I noticed some of the MRIs patient positions are FFS. How are they labeled actually? Should I standardize their left/right labels with respect to patient positions, e.g.; if an Axial T2 MRI has severe right subarticular stenosis, is it right based on the patient position and if I flip it on the x axis, does it become left?
", "messages": [ { "id": 2929935, "postDate": "2024-07-20T13:17:47.810Z", "content": "I noticed some of the MRIs patient positions are FFS. How are they labeled actually? Should I standardize their left/right labels with respect to patient positions, e.g.; if an Axial T2 MRI has severe right subarticular stenosis, is it right based on the patient position and if I flip it on the x axis, does it become left?
", "rawMarkdown": "I noticed some of the MRIs patient positions are FFS. How are they labeled actually? Should I standardize their left/right labels with respect to patient positions, e.g.; if an Axial T2 MRI has severe right subarticular stenosis, is it right based on the patient position and if I flip it on the x axis, does it become left? ", "votes": 12 }, { "id": 2931851, "postDate": "2024-07-22T11:55:06.910Z", "content": "The standard in radiology is patient right is image left and patient left is image right (inverted). It can be very difficult to tell which side is true patient right and true patient left from an axial T2 image of the lumbar spine (whereas, for example, if I can see both liver and spleen on the image, then I know that liver is true right and spleen is true left, unless the patient has rare variant anatomy where everything is flipped).
\nSo if I am horizontally flipping the image (i.e. x-axis), I also flip the labels (right becomes left and vice versa).
", "rawMarkdown": "The standard in radiology is patient right is image left and patient left is image right (inverted). It can be very difficult to tell which side is true patient right and true patient left from an axial T2 image of the lumbar spine (whereas, for example, if I can see both liver and spleen on the image, then I know that liver is true right and spleen is true left, unless the patient has rare variant anatomy where everything is flipped). \n\nSo if I am horizontally flipping the image (i.e. x-axis), I also flip the labels (right becomes left and vice versa). ", "votes": 9, "replies": [ { "id": 2933997, "postDate": "2024-07-24T05:45:22.183Z", "content": "Thanks for the detailed answer. I guess the labels are patient left/right then or I can find out by visualizing the labeled slice. Is sagittal plane inverted too like that or is it only two dimensional slices?
", "rawMarkdown": "Thanks for the detailed answer. I guess the labels are patient left/right then or I can find out by visualizing the labeled slice. Is sagittal plane inverted too like that or is it only two dimensional slices?", "replies": [ { "id": 2935600, "postDate": "2024-07-25T12:36:47.900Z", "content": "On a given sagittal slice, this is not an issue because patient left and right are perpendicular to the image plane.
\nAcross sagittal series of images, if you sort in ascending order by ImagePositionPatient[0], then by DICOM convention you move from patient right to left (i.e., index 0 is rightmost image and index -1 is leftmost image).
", "rawMarkdown": "On a given sagittal slice, this is not an issue because patient left and right are perpendicular to the image plane.\n\nAcross sagittal series of images, if you sort in ascending order by ImagePositionPatient[0], then by DICOM convention you move from patient right to left (i.e., index 0 is rightmost image and index -1 is leftmost image). ", "votes": 1 }, { "id": 2992990, "postDate": "2024-09-19T10:49:20.840Z", "rawMarkdown": "", "isDeleted": true } ] }, { "id": 2934162, "postDate": "2024-07-24T08:37:51.737Z", "content": "Is it possible to identify the left and right from the aorta adjacent to the lumbar vertebrae?
", "rawMarkdown": "Is it possible to identify the left and right from the aorta adjacent to the lumbar vertebrae?", "replies": [ { "id": 2935596, "postDate": "2024-07-25T12:35:03.197Z", "content": "Yes, if the aorta and inferior vena cava are visible in the slice, then standard anatomy is that the aorta is to the patient left of the inferior vena cava. However these structures may not always be visible depending on the field of view and use of a saturation band which can obscure them.
", "rawMarkdown": "Yes, if the aorta and inferior vena cava are visible in the slice, then standard anatomy is that the aorta is to the patient left of the inferior vena cava. However these structures may not always be visible depending on the field of view and use of a saturation band which can obscure them.", "votes": 3 } ] } ] } ], "comments": [ { "id": 2931851, "author_name": "Ian Pan", "author_url": "", "post_date": "2024-07-22T11:55:06.910000", "content": "The standard in radiology is patient right is image left and patient left is image right (inverted). It can be very difficult to tell which side is true patient right and true patient left from an axial T2 image of the lumbar spine (whereas, for example, if I can see both liver and spleen on the image, then I know that liver is true right and spleen is true left, unless the patient has rare variant anatomy where everything is flipped).
\nSo if I am horizontally flipping the image (i.e. x-axis), I also flip the labels (right becomes left and vice versa).
", "votes": 9, "replies": [ { "id": 2933997, "author_name": "Gunes Evitan", "author_url": "", "post_date": "2024-07-24T05:45:22.183000", "content": "Thanks for the detailed answer. I guess the labels are patient left/right then or I can find out by visualizing the labeled slice. Is sagittal plane inverted too like that or is it only two dimensional slices?
", "votes": 0, "replies": [ { "id": 2935600, "author_name": "Ian Pan", "author_url": "", "post_date": "2024-07-25T12:36:47.900000", "content": "On a given sagittal slice, this is not an issue because patient left and right are perpendicular to the image plane.
\nAcross sagittal series of images, if you sort in ascending order by ImagePositionPatient[0], then by DICOM convention you move from patient right to left (i.e., index 0 is rightmost image and index -1 is leftmost image).
", "votes": 1, "replies": [] }, { "id": 2992990, "author_name": "", "author_url": "", "post_date": "2024-09-19T10:49:20.840000", "content": "", "votes": 0, "replies": [] } ] }, { "id": 2934162, "author_name": "patriot", "author_url": "", "post_date": "2024-07-24T08:37:51.737000", "content": "Is it possible to identify the left and right from the aorta adjacent to the lumbar vertebrae?
", "votes": 0, "replies": [ { "id": 2935596, "author_name": "Ian Pan", "author_url": "", "post_date": "2024-07-25T12:35:03.197000", "content": "Yes, if the aorta and inferior vena cava are visible in the slice, then standard anatomy is that the aorta is to the patient left of the inferior vena cava. However these structures may not always be visible depending on the field of view and use of a saturation band which can obscure them.
", "votes": 3, "replies": [] } ] } ] } ], "raw_markdown_by_id": { "2929935": "I noticed some of the MRIs patient positions are FFS. How are they labeled actually? Should I standardize their left/right labels with respect to patient positions, e.g.; if an Axial T2 MRI has severe right subarticular stenosis, is it right based on the patient position and if I flip it on the x axis, does it become left? ", "2931851": "The standard in radiology is patient right is image left and patient left is image right (inverted). It can be very difficult to tell which side is true patient right and true patient left from an axial T2 image of the lumbar spine (whereas, for example, if I can see both liver and spleen on the image, then I know that liver is true right and spleen is true left, unless the patient has rare variant anatomy where everything is flipped). \n\nSo if I am horizontally flipping the image (i.e. x-axis), I also flip the labels (right becomes left and vice versa). " } }