INTRODUCTION
Cardiac ultrasound also known as echocardiography is an invasive method use widely for detailed and accurate evaluation of the cardiac structure and function. Nowadays, the advancement in technologies creates development in the ultrasound machine for better clinical benefit. The aim of this proposal is to recommend new ultrasound machine for cardiac imaging. The remarks which highlighted are technical specification needed and overall budget to purchase this machine.
TECHNICAL SPECIFICATION
1.1 IMAGING PARAMETER
1.1.1 FREQUENCY
Image quality is superior in this imaging; ability to utilize accuracy in diagnosis. The preference of the frequency is compensate with penetration depth. Higher frequency will lessen penetration depth but image resolution is better. Adequate resolution needed for echocardiography are axial resolution <0.5 mm, lateral <5 mm at all depths and <2 mm in focal zones (Cavanagh & Smith, 2014).
In cardiac, the imaging depth is deep which depending on the patient size. Consequently, cardiac ultrasound priority in adults requires the use of lower frequencies regularly 2-4 MHz to enhance penetration depth (Hoffmann & Bahner, 2008) . The frequency range of the transducer will influence mode of scanning. Doppler-based imaging modes usually operate with lower frequencies than the B-mode frequency to minimize aliasing (Szabo & Lewin, 2013).
1.1.2 TRANSDUCER/ PROBE
Selection of transducer or probe determines the coverage of the region of interest, maximum scan depth and coverage of essential diagnostic modes required to optimize a patient’s diagnosis (Szabo & Lewin, 2013). Besides, it can be used to performed advanced function such as 3D and 4D echocardiography. The probe used is small “footprints” either phased or microconvex. However, curvilinear probes also can be used to visualize the heart, predominantly in the subxiphoid view (Hoffmann & Bahner, 2008) . Microconvex transducer provides larger field of view. Option of the transducer limits the echocardiogram examination. Therefore, requires having more than one transducer for better evaluation.
Figure 1: Transducer from Sonosite manufacturer with frequency 5-1 MHz
1.1.3 SCANNING MODE
The common requirement modes of scanning for echocardiography are B-mode, M-mode, color-flow imaging, and spectral and tissue Doppler. Mode of scanning will intensify contrast enhancement of the image. The high temporal resolution of M-mode echocardiography allows precise depiction of rapidly moving structures. While, basis of assessment of cardiac chambers and valves and enable identification of structural abnormalities is based on 2D transthoracic echocardiography (TTE) (Ashley & Niebauer, 2004) .
Moreover, Doppler echocardiography comprising spectral Doppler (pulsed wave and continuous wave) and colour Doppler imaging is used to evaluate the direction, velocity, amplitude and timing of blood flow through the heart. 3D echocardiography also widely used to assess ventricular mechanical dyssynchrony, evaluate valvular disease and long-term response to cardiac resynchronization therapy (Shah, 2013).
Figure 2: Image scanning based on M-mode (left), 2D echocardiography and Colour Doppler
1.1.4 DATA ACQUISITION, INTEPRETATION AND STORAGE
Training like image acquisition and image interpretation is compulsory. So, image analysis and interpretation is well documented and ensure appropriate use of echocardiography in many clinical studies. Position of the transducer play important role in cardiac ultrasound. So, imaging procedure of heart is taken from various orthogonal planes based on the heart’s position within the chest
Echocardiographic data must able to store images in a method compatible with DICOM (Digital Imaging and Communications in Medicine) standards. So, it easily to access, share and discuss about the image. For the real time image visualization, it needs suitable screen size because small screen will limit recognition of diagnostic findings. The compatible ultrasound machine with ECG yield advanced signal processing and electrocardiographic (EKG) gating (Spencer et al., 2013).
1.2 SIZE AND TYPE OF MACHINE
Portable echocardiography machine is most preferable. So, it can take from one place to another place effortlessly. Size of the machine is medium size and not required a lot of space to place it mainly when use in moderate room with limited space.
1.3 POWER OUTPUT
The electrical safety indices (mechanical index [MI] and thermal index [TI]) following American Institute of Ultrasound in Medicine (AIUM) or National Electrical Manufacturers Association (NEMA) display standard. While Certification Acquisition for Quality Management Systems based on ISO 9001:2008. These certifications ensure machine is specification strict according safety standard. The stability of the electrical component within ultrasound machine will yield better image quality.
COMPARISON OF THE CARDIAC ULTRASOUND MACHINE
Table 1: Comparison between Philips iE33 and GE Vivid 7 (Cardiovascular Sale; UMI)
SPECIFICATION
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ULTRASOUND MACHINE
|
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Philips iE33
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GE Vivid 7
|
|
User interface
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· Monitor size: 20”
· Monitor type: LCD Flat Panel
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· Monitor size: 17”
· Monitor type: CRT
|
Imaging mode
|
2D and M-mode
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2D and M-mode
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Doppler Mode
|
High Frame Rate Color Flow, Color Doppler Velocity, Color Flow Mapping, Color Doppler Energy, Color Power Doppler, Directional Color Power, Direction Tissue Imaging (TDI), Pulse Wave (PW) And Continuous Wave (CW)
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High Frame Rate Color Flow, Color Doppler Velocity, Color Flow Mapping, Color Doppler Energy, Color Power Doppler, Direction Tissue Imaging (TDI), Pulse Wave (PW) And Continuous Wave (CW)
|
Software technologies
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3D imaging, tissue harmonic imaging (THI), auto gain
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3D imaging, tissue harmonic imaging (THI), auto gain
|
Cardiac transducers/ probes
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· Adult cardiac: 1-12 MHz
· Fetal cardiac: 3-8 MHz
· Pediatric cardiac: 1-12 MHz
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· Adult cardiac: 1.5-5 MHz
· Neonatal cardiac: 4-10 MHz
· Pediatric cardiac: 3.5-8 MHz
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Cardiac imaging
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Adult echo, cardiac screening, fetal echo, ECG, neonatal echo, pediatric echo, stress echo
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Adult echo, cardiac screening, ECG, Neonatal echo, pediatric echo, stress echo is option
|
Structured reporting
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DICOM-Cardiac structured reporting and DICOM-Vascular structured reporting
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DICOM-Cardiac structured reporting and DICOM-Vascular structured reporting
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Power supply
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· AC: 100-240 V, 50/60 Hz
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· AC: 100-240 V
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Standard Warranty
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1 year
|
1 year
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Price
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$55k
|
$38k
|
Rating
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Best
|
Best
|
REFERENCES
Cavanagh, P., & Smith, K. (2014). Standards for the provsion of an ultrasound service. The Royal College of Radiologists. Retrieved from www.rcr.ac.uk
Shah, B. N. (2013). Echocardiography in the Era of Multimodality Imaging. BioMed Research International, 19(3), 175–184. http://doi.org/10.1016/j.hlc.2010.01.006
Spencer, K. T., Kimura, B. J., Korcarz, C. E., Pellikka, P. A., Rahko, P. S., Siegel, R. J., … Angeles, L. (2013). Focused Cardiac Ultrasound : Recommendations from the American Society of Echocardiography. Journal of the American Society of Echocardiography, 26(6), 567–581. http://doi.org/10.1016/j.echo.2013.04.001
Szabo, T. L., & Lewin, P. A. (2013). Ultrasound Transducer Selection in Clinical Imaging Practice. American Institute of Ultrasound in Medicine, (32), 573–582. Retrieved from www.aium.org
Ashley EA, Niebauer J. Cardiology Explained. London: Remedica; 2004. Chapter 4, Understanding the echocardiogram. Available from: http://www.ncbi.nlm.nih.gov/books/NBK2215
Hoffmann, B., & Bahner, P. D. (2008). Ultrasound Guide for Emergency Physicians. Retrieved 15 May, 2016, from Echocardiographt for emergency Physicians: http://www.sonoguide.com
Cardiovascular Sale. (n.d.). Retrieved 14 May, 2016, from Cardiac Ultrasound Machine: http://www.cvsales.com
UMI. (n.d.). Retrieved 14 May, 2016, from Ultrasound Machine Comparison Chart: http://www.umiultrasound.com
