Cardiology Update DAVOS 2011 Computed Tomography of the Coronary Arteries Anders Persson M.D., Ph.D Director, Assoc. Professor Center for Medical Image Science and Visualization Linköping University SWEDEN
CT Time Line 4 th Gen 3 rd Gen 2 nd Gen 1 st Gen MR EBCT Spiral CT MDCT Cardiac MDCT DE 1970 1980 1990 2000 Cardiac MR Calcium Scoring MDCT Coronar Angiography
1972
1985
2006
2009
3sec.
0.25 sec.
9
Evolution of MDCT 1989 single slice spiral CT 1992 dual slice spiral CT 1999 four slice spiral CT 2001 eight slice spiral CT 2002 sixteen slice spiral CT 2004 sixty four slice spiral CT 2005 64 Dual source MDCT 2007 128, 256 and 320 MDCT 2008 128 Dual source MDCT
To consider Type of scanner, MDCT 4, 16, 64, DS, 320, DS2 slice? I.v contrast Type of patient Staff Type of hospital...
Retrospectiv ECG Triggered Spiral
Prospectiv ECG Triggered Sequential Siemens
High pitch 0.25 sec.
3D < 65 bpm 1-4 msv > 65 bpm > 3-20 msv 4D
CTCA as filter test symptoms age, gender stress tests 0% 100% risk of CAD no catheter indicated??? catheter indicated CT coronary angiography - + + no catheter catheter surgery
Top 5 indications 1. Rule out coronary stenosis in patients with low to intermediate likelihood of CAD 2. Evaluation of suspected coronary artery anomaly 3. Resolve questions after cardiac catheter 4. Establish patency of bypass grafts 5. Preoperative evaluation, non-coronary surgery
Limitations of cardiac CT; high radiation dose?
CT Dose? Ca ALARA 100 msv
Limitations of cardiac CT; high radiation dose? 16-slice 6 11 msv 64-slice 9 21 msv Dual-Source 0.7-9 msv Diagnostic Cardiac Catheter 3-23 msv # ± similar to the reference standard *Stolzmann et al. Eur Radiol 2008; 18(3): 592-599 *Alkadhi et al. Eur J Radiol 2008; 68(3): 385-391 # Einstein et al. Circulation 2007; 116(11): 1290-1305
Limitations of cardiac CT; high radiation dose? Alkadhi et al, Eur J Radiol 2008; 68(3): 385-391
Cardiac sequence technique, step-and-shoot mode <65 bpm -> 0.4 msv Joerg Hausleiter, MD; Franziska Herrmann, MD; Stefan Martinoff, MD, German Heart Center, Munich, Germany
Cardiac CT Dose msv 9 8 7 6 5 4 3 2 1 Gating - kv
0.6 msv 0.6 sec.
0.7 msv 0.6 sec.
Multi-center multi-vendor trial, 50 sites, 1965 coronary CTAs Mean radiation dose: 5.7 msv 36.5 msv Definition Flash: ~ 1 msv Source: 1: Hausleiter et al, JAMA 2009 Feb 4;301(5):500-7
SCAAR annual report 2009
2D?, 3D?, MPR?, cmpr?, MIP?, 4D?, 5D
CT heart
Diagnostic performance of CT Recent CT scanner generations: n notevaluative sensitivity specificity PPV NPV all 4-slice CT 554 21.2% 79% 94% 52% 96% all 16-slice CT 707 9.6% 88% 97% 70% 97% alle 64-slice CT 642 3.1% 89% 97% 76% 99% Dual Source CT scanner: Author year n notevaluative sensitivity specificity PPV NPV Scheffel 2006 30 1% 96% 98% 86% 99% Leber 2007 90 2% 90% 98% 91% 99% all DSCT 679 1.9% 93% 97% 85% 99%
Diagnostic performance of CT Study TP FP FN TN Sensitivity Specificity Sensitivity Specificity Alkadhi HP 2010 Alkadhi SAS 2010 de Graaf 2010 Dewey 2009 Labounty ns 2010 Labounty s 2010 Marwan 2010 Meng 2009 Rasmussen 2010 Tsiflikas 2010 van Werkhoven 2010 Weustink o 2009 Weustink s 2009 17 16 35 11 20 18 14 83 49 98 16 229 83 3 2 3 1 1 4 7 5 43 13 5 15 3 1 1 0 0 0 0 0 2 2 6 0 1 0 29 31 22 17 17 23 39 19 73 53 40 82 23 0.94 [0.73, 1.00] 0.94 [0.71, 1.00] 1.00 [0.90, 1.00] 1.00 [0.72, 1.00] 1.00 [0.83, 1.00] 1.00 [0.81, 1.00] 1.00 [0.77, 1.00] 0.98 [0.92, 1.00] 0.96 [0.87, 1.00] 0.94 [0.88, 0.98] 1.00 [0.79, 1.00] 1.00 [0.98, 1.00] 1.00 [0.96, 1.00] 0.91 [0.75, 0.98] 0.94 [0.80, 0.99] 0.88 [0.69, 0.97] 0.94 [0.73, 1.00] 0.94 [0.73, 1.00] 0.85 [0.66, 0.96] 0.85 [0.71, 0.94] 0.79 [0.58, 0.93] 0.63 [0.53, 0.72] 0.80 [0.69, 0.89] 0.89 [0.76, 0.96] 0.85 [0.76, 0.91] 0.88 [0.70, 0.98] 0 0.2 0.4 0.6 0.8 1 0 0.2 0.4 0.6 0.8 1
Diagnostic performance of CT
Strengths of CT coronary angiography fast imaging method comprehensive evaluation low risk (non invasive) stenosis assessment beyond pure luminography cross-sectional vs luminographic imaging stenosis and cause of stenosis stenosis
Stages of Atherosclerosis Naghavi Circulation 2003
Soft <50HU, Intermediate 50-120HU, Calcified >120HU
Today TO RULE OUT SIGNIFICANT CORONARY ARTERY DISEASE IN INTERMEDIATE RISK CHEST PAIN PATIENTS
Tomorrow? TO VISUALIZE MYOCARDIAL PERFUSION?
Soft Plaque
Contrast Kinetics Ischemic Myocardium Iodinated IV Contrast Mostly intravascular during early first pass circulation Time to Contrast Arrival: 3.6±2.3 vs. 11.6±3.9 secs Time to Peak Contrast: 15.9±4.9 vs. 22.0±7.3 secs Overall Peak Contrast: 125.6±33.6 vs. 106.9±24.9 Ischemic
SOMATOM Definition Flash Heart Perfusion
Cardiac Perfusion Imaging CT Early attempts at CT imaging of LV perfusion and viability Limited by experimental nature Limited by dedicated acquisition protocols Dual-energy CT for myocardial perfusion defects Delayed enhancement dual-energy CT Adenosin stress dual-energy CT
One stop shop? CT cor. Syst. CT perfusion. DECT Spect.. Test inj Adenosin. Tc-inj. 7 min. 4-5 min. 60 min.
One stop shop? DECT
MRI
Cardiac flow patterns, healthy subject Direct Flow Retained Inflow Delayed Ejection Flow Residual Volume Ref: Eriksson J, Carlhäll CJ, Dyverfeldt P, Engvall J, Bolger AF, Ebbers T. Sem i-automatic Quantification of 4D Left Ventricular Blood Flow. J Cardiovasc Magn Reson 2010;12(1):9.
Turbulent flow at peak systole in the ascending aorta of a patient with a stented aortic valve prosthesis, measured by generalized phase-contrast MRI Left: 3D streamlines outline the instantaneous mean velocity field. High velocities are seen in the flow jet downstream from the coarctation. Right: A map showing turbulent kinetic energy (TKE). Ref: Dyverfeldt P, et al. J Magn Reson Imaging 2008;28:655-63.
Functional MRI imaging