{
  "id": 429323,
  "title": "How to find the best HU value for all abnormal findings in the competition?",
  "url": "/competitions/rsna-2023-abdominal-trauma-detection/discussion/429323",
  "author_name": "SenTran",
  "post_date": "2023-08-05T03:53:28.623000",
  "votes": 1,
  "comment_count": 1,
  "views": 0,
  "content": "<p>In CT scan images, we can control the HU values to easily identify abnormalities in specific findings.</p>",
  "messages": [
    {
      "id": 2374511,
      "postDate": "2023-08-05T03:53:28.623Z",
      "content": "<p>In CT scan images, we can control the HU values to easily identify abnormalities in specific findings.</p>",
      "rawMarkdown": "In CT scan images, we can control the HU values to easily identify abnormalities in specific findings.",
      "votes": 1
    },
    {
      "id": 2375307,
      "postDate": "2023-08-05T14:42:06.463Z",
      "content": "<p>Hounsfield Unit is just a measure of relative density. You can think of CT scans as being \"calibrated\" so that all densities can be compared to the denseness of water and air. For instance, blood is similar in density to water .. but metal objects have very high density compared to water, so a metal object will have a higher HU value than water. </p>\n<p>Likewise, iodinated contrast media injected into the patients veins increases the HU value of the blood significantly. This makes it easier to find occluded vessels and extravasations .. or issues where blood is where it isn't supposed to be, or isn't where it is supposed to be.</p>\n<p>Keep in mind, HU has nothing to do with the way the image is displayed. No matter what \"window\" the image is displayed in, the HU values remain the same. If we measure the HU of the aorta on a slice that is windowed to display bone detail, then window the image to show soft tissue detail .. the HU values in the aorta will be the same.</p>",
      "rawMarkdown": "Hounsfield Unit is just a measure of relative density. You can think of CT scans as being \"calibrated\" so that all densities can be compared to the denseness of water and air. For instance, blood is similar in density to water .. but metal objects have very high density compared to water, so a metal object will have a higher HU value than water. \n\nLikewise, iodinated contrast media injected into the patients veins increases the HU value of the blood significantly. This makes it easier to find occluded vessels and extravasations .. or issues where blood is where it isn't supposed to be, or isn't where it is supposed to be.\n\nKeep in mind, HU has nothing to do with the way the image is displayed. No matter what \"window\" the image is displayed in, the HU values remain the same. If we measure the HU of the aorta on a slice that is windowed to display bone detail, then window the image to show soft tissue detail .. the HU values in the aorta will be the same.",
      "votes": 2
    }
  ],
  "comments": [
    {
      "id": 2375307,
      "author_name": "David Roberts",
      "author_url": "",
      "post_date": "2023-08-05T14:42:06.463000",
      "content": "<p>Hounsfield Unit is just a measure of relative density. You can think of CT scans as being \"calibrated\" so that all densities can be compared to the denseness of water and air. For instance, blood is similar in density to water .. but metal objects have very high density compared to water, so a metal object will have a higher HU value than water. </p>\n<p>Likewise, iodinated contrast media injected into the patients veins increases the HU value of the blood significantly. This makes it easier to find occluded vessels and extravasations .. or issues where blood is where it isn't supposed to be, or isn't where it is supposed to be.</p>\n<p>Keep in mind, HU has nothing to do with the way the image is displayed. No matter what \"window\" the image is displayed in, the HU values remain the same. If we measure the HU of the aorta on a slice that is windowed to display bone detail, then window the image to show soft tissue detail .. the HU values in the aorta will be the same.</p>",
      "votes": 2,
      "replies": []
    }
  ],
  "raw_markdown_by_id": {
    "2374511": "In CT scan images, we can control the HU values to easily identify abnormalities in specific findings.",
    "2375307": "Hounsfield Unit is just a measure of relative density. You can think of CT scans as being \"calibrated\" so that all densities can be compared to the denseness of water and air. For instance, blood is similar in density to water .. but metal objects have very high density compared to water, so a metal object will have a higher HU value than water. \n\nLikewise, iodinated contrast media injected into the patients veins increases the HU value of the blood significantly. This makes it easier to find occluded vessels and extravasations .. or issues where blood is where it isn't supposed to be, or isn't where it is supposed to be.\n\nKeep in mind, HU has nothing to do with the way the image is displayed. No matter what \"window\" the image is displayed in, the HU values remain the same. If we measure the HU of the aorta on a slice that is windowed to display bone detail, then window the image to show soft tissue detail .. the HU values in the aorta will be the same."
  }
}