IMAGES THAT TEACH Utility of multimodality imaging in suspected prosthetic valve endocarditis Stephen J. Horgan, MD, PhD,a Alfonso H. Waller, MD,b Vikas Veeranna, MD,c James Kirshenbaum, MD,a Sharmila Dorbala, MBBS, MPH,a and Marcelo F. Di Carli, MDa a
Department of Radiology, Non-invasive Cardiovascular Imaging, Brigham and Women’s Hospital, Boston, MA b Department of Medicine (Division of Cardiology) and Radiology, Rutgers New Jersey Medical School, Newark, NJ c Division of Cardiology, Department of Medicine, Berkshire Medical Center, Pittsfield, MA Received Oct 30, 2015; accepted Oct 30, 2015 doi:10.1007/s12350-015-0340-z
INTRODUCTION Prosthetic valve endocarditis (PVE) can be a challenging diagnosis. This case demonstrates the utility of multimodality imaging in suspected PVE. CASE An 85-year-old man with a history of three aortic valve replacements and pelvic surgery for bladder cancer presented with episodic fevers over a 2-week period. Urine and blood cultures grew pan-sensitive Escherichia coli. His evaluation confirmed three minor modified Duke criteria, indicating possible endocarditis. Transthoracic echocardiography did not reveal any abnormality of the bioprosthetic aortic valve. This patient was discharged on antibiotics but re-presented 3 days later with fevers. Transesophageal echocardiography demonstrated thickening of the aortic root without definite vegetations (Figure 1). Due to ongoing fevers, the suspicion for PVE was high, and an 18F-fluorodeoxyglucose (FDG) positron emission tomography
Reprint requests: Stephen J. Horgan, MD, PhD, Department of Radiology, Non-invasive Cardiovascular Imaging, Brigham and Women’s Hospital, 75 Francis Street, Boston, MA, 02115; [email protected] J Nucl Cardiol 1071-3581/$34.00 Copyright Ó 2015 American Society of Nuclear Cardiology.
(FDG-PET)/computed tomography (CT) scan was performed. That scan revealed an intensely FDG-avid periaortic fluid collection consistent with an abscess (Figure 2) confirming PVE. The peri-aortic fluid collection was further characterized on a contrast-enhanced cardiac CT, which uncovered a pseudoaneurysm adjacent to the abscess and findings suggestive of a mycotic aneurysm (Figures 3 and 4). Due to co-morbidities, advanced age, and high surgical risk of a fourth aortic valve surgery, this patient elected to be treated conservatively. This case illustrates the complementary use of FDG-PET/CT and contrast-enhanced cardiac CT, in individuals with possible PVE, when echocardiography is inconclusive. It endorses the utility of the proposed algorithm described by Saby et al1 for evaluating patients with suspected PVE using FDG-PET/CT. Cardiac CT, a class IIa recommendation for suspected PVE in the 2014 ACC/AHA Valvular Heart Disease guidelines,2 uncovered a pseudoaneuysm. Periannular extensions complicate PVE in approximately 50% with PVE on echocardiography; FDG-PET/CT or cardiac CT
Horgan et al Utility of multimodality imaging in suspected prosthetic valve endocarditis
Journal of Nuclear CardiologyÒ
Figure 1. Transesophageal echocardiogram. On readmission the patient underwent a transesophageal echocardiograph (TEE), which demonstrated thickening of the aortic root (Panels A and C show long and short axis views respectively) similar to the intra-operative TEE performed five years earlier (Panel B—long axis view). No vegetations were identified.
Journal of Nuclear CardiologyÒ
Horgan et al Utility of multimodality imaging in suspected prosthetic valve endocarditis
Figure 2. 18F-fluorodeoxyglucose positron emission tomography. 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) was performed as a result of ongoing fevers and a high index of suspicion for prosthetic valve endocarditis. 11.9 mCi of FDG was administered following a high fat/low carbohydrate diet for a period of 24 hours. Approximately 90 minutes following FDG administration, PET was performed from the base of the skull through the mid-thighs. Non-contrast helical CT imaging was performed over the same range without breath-hold for attenuation correction of PET images and anatomic correlation. The FDG-PET/CT revealed an intensely FDG-avid periaortic fluid collection with a standardized uptake value (SUV) max of 14.5. Multiple mildly FDG avid mediastinal lymph nodes were also present. Abdominal findings were consistent with a urinary diversion ileostomy. The intensely FDG-avid periaortic fluid collection is consistent with infection in the context of the clinical setting and cardiac CT findings.
Horgan et al Utility of multimodality imaging in suspected prosthetic valve endocarditis
Journal of Nuclear CardiologyÒ
Figure 3. Gated cardiac CT with contrast. Breath-held gated cardiac computed tomography (CT) with 75 cc of contrast was undertaken. Post-processing using multiplanar reformation (Vitrea Software; Vital Images, Minnetonka, Minnesota, USA) is shown in the figure. The panels with blue, green and red borders correspond to the imaging planes indicated by the crosshairs in each panel. A 3.3 9 1.2 cm peripheral enhancing fluid collection is seen between the ascending aorta and pulmonary artery, which correlates with the region of increased FDG uptake on PET/CT imaging. A 1 cm contrast extravasation was also noted at 6 o’clock in the region of the sinotubular junction (red plane, en face), which is contiguous with the ascending aortic lumen and has a narrow neck, likely representing a pseudoaneurysm. There is aneurysmal dilatation of the distal ascending and proximal descending aorta. The pseudoaneurysm is well illustrated on the 3D rendered image (bottom left panel). The pseudoaneurysm adjacent to the abscess raised concern for a mycotic aneurysm.
Journal of Nuclear CardiologyÒ
Horgan et al Utility of multimodality imaging in suspected prosthetic valve endocarditis
Figure 4. FDG-PET and CT fusion images. The non-contrast free-breathing helical computed tomography (CT) (Panel A) fused with the FDG-PET image demonstrates an intensely FDG-avid peri-aortic fluid collection (orange arrow). The CT angiogram (Panel B) demonstrates the pseudoaneurysm (white arrow). Fused FDG-PET and the contrast-enhanced CT (Panel C) demonstrates the adjacent proximity of the pseudoaneurysm (white arrow) and the FDG-avid fluid collection (orange arrow), consistent with a mycotic pseudoaneurysm. The value of the contrast enhanced gated study is clearly seen as the pseudoaneurysm is identified, there is superior spatial resolution and there are no motion artifacts. Fusion imaging across modalities permits very accurate anatomic and metabolic pathological localization.
may be helpful in these cases.3 However, currently, neither FDG-PET/CT nor CT is appropriate as ‘‘firstline’’ imaging in individuals with suspected PVE. Disclosures None.
References 1. Saby L, Laas O, Habib G, Cammilleri S, Mancini J, Tessonnier L, et al. Positron emission tomography/computed tomography for diagnosis of prosthetic valve endocarditis: Increased valvular 18F-
fluorodeoxyglucose uptake as a novel major criterion. J Am Coll Cardiol 2013;61:2374-82. 2. Nishimura RA, Otto CM, Bonow RO, Carabello BA, Erwin JP 3rd, Guyton RA, et al. 2014 AHA/ACC Guideline for the Management of Patients with Valvular Heart Disease: A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Circulation 2014;129:e521-643. 3. Hill EE, Herijgers P, Claus P, Vanderschueren S, Peetermans WE, Herregods MC. Abscess in infective endocarditis: The value of transesophageal echocardiography and outcome: A 5-year study. Am Heart J 2007;154:923-8.
Department of Radiology, Non-invasive Cardiovascular Imaging, Brigham and Women’s Hospital, Boston, MA b Department of Medicine (Division of Cardiology) and Radiology, Rutgers New Jersey Medical School, Newark, NJ c Division of Cardiology, Department of Medicine, Berkshire Medical Center, Pittsfield, MA Received Oct 30, 2015; accepted Oct 30, 2015 doi:10.1007/s12350-015-0340-z
INTRODUCTION Prosthetic valve endocarditis (PVE) can be a challenging diagnosis. This case demonstrates the utility of multimodality imaging in suspected PVE. CASE An 85-year-old man with a history of three aortic valve replacements and pelvic surgery for bladder cancer presented with episodic fevers over a 2-week period. Urine and blood cultures grew pan-sensitive Escherichia coli. His evaluation confirmed three minor modified Duke criteria, indicating possible endocarditis. Transthoracic echocardiography did not reveal any abnormality of the bioprosthetic aortic valve. This patient was discharged on antibiotics but re-presented 3 days later with fevers. Transesophageal echocardiography demonstrated thickening of the aortic root without definite vegetations (Figure 1). Due to ongoing fevers, the suspicion for PVE was high, and an 18F-fluorodeoxyglucose (FDG) positron emission tomography
Reprint requests: Stephen J. Horgan, MD, PhD, Department of Radiology, Non-invasive Cardiovascular Imaging, Brigham and Women’s Hospital, 75 Francis Street, Boston, MA, 02115; [email protected] J Nucl Cardiol 1071-3581/$34.00 Copyright Ó 2015 American Society of Nuclear Cardiology.
(FDG-PET)/computed tomography (CT) scan was performed. That scan revealed an intensely FDG-avid periaortic fluid collection consistent with an abscess (Figure 2) confirming PVE. The peri-aortic fluid collection was further characterized on a contrast-enhanced cardiac CT, which uncovered a pseudoaneurysm adjacent to the abscess and findings suggestive of a mycotic aneurysm (Figures 3 and 4). Due to co-morbidities, advanced age, and high surgical risk of a fourth aortic valve surgery, this patient elected to be treated conservatively. This case illustrates the complementary use of FDG-PET/CT and contrast-enhanced cardiac CT, in individuals with possible PVE, when echocardiography is inconclusive. It endorses the utility of the proposed algorithm described by Saby et al1 for evaluating patients with suspected PVE using FDG-PET/CT. Cardiac CT, a class IIa recommendation for suspected PVE in the 2014 ACC/AHA Valvular Heart Disease guidelines,2 uncovered a pseudoaneuysm. Periannular extensions complicate PVE in approximately 50% with PVE on echocardiography; FDG-PET/CT or cardiac CT
Horgan et al Utility of multimodality imaging in suspected prosthetic valve endocarditis
Journal of Nuclear CardiologyÒ
Figure 1. Transesophageal echocardiogram. On readmission the patient underwent a transesophageal echocardiograph (TEE), which demonstrated thickening of the aortic root (Panels A and C show long and short axis views respectively) similar to the intra-operative TEE performed five years earlier (Panel B—long axis view). No vegetations were identified.
Journal of Nuclear CardiologyÒ
Horgan et al Utility of multimodality imaging in suspected prosthetic valve endocarditis
Figure 2. 18F-fluorodeoxyglucose positron emission tomography. 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) was performed as a result of ongoing fevers and a high index of suspicion for prosthetic valve endocarditis. 11.9 mCi of FDG was administered following a high fat/low carbohydrate diet for a period of 24 hours. Approximately 90 minutes following FDG administration, PET was performed from the base of the skull through the mid-thighs. Non-contrast helical CT imaging was performed over the same range without breath-hold for attenuation correction of PET images and anatomic correlation. The FDG-PET/CT revealed an intensely FDG-avid periaortic fluid collection with a standardized uptake value (SUV) max of 14.5. Multiple mildly FDG avid mediastinal lymph nodes were also present. Abdominal findings were consistent with a urinary diversion ileostomy. The intensely FDG-avid periaortic fluid collection is consistent with infection in the context of the clinical setting and cardiac CT findings.
Horgan et al Utility of multimodality imaging in suspected prosthetic valve endocarditis
Journal of Nuclear CardiologyÒ
Figure 3. Gated cardiac CT with contrast. Breath-held gated cardiac computed tomography (CT) with 75 cc of contrast was undertaken. Post-processing using multiplanar reformation (Vitrea Software; Vital Images, Minnetonka, Minnesota, USA) is shown in the figure. The panels with blue, green and red borders correspond to the imaging planes indicated by the crosshairs in each panel. A 3.3 9 1.2 cm peripheral enhancing fluid collection is seen between the ascending aorta and pulmonary artery, which correlates with the region of increased FDG uptake on PET/CT imaging. A 1 cm contrast extravasation was also noted at 6 o’clock in the region of the sinotubular junction (red plane, en face), which is contiguous with the ascending aortic lumen and has a narrow neck, likely representing a pseudoaneurysm. There is aneurysmal dilatation of the distal ascending and proximal descending aorta. The pseudoaneurysm is well illustrated on the 3D rendered image (bottom left panel). The pseudoaneurysm adjacent to the abscess raised concern for a mycotic aneurysm.
Journal of Nuclear CardiologyÒ
Horgan et al Utility of multimodality imaging in suspected prosthetic valve endocarditis
Figure 4. FDG-PET and CT fusion images. The non-contrast free-breathing helical computed tomography (CT) (Panel A) fused with the FDG-PET image demonstrates an intensely FDG-avid peri-aortic fluid collection (orange arrow). The CT angiogram (Panel B) demonstrates the pseudoaneurysm (white arrow). Fused FDG-PET and the contrast-enhanced CT (Panel C) demonstrates the adjacent proximity of the pseudoaneurysm (white arrow) and the FDG-avid fluid collection (orange arrow), consistent with a mycotic pseudoaneurysm. The value of the contrast enhanced gated study is clearly seen as the pseudoaneurysm is identified, there is superior spatial resolution and there are no motion artifacts. Fusion imaging across modalities permits very accurate anatomic and metabolic pathological localization.
may be helpful in these cases.3 However, currently, neither FDG-PET/CT nor CT is appropriate as ‘‘firstline’’ imaging in individuals with suspected PVE. Disclosures None.
References 1. Saby L, Laas O, Habib G, Cammilleri S, Mancini J, Tessonnier L, et al. Positron emission tomography/computed tomography for diagnosis of prosthetic valve endocarditis: Increased valvular 18F-
fluorodeoxyglucose uptake as a novel major criterion. J Am Coll Cardiol 2013;61:2374-82. 2. Nishimura RA, Otto CM, Bonow RO, Carabello BA, Erwin JP 3rd, Guyton RA, et al. 2014 AHA/ACC Guideline for the Management of Patients with Valvular Heart Disease: A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Circulation 2014;129:e521-643. 3. Hill EE, Herijgers P, Claus P, Vanderschueren S, Peetermans WE, Herregods MC. Abscess in infective endocarditis: The value of transesophageal echocardiography and outcome: A 5-year study. Am Heart J 2007;154:923-8.
