MRI scans of sushi

 Trevor Corson Sushiconcierge Blog Entries 2009 7 17 Want To See The Inner Secrets Of Perfect Sushi Use An Mri Scanner Files Shapeimage 1
Seen above and below are MRI scans of sushi. Uhei Naruse scanned the rolls at a hospital in a personal research project to tease out the secret of good sushi. Trevor Corson, author of "The Story of Sushi," has the details of this experiment on his Sushi Concierge blog. From Sushi Concierge:
 Trevor Corson Sushiconcierge Blog Entries 2009 7 17 Want To See The Inner Secrets Of Perfect Sushi Use An Mri Scanner Files Shapeimage 2 Pictured (at left) are three sushi nigiri–hand squeezed rectangles of rice topped with a slice of fish. The first was made by the veteran chef. It was small and light, weighing in at only 12 grams, and the MRI scan revealed a lot of empty space inside it, between the grains of rice. It also revealed another secret of a veteran chef's skill–the grains of rice were mostly aligned lengthwise, which helps the nigiri hold together without being too dense, by creating adhesion along the edges of the aligned grains.

The second nigiri was made by the apprentice. It was denser–about the same size, but weighing 15 grams. And the rice grains were less uniform in their orientation.

The third nigiri was made by the robot, which couldn't come close to matching human skill. The grains of rice were hopelessly jumbled and the sushi was thick and heavy, clocking in at 20 grams. Naruse ate some of it and described it as "sticky." This is closer to the typical sushi that, sadly, we're content to eat in the States.
"Want to See the Inner Secrets of Perfect Sushi?" (Sushi Concierge)
"The Story of Sushi: An Unlikely Saga of Raw Fish and Rice" (Amazon)



  1. so, a machine that aligns grains and extrudes them in a continuous run? (ow! ow! stop hitting me!)

  2. By the way, in the top photos the order is reversed; the one at left is made by the robot.

  3. Where in the USA are you? We have incredible, “AUTHENTIC” sushi in the Northwest…

    Specifically where I am.. .. .

  4. MRI sure sounds like overkill, but I guess CAT isn’t any more so. What happened to the good old fashionedfreezing and sectioning (I guess it’s called cryosectioning)?

    Or you can do all three.

  5. “The third nigiri was made by the robot…”

    Huh? What robot? Robots make sushi now? Anyway, I was waiting for the article to say that the MRI scan saw some micro-organisms living within the sushi host.

    Don’t get me wrong: sushi is my FAVORITE.

  6. We’ve had sushi making robots in the US since 1984. Didn’t you ever see Runaway? “Hai! You wan’ sushi?”

  7. Actually, one of the dirty little secrets is that we do have sushi robots in the US, they’re just kept hidden in the back rooms and basements of the restaurants, for making takeout sushi. More on that in my book, The Story of Sushi.

  8. Apropos, as I had delicious Unagi tonight at Piranha’s in Dallas. A -very- good sushi Restaurant. Wasn’t sticky at all. They also have devilishly good martinis.

    I am blessed to be so near the Metroplex. Around here, you can get authentic- or the closest to authentic in America- food from all over the world.

  9. @ #11

    Trevor, thanks for this! I have recently “discovered” sushi and love everything about it. I’m now following you on twitter and look forward to learning a LOT.

  10. This is hilarious! Did the author read about this in the Japanese comic book Oishinbo back in the ’80s? This was a technique used by the hero to expose an arrogant, overbearing sushi chef who had succumbed to money and fame. The hero takes the chef’s sushi and compares it to sushi made by an old master who owns an unpretentious sushi shop by using a CAT scanner. The old man was once famous but he escaped the “foodies” and media and secretly opened up a small shop in a old Tokyo neighborhood to concentrate on his trade.

  11. Jorgebob, right on! I know and love that story in Oishinbo. While the Oishingo sushi-scanning project was fictional, the one I blogged about was real, conducted by the researcher mentioned above in the post, Uhei Naruse, and reported his scholarly book on sushi, Sushi no Unchiku, Umasa no Himitsu すしの蘊蓄甘さの秘密 [Knowledge of Sushi and the Secrets of Taste]. I first read about Naruse’s real experiment and later ran across the Oishinbo story. I don’t know if one inspired the other, that would be fascinating to find out. An interesting footnote: unlike the Oishinbo episode, in his real experiments Naruse tried both CAT scans and MRI scans and found the CAT scan didn’t provide good-enough quality images of the sushi, only the MRI scans did.

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