\n
![\"\"](\"https://i.imgur.com/8sfiEUU.jpg\")
A pulmonary embolism (PE) is a blood clot in the blood vessels of the lungs that can be potentially life-threatening. PEs typically arise from blood clots in the leg veins (deep vein thromboses, or DVTs) that dislodge and become trapped in the pulmonary vasculature. The clinical presentation of PE can vary from asymptomatic to severe illness requiring intensive care (shock, cardiac arrest, etc).
It can damage part of the lung due to restricted blood flow, decrease oxygen levels in the blood, and affect other organs as well. Large or multiple blood clots can be fatal. The blockage can be life-threatening. According to the Mayo Clinic, it results in the death of one-third of people who go undiagnosed or untreated. However, immediate emergency treatment greatly increases your chances of avoiding permanent lung damage.
There are various tools for diagnosing PE; however, current practice relies primarily on CT angiography. Intravenous contrast is administered through the patient's veins just prior to obtaining the CT, and the CT scan is timed to obtain images when the contrast is primarily in the pulmonary blood vessels. Note: this is where quality issues can occur. Sometimes the timing of the scan is off, resulting in a suboptimal scan. This can result in non-diagnostic or equivocal studies. In addition, if the patient is moving a lot or has metal in their body, this can cause artifacts which may obscure a clot.
\n
This image shows a single axial slice of a CT pulmonary angiogram (CTPA or CTPE) at this level of the pulmonary trunk. The pulmonary trunk (the green annotated part in the image ) is a major blood vessel that comes from the right side of your heart to supply blood to your lungs. Note how bright the blood vessels are - this is due to the intravenous contrast.
\n![\"\"](\"https://imgur.com/eUWTVwU.jpg\")
In this image, notice how there are \"filling defects\" in red color in the pulmonary trunk. Unlike the previous image, there are areas in the blood vessels (marked in red) that are more gray. This is evidence of a pulmonary embolism in the blood vessel, as the blood clot prevents the contrast from filling up the entire vessel. This type of PE would be a central PE in our dataset (it is in the central blood vessel of the lungs).
\n![\"\"](\"https://prod-images-static.radiopaedia.org/images/17483790/2cc61c62b20f31c98b8b9df642b4d9_gallery.jpeg\")
\nNote that PEs can occur anywhere in the lung vasculature, which is very extensive and resembles a tree. However, the finding we are looking for is the same: filling detects. . Patients can have multiple PEs across both lungs: hence, we have labels for right-sided, left-sided, and central PEs, but these are not mutually exclusive which means same image can have more than one-sided PEs.
![\"left](\"https://pubs.rsna.org/cms/10.1148/rg.245045008/asset/images/medium/g04se15g04x.jpeg\")
\nIn the image above, Acute occlusive pulmonary embolism in a 32-year-old woman who presented with chest pain. CT scan shows a pulmonary embolus within the posterobasal segment of the right lower lobe artery (arrow). The artery is enlarged compared with adjacent patent vessels.
![\"right](\"https://pubs.rsna.org/cms/10.1148/rg.245045008/asset/images/medium/g04se15g07x.jpeg\")
\nIn the image above, Acute pulmonary embolism in a 58-year-old woman who presented with chest pain and dyspnea. CT scan demonstrates a pulmonary embolus that results in an eccentrically positioned partialfilling defect, which is surrounded by contrast material and forms acute angles with the arterial wall (arrows) is left PE
![\"central](\"https://prod-images-static.radiopaedia.org/images/36787671/60da4496798220ab2a3b52f1978e49_gallery.jpeg\")
\nIn this image above, notice how there are \"filling defects\" in the pulmonary trunk. This is evidence of a pulmonary embolism in the blood vessel, as the blood clot prevents the contrast from filling up the entire vessel. This type of PE would be a central PE in our dataset (it is in the central blood vessel of the lungs).
Not all PEs result in symptoms. Generally, acute (sudden-onset) PEs are more likely to cause symptoms, as your body has not had time to adapt to the presence of a clot. There are imaging findings that can distinguish acute from chronic PEs, but this can be challenging to discern. For more on this topic you can have a look at this paper Acute and Chronic Pulmonary Emboli: Angiography–CT Correlation
\nYour heart has 4 chambers. The muscular chambers that do most of the pumping are known as the ventricles. Your right ventricle pumps blood to your lungs; your left ventricle pumps blood to the rest of your body.
\n![\"\"](\"https://imgur.com/iNIoOkN.jpg\")
Remember - everything is flipped in radiology, so the RIGHT SIDE of the body is on the LEFT, and vice versa. That giant ball just off-center in this image is the heart. Normally, your left ventricle (lower right) is larger than your right ventricle (upper left), like in this image above. This is because the left ventricle has a much harder job to do: pump body throughout the entire body versus just the lungs.
\n![\"\"](\"https://imgur.com/4lUEZG9.jpg\")
\nHowever, having a PE can put a big strain on the right side of your heart. Intuitively, this makes sense - if you have a blockage in the blood vessels in your lungs, the right side of your heart has to work a lot harder to try and pump blood through the obstruction. Sometimes, we can see evidence of this on the CT - we call this right heart strain. This suggests a more severe PE because the blood clot is forcing your right heart to work harder and causing blood to become backed up into the right ventricle (it's just plumbing!). We can measure the ratio of diameters of the right ventricle to the left ventricle to see if this is high. A high ratio is suggestive of right heart strain.
![\"\"](\"https://prod-images-static.radiopaedia.org/images/807719/db43f21911fc4f6f8522ca7a3af124_gallery.jpg\")
Notice how the upper left part (right ventricle) is much larger than the lower right part (left ventricle). This patient is having a severe PE causing significant right heart strain.
\nBecause of its importance as a prognostic indicator, detecting RV/LV ratio > 1 in this competition is weighed most heavily across all the other classes. Please note that this is a 3D image. The proper way to compute RV/LV ratio is to find the maximum diameter across all slices. The maximum diameters of each ventricle are usually on different slices.
\nTreatment depends on the severity of the clot. Typically, we will use blood thinners, either IV or oral. In severe cases, we may attempt catheter-directed thrombolysis. An interventional radiologist inserts a catheter into the pulmonary blood vessels to deliver clot-busting medication directly to the clot. Rarely, surgery may be required.
\n■ Pulmonary Embolism: A Brief Intro by Dr. Ian Pan
\n■ https://www.rsna.org/
\n■ https://prod-images-static.radiopaedia.org/images/17056972/2ef2ae41c8a0b5a070aa21140a14e0_gallery.jpeg
\n■ Mattia Arrigo et.al, Right Ventricular Failure: Pathophysiology, Diagnosis And Treatment
\n■ The Ratio of Descending Aortic Enhancement to Main Pulmonary Artery Enhancement Measured on Pulmonary CT Angiography as a Finding to Predict Poor Outcome in Patients with Massive or Submassive Pulmonary Embolism
\n■ Acute and Chronic Pulmonary Emboli: Angiography–CT Correlation
\n■ Pulmonary embolism Acute vs Chronic
if there is any misinformation, please do let me know. I will correct them swiftly
A pulmonary embolism (PE) is a blood clot in the blood vessels of the lungs that can be potentially life-threatening. PEs typically arise from blood clots in the leg veins (deep vein thromboses, or DVTs) that dislodge and become trapped in the pulmonary vasculature. The clinical presentation of PE can vary from asymptomatic to severe illness requiring intensive care (shock, cardiac arrest, etc).
It can damage part of the lung due to restricted blood flow, decrease oxygen levels in the blood, and affect other organs as well. Large or multiple blood clots can be fatal. The blockage can be life-threatening. According to the Mayo Clinic, it results in the death of one-third of people who go undiagnosed or untreated. However, immediate emergency treatment greatly increases your chances of avoiding permanent lung damage.
There are various tools for diagnosing PE; however, current practice relies primarily on CT angiography. Intravenous contrast is administered through the patient's veins just prior to obtaining the CT, and the CT scan is timed to obtain images when the contrast is primarily in the pulmonary blood vessels. Note: this is where quality issues can occur. Sometimes the timing of the scan is off, resulting in a suboptimal scan. This can result in non-diagnostic or equivocal studies. In addition, if the patient is moving a lot or has metal in their body, this can cause artifacts which may obscure a clot.
\n
This image shows a single axial slice of a CT pulmonary angiogram (CTPA or CTPE) at this level of the pulmonary trunk. The pulmonary trunk (the green annotated part in the image ) is a major blood vessel that comes from the right side of your heart to supply blood to your lungs. Note how bright the blood vessels are - this is due to the intravenous contrast.
\n
In this image, notice how there are \"filling defects\" in red color in the pulmonary trunk. Unlike the previous image, there are areas in the blood vessels (marked in red) that are more gray. This is evidence of a pulmonary embolism in the blood vessel, as the blood clot prevents the contrast from filling up the entire vessel. This type of PE would be a central PE in our dataset (it is in the central blood vessel of the lungs).
\n
\nNote that PEs can occur anywhere in the lung vasculature, which is very extensive and resembles a tree. However, the finding we are looking for is the same: filling detects. . Patients can have multiple PEs across both lungs: hence, we have labels for right-sided, left-sided, and central PEs, but these are not mutually exclusive which means same image can have more than one-sided PEs.
\nIn the image above, Acute occlusive pulmonary embolism in a 32-year-old woman who presented with chest pain. CT scan shows a pulmonary embolus within the posterobasal segment of the right lower lobe artery (arrow). The artery is enlarged compared with adjacent patent vessels.
\nIn the image above, Acute pulmonary embolism in a 58-year-old woman who presented with chest pain and dyspnea. CT scan demonstrates a pulmonary embolus that results in an eccentrically positioned partialfilling defect, which is surrounded by contrast material and forms acute angles with the arterial wall (arrows) is left PE
\nIn this image above, notice how there are \"filling defects\" in the pulmonary trunk. This is evidence of a pulmonary embolism in the blood vessel, as the blood clot prevents the contrast from filling up the entire vessel. This type of PE would be a central PE in our dataset (it is in the central blood vessel of the lungs).
Not all PEs result in symptoms. Generally, acute (sudden-onset) PEs are more likely to cause symptoms, as your body has not had time to adapt to the presence of a clot. There are imaging findings that can distinguish acute from chronic PEs, but this can be challenging to discern. For more on this topic you can have a look at this paper Acute and Chronic Pulmonary Emboli: Angiography–CT Correlation
\nYour heart has 4 chambers. The muscular chambers that do most of the pumping are known as the ventricles. Your right ventricle pumps blood to your lungs; your left ventricle pumps blood to the rest of your body.
\n
Remember - everything is flipped in radiology, so the RIGHT SIDE of the body is on the LEFT, and vice versa. That giant ball just off-center in this image is the heart. Normally, your left ventricle (lower right) is larger than your right ventricle (upper left), like in this image above. This is because the left ventricle has a much harder job to do: pump body throughout the entire body versus just the lungs.
\n
\nHowever, having a PE can put a big strain on the right side of your heart. Intuitively, this makes sense - if you have a blockage in the blood vessels in your lungs, the right side of your heart has to work a lot harder to try and pump blood through the obstruction. Sometimes, we can see evidence of this on the CT - we call this right heart strain. This suggests a more severe PE because the blood clot is forcing your right heart to work harder and causing blood to become backed up into the right ventricle (it's just plumbing!). We can measure the ratio of diameters of the right ventricle to the left ventricle to see if this is high. A high ratio is suggestive of right heart strain.
Notice how the upper left part (right ventricle) is much larger than the lower right part (left ventricle). This patient is having a severe PE causing significant right heart strain.
\nBecause of its importance as a prognostic indicator, detecting RV/LV ratio > 1 in this competition is weighed most heavily across all the other classes. Please note that this is a 3D image. The proper way to compute RV/LV ratio is to find the maximum diameter across all slices. The maximum diameters of each ventricle are usually on different slices.
\nTreatment depends on the severity of the clot. Typically, we will use blood thinners, either IV or oral. In severe cases, we may attempt catheter-directed thrombolysis. An interventional radiologist inserts a catheter into the pulmonary blood vessels to deliver clot-busting medication directly to the clot. Rarely, surgery may be required.
\n■ Pulmonary Embolism: A Brief Intro by Dr. Ian Pan
\n■ https://www.rsna.org/
\n■ https://prod-images-static.radiopaedia.org/images/17056972/2ef2ae41c8a0b5a070aa21140a14e0_gallery.jpeg
\n■ Mattia Arrigo et.al, Right Ventricular Failure: Pathophysiology, Diagnosis And Treatment
\n■ The Ratio of Descending Aortic Enhancement to Main Pulmonary Artery Enhancement Measured on Pulmonary CT Angiography as a Finding to Predict Poor Outcome in Patients with Massive or Submassive Pulmonary Embolism
\n■ Acute and Chronic Pulmonary Emboli: Angiography–CT Correlation
\n■ Pulmonary embolism Acute vs Chronic
if there is any misinformation, please do let me know. I will correct them swiftly
@redwankarimsony thanks for your detailed posts. However there are some inconsistencies i find in terms of labels that we have in train cv.
\nI expected that if pe present on image is 0 -ve exam for PE is always 1 but i find that for about 2.2k patients its 0 is it a inconsistency of labels ?
@Thanks @jaideepvalani for your nice observation. In my opinion, it if pe present then, that patient is an example of a healthy patient. It should not be considered as an inconsistency of labels.
\nBtw I am not 100% confident about my answer yet. I have to dig deeper…
", "rawMarkdown": "@Thanks @jaideepvalani for your nice observation. In my opinion, it if pe present then, that patient is an example of a healthy patient. It should not be considered as an inconsistency of labels. \n\nBtw I am not 100% confident about my answer yet. I have to dig deeper... " } ] }, { "id": 1024326, "postDate": "2020-09-23T18:59:31.807Z", "content": "Insightful , Thanks for sharing @Md. Redwan Karim Sony
", "rawMarkdown": "Insightful , Thanks for sharing @Md. Redwan Karim Sony\n", "votes": 1, "replies": [ { "id": 1024588, "postDate": "2020-09-24T02:10:15.470Z", "content": "Thank you @pinakimishrads
", "rawMarkdown": "Thank you @pinakimishrads ", "votes": 1 } ] }, { "id": 1020644, "postDate": "2020-09-21T10:19:52.640Z", "content": "Big Thanks , it helps a lot
", "rawMarkdown": "Big Thanks , it helps a lot\n", "votes": 1, "replies": [ { "id": 1020973, "postDate": "2020-09-21T14:44:30.827Z", "content": "You are welcome @benyaengineering
", "rawMarkdown": "You are welcome @benyaengineering " } ] }, { "id": 1015655, "postDate": "2020-09-18T10:31:08.880Z", "content": "Thanks - this helps!
\nHow did you end up plotting the images please? :)
", "rawMarkdown": "Thanks - this helps! \n\nHow did you end up plotting the images please? :)", "votes": 1, "replies": [ { "id": 1015682, "postDate": "2020-09-18T11:01:15.087Z", "content": "Thanks for your query. This is actually is a part of my notebook RSNA-STR Pulmonary Embolism [EDA + Domain Info].
", "rawMarkdown": "Thanks for your query. This is actually is a part of my notebook [RSNA-STR Pulmonary Embolism [EDA + Domain Info]](https://www.kaggle.com/redwankarimsony/rsna-str-pulmonary-embolism-eda-domain-info). ", "votes": 1 } ] } ], "comments": [ { "id": 1045420, "author_name": "Jaideep", "author_url": "", "post_date": "2020-10-10T16:04:01.320000", "content": "@redwankarimsony thanks for your detailed posts. However there are some inconsistencies i find in terms of labels that we have in train cv.
\nI expected that if pe present on image is 0 -ve exam for PE is always 1 but i find that for about 2.2k patients its 0 is it a inconsistency of labels ?
@Thanks @jaideepvalani for your nice observation. In my opinion, it if pe present then, that patient is an example of a healthy patient. It should not be considered as an inconsistency of labels.
\nBtw I am not 100% confident about my answer yet. I have to dig deeper…
", "votes": 0, "replies": [] } ] }, { "id": 1024326, "author_name": "Pinaki MIshra", "author_url": "", "post_date": "2020-09-23T18:59:31.807000", "content": "Insightful , Thanks for sharing @Md. Redwan Karim Sony
", "votes": 1, "replies": [ { "id": 1024588, "author_name": "Redwan Sony", "author_url": "", "post_date": "2020-09-24T02:10:15.470000", "content": "Thank you @pinakimishrads
", "votes": 1, "replies": [] } ] }, { "id": 1020644, "author_name": "YahiaMor", "author_url": "", "post_date": "2020-09-21T10:19:52.640000", "content": "Big Thanks , it helps a lot
", "votes": 1, "replies": [ { "id": 1020973, "author_name": "Redwan Sony", "author_url": "", "post_date": "2020-09-21T14:44:30.827000", "content": "You are welcome @benyaengineering
", "votes": 0, "replies": [] } ] }, { "id": 1015655, "author_name": "Aman Arora", "author_url": "", "post_date": "2020-09-18T10:31:08.880000", "content": "Thanks - this helps!
\nHow did you end up plotting the images please? :)
", "votes": 1, "replies": [ { "id": 1015682, "author_name": "Redwan Sony", "author_url": "", "post_date": "2020-09-18T11:01:15.087000", "content": "Thanks for your query. This is actually is a part of my notebook RSNA-STR Pulmonary Embolism [EDA + Domain Info].
", "votes": 1, "replies": [] } ] } ], "raw_markdown_by_id": { "1015580": "### What is Pulmonary Embolism (PE)?\nA pulmonary embolism (PE) is a blood clot in the blood vessels of the lungs that can be potentially life-threatening. PEs typically arise from blood clots in the leg veins (deep vein thromboses, or DVTs) that dislodge and become trapped in the pulmonary vasculature. The clinical presentation of PE can vary from asymptomatic to severe illness requiring intensive care (shock, cardiac arrest, etc).