**Introduction/Hypothesis:**
For evaluation of hernias, patients may be asked to perform voluntary Valsalva during their CT scan, which has been reported to produce a transient narrowing of the aorta and iliac arteries (1, 2). This case highlights a rarely imaged phenomenon, captured as the patient involuntarily retched in the middle of a multiphase CT scan, with the venous phase images showing transient aortic collapse.

**Methods**
A 67 year old patient with metastatic colon adenocarcinoma underwent surveillance imaging that consisted of combined contrast-enhanced chest CT and multiphase abdomen and pelvis CT. On the chest CT images (acquired during venous phase of contrast injection), the descending aorta at the level of the diaphragmatic hiatus was severely compressed and had a flattened appearance with greater than 50% luminal narrowing (Fig 1).

**Results**
The aorta was normal caliber on the previous surveillance chest CT from just seven months prior.
Review of the same-day CT abdomen and pelvis images showed the aorta to be normal caliber on the delayed phase images. After discussion with the CT technologists, the radiologist learned that the patient had become nauseated during the scan and vomited, corresponding to the time of imaging findings. A 3D reformatted image of the aorta was created comparing venous and delayed phase acquisitions showing marked aortic luminal narrowing during the venous acquisition with resolution on delayed phase. The patient denied any symptoms of mesenteric or lower extremity ischemia.

**Conclusion**
While this involuntary Valsalva maneuver did not compromise the other imaging findings, it could lead to a diagnostic pitfall and false positive interpretation of aortic stenosis. In a similar case, unbeknownst to the reading radiologist, a patient vomited during their CT scan and had signs of increased abdominal pressure, including narrowing of the aorta, for which the radiologist suggested further workup for abdominal compartment syndrome (3). Knowledge of this phenomenon, review of multiphase CT images, and discussion with CT technologists can avoid false positive diagnoses of aortic stenosis. Thus, for patient comfort and better images, it is recommended to suspend imaging while a patient is actively vomiting.



**Introduction/Hypothesis:**
For evaluation of hernias, patients may be asked to perform voluntary Valsalva during their CT scan, which has been reported to produce a transient narrowing of the aorta and iliac arteries (1, 2). This case highlights a rarely imaged phenomenon, captured as the patient involuntarily retched in the middle of a multiphase CT scan, with the venous phase images showing transient aortic collapse.

**Methods**
A 67 year old patient with metastatic colon adenocarcinoma underwent surveillance imaging that consisted of combined contrast-enhanced chest CT and multiphase abdomen and pelvis CT. On the chest CT images (acquired during venous phase of contrast injection), the descending aorta at the level of the diaphragmatic hiatus was severely compressed and had a flattened appearance with greater than 50% luminal narrowing (**Fig 1**).

**Results**
The aorta was normal caliber on the previous surveillance chest CT from just seven months prior.
Review of the same-day CT abdomen and pelvis images showed the aorta to be normal caliber on the delayed phase images. After discussion with the CT technologists, the radiologist learned that the patient had become nauseated during the scan and vomited, corresponding to the time of imaging findings. A 3D reformatted image of the aorta was created comparing venous and delayed phase acquisitions showing marked aortic luminal narrowing during the venous acquisition with resolution on delayed phase. The patient denied any symptoms of mesenteric or lower extremity ischemia.

**Conclusion**
While this involuntary Valsalva maneuver did not compromise the other imaging findings, it could lead to a diagnostic pitfall and false positive interpretation of aortic stenosis. In a similar case, unbeknownst to the reading radiologist, a patient vomited during their CT scan and had signs of increased abdominal pressure, including narrowing of the aorta, for which the radiologist suggested further workup for abdominal compartment syndrome (3). Knowledge of this phenomenon, review of multiphase CT images, and discussion with CT technologists can avoid false positive diagnoses of aortic stenosis. Thus, for patient comfort and better images, it is recommended to suspend imaging while a patient is actively vomiting.



Transient Aortic Collapse Captured on Multiphase CT During Involuntary Retching

This course will explore basic and cutting-edge imaging techniques to improve patient care and hone individual skills in performance and interpretation of echocardiography, nuclear cardiology, cardiac computed tomography, and cardiovascular magnetic resonance imaging. Days will reinforce how cardiovascular imaging may improve comprehension in ischemic heart disease, structural heart disease, cardiomyopathies, and heart failure. Experts will utilize novel techniques to reinforce key topics including taped interventional cases and a strong emphasis on case presentations.