.; Collier, B. David; Carretta, Robert F.; Henkin, Robert E.; O'Mara, Robert E.; Royal, Henry D. (20 June 2003).
Procedure Guideline for Bone Scintigraphy(PDF) (Report). Society of Nuclear Medicine. 3.0.
^Kane, Tom; Kulshrestha, Randeep; Notghi, Alp; Elias, Mark (2013).
"Clinical Utility (Applications) of SPECT/CT". In Wyn Jones, David; Hogg, Peter; Seeram, Euclid (eds.). Practical SPECT/CT in nuclear medicine. London: Springer. p. 197.
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^Schauwecker, D S (January 1992). "The scintigraphic diagnosis of osteomyelitis". American Journal of Roentgenology. 158 (1): 9–18.
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^Mettler, Fred A.; Huda, Walter; Yoshizumi, Terry T.; Mahesh, Mahadevappa (July 2008). "Effective Doses in Radiology and Diagnostic Nuclear Medicine: A Catalog". Radiology. 248 (1): 254–263.
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10.1148/radiol.2481071451.
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^Langsteger, Werner; Rezaee, Alireza; Pirich, Christian; Beheshti, Mohsen (November 2016). "18F-NaF-PET/CT and 99mTc-MDP Bone Scintigraphy in the Detection of Bone Metastases in Prostate Cancer". Seminars in Nuclear Medicine. 46 (6): 491–501.
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