Download 524 Imaging technical aspects

524
Imaging technical aspects
75±31 ml, p<0.01, respectively). (3) The %LV particles in patients with vortex
was higher than that in patients without vortex (14% vs. 2%, medians, p<0.01).
The %LV particles from right PVs was also higher than that from left PVs in patients with vortex (22% vs. 5%, p<0.01), whereas it did not differ in patients without vortex (2% vs. 0%, p=ns).
Conclusions: 4D-Flow MRI can visualize the intra-LA vortex formation and flow
dynamics from PVs to LV. The vortex formation may be dependent on the LV and
LA volume, and may affect the flow dynamic from PVs to LV. The blood flow from
left PVs seems to be more stagnant within LA than that from right PVs.
P2940 | BEDSIDE
Stress-induced myocardial ischemia modifies phase analysis
indices obtained from Tc-99m sestamibi gated single photon
emission computed tomography myocardial perfusion imaging
J.F. Casuscelli, E.N. Aramayo G, M. Daicz, C.M. Cortes, M. Embon. Hospital
Universitario Fundacion Favaloro, Ciudad Autonoma de Buenos Aires, Argentina
Purpose: Phase analysis of gated myocardial perfusion single photon emission
computed tomography (GSPECT) images allows the assessment of left ventricle (LV) mechanical synchrony. The aim of our study was to determine whether
stress-induced ischemia modifies the two most commonly used phase analysis
synchrony parameters: Histogram bandwidth (HB) and Standard deviation (SD)
obtained from Tc 99m sestamibi of GSPECT images and to evaluate the correlation between these indices and different amounts of ischemia.
Methods: We included 92 consecutive ischemic patients defined by SDS≥2 who
underwent a two-day stress-rest protocol Tc99 sestamibi GSPECT between August 2011 and July 2012 and we compared them to a group of 22 normal subjects
defined as asymptomatic, without known coronary artery disease, with low pretest
of coronary artery disease, and normal ECG, stress test, left ventricular function
and perfusion (SSS: 0), who followed the same GSPECT protocol. Patients with
left bundle branch block, ventricular pacing and fixed perfusion defects were excluded. Phase analysis indices HB and SD were obtained from stress and rest
images in both groups. We obtained the change (stress minus rest) of SD and
HB indices for each patient. The ischemic group was divided into moderate-tosevere ischemia (SDS≥5), and severe ischemia (SDS≥8).
Results: The ischemic group had a mean age of 63±10 years, 47 were men,
21 had moderate-to-severe ischemia and 10 severe ischemia. Ischemic patients showed higher stress SD and HB values than normal subjects (SD 15.65
vs 11.76, p=0.0002 and HB 47.74 vs 38.04, p=0.002 respectively) and larger
amounts of ischemia showed higher values: moderate to severe ischemia (SD
20.08 vs 11.76, p<0.001 and HB 59.61 vs 38.04 p=0.001 respectively) and severe
ischemia (SD 19 vs 11.76, p<0.0001 and HB 60.4 vs 38, p<0.0001 respectively).
Changes in SD and HB were significatively higher in ischemic patients than in
normal subjects (SD -0.19 vs -0.58, p<0.0001; HB 1.27 vs -0.95, p=0.0002 respectively). These differences were even higher in moderate to severe ischemia
(SD 2.49 vs -0.58, p=0,0002; HB 4.76 vs -0.95, p<0.0001) and severe ischemia
(SD 2.42 vs -0.58, p=0,0001; HB 12.5 vs -0.95, p<0.0001).
Conclusion: In our population left ventricular mechanical synchrony indices obtained by phase analysis of Tc99sestamibi GSPECT imaging, HD and SD are
altered in the presence of myocardial ischemia. Larger amounts of ischemia are
related to higher dyssynchrony values of the phase-derived indices HB and SD.
P2941 | BEDSIDE
Evaluation of knowledge-based reconstruction for magnetic
resonance volumetry of the right ventricle in tetralogy of fallot
E.C.A. Nyns, A. Dragulescu, S.J. Yoo, L. Grosse-Wortmann. Labatt Family Heart
Center, Hospital for Sick Children and University of Toronto, Toronto, Canada
Purpose: Evaluating right ventricular (RV) volumes and function is important in
the clinical management of patients after tetralogy of Fallot (TOF) repair. Currently, cardiac magnetic resonance (CMR) using Simpson’s method is the gold
standard for RV quantitative assessment. However, this method is time consuming and not without sources of error. Knowledge-based reconstruction (KBR) is
a new imaging tool for RV volumetry and has been recently validated on echocardiography. The aim of this study was to assess the feasibility, accuracy, and
Projection of the 3D model on a 2D image
labor intensity of KBR on CMR datasets in a group of repaired TOF patients by
comparison with measurements obtained by Simpson’s method.
Methods: Thirty five patients (mean age 14±3 years) after TOF repair were
studied using KBR and Simpson’s method. Parameters analyzed were RV enddiastolic volume (EDV), end-systolic volume (ESV), ejection fraction (EF) and
post-processing time. All measurements were compared with the standard Simpson’s method. Intraobserver, interobserver and intermethod variability was assessed using Pearson’s correlation analysis, coefficients of variation and BlandAltman analysis.
Results: KBR was feasible and highly accurate as compared to Simpson’s
method. Intra- and intermethod variability for KBR measurements showed good
agreements. When compared with Simpson’s method, volumetry using KBR was
faster (10.9±2.0 vs. 7.1±2.4 minutes, P<.001, respectively).
Conclusion: In repaired TOF patients, KBR is a feasible, accurate and reproducible method for measuring RV volumes and function. In addition, the postprocessing time of RV volumetry using KBR was significantly shorter when compared with Simpson’s method.
P2942 | BEDSIDE
Comparison of myocardial perfusion and function with the severity
of coronary artery disease between 201Tl and 99mTc-agent using a
cadmium-zinc-telluride camera
S. Hida, T. Chikamori, H. Tanaka, Y. Igarashi, C. Shiba, Y. Usui, T. Hatano,
A. Yamashina. Tokyo Medical University, Tokyo, Japan
Background: Although cadmium-zinc-telluride (CZT) camera system (Discovery
NM 530c) have recently been introduced in myocardial perfusion imaging (MPI),
no study has shown whether myocardial perfusion analysis using CZT camera
is affected by the type of radiotracer or the severity of coronary artery disease
(CAD).
Methods: The study group comprised 164 consecutive patients who underwent
both stress MPI and coronary angiography within 3 months. Standard dose 1-day
99mTc-radiotracer (370/740MBq) protocol was performed in 74 patients with a
5-min scan time for stress, a 3-min for at rest, while 201Tl (111MBq) protocol was
performed in 90 patients with a 5-min for stress, a 10-min for at rest. Myocardial
perfusion was assessed visually using a 17-segment model, and the changes in
LV volume and function with stress were analyzed using a QGS software. Highrisk CAD was defined as a Duke CAD Prognostic Index of ≥42 and non-high-risk
CAD was defined as those of <42.
Results: Average of Duke CAD prognostic index in patients who underwent
99mTc scans was similar to those who had 201Tl scan, either in the high-risk CAD
(64.1±7.8 vs 65.3±11.2) or in the non-high-risk CAD (21.3±15.1 vs 20.9±16.1).
Summed difference score was less with 99mTc MPI than with 201Tl MPI either
in patients with high-risk (4.8±4.4 vs 10.6±6.2; p=0.004) or with non-high-risk
CAD (3.1±4.4 vs 6.0±4.9; p=0.001). LV functional analysis demonstrated that
post-stress changes were greater with 99mTc MPI than with 201Tl MPI in endsystolic volume (7.9±2.8ml vs 3.2±9.1ml; p<0.03 for high-risk CAD, 3.9±6.5ml
vs 0.9±5.8ml; p=0.01, for non-high-risk CAD, respectively) and ejection fraction
(-6.9±3.3% vs -1.2±6.6%; p=0.001, for high-risk CAD, -2.8±4.8% vs 0.0±5.3%;
p=0.003, for non-high-risk CAD, respectively). In patients with 99mTc MPI, poststress changes such as ESV and EF were greater in those with high-risk than in
non-high risk CAD (p=0.001 for ESV and p<0.005 for EF) whereas post-stress
changes were similar between those with high-risk and non-high risk CAD in patients who had 201Tl MPI.
Conclusions: These results suggested that although 99mTc MPI using the CZT
camera system may underestimate the extent and severity of myocardial ischemia
with 201Tl MPI, 99mTc is superior to 201Tl MPI in the functional analysis to reveal
post-ischemic stunning.
P2943 | BEDSIDE
Non-contrast angiography of renal artery in 3T magnetic
resonance in patients with refractory arterial hypertension before
renal denervation
U. Speiser, L. Schmiedel, C. Henke, A. Abas, S. Jellinghaus, V. Sandfort,
A. Traenkner, H. Schroetter, R.H. Strasser. Dresden University of Technology,
Heart Center, University Hospital, Germany, Dresden, Germany
Introduction: Catheter-based renal sympathic denervation is a technique for
treatment of resistant arterial hypertension. Planning this procedure magnetic
resonance (MR) is a non-invasive method without any radiation to reliably image
the anatomical conditions like diameters, possible stenosis or abnormalities of renal arteries. Impaired renal function (GFR<30 ml/min) is a known contraindication
for gadolinium based contrast agent due to the risk of nephrogenic systemic fibrosis. To address the question if imaging of the anatomy of renal arteries in 3T MR
may be feasible and reliable without using contrast agent the present prospective
study was performed.
Methods: 34 Patients with resistant hypertension (taking four antihypertensive
drugs including diuretics and long term blood pressure measurement larger than
135/85mmHg) for whom renal denervation was planned were included prospectively.
In 3T magnetic resonance 3D conventional contrast MR angiography (CMRA)
was performed after antecubital injection of gadopentetat-dimeglumin during
Imaging technical aspects
breath-hold. Additionally, an inflow inversion recovery steady state free precession sequence (Inhance) was used for non-contrast MR angiography (NCMRA).
Diameters of renal artery were assessed 20 mm from aortic ostium. Furthermore,
the aortic diameter was measured at height of renal artery orifice.
Results: 34 patients (66±8 years) were included in both conventional contrast
and non-contrast MR angiography and presented a total of 76 main and accessory renal arteries. In CMRA mean renal artery diameter was 6.2±1.8 mm, in
NCMRA mean renal artery was determined with 6.0±2.0 mm. Mean aortic diameters were identified with 20.4±3.2 in CMRA and with 20.1±2.8 in NCMRA. Measurements of renal artery by NCMRA closely correlate to renal artery diameters
assigned by CMRA (r=0.97). Furthermore, detection of aortic diameters showed
also good correlation between both MRA (r=0.92). Bland-Altman-analysis did not
present any signs of under- and overestimation of both measurement methods.
Conclusion: At 3T CMR determination of renal artery and aortic diameter at the
orifice of the renal arteries is possible by non-contrast MR angiography as well as
by 3D contrast MR angiography. Both methods provide reliable estimates of the
diameter of the vessel without relevant under- or overestimation. Non-contrast
MR angiography should be regarded as a powerful completely non-invasive tool
to image renal arteries without the need to use potentially nephrotoxic contrast
media.
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by CMR in four different ways: 1) Phase-contrast (PC) on the pulmonary artery
(PA) as PA systolic volume*heart rate (HR); 2) PC on the aorta as aortic systolic
volume*HR; RV Sympson method as [RV end-diastolic volume – RV end-sistolic
volume]* HR; and 4) Left ventricular (LV) Sympson method as [LV end-diastolic
volume – LV end-sistolic volume]*HR. Accuracy was assessed using intraclass
correlation coefficient for absolute agreement and Bland-Altman analysis.
Results: Intraclass correlation coefficients for CMR measurements using RHCquantified CO as the gold standard were: 0.94 (95% CI 0.90-0.96) for PC on
the PA; 0.87 (95% CI 0.69-0.94) for PC on the aorta; 0.90 (95% CI 0.84-0.94)
for RV Sympson method; and 0.89 (95% CI 0.82-0.93) for LV Sympson method.
According to Bland-Altman analysis, mean bias and limits of agreement were
respectively: -0.13 (-1.45,1.18); -0.47 (-2.02, 1.08); -0.20 (-1.80, 1.40); and -0.23
(-1.78, 1.31). Concordance between the different CMR methods was excellent
(Figure).
P2944 | BEDSIDE
Sonographic position monitoring of central venous catheters by
microbubble-injection in real time: development of a new
procedure
M. Campo Dell Orto 1 , S. Schellknecht 2 , F.H. Seeger 2 , C. Hamm 1 ,
R. Breitkreutz 3 . 1 Kerckhoff Clinic Bad Nauheim, Bad Nauheim, Germany;
2
University of Frankfurt, Frankfurt, Germany; 3 Hospital of the City of Frankfurt
(Hoechst), Frankfurt, Germany
Background: Central venous catheter placement requires immediate confirmation of its orthotopic position in the central vena cava to avoid arterial or paravasal
infusions which could potentially harm the patient. The correct position is usually
verified by chest x-ray or ECG. Echocardiography might offer a fast and safe alternative. This study aimed at developing a new non-invasive, ultrasound-based procedure to determine the orthotopic position of Central Venous Catheters (CVC)
position by sonographic detection of injected Microbubbles (MB)
Methods: With approval of the local ethics committee 95 patients with 98 CVC
and 5 peripheral catheters were examined. The appearance of MB in the right
heart can be observed after injection of agitated saline in the subcostal fourchamber view. MB are hyperechogenic and dissolve later. The time from injection at the catheter to the appearance in the RV can be recorded by M-Mode
registration allowing an exact measurement independent of user interaction and
reaction. To determine positioning, time of appearance of MB was recorded. The
transit time was correlated with radiologically confirmed catheter positions. A self
assessment of the procedures practicability was performed on a linear anologue
scale (0-100%).
Results: We report a total of 95 Patients (65.0±18 years, 57% male). The jugular vein was used in 85 and the subclavian vein in 13 cases. The main diagnoses
requiring catheter placement were pneumonia (n=49), aortic valve reconstruction
(n=9), myocardial infarction (n=6), heart failure (n=6), gastrointestinal bleeding
(n=6) or others (n=9). In 95 patients with radiologically confirmed orthotopic position MB appeared in the right heart in less than one second after injection with a
reliability of 100%. In 3 patients, quantitatively measured appearance of MB was
even below 0.5 seconds. In 5 patients with peripheral venous catheters MB were
observed later than 2 sec after injection and in one patient with a heterotopic
CVC within 1-2 seconds after injection. Duration of the procedure was 146 (111)
seconds (mean, (SD)). Physician’s impression of practicalness was 91% (linear
analogue self assessment).
Conclusion: Ultrasound-based real-time position monitoring of CVC by this new
description of the MB-injection technique has the potential to serve as an alternative to X-ray or other methods. Appearance of MBs in less than one second can
be assumed to predict orthotopic position with high accuracy. Appearance of MB
in more than two seconds indicates malpositioning. Transit times between one
and two seconds require additional X-ray confirmation.
P2945 | BENCH
Accuracy of magnetic resonance for noninvasive cardiac output
quantification in postcapillary pulmonary hypertension
A. Garcia-Alvarez, L. Fernandez-Friera, D. Pereda, R. Fernandez-Jimenez,
M. Nuno-Ayala, J.M. Garcia-Ruiz, G. Guzman, G. Pizarro, V. Fuster, B. Ibanez.
Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain
Purpose: Right ventricular (RV) failure is the main prognostic factor in pulmonary
hypertension (PH). Our aim was to evaluate the precision of different noninvasive approaches to calculate cardiac output (CO) by cardiac magnetic resonance
(CMR) in an experimental model of chronic postcapillary PH.
Methods: Postcapillary PH (N=13) was generated by banding of the inferior pulmonary vein in piglets. Animals were followed for 4 months. Two animals died at 2
and 3 moths due to severe PH. At baseline and every 4 weeks, animals underwent
RHC and immediate 3T CMR (N=62 pairs of measurements). CO was assessed
by RHC using a Swan-Ganz catheter (thermodilution method). CO was measured
Concordance among different CO measures
Conclusion: CMR accurately quantifies CO noninvasively in postcapillary PH.
Phase-contrast on the PA seems the best CMR method.
P2946 | BENCH
LAA closure monitoring by trans-esophageal echocardiography
using ICE probe
J. Ternacle, N. Lellouche, R. Gallet, P. Gueret, J.-L. Dubois-Randes, E. Teiger,
P. Lim. AP-HP - University Hospital Henri Mondor, Department of Cardiology,
Creteil, France
Background: Intracardiac echocardiography probe can be used trough
esophageal route (ICE-TEE) to monitor transeptal puncture and evaluate left atrial
appendage (LAA) without requiring general sedation.
The purpose of the study is to evaluate the accuracy and the safety of ICE-TEE
during Amplatzer Cardiac Plug (ACP) implantation.
Methods: The study included 16 consecutive patients (75±7 years) in atrial fibrillation with high risk of embolism (CHAD-Vasc=5±1.4) that required LAA closure
by ACP because of severe bleeding complications occurring under vitamin K antagonist (HAS-BLED=4±0.9). Standard TEE was performed the day before the
device implantation for LAA sizing and excluding thrombosis. During the procedure, ICE-TEE was used under local anesthesia to determine ACP diameter (ACP
diameter=1.2*LAA diameter by ICE-TEE) and monitor ACP positioning. LAA size
by ICE-TEE was compared to the size obtained by fluoroscopy and standard TEE
and ACP lobe size after device implantation by ICE-TEE to cardiac computed tomography (CT).
Results: LAA maximal diameter by ICE-TEE did not differ from TEE (21±3 mm
vs. 20±3 mm, r=0.9, P<0.001), while fluoroscopy measurement was lower (19±3
mm, P<0.05 vs. ICE-TEE and P=0.08 vs. TEE). ACP was successfully implanted
in 13 patients after one device, 2 patients after 2 devices and one failed because
of a complex LAA anatomy. As expected ACP diameter implanted was 1.2±0.04
(mean=25±3mm, ≤26mm in 10/16 patients) greater than LAA size measured
by ICE-TEE. ACP size by ICE-TEE at the end of the procedure was similar to
cardiac CT measurement (23±7 mm vs. 23±4mm, R=0.98, p<0.001). Finally,
the procedure (mean duration=62±27 minutes, X-ray exposure=78±51 gray/m2 )
was safely conducted in all without pericardial effusion and prosthesis migration.
Conclusions: ICE-TEE probe through esophageal route may be used for the sizing and the monitoring of ACP device implantation. Compared to standard TEE,
ICE-TEE does not required general sedation.