Hi, this is Sagar Wagle, one of the musculoskeletal radiology fellows at Stanford University. A 58-year-old male with recurrent hemoptysis during open water triathlon events was diagnosed with swimming-induced pulmonary edema. While there are no specific imaging findings for swimming-induced pulmonary edema, let's look at some cases for pulmonary edema. Pulmonary edema can happen due to volume overload, for example in cases of heart failure or renal failure, or they can happen due to endothelial dysfunction of blood vessels in the lungs, which have a lot of causes, couple of them include drug toxicity or high-altitude pulmonary edema. In volume overload, the heart tends to get enlarged, compare the size of this heart with the size of the heart on the right. In volume overload, the asgus vein also gets enlarged. Asgus vein comes up in a paraspinal location, and in the group between the trachea and the right main stem bronchus, the asgus vein comes anteriorly to meet the superior vena cava. Compare the case on the left to case on the right. In the group between the trachea and the right main stem bronchus, we don't even see asgus vein here. There are bilateral pleural effusions, which is a finding for pulmonary edema. Look at the costophrenic angle on the normal case on the right and see how we don't see the costophrenic angle on the left, that's due to pleural effusion. The pulmonary airspace opacity has this perihilar appearance, which is called bat wing pattern of pulmonary edema. At times, it can be difficult to tell pulmonary edema apart from other causes such as pneumonia or aspiration, and one way to tell them apart is if you diuresis the patient, pulmonary edema can go away in imaging as quickly as 12 hours or a day. Pneumonia takes 8-12 weeks to go away on radiograph, and aspiration also usually takes longer than a day to go away. So if you diuresis the patient, the patient feels a lot better and the imaging abnormality goes away, that's one way to tell that it's pulmonary edema. In this case of pulmonary edema, we see that the heart is enlarged, we also see cephalization of blood vessel. Cephalization of blood vessel means that the blood vessels in the upper lungs are enlarged. vessel, this blood vessel, this blood vessel, and compare it to the blood vessel on the right image. See how skinny these blood vessels are. So cephalization on the left is a finding of volume overload. These horizontal lines are called KERDI-B lines and KERDI-B lines are also seen in pulmonary edema. The airspace opacity in this case has a bi-basilar distribution. In this case of pulmonary edema, we see bilateral pulmonary effusions, the cardiac silhouette is obscured, and there's this diffuse hazy bilateral pulmonary opacities. In this case of pulmonary edema on the left on the CT, the heart is enlarged, compare that to the heart on the right, and this thickened pulmonary receptor, this is what we see as KERDI-B lines in radiograph. That's all for pulmonary edema. Thank you for watching the video.

3rd Edition, CASE 33

3rd Edition

Lung

swimming-induced pulmonary edema

imaging findings

volume overload

differential diagnosis

Kerley-B lines