A Novel Magnetic Resonance Quality Assurance Phantom (KMRP-4):Multi-Site Comparison With the American College of Radiology Phantom
	    		
		   		
		   			
		   		
	    	
    	- Author:
	        		
		        		
		        		
			        		Suchit KUMAR
			        		
			        		
			        		
			        			1
			        			
			        		
			        		
			        		
			        		
			        		;
		        		
		        		
		        		
			        		Jong-Min KIM
			        		
			        		;
		        		
		        		
		        		
			        		Jang Gyu CHA
			        		
			        		;
		        		
		        		
		        		
			        		Ji Young HWANG
			        		
			        		;
		        		
		        		
		        		
			        		Seung Eun JUNG
			        		
			        		;
		        		
		        		
		        		
			        		Chulhyun LEE
			        		
			        		;
		        		
		        		
		        		
			        		Chang-Hyun OH
			        		
			        		
		        		
		        		
		        		
			        		
			        		Author Information
			        		
 - Publication Type:Original Article
 - From:Investigative Magnetic Resonance Imaging 2023;27(1):10-20
 - CountryRepublic of Korea
 - Language:English
 - 
		        	Abstract:
			       	
			       		
				        
				        	 Purpose:To propose a novel standard magnetic resonance imaging (MRI) phantom, hereafter called the Korea Magnetic Resonance Phantom-4th edition (KMRP-4). Its related quality control (QC) assessment protocols and its comparison with the American College of Radiology (ACR) phantom and its QC assessment protocols. 
				        	
Materials and Methods:Internally, the KMRP-4 phantom is composed of cubic and triangular vessels, brain tissue structures, and a uniform region designed to facilitate a variety of QC protocols. Using magnetic resonance (MR) images of these structures, we quantitatively evaluated a total of 10 parameters, seven from those of existing ACR protocols (i.e., geometric accuracy, high-contrast spatial resolution, slice thickness accuracy, slice position accuracy, image intensity uniformity, percent signal ghosting, and low-contrast object detectability) and three additional parameters for evaluating vessel conspicuity, brain tissue contrast, and signal-to-noise ratio (SNR) introduced in the KMRP-4 protocols. Twentytwo MRI systems of 0.32–3.0 T static magnetic field strength were tested using both ACR and KMRP-4 phantoms. Mann–Whitney U-tests were performed on the seven evaluation items of the ACR method to compare KMRP-4 and ACR methods.
Results:The results of Mann–Whitney U-test demonstrated that p-values were more than 0.05 for all seven items that could be assessed with both ACR and KMRP-4, indicating similar results between the two methods. Additionally, assessments of vessel conspicuity, brain tissue contrast, and SNR using the KMRP-4 method demonstrated utility of the KMRP-4 phantom.
Conclusion:A novel standard phantom and related QC methods were developed to perform objective, observer-independent, and semi-automatic QC tests. Quantitative comparisons of MR images with KMPR-4 and ACR phantoms were performed. Results demonstrated the utility of the newly proposed KMRP-4 phantom and its related QC methods. 
            