Equis ISSN 2398-2977

Bone: scintigraphy

Contributor(s): Steve Adair, Tim Donovan, Sue Dyson, Rachel Murray

Introduction

  • Bone scintigraphy is a non-invasive imaging modality that is indicated in a wide variety of skeletal problems because of its high sensitivity, and the ease with which the entire skeleton can be imaged.
  • Images obtained represent physiology in contrast to morphology.
  • Bony lesions are associated with increased local metabolism of calcium and osteoblastic activity which is demonstrated by increased uptake of a suitable tracer.
  • The changes visualized represent increased new bone turnover and/or increased bone blood flow.
  • Factors influencing rate of uptake:
    • Quantity of mineralized bone.
    • Capillary permeability.
    • Local acid base balance.
    • Fluid pressure within bones.
    • Hormones.
    • Dehydration.
  • Radiopharmaceutical:
    • The radiopharmaceutical used are 99mTc-Diphosphonates.
    • This is the radionuclide technetium -99m which emits gamma rays of the energy 140 KeV and has a half life of 6 h to which is attached a diphosphonate. The most commonly used are methylene diphosphate (MDP) and hydroxymethylene diphosphate (HDP).
    • Diphosphonates are stable in vivo, having their phosphorus bound to carbon rather than oxygen and are therefore rapidly cleared from the soft tissue; because of rapid renal excretion of the diphosphonate they have a high bone to soft tissue ratio by 2-3 h after injection.
    • 50% to 60% of the injected dose localizes in bone the remainder being excreted by the kidneys.
  • The three phases of a bone scan:
    • Phase I: an initial dynamic flow study (vascular phase) with rapid images 0-1 min following injection.
    • Phase II: the soft tissue image phase at 5-15 min when the tracer is still within the vascular compartment.
    • Phase III: static bone phase images at 2-4 h.
  • The detector system:
    • The detector can be a probe based system, or a gamma camera which consists of a sodium iodide crystal, which when exposed to gamma rays produces light flashes which are detected by a photomultiplier tube behind the crystal. This then emits an electrical pulse which is monitored by electronic counting circuitry.
Print off the Owner factsheet on Diagnostic imaging to give to your clients. Clinical tip
Question: Can scintigraphy help my diagnosis?
Answer: Yes; nuclear bone imaging is very sensitive to localizing and quantifying dynamic bone change, before changes are demonstrable by radiography.

Uses

Advantages

  • Nuclear bone imaging is very sensitive to localizing and quantifying dynamic bone change, before changes are demonstrable by radiography.

Disadvantages

  • Low specificity.
  • Results should be interpreted with clinical examinations and other investigations.
  • Equipment is expensive and requires a dedicated room with air conditioning to avoid temperature fluctuations that may damage the crystal in the camera.
  • An authorization to receive and dispose of radioactive substances, under the Radioactive Substances Act 1993, will need to be obtained.

Requirements

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Preparation

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Procedure

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Aftercare

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Outcomes

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Powell S (2011) Investigation of pelvic problems in horses. In Pract 33 (10), 518-524 VetMedResource.
  • O'Mera B, O'Neill & Fraser B (2010) Applications of nuclear scintigraphy in the investigation of equine lameness. Part 2: The Thoroughbred racehorse. UK Vet 15 (1), 4-7 VetMedResource.
  • Parker R A, Bladon B M, Parkin T D H & Fraser B S L (2010) Quantitative evaluation of subchondral bone injury of the plantaro-lateral condyles of the third metatarsal bone in Thoroughbred horses identified using nuclear scintigraphy: 48 cases. Equine Vet J 42 (6), 552-557 PubMed.
  • Redding W R & Pease A P (2010) Imaging of the shoulder. Equine Vet Educ 22 (4), 199-209 VetMedResource.
  • Didierlaurent D, Contremoulins V, Denoix J-M & Audigie F (2009) Scintigraphic pattern of uptake of 99mTechnetium by the cervical vertebrae of sound horses. Vet Rec 164 (26), 809-813 PubMed
  • Gillen A, Dyson S & Murray R (2009) Nuclear scintigraphic assessment of the thoracolumbar synovial intervertebral articulations. Equine Vet J 41 (6), 534-540 PubMed.
  • O'Neill H, O'Meara B & Fraser B (2009) Applications of nuclear scintigraphy in the investigation of equine lameness Part 1: The Sport Horse. UK Vet 14 (7), 13-18 VetMedResource.
  • O'Neil H & Fraser B (2009) Equine scintigraphy Part 2: Patient selection, image protocols and common diagnoses. UK Vet 14 (4), 9-13 VetMedResource.
  • Dyson S & Murray R (2007) Use of concurrent scintigraphic and magnetic resonance imaging evaluation to improve understnding of the pathogenesis of injury of the podotrochlear apparatus. Equine Vet J 39 (4), 365-369 PubMed.
  • Dyson S & Murray R (2007) Verification of scintigraphic imaging for injury diagnosis in 264 horses with foot pain. Equine Vet J 39 (4), 350-355 PubMed.
  • Nagy A, Dyson S J & Murray R M (2007) Radiographic, scintigraphic and magnetic resonance imaging findings in the palmar processes of the distal phalanx. Equine Vet J 40 (1), 57-63 PubMed.
  • Nagy A, Dyson S J & Murray R M (2007) Scintigraphic examination of the cartilages of the foot. Equine Vet J 39 (3), 250-256 PubMed.
  • Boado A, Kristoffersen M, Dyson S & Murray R (2005) Use of nuclear scintigraphy and magnetic resonance imaging to diagnose chronic penetrating wounds in the equine foot. Equine Vet Educ 17 (2), 62-68 VetMedResource.
  • Ruohoniemi M, Makela O & Eskonen T (2004) Clinical significance of ossification of the cartilages of the front feet based on nuclear bone imaging, radiography and lameness examinations in 21 Finnhorses. Equine Vet J 36 (2), 143-148 PubMed.
  • Ramzan P H L, Newton J R, Shepherd M C & Head M J (2003) The application of a scintigraphic grading system to equine tibial stress fractures. Equine Vet J 35 (4), 382-388 PubMed.
  • Boswell J C, Schramme M C, Livesey L C & Butson R J (1999) Use of scintigraphy in the diagnosis of dental disease in four horses. Equine Vet Educ 11 (6), 294-298 VetMedResource.
  • Pilsworth R C (1999) Gamma camera installations. Equine Vet Educ 11 (5), 247-250 VetMedResource.
  • Ehrlich P A, Seeherman H J, O'Callaghan W, Dohoo I R & Brimacombe M (1998) Results of bone scintigraphy in show jumping horses. JAVMA 213, 1460 PubMed.
  • Pilsworth R C (1996) Establishing a probe point counting scintigraphy system in practice. Equine Vet Educ 8 (1), 41-46 VetMedResource.
  • Trout D R, Hornof W J & Fisher P E (1991) The effects of intra-articular anesthesia on soft-tissue and bone phase scintigraphy in the horse. Vet Rec 32 (5), 251-255 VetMedResource.
  • Trout D R, Hornof W J & Fisher P E (1991) The effects of regional perineural anesthesia on soft-tissue and bone phase scintigraphy in the horse. Vet Rec 32 (3), 140-144 VetMedResource.
  • Gaughin E M et al (1990) Local anesthetics and nuclear medical bone images of the equine forelimb. Vet Surg 19 (2), 131-135 PubMed.

Other sources of information

  • Dyson S J (2004)How does Nuclear Scintigraphy Enhance our Evaluation and Management of Joint Disease in Non-Racehorses?In:Proc 43rd BEVA Congress.Equine Vet J Ltd, Newmarket. pp 261.
  • Ross M W (2004)Nuclear Scintigraphy in the Racehorse.In:Proc 43rd BEVA Congress.Equine Vet J Ltd, Newmarket. pp 260.
  • Ross M W (2004)Scintigraphic Examination of the Spine and Upper Limbs.In:Proc 43rd BEVA Congress. Equine Vet J Ltd, Newmarket. pp 79.
  • Berry C R & Daniel G B (1996)Handbook of Veterinary Nuclear Medicine.North Carolina State University.


ADDED