*SKELETON-USEFUL TIPS*


1* A FULL BLADDER MAY PRODUCE ARTEFACTS ON SPECT RECONSTRUCTION DUE TO HIGH ACTIVITY LEVELS*

2* SPECT IMAGES MUST BE INTERPRETED WITH CAUTION IN ADOLESCENTS AND YOUNG ADULTS AS THE EPIPHYSES MAY APPEAR ASYMMETRICAL*

3*PRIOR TO SKELETAL IMAGING, A PATIENT SHOULD EMPTY THE BLADDER, SINCE RETAINED ACTIVITY MAY LEAD TO DIFFICULTIES IN SCAN INTERPRETATION* *IT IS NOT POSSIBLE TO EXCLUDE ABNORMALITIES IN THE PELVIS UNLESS THE BLADDER IS EMPTY. IF THE BLADDER OBSCURES THE PELVIC BONES, THE PATIENT MAY BE CATHETERIZED OR A PELVIC X-RAY SHOULD BE PERFORMED* *A SQUAT VIEW MAY BE USEFUL WHEN BLADDER ACTIVITY OBSCURES THE PELVIS*

4*IF DIGITAL IMAGES ARE OBTAINED, THE DATA CAN BE REVIEWED AND THE CONTRAST ALTERED IF NECESSARY. WITH ANALOGUE IMAGES, THE CORRECT CONTRAST HAS TO BE OBTAINED AT THE OUTSET; AND IF THE QUALITY OF IMAGES IS INADEQUATE, THE STUDY HAS TO BE REPEATED*

5*IN NON-ACCIDENTAL INJURY THE BONE SCAN MAY OCCASIONALLY MISS SKULL FRACTURES, SO A SKULL X-RAY SHOULD BE OBTAINED ROUTINELY* *SOMETIMES, PINHOLE VIEWS OF THE EPIPHYSES MAY BE OF VALUE, SINCE THIS IS A COMMON SITE OF FRACTURE; A LESION MAY NOT BE APPARENT ON THE INITIAL STUDY* *RIB FRACTURES AT DIFFERENT STAGES OF HEALING MAY BE VISUALIZED, CONFIRMING REPEATED INJURY*

6*WHILE AVASCULAR BONE IS REPRESENTED BY A PHOTON-DEFICIENT AREA ON A BONE SCAN, IN PRACTICE THIS IS SELDOM SEEN UNLESS IMAGES ARE PERFORMED EARLY IN THE DISEASE PROCESS. THE MOST FREQUENT FINDING IS INCREASED TRACER UPTAKE; THIS REFLECTS THE HEALING RESPONSE BY SURROUNDING BONE*

7*MARKERS MAY HELP IN THE EVALUATION OF A DYNAMIC STUDY, SINCE IT IS FREQUENTLY DIFFICULT TO KNOW IF A VASCULAR BLUSH CORRESPONDS EXACTLY TO A METABOLICALLY ACTIVE LESION*

8*WHILE THE BONE SCAN MAY UNDERESTIMATE THE EXTENT OF DISEASE IN MULTIPLE MYELOMA, IT MAY, AS IN OTHER SITUATIONS, IDENTIFY DISEASE WHICH IS NOT APPARENT ON X-RAYS. RADIOGRAPHY AND BONE SCANNING CAN BE CONSIDERED AS COMPLEMENTARY INVESTIGATIONS, WHEN ACCURATE DOCUMENTATION OF ALL SKELETAL DISEASE IS REQUIRED*

9*ALTHOUGH PHOTOPAENIC LESIONS ARE RELATIVELY UNCOMMON, IT IS IMPORTANT TO IDENTIFY THEM SINCE THEY USUALLY INDICATE SIGNIFICANT BONY DESTRUCTION. PHOTOPAENIC AREAS ARE SEEN IN ASSOCIATION WITH AGGRESSIVE LYTIC DISEASE, WHICH DOES NOT INDUCE AN OSTEOBLASTIC RESPONSE*

10*THE BONE SCAN MAY DETECT METASTATIC DISEASE BEFORE ANY ABNORMALITY IS SEEN ON X-RAYS. THE KNOWLEDGE THAT SKELETAL METASTASES ARE PRESENT MAY SIGNIFICANTLY ALTER PATIENT MANAGEMENT*

11*WHILE SOLITARY PERIPHERAL METASTASES ARE RELATIVELY UNCOMMON, THEY DO OCCUR. THERE HAS BEEN SOME CONTROVERSY AS TO WHETHER ROUTINE VIEWS OF THE SKULL AND LOWER LIMBS ARE NECESSARY; HOWEVER, IF THEY ARE NOT OBTAINED, SOME LESIONS WILL BE MISSED* *SITES SUCH AS THE STERNUM, RIBS AND SCAPULA CAN BE DIFFICULT TO EVALUATE ON ROUTINE RADIOGRAPHY, WHEREAS A BONE SCAN WILL PROVIDE CLEAR VISUALIZATION OF THESE AREAS*

12*LESIONS SHOULD BE VISUALIZED IN TWO VIEWS WHENEVER POSSIBLE* *ON OCCASION, THE PRECISE LOCALIZATION OF AN ABNORMALITY MAY NOT BE APPARENT, BUT WILL OFTEN BE CLARIFIED IF ADDITIONAL VIEWS ARE OBTAINED*

13*IN A PATIENT WITH METASTATIC DISEASE IT MAY NOT BE POSSIBLE TO EVALUATE RESPONSE TO THERAPY IN THE INITIAL MONTHS, SINCE APPARENT DETERIORATION IN SCAN FINDINGS MAY REFLECT BONE HEALING*

14*FOLLOWING RADIOTHERAPY, FRACTURE OF THE RIBS MAY OCCUR SPONTANEOUSLY. THIS IS SEEN MOST OFTEN IN CARCINOMA OF THE BREAST*

15*IT WILL BE RECOGNIZED THAT PULMONARY DEPOSITS OF OSTEOGENIC SARCOMA MAY TAKE UP DIPHOSHONATE*

16*FOLLOWING HIP REPLACEMENT, THE BONE SCAN WILL NORMALLY BE POSITIVE FOR UP TO ONE YEAR AFTER SURGERY- INCREASED UPTAKE BEYOND THIS TIME GENERALLY INDICATES PATHOLOGY. WITH NEW CEMENTLESS PROSTHESES, INCREASED UPTAKE MAY BE OBSERVED FOR SEVERAL YEARS AFTER SURGERY WITH NO EVIDENCE OF PATHOLOGY*

17*IN SOME CASES IT WILL NOT BE POSSIBLE TO DIFFERENTIATE BETWEEN INFECTION AND LOOSENING ON THE BASIS OF THE BONE SCAN ALONE, AND A REPEAT STUDY EITHER WITH GALLIUM- OR INDIUM-LABELLED WHITE CELL SHOULD PROVIDE ADDITIONAL INFORMATION*

18*HAEMANGIOMA OF THE SPINE MAY APPEAR EITHER PHOTON-DEFICIENT OR SHOW SLIGHTLY INCREASED TRACER UPTAKE ON THE BONE SCAN STUDY*

19*SCAPHOID FRACTURE MAY BE MISSED ON YEARLY X-RAYS. A BONE SCAN WITH DYNAMIC VIEWS IS SENSITIVE METHOD OF DIAGNOSING SCAPHOID FRACTURE*

20*THE ACCURATE, ANATOMICAL LOCALIZATION OF BONE SCAN LESION MAY NOT BE POSSIBLE* *BY INCORPORATING THE BONE SCAN AND THE X-RAY IMAGE, ACCURATE ANATOMICAL LOCALIZATION OF THE LESION IDENTIFIED ON THE BONE SCAN CAN BE OBTAINED*

21*DIFFERENTIATION BETWEEN SHIN SPLINTS AND STRESS FRACTURE IS IMPORTANT. SHIN SPLINT IS A SYNDROME DUE TO A PERIOSTEAL REACTION AT THE SITE OF MUSCLE INSERTION AT THE LOWER THIRD OF THE POSTERIOR TIBIA. PATIENTS CAN CONTINUE WITH EXERCISE AS LONG AS THEY FEEL COMFORTABLE. HOWEVER, PATIENTS WITH STRESS FRACTURE MUST AVOID EXERCISE FOR AT LEAST SIX WEEKS, SINCE THEY ARE AT RISK OF SUSTAINING COMPLETE FRACTURE* *IT IS IMPORTANT TO OBTAIN LATERAL VIEWS IN PATIENTS WHO ARE COMPLAINING OF PAIN IN LOWER LIMB, SINCE OTHERWISE THE DIAGNOSIS OF SHIN SPLINT WILL BE MISSED*

22*NOTE THAT NOT ALL SITES OF DEGENERATIVE CHANGES ARE SEEN ON THE BONE SCAN. A POSITIVE SCAN RESULT DEPENDS ON METABOLIC ACTIVITY, AND INACTIVE LESIONS, ie 'BURNT-OUT' DISEASE, WILL NOT BE VISUALIZED*

23*METABOLIC FRACTURES ARE NON-SPECIFIC AND MAY BE SEEN WHERE IS INCREASED SKELETAL METABOLISM, FROM WHATEVER CAUSE*

24*THE BONE SCAN MAY BE OF VALUE IN PATIENTS WITH KNOWN OSTEOPOROTIC COLLAPSE IN ASSESSING THE TIME INTERVAL SINCE COLLAPSE OCCURRED*

25*MONOSTOTIC PAGET'S DISEASE IS NOT UNCOMMON, AND ACCOUNTS FOR APPROXIMATELY 20% OF CASES*

26*IF CHANGES OCCUR IN A BONE SCAN OVER A RELATIVELY SHORT PERIOD OF TIME, THEY SHOULD NOT BE ATTRIBUTED TO PAGET'S DISEASE, AND OTHER PATHOLOGY SHOULD BE CONSIDERED*

27*THE BONE SCAN IS NOT ADEQUATE TO EXCLUDE FRACTURE IN PATIENTS WITH PAGET'S DISEASE. THIS IS BECAUSE INCREASED TRACER UPTAKE ASSOCIATED WITH FRACTURE MAY NOT BE RECOGNIZED AGAINST HIGH BACKGROUND ACTIVITY*

28*IF SARCOMATOUS CHANGE IS SUSPECTED IN A PATIENT WITH KNOWN PAGET'S DISEASE, RADIOGRAPHIC INVESTIGATION IS REQUIRED FOR EVALUATION, BECAUSE, AS WITH FRACTURE, INCREASED UPTAKE MAY NOT BE ALWAYS BE APPARENT* *WHILE SARCOMATOUS CHANGE NORMALLY APPEARS 'HOT' ON THE BONE SCAN, THIS IS NOT ALWAYS THE CASE*

29*ALTHOUGH PAGET'S DISEASE AND METASTASES USUALLY SHOW CHARACTERISTIC SCAN PATTERNS OF ABNORMALITY AND CAN BE EASILY DIFFERENTIATED, RADIOGRAPHIC EXAMINATION IS STILL REQUIRED FOR CONFIRMATION, BECAUSE ON OCCASION EACH OF THESE CONDITION CAN MIMIC THE OTHER*

30*WHILE A BONE ISLAND USUALLY APPEARS NORMAL ON A BONE SCAN, THIS IS NOT ALWAYS THE CASE*

31*SCAN FEATURES OF ECTOPIC CALCIFICATION MAY BE REVERSIBLE IN THE SHORT TERM*

32*IT IS IMPORTANT TO REMEMBER THAT ABNORMALITIES OF THE KIDNEY MAY BE DIAGNOSED ON A BONE SCAN*

33*IT SHOULD NOT BE ASSUMED THAT A DILATED COLLECTING SYSTEM IS OBSTRUCTED*

34*BONE METASTASES FROM THYROID CARCINOMA ARE OCCASIONALLY LYTIC*

35*REPEAT BONE SCAN SHOULD GENERALY NOT BE PERFORMED IN UNDER 6 MONTHS UNLESS NEW SYMPTOMS DEVELOP IN THE INTERIM*

*SKELETON CLINICAL APPLICATIONS*
*BONE IMAGING INTERPRETATION*
* SKELETON *