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Letters Differentiation of Hepatolithiasis and Intrahepatic Pneumobilia I read with great interest the article by Erden and colleagues [1] in the January 2014 issue of the AJR about the diagnostic value of T1-weighted gradient-echo inphase imaging in differentiation of hepatolithiasis and intrahepatic pneumobilia. They concluded that MRCP coupled with T1-weighted gradient-echo in-phase imaging had a greater sensitivity than did MRCP to detect pneumobilia. They explained that susceptibility artifacts originating from pneumobilia were more pronounced on inphase gradient-echo images because of lack of a 180° refocusing pulse with gradientecho imaging and use of a longer TE.
I strongly agree that in-phase T1-weighted gradient-echo imaging is mandatory for detection of pneumobilia. On the other hand, I believe that fat-saturated images are very useful for differentiating highsignal-intensity hepatolithiasis from fat within the porta hepatis. Recently 3D fast spoiled gradient-recalled echo imaging techniques that generate water-only and fat-only in-phase and out-of-phase echoes in one signal acquisition have been developed and are available on most modern MRI systems [2]. Therefore, I believe that such a sequence should improve detection of intrahepatic pneumobilia with in-phase images and detection of hepatolithiasis with water-only images.
Lionel Arrivé Université Pierre et Marie Curie, AP/HP – Hôpital Saint-Antoine, Paris, France DOI:10.2214/AJR.14.12580 WEB—This is a web exclusive article.
References 1. Erden A, Haliloglu N, Genç Y, Erden I. Diagnostic value of T1-weighted gradient-echo in-phase images added to MRCP in differentiation of hepatolithiasis and intrahepatic pneumobilia. AJR 2014; 202:74–82 2. Rampton JW, Young PM, Fidler JL, Hartman RP, Herfkens RJ. Putting the fat and water protons to work for you: a demonstration through clinical cases of how fat-water separation techniques can benefit your body MRI practice. AJR 2013; 201:1303–1308
AJR 2014; 203:W450 0361–803X/14/2034–W450 © American Roentgen Ray Society
W450
AJR:203, October 2014
Letters Differentiation of Hepatolithiasis and Intrahepatic Pneumobilia I read with great interest the article by Erden and colleagues [1] in the January 2014 issue of the AJR about the diagnostic value of T1-weighted gradient-echo inphase imaging in differentiation of hepatolithiasis and intrahepatic pneumobilia. They concluded that MRCP coupled with T1-weighted gradient-echo in-phase imaging had a greater sensitivity than did MRCP to detect pneumobilia. They explained that susceptibility artifacts originating from pneumobilia were more pronounced on inphase gradient-echo images because of lack of a 180° refocusing pulse with gradientecho imaging and use of a longer TE.
I strongly agree that in-phase T1-weighted gradient-echo imaging is mandatory for detection of pneumobilia. On the other hand, I believe that fat-saturated images are very useful for differentiating highsignal-intensity hepatolithiasis from fat within the porta hepatis. Recently 3D fast spoiled gradient-recalled echo imaging techniques that generate water-only and fat-only in-phase and out-of-phase echoes in one signal acquisition have been developed and are available on most modern MRI systems [2]. Therefore, I believe that such a sequence should improve detection of intrahepatic pneumobilia with in-phase images and detection of hepatolithiasis with water-only images.
Lionel Arrivé Université Pierre et Marie Curie, AP/HP – Hôpital Saint-Antoine, Paris, France DOI:10.2214/AJR.14.12580 WEB—This is a web exclusive article.
References 1. Erden A, Haliloglu N, Genç Y, Erden I. Diagnostic value of T1-weighted gradient-echo in-phase images added to MRCP in differentiation of hepatolithiasis and intrahepatic pneumobilia. AJR 2014; 202:74–82 2. Rampton JW, Young PM, Fidler JL, Hartman RP, Herfkens RJ. Putting the fat and water protons to work for you: a demonstration through clinical cases of how fat-water separation techniques can benefit your body MRI practice. AJR 2013; 201:1303–1308
AJR 2014; 203:W450 0361–803X/14/2034–W450 © American Roentgen Ray Society
W450
AJR:203, October 2014
