Glomerular filtration rate with MDCT

Transcription

1 Glomerular filtration rate with MDCT Dr Laurent Juillard, MD, PhD Département de Néphrologie, H. E. Herriot Inserm ERI 22, Université de Lyon. Lyon, France

2 Outline Functional parameter definition Tools : EBCT Spiral CT MDCT Modeling methods Gamma variate Patlak Experimental data

3 The challenge of renal functional evaluation

4 Renal Functional Imaging MRI CT SCAN / EBCT MDCT Non invasive evaluation PET Split renal function Absolute quantification

5 Renal Functional parameters Tissue Injury CT, MR MR BOLD PET CT, MR Blood Flow Perfusion Oxygen content Oxydative metabolism GFR CT, PET REDUCTION Glomerular Filtration Rate

6 Electron Beam Computed-Tomography MDCT Gamma variate :»Glomerular filtration rate»renal blood flow»renal perfusion

7 Electron Beam Computed-Tomography EBCT cardiac and renal functional imaging Cortical and medulla volume Regional blood flow, tissue perfusion Glomerular filtration rate Split renal function Few evaluation in humans Breath control

8 EBCT: Principles High temporal resolution Good spatial resolution Multi slices

9 Krier et al AJP, 2001

10 EBCT: gamma variate INJECTION VVC : 0,5 ml/kg, 15 ml/s Krier et al AJP, 2001

11 METHODS Densité Corticale (HU) Cortical density (HU) Renal blood flow Glomerular filtration rate Intratubular concentration Index Time (s) Temps (s) Data Vasculaire Proximal Distal Total INJECTION VVC : 0,5 ml/kg, 15 ml/s

12 Krier et al AJP, 2001

13 Chade et al Circulation, 2001

14 Chade et al Circulation, 2001

15 PATIENTS Hypertension Unilateral RAS with FMD MR or Conventional angiography «Hemodynamically significant» US

16 Results: Regional Volumes Regional volume (cm3) Volume Régional (cm3) * Sténose Stenosis Contra-lateral Kidney Contralateral Rein Cortex Medulla

17 Results: Blood Flow Cortex Medulla * Sténose Contra-lateral Rein Stenosis Kidney Contralateral Regional Blood Flow (ml/min) Débit Sanguin Rénal Régional (ml/min)

18 Results: Perfusion Cortex Medulla Sténose Contra-lateral Rein Stenosis Kidney Contralateral Regional perfusion Perfusion Régionale (ml/min/g) (ml/min/g)

19 Results: GFR Glomerular Flow Rate (ml/min) DFG (ml/min) Stenosis Sténose Kidney Contro-lateral Rein Contralateral 1 2

20 Pelaez et al NDT, 2005

21 Pelaez et al NDT, 2005

22 MDCT : Principles Vs EBCT Identical parameters

23 Cortical TDC MDCT EBCT Daghini et al, Radiology, 2007

24 MDCT EBCT Medulla TDC Daghini et al, Radiology, 2007

25 Daghini et al, Radiology, 2007

26 Daghini et al, Radiology, 2007

27 14 patients with ARAS 14 patients with EH MRI BOLD for oxygen content MDCT study Gloviczki et al, Hypertension 2010

28 GFR?? Gloviczki et al, Hypertension 2010

29 Spiral CT Scanner Patlak : Glomerular filtration rate

30 Tsushima et al, AJKD 99

31 Tsushima et al, AJKD 99

32 Tsushima et al, AJR 01

33 Tsushima et al, AJR 01

34 Hackstein et al, Radiology 05

35 Hackstein et al, Radiology 05

36 Hackstein et al, Radiology 05

37 Patlak GFR Correlation between GFR Patlak and Creatinine clairance EDTA scintigraphy BUT ROI cortex AND medulla No comparaison with reference method Tsushima, AJKD, 1999 Dawson, Invest Radiol, 1993 Miles, Br J Radiol, 1999 Tsushima, AJKD, 1999 Hackstein, Eur Radiol, 2001

38 Daghini et al, Radiology, 2007 PATLAK

39 PATLAK r=0.12 PATLAK modified r=0.75 Daghini et al, Radiology, 2007 Gamma Variate r=0.79

40 PATLAK modified -29+/- 12 PATLAK Gamma Variate -12+/-10 Daghini et al, Radiology, 2007

41 Summary CT Most powerful method GFR, RBF, Perfusion, ICT, Volume But Remain invasive Contrast media toxicity

42 Validation of Renal Perfusion and Glomerular Filtration Rate measurement with MDCT and low rate CM Injection. Sandrine LEMOINE, Laurent JUILLARD

43 Aim Validation of the measurement of Cortical perfusion Glomerular filtration rate using MDCT With a low rate CM injection (3mL/s) and using a peripheral vein injection Using the gamma variate modeling Using fluorescent microspheres as a reference for RBF and Inulin clearance for GFR

44 Materiel et Methods Images dynamiques sur 144 secondes au niveau d une coupe du porc n 6 après injection de dopamine. Une image toute les secondes les 30 premières secondes puis une image toutes les 6 secondes

45 Materiel et Methods Régions d intérêt tracée manuellement

46 Materiel et Methods Vascular = Perfusion Proximal peak = GFR Gamma variate

47 Materiel et Methods 10 pigs Protocole: Dopamine 10 µg/kg/min Dopamine + SSI 10 µg/kg/min Angiotensine II (500ng/kg/min) MS 1 = Perf 1 MDCT: PERF 1 GFR 1 MS 2 = Perf 2 MDCT: PERF 2 GFR 2 MS 3 =Perf 3 MDCT: PERF 3 GFR 3 Sacrifice DFG 1 Urine + blood DFG 2 Urine + blood DFG 3 Urine + blood

48 Results Perfusion * NS NS * NS Perfusion scanner Perfusion microsphères NS Dopamine Dopamine + SSI Angiotensine II

49 Results Perfusion 6 5 P e r f u s i o n M D C T (m L.m in.-1.g -1 ) y = 0,8421x + 0,2496 p< R 2 = 0,8758 R = 0, Perfusion Microspheres Corrélation entre les mesures de perfusion (ml.min.-1.g-1) avec le scanner et avec les microsphères.

50 Results Perfusion Perfusion MDCT-MS ,2 +/- 0,3 ml/min Mean (ml/min/g)

51 Results GFR gamma variate GFR inuline (ml/min) R 2 = 0, GFR MDCT (ml/min) Corrélation entre les mesures de DFG mesurée avec la clairance de l inuline et avec le scanner.

52 Results GFR Patlak GFR Inulin (ml/min) y = 0,4844x + 13,186 R 2 = 0, Corrélation entre les mesures de DFG mesurée avec la clairance de l inuline et avec le scanner. GFR Patlak (ml/min)

53 Conclusion Most powerful functional imaging modality for quantitative assessment of renal performance Limits : CM toxicity and high rate injection for gamma variate Low rate injection : compartmental modeling to be tested for GFR