QCT and CT applications in Osteoporosis Imaging

Transcription

1 Q appli in Osteoporosis Imaging Thomas M. Link, MD, PhD Department of Radiology Biomedical Imaging University of California, San Francisco

2 Goals 1. To identify advantages disadvantages of Q compared to in measuring bone mral density. To report potential indi for Q. To describe the role of in identifying incidental osteoporotic vertebral their clinical significance. To show the potential of rout pelvic abdominal in assessing bone mral density.

3 Q Q stard techniques Stard techniques Single slice Q Volumetric Q Peripheral Q

4 1. Q Single slice Q technique L 1-3 HU mg Hydroxyapatite/ml Calibration phantom

5 Q SAM Question 3 Slice thickness 8-10 mm Dedicated gantry tilt for each section 2D- Q imaging parameters Low-energy low dose protocol e.g. 80 kvp, 120 mas (or 120 kvp, mas) Effective dose < 200 µsv (80 kvp, 120 mas) Engelke et al ISCD official positi, J Clin Densitom 2008; 11:

6 Q Single slice Q - analysis Calibration phantoms Cann- Genant offsprings Kalender phantom 3-5 density phases 2 density phases Adams JE, Eur J Radiol 71; 2009: Griffith Genant, Best Practice & Research Clin Endocr & Met. 22, 2008:

7 Q Single slice Q - analysis oval Pacman ROIs manual vs automated peeled (Pacman) vs oval Adams JE, Eur J Radiol 71; 2009: Griffith Genant, Best Practice & Research Clin Endocr & Met. 22, 2008:

8 Q Single slice Q result interpretation WHO - criteria do not apply! A T-score < -5 is NOT defd as osteoporosis Engelke et al ISCD official positi, J Clin Densitom 2008; 11:

9 Q Single slice Q result interpretation WHO - criteria do not apply! A T-score < -5 is NOT WHY defd! as osteoporosis With this threshold substantially more patients would be defd as osteoporotic than with A similar number of patients would be identified with a T-score of approximately -2 Engelke et al ISCD official positi, J Clin Densitom 2008; 11:

10 Q Single slice Q result interpretation Thresholds were defd analogous to WHO-criteria for single slice Q mg Hydroxyapatite/ml = Osteopenia < 80 mg Hydroxyapatite/ml = Osteoporosis ACR PRAICE GUIDELINE FOR THE PERFORMANCE OF QUANTITATIVE COMPUTED TOMOGRAPHY (Q) BONE DENSITOMETRY; 2008 Link et al, Radiology, 2004; 231:805-11

11 Q Q - potential caveats 1. Do not measure in ured vertebrae Do not measure after intravenous contrast applion Analyze images in bone soft tissue window for bony soft tissue abnormalities (e.g. renal tumors) Engelke et al ISCD official positi, J Clin Densitom 2008; 11:

12 Q Q stard techniques Stard techniques Single slice Q Volumetric Q Peripheral Q

13 Q Volumetric Q L1-L2 (or L1-L3) Contiguous 3 mm secti = images over 8-12 cm volume No scanner gantry angulation Data acquisition <30-40 seconds Engelke et al ISCD official positi, J Clin Densitom 2008; 11:

14 Volumetric Q Stard automated elliptical VOI to measure trabecular in mg/cc Can be extended to measure - total mass - volume of whole vertebrae - structural parameters Engelke et al ISCD official positi, J Clin Densitom 2008; 11:

15 Q Volumetric Q Fracture risk assessment average sp -value mg/cc = mild increase of ure risk mg/cc = moderate <50 mg/cc = severe increase of ure risk Manufacturer s information: Mindways Software Inc. Austin, Tx, ( Engelke et al ISCD official positi, J Clin Densitom 2008; 11:

16 Q Volumetric Q Thresholds were defd analogous to WHO-criteria for volumetric Q mg Hydroxyapatite/ml = Osteopenia < 80 mg Hydroxyapatite/ml = Osteoporosis ACR PRAICE GUIDELINE FOR THE PERFORMANCE OF QUANTITATIVE COMPUTED TOMOGRAPHY (Q) BONE DENSITOMETRY; 2008 Link et al, Radiology, 2004; 231:805-11

17 Comparison of single slice volumetric Q Conventional (2D) Volumetric (3D) <0.2 msv effective dose 1.5 msv - sp 5-3 msv femur Clinical precision 3-5% Clinical precision 1-5% Engelke et al ISCD official positi, J Clin Densitom 2008; 11:

18 Q Volumetric Q - of the hip Volumetric data acquisition Acetabulum to 1cm below lesser trochanter Femoral head analysis possible as well as stard ROIs from

19 XA TM -Equivalent Q 3D Q hip data set oriented to stard projection 2D -type image femoral neck trochanter Stard ROIs intertrochanter

20 XA TM -Equivalent Q Total femur Correlation between XA vs of the proximal femur (NHANES III database) = R= T-scores may be applied in post-menopausal, Caucasian females (g/cm2) Average versus Age T-Score XA -1.2 NHANES III -1.6 Average T-Score versus Age XA NHANES III Age (years) Age (years) Khoo et al et al., Osteoporos Int 2008; 11: 2009 Sep;20(9):

21 Q Q stard techniques Stard techniques Single slice Q Volumetric Q Peripheral Q

22 1. Q p-q/hr-pq Low effective dose (<0.01 msv) Separate measurement of trabecular bone structure Low precision error (1%) Minimal impact of degenerative changes pros Engelke et al ISCD official positi, J Clin Densitom 2008; 11: Adams JE, Eur J Radiol 71; 2009:

23 p-q/hr-pq Low change in /year at peripheral sites reduces significance of good precision Does not predict sp Predicts hip only in postmenopausal women but not men c Engelke et al ISCD official positi, J Clin Densitom 2008; 11: Adams JE, Eur J Radiol 71; 2009:

24 Q Q vs

25 Q Advantages Q vs SAM Question 1 Separate measurement of cortical trabecular bone vs projectional in Volumetric measurement vs areal in Less impact of degenerative changes on compared to (particularly important in older patients) pros

26 Q Q vs Advantages Very sensitive to change of in particular perimenopausal - because trabecular bone has substantially higher metabolic activity Cross-sectional studies show better discrimination of patients with without vertebral pros

27 Q Q vs - studies pros Yu et al. Osteoporos Int : Odds ratio for vertebral ure patients Q: 67 lateral: 0 p.a.: 1.54 Bergot et al. Calcif Tissue Int :74-82 ROC analysis to differentiate subjects with without ure Q: 0.85 vertebral 0.72 peripheral p.a.: 0.79 p< p<0.05

28 Q vs - studies Effect of PTH, Alendronate on 24% 6% Black et al. N Engl J Med :

29 Q vs - studies Q Effect of PTH, Alendronate on 24% 6% Lumbar sp PTH vs Alendronate Black et al. N Engl J Med :

30 Q Disadvantages Q vs SAM Question 2 WHO criteria do not apply, T-scores may not be used to diagnose osteoporosis is preferred for making therapeutic decisi, but if not available Q can be used c Engelke et al ISCD official positi, J Clin Densitom 2008; 11:

31 Q Q vs Disadvantages Exposure dose higher than that of approximately msv vs 1-50 µsv Limited number of longitudinal, ure prediction studies comparing versus Q c

32 Q Q vs Disadvantages Large number of images Iliopsoas bursitis

33 Q Q vs - Reimbursement Unfortunately Deficit Reduction Act Limits reimbursement to $90 Q(axial) - CPT code pro-fee $122 tech-fee $ total $ (axial) - CPT code pro-fee $10.11 tech-fee $50.78 total $60.89 CPT code = Clinical Procedural Terminology code Medicare professional technical payment amounts

34 Q Goals 1. To identify advantages disadvantages of Q compared to in measuring bone mral density. To report potential indi for Q. To describe the role of in identifying incidental osteoporotic vertebral their clinical significance. To show the potential of rout pelvic abdominal in assessing bone mral density.

35 Q Q - recommendati for use Sp in older patients with more extensive degenerative changes of the lumbar sp In particular lumbar diffuse idiopathic hyperostosis (DISH) Degenerative more frequent in men Diederichs et al., Osteoporos Int. 2011; 22: yo woman

36 Q Q - recommendati for use Patients who are very small or large suggests osteopenia/ osteoporosis in small patients, who may have normal volumetric May also be useful in children Schoenau et al. European Journal of Endocrinology 2004; 151: 87 91

37 Q Q - recommendati for use Obesity is limited in obese subjects as dual energy only incompletely removes fat error Weigert JM, Cann CE. J Womens Imaging :1-8

38 Q Q - recommendati for use Longitudinal examinati which require high sensitivity to monitor metabolic changes Perimenopausal bone loss Effectivity of new pharmacologic agents (PTH, alendronate) Q Black et al. N Engl J Med : Long. change PTH vs alendr.

39 Q frac ture s Goals 1. To identify advantages disadvantages of Q compared to in measuring bone mral density. To report potential indi for Q. To describe the role of in identifying incidental osteoporotic vertebral their clinical significance. To show the potential of rout pelvic abdominal in assessing bone mral density.

40 Q frac ture s - Incidental Fract - Significance SAM Question 4 Background Prevalent sp ure has 3-5-fold risk for future associated with disability increased mortality can be reduced with appropriate treatment early recognition diagnosis are of tremendous importance Ensrud et al. J Am Geriatr Soc 48: Johnell at al. Osteoporos Int 16(Suppl 2):S3 S7

41 Q frac ture s - incidental Fract missed in axial images sagittal reformati demtrate Bauer et al. Osteoporos Int. 2006;17(4): Mueller et al. Eur Radiol Aug;18(8):

42 Q frac ture s - incidental Fract detected in axial images vs. sagittal reformati only 4/28 detected in axial images compared to sagittal reformati# minimum requirements for sagittal reformation 3 mm slice thickness in axial images* 30 Mueller et al. Eur Radiol Aug;18(8): # Bauer et al. Osteoporos Int. 2006;17(4):608-15* 5 Number of axial recon

43 Q frac ture s incidental Underreporting of 200 s in patients > 55 years 5% in official report Midl sagittal images demtrated 19.8% sagittal reformati highly recommended directly impacts patient management Williams et al. Eur J Radiol Jan;69(1):179-83

44 Q frac ture s incidental Scout views SAM Question 5 Provides information on ure status up to T8# thus only 10% of (T7-1) are missed* Link et al. Osteoporos Int. 2000;11(4):304-9# Gilsanz et al. Radiology 1994; 190: # Davis et al. Bone 1999;24: *

45 Q Goals 1. To identify advantages disadvantages of Q compared to in measuring bone mral density. To report potential indi for Q. To describe the role of in identifying incidental osteoporotic vertebral their clinical significance. To show the potential of rout pelvic abdominal in assessing bone mral density.

46 Q Clinical for measurement Background Clinical can be used to measure Stard abdominal Thoracic with coronary artery calcium quantifion Link et al. et al. Radiology : Lenchik et al. J Comput Assist Tomogr. 2004; 28(1):134-9 Wong et al. Calcif Tissue Int. 2005; 76(1):7-10 Bauer et al. AJR Am J Roentgenol. 2007; 188(5):

47 Q Contrast-enhanced clinical for measurement Contrast-enhanced clinical versus stard Q r 2 = 0.92 in mg/cm 3 Q MD Q in mg/ cm Link et al. et al. Radiology : y = 0,7818x + 0,344 R 2 = 0, Contrast-enhanced in mg/ cm 3

48 Q Contrast-enhanced clinical for measurement Potential appli Basic study obtad from abdominal thoracic Useful in long-term follow-up patients after chemotherapy, lymphoma, gastric cancer Epidemiological studies in patients undergoing coronary calcium screening

49 Conclusi - 1 Q preferred to in degenerative disease of the sp in small/large patients in obese patients to more sensitively monitor therapy

50 Conclusi - 2 Use sagittal rectructi lateral digital radiographs to diagnose vertebral osteoporotic Clinical abdominal thoracic may be used to measure