{"id":2366,"date":"2025-03-28T18:06:33","date_gmt":"2025-03-28T22:06:33","guid":{"rendered":"https:\/\/wordpress.forensicpath.us\/?p=2366"},"modified":"2025-03-28T22:31:51","modified_gmt":"2025-03-29T02:31:51","slug":"photomicrography-how-i-measure-coronary-artery-atherosclerosis","status":"publish","type":"post","link":"https:\/\/wordpress.forensicpath.us\/index.php\/2025\/03\/28\/photomicrography-how-i-measure-coronary-artery-atherosclerosis\/","title":{"rendered":"Photomicrography — How I measure coronary artery atherosclerosis"},"content":{"rendered":"

One of the common tasks at autopsy is estimation of the degree of atherosclerotic stenosis of the coronary arteries.\u00a0 Most of the time it’s done in passing — nobody really cares if a person who’s been shot in the head has bad coronary arteries.\u00a0 So, most of the time it’s good enough to say “There is diffuse mild atherosclerotic stenosis of the coronary arteries.”\u00a0 And, sometimes, it’s good enough to say “There is severe diffuse atherosclerotic disease with greater than 95% percent stenosis of the left anterior descending coronary artery.”<\/p>\n

So, most of the time I eyeball it.\u00a0 And I’ll say that by dictating something like “There is approximately 60% atherosclerotic stenosis of the right coronary artery by visual estimation.”\u00a0 But, sometimes all you have is coronary artery disease in a sudden death, and it’s right at that 75% threshold that many of us use for feeling good about calling sudden cardiac death.\u00a0 \u00a0In those cases, I try to measure the atherosclerosis a bit more carefully.<\/p>\n

So, I take a section and do a little morphometry.\u00a0 This is how I do it.<\/p>\n

    \n
  1. Take a section (Doh!).\u00a0 This can be more challenging that one might think.\u00a0 If it’s calcified, then it might crumble.\u00a0 Unfortunately, with the workload of today’s job situation, I really don’t want to spend a day decalcifying it.\u00a0 So, in those cases, I’ll just eyeball it and there you go.\u00a0 I usually don’t bother to make a gross photo, since macro photography can be a hassle. It’s all a matter of how much time I have and how busy the day is…\u00a0 \u00a0So– people have to take my word for it.\u00a0 Also, if your blade isn’t sharp, you can push the plaque right out of the artery.\u00a0 I’ve done that.\u00a0 But, if you can get a section…<\/li>\n
  2. Take a photomicrograph.\u00a0 I’ve been through how I do that.\u00a0 I have a camera set up on my scope, so it’s not much of a hassle.\u00a0 Here’s an example, after division with a brightfield section:\"\"<\/a><\/li>\n
  3. I now load it into my favorite open source scientific image analysis package, ImageJ\/Fiji\u00a0 ( https:\/\/fiji.sc\/<\/a> ).\u00a0 \u00a0This pic is a little low on contrast and a bit washed out, so I’ll do a quick contrast enhancement to make it easier to see details, using the contrast limited adaptive histogram equalization method (CLAHE).\u00a0 In Fiji, you click on Process-> Enhance Local Contrast (CLAHE).\u00a0 For this I’ll use the default parameters, since I really don’t care:\"\"<\/a><\/li>\n
  4. Now, I’ll choose the polygon tool:\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 .\"\"<\/a><\/li>\n
  5. And enclose what the artery should look like without plaque.\u00a0 In the contrast-enhanced image, you can see the muscularis:<\/li>\n
  6. \"\"<\/a><\/li>\n
  7. Now, I choose Analyze->Measure, and Fiji provides the Area enclosed by the polygon, 2067360 pixels:\"\"<\/a><\/li>\n
  8. Now, I choose Edit- Selection-> Select None to clear the polygon, and create another polygon that just has the lumen:\u00a0 \u00a0 \u00a0 \u00a0 .<\/li>\n
  9. \"\"<\/a><\/li>\n
  10. I get the area of that polygon in the same way as step 6:\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 .\"\"<\/a><\/li>\n
  11. Now, I just divide the second number by the first, to get\u00a0 410121\/2067360 = 0.1983, or 80% stenosis.<\/li>\n<\/ol>\n

    In my report, I can then write “Examination of the right coronary artery reveals 80% atherosclerotic stenosis by morphometry.”\u00a0 That gives me warm fuzzies.<\/p>\n

    Update:\u00a0 Someone asked me if I thought everybody should do this routinely.\u00a0 Nope, not at all.\u00a0 I do this because I like photomicrography, image processing, and like to quantify things.\u00a0 I do this because it amuses me.\u00a0 Frankly, noticing that a plaque is big enough to be a risk for sudden death isn’t rocket surgery.\u00a0 If you’ve been through fellowship, you can do it.\u00a0 Your sampling technique may mean that you *miss* some lesions, but if you see it, you can tell grossly whether or not it was life-threatening.\u00a0 I don’t even think that you need to do gross photographs of it.\u00a0 If some moron thinks you are lying about it, then they will think you are faking the photo. Screw them.\u00a0 I like the idea of doing this, and I think it makes my reports marginally better, but I don’t think it should be a standard.<\/p>\n","protected":false},"excerpt":{"rendered":"

    One of the common tasks at autopsy is estimation of the degree of atherosclerotic stenosis of the coronary arteries.\u00a0 Most…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[60],"tags":[59,26],"class_list":["post-2366","post","type-post","status-publish","format-standard","hentry","category-photomicrographs","tag-autopsy","tag-photomicrography"],"_links":{"self":[{"href":"https:\/\/wordpress.forensicpath.us\/index.php\/wp-json\/wp\/v2\/posts\/2366","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wordpress.forensicpath.us\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wordpress.forensicpath.us\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wordpress.forensicpath.us\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/wordpress.forensicpath.us\/index.php\/wp-json\/wp\/v2\/comments?post=2366"}],"version-history":[{"count":5,"href":"https:\/\/wordpress.forensicpath.us\/index.php\/wp-json\/wp\/v2\/posts\/2366\/revisions"}],"predecessor-version":[{"id":2378,"href":"https:\/\/wordpress.forensicpath.us\/index.php\/wp-json\/wp\/v2\/posts\/2366\/revisions\/2378"}],"wp:attachment":[{"href":"https:\/\/wordpress.forensicpath.us\/index.php\/wp-json\/wp\/v2\/media?parent=2366"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wordpress.forensicpath.us\/index.php\/wp-json\/wp\/v2\/categories?post=2366"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wordpress.forensicpath.us\/index.php\/wp-json\/wp\/v2\/tags?post=2366"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}