- Email: [email protected]
Imaging findings in cardiac masses (Part i ): Study protocol and benign tumors
Radiología. 2015;57(6):480---488
www.elsevier.es/rx
RADIOLOGY THROUGH IMAGES
Imaging findings in cardiac masses (Part i): Study protocol and benign tumors夽 C. Díaz Angulo, C. Méndez Díaz, E. Rodríguez García, R. Soler Fernández∗ , A. Rois Siso, M. Marini Díaz na (CHUAC), A Coru˜ na, Spain Servicio de Radiodiagnóstico, Complejo Hospitalario Universitario A Coru˜ Received 12 November 2014; accepted 9 July 2015
KEYWORDS Cardiac masses; Myxoma; Fibroelastoma; Lipoma; Rhabdomyoma
PALABRAS CLAVE Masas cardíacas; Mixoma; Fibroelastoma; Lipoma; Rabdomioma
Abstract Cardiac masses represent a diagnostic challenge because decisions about treatment are based on imaging techniques. Echocardiography, magnetic resonance (MR) and computed tomography (CT) are fundamental for the detection, characterization, and staging of cardiac masses as well as for planning their treatment. Most primary cardiac tumors are benign; myxomas, papillary fibroelastomas, and lipomas are the most common. The location of the tumors and its characteristics on CT and MR orient the etiologic diagnosis in most cases. This article describes the protocols for CT and MR studies of cardiac masses as well as the morphologic findings, predominant locations, and most useful characteristics for characterizing benign cardiac masses and establishing the differential diagnosis with malignant cardiac tumors and non-neoplastic pseudotumors. © 2014 SERAM. Published by Elsevier España, S.L.U. All rights reserved.
Hallazgos de imagen de las masas cardíacas (parte i): protocolo de estudio y tumores benignos Resumen Las masas cardíacas son un reto diagnóstico porque las decisiones terapéuticas se basan en los hallazgos de las técnicas de imagen. La ecocardiografía, la resonancia magnética (RM) y la tomografía computarizada (TC) son fundamentales para la detección, caracterización, estadificación y planificación del tratamiento. La mayoría de los tumores primarios son benignos; los más frecuentes son el mixoma, el fibroelastoma papilar y el lipoma. La localización del tumor y sus características en la TC y la RM orientan el diagnóstico etiológico en la mayor parte de los casos.
夽
Please cite this article as: Díaz Angulo C, Méndez Díaz C, Rodríguez García E, Soler Fernández R, Rois Siso A, Marini Díaz M. Hallazgos de imagen de las masas cardíacas (parte I): protocolo de estudio y tumores benignos. Radiología. 2015;57:480---488. ∗ Corresponding author. E-mail address: [email protected] (R. Soler Fernández). 2173-5107/© 2014 SERAM. Published by Elsevier España, S.L.U. All rights reserved.
Imaging findings in cardiac masses: Part i
481
Se describen los protocolos de estudio de TC y RM de las masas cardíacas, así como los hallazgos morfológicos, las localizaciones preferentes y las características más útiles para caracterizar las masas cardíacas benignas y establecer el diagnóstico diferencial con los tumores cardíacos malignos y las lesiones pseudotumorales no neoplásicas. © 2014 SERAM. Publicado por Elsevier España, S.L.U. Todos los derechos reservados.
Introduction Primary heart tumors are uncommon (0.002---3%) and most are benign.1,2 Clinical manifestations are usually unspecific; they can simulate other cardiovascular diseases and can be potentially deadly due to their hemodynamic repercussion. Most of them are initially detected through ultrasound, the modality of choice due to its availability and innocuousness. However, magnetic resonance imaging (MRI) and computed tomography (CT) provide additional information for diagnosis, therapeutic decision and surgical planning.3,4 Image findings in cardiac masses are presented in two parts. In this first part, the CT and MRI study protocols are described and the findings in benign cardiac masses, and malignant tumors and pseudotumoral lesions are described in the second part.
Protocols of image acquisition Protocol with computed tomography General overview The CT is the complementary image modality in the study of cardiac masses in unstable patients who do not tolerate prolonged decubitus or cannot do apneas who have rhythm disorders that prevent electrocardiographic synchronization, and in patients with claustrophobia, since it is a quick technique that can be performed without cardiac synchronism.4 Also it is the modality of choice to detect calcifications, establish the relation between the masses and the coronary arteries and assess the primary tumor and its spread when suspicion of metastasis.5 Occasionally, cardiac masses are an incidental finding in examinations performed due to symptoms of unspecific thoracic pathology or during the staging of malignant neoplasms in which the study protocol is that of the suspected disease. Study acquisition The protocol includes the acquisition of a topogram on which the examination is planned from the cervico-thoracic union up to the diaphragm which allows assessing the vascular structures, the pulmonary parenchyma and the chest cavity; it is useful for pre-surgery planning and to analyze tumor spread to adjacent structures.4 A series is acquired without intravenous (IV) contrast followed by a second series at 60 s after the IV administration of 100---120 ml of iodized contrast
through an automatic injector, followed by a bolus of 40 ml of saline solution with a flow of 3---4 ml/s. The acquisition parameters depend on the characteristics of the machine. In a 64-detector machine, adequate images are obtained in patients weighing over 80 kg, with a collimation of 64 × 0.625, a rotation time of 500 ms, 300 mA and 80 or 100 kV. The studies can be performed with or without electrocardiographic synchronism.5
Magnetic resonance protocol General overview MRI is a complementary modality to ultrasound in the study of cardiac masses. It is an objective, reproducible, innocuous modality, with a high temporal and contrast resolution which allows us to use wide fields of vision to analyze the heart and the remaining thoracic structures.3,5 MRI examinations will be performed preferably in 1.5 or 3.0 T machines, with surface phase-coupled antennas and electrocardiographic synchronization. Study acquisition The usual study protocol consists of (Table 1): 1. Multiplanar locator with electrocardiographic synchronization and in respiratory apnea in order to know the position of the heart in the thorax. 2. Functional sequences, cine-MRI, of ‘‘white blood’’ based on gradient echo (GE) (fast imaging with steady-state precession, SSFP). They are sequences with mixed T2 and T1 weighting (T2/T1), with great differentiation in the signal intensity of the blood and the myocardium which facilitates the detection of intracavitary lesions. In addition, its high temporal resolution allows us to obtain cine-MR images with electrocardiographic synchronization in order to analyze the functional repercussions of the masses and quantify the ventricular function. 3. Morphological and tissue characterization sequences, of ‘‘black blood’’ based on turbo or fast spin echo (TSE), usually with double or triple inversion pulse to improve the intracavitary flow cancelation. T1- and T2weighted sequences will be obtained and optionally, fat-suppression sequences. 4. First-step perfusion during IV administration of gadolinium chelates. Ultrafast T1-weighted sequences in GE with high temporal resolution to analyze the arrival of the contrast bolus, and assess myocardial perfusion.6
482 Table 1
C. Díaz Angulo et al. Magnetic resonance (MR) protocol for the study of cardiac masses.
Sequence
Acquisition
Views
Other
Localizer
Multiplane
Transversal Coronal Sagittal Transversal 3 chambers 2 chambers 4 chambers Short axis Depending on the location of the mass Transversal or 4 chambers or short axis Depending on the location of the mass Transversal or 4 chambers or short axis Depending on the location of the mass 4 chambers or short axis
In mild breathing apnea
Cine-RM SSFP
TSE-T1
TSE-T2
Multicut-multiphase 1 multiphase cut 1 multiphase cut 1 multiphase cut Multicut-multiphase 2D multicut
2D multicut
First-step perfusion
2D or 3D multicut
Delayed enhancement
TEG-T1 with inversion pulse or 2D or 3D multicut PSIR
3 chambers 2 chambers 4 chambers Short axis
In In In In In In
mild mild mild mild mild mild
breathing breathing breathing breathing breathing breathing
apnea apnea apnea apnea apnea apnea
Optional, suppression of fat In mild breathing apnea Optional, suppression of fat, Gadolinium contrast. Dose: 0.05---0.1 mmol/kg Flow of 3---7 ml/s. Saline solution (30 ml in adults and twice as much contrast volume in children) Gadolinium contrast. Dose: 0.1---0.2 mmol/kg Delay time: 10 min. Inversion time: 150---300 ms. Diastolic synchronization.
PSIR: phase sensitive inversion-recovery.
5. Late enhancement sequences (black myocardium). T1weighted sequences with a 180◦ inversion pulse applied in a given time (inversion time) to cancel the signal of the healthy myocardium. They can be turbo or fast gradient echo (TGE) or phase-sensitive inversion-recovery (PSIR) sequences. The inversion time to cancel the myocardium ranges from 150 to 300 ms. However, a 500---550 ms inversion time in 1.5 T machines and 850---900 ms in 3 T machines is useful to differentiate tumor thrombi.6 The late enhancement sequences allow us to outline the tumor more clearly and they are essential to detect and characterize the thrombi.7 Planes/views of acquisition Cine-MR images are usually obtained on the transversal plane toward the thorax and on intrinsic cardiac planes on the long horizontal axis (three cameras), the long vertical axis (two cameras), four cameras and short axis. TSE-T1 and TSE-T2 sequences (with or without fat suppression) and the first-step perfusion sequences will be obtained on the plane from which the lesion is better observed.
It must be remembered that MRI is a complementary modality to ultrasound in the study of cardiac masses.
Benign tumors Primary tumors of the heart are usually benign. They can have an intracavitary location and be attached to the endocardium or the myocardium through a broad implantation base or a pedicle, or they can be intra-myocardial. The myxoma, the papillary fibroelastoma and the lipoma are the most frequent ones.
Myxoma The myxoma is the most frequent primary heart tumor (25---50%).1 The vast majority are sporadic and they affect women of between 40 and 70 years of age. They are usually asymptomatic or they occur with heart failure, embolism, syncope or sudden death, mainly when they prolapse through the mitral valve8 ; 7% is part of the Carney complex---autosomal dominant syndrome characterized by myxoma, hyperpigmentation and extracardiac tumors.9 They are more frequent in the left atrium (LA) (75%), they are usually attached by a pedicle to the interatrial septum, close to the fossa ovalis, and they can prolapse through the atrial-ventricular valves (Fig. 1). Other locations are the right atrium (RA) (Fig. 2), the right ventricle (RV), the left ventricle (LV), the aortic valve and the inferior vena cava.1 Myxomas kick in as intracavitary oval, heterogeneous masses of variable sizes (1---15 cm), due to the presence
Imaging findings in cardiac masses: Part i
483
We need to remember that myxomas are the most common heart tumors, they are usually located in the LA and they are attached to the interatrial septum by a pedicle. Its MRI signal is variable and its enhancement is heterogeneous.
The papillary fibroelastoma
Figure 1 Myxoma in a 53-year-old woman with dyspnea and weight loss. The CT with IV contrast shows a polylobulated mass (asterisk) in the left atrium attached to the interatrial septum with prolapse toward the left ventricle toward the mitral ring.
Papillary fibroelastomas account for 10% of primary heart tumors.14,15 They are often asymptomatic and do not usually cause valvular dysfunction14,16 ; 90% of them are located on the endocardial surface of the aortic (29%) or mitral (25%) valves.9 They are small (<1 cm), well-outlined lesions, showing soft-tissue attenuation in the CT and hypointense or intermediate signals in the T1-weighted sequences, intermediate signals in T2-weighted sequences and hypointense in cineMR SSFP sequences. They are not usually enhanced after the administration of contrast (Fig. 5).14,16 Differential diagnosis is established with the endocarditis warts that are usually associated with valvular destruction and insufficiency and intracavitary thrombi.
Lipoma of necrosis, calcifications, bleeding, cystic formations or fibrosis (Figs. 3 and 4).10 In the CT, most of them are of low attenuation (Fig. 1). In the MRI they show one iso/hypointense or hyperintense signal with respect to the myocardium in T1-weighted sequences and hyperintense in the T2-weighted sequences (Fig. 3). Enhancement in CT and MRI after the administration of contrast is usually scarce and heterogeneous.2,11 Differential diagnosis must be performed with the malignant intracavitary thrombi and neoplasms. The absence of enhancement with IV contrast is the most useful sign to differentiate an intracavitary thrombus from a myxoma.11---13
Lipomas (8% of the heart tumors)17 are more frequent in obese adults but they can be detected at any age. They are generally solitary, although multiple cases have been described associated to tuberous sclerosis and congenital heart conditions.18 They do not cause symptoms or show rhythm disorders or with clinical manifestations of hemodynamic affectation due to obstruction or compression of adjacent structures. The most frequent location is endocavitary in the RA and the LV; other locations are the cardiac valves, intramyocardial (25%) and pericardial (25%).17,19 In the CT and the MRI, endocavitary lipomas occur as small sessile homogeneous masses attached to the
Figure 2 Myxoma in a 63-year-old asymptomatic male. The cine-MR SSFP images in the four-chamber view, in systole (A) show one well-outlined and polylobulated intracavitary mass (arrows) in the right atrium with one pedicle anchored to the distal part of the interatrial septum that prolapses in the diastole (B) (arrow heads) through the triscuspid valve.
484
C. Díaz Angulo et al.
Figure 3 Myxoma in a 53-year-old woman with dyspnea of one year duration. (A) In the T1-TSE-weighted sequence in the transversal view one endocavitary mass can be identified in the left atrium well-outlined and of intermediate signal (asterisk). (B) In the first-step perfusion sequence after the administration of gadolinium contrast the mass is hypointense in early stages. Note the pedicle anchored to the interatrial septum (arrow head).
interatrial septum or the atrial roof; and the intramyocardial ones, as oval well-outlined, homogeneous masses. In CT without contrast, they are of low attenuation (−50 UH) and they do not enhance after the administration of contrast. In the MRI, they are hyperintense in T1-TSE weighted sequences and hypointense in specific fat suppression sequences, and they usually shoe one hypointense capsule (Fig. 6).2,9,19 Differential diagnosis in children must be performed with teratoma and in adults with lipomatous hypertrophy of the interatrial septum and with liposarcoma. Unlike intracavitary lipomas, lipomatous hypertrophy infiltrates the interatrial septum and respects the fossa ovalis in a peculiar way.20 Liposarcoma is a lipomatous tumor with attenuation and intensity of heterogeneous signal that is enhanced after
the administration of contrast and capable of infiltrating adjacent structures.20 Surgical resection will depend on its size, location and functional repercussion; CT is essential to establish the relation between the lipoma and the coronary arteries as well as to plan surgery.21---23
We need to remember that attenuation in the CT and signal characteristics in the MRI of lipomas are enough to establish diagnosis.
Rhabdomyoma Rhabdomyoma is the most frequent heart tumor in children. They are often diagnosed in the neonatal period, in isolation or associated with tuberous sclerosis2,18,24 and most relapse spontaneously.23 They are usually asymptomatic, but they can cause obstruction of the ventricular outflow tract or arrhythmias.18,25 Rhabdomyomas are usually multiple (90%) and intramyocardial. They are isointense in the MRI in T1-weighted sequences and slightly hyperintense in T2weighted sequences. With IV contrast, enhancement is minimal or absent (Fig. 7).2,18,26
We need to remember that rhabdomyomas are the most common tumors in children; they are often multiple and intramyocardial and most relapse spontaneously.
Figure 4 Myxoma in a 69-year-old woman with dyspnea. The TC with IV contrast shows one partially calcified mass in the left atrium (arrow) attached to the interatrial septum by a wide implantation base.
Fibroma The fibroma is the second most frequent benign heart tumor in children.25 It can be asymptomatic or occur with
Imaging findings in cardiac masses: Part i
485
Figure 5 Papillary fibroelastoma. (A) The TC with IV contrast identifies one small node of soft tissue attenuation (arrow heads) attached to the atrial surface of the tricuspid valve. (B) In the cine-MR images the node shows a hypointense signal (arrow).
arrhythmia or sudden death. There is increased prevalence in the Gorlin and Gardner syndromes.9,18 Fibromas are usually single, well-outlined tumors, often located in the interventricular septum and the lateral wall of the LV (Fig. 8).18 They show heterogeneous, hypointense
or hyperintense signals in T1- and T2-weighted sequences. In first-step perfusion they show hypointense and hyperintense signals in late enhancement sequences, occasionally with central hypointensity. Calcifications are frequent (25%) and easier to detect in CT studies without contrast.9,18
Figure 6 Lipoma in a 67-year-old woman with incidental finding of one mass in an ultrasound. The T1-TSE-weighted sequences in the transversal (A) and sagittal (B) views show one intracavitary mass (arrows) originating in the posterior wall if the left atrium of homogeneous and hyperintense signal. In the T1-TSE-weighted sequences with selective suppression of fat (C) the mass is hypointense (arrow head).
486
C. Díaz Angulo et al.
Figure 7 Rhabdomyoma in a newly born female baby with arryhtmia. The transversal TSE-T1 (A) and TSE-T1 (B) images show one large mass in the right ventricle (asterisk) of hyperintense, heterogeneous signal. The mass is similar to the myocardium (arrows) in the cine-MR SSFP sequences (C).
Figure 8 Fibroma in an asymptomatic 8-year-old girl. Cine-MR in the short axis view (A) and T2-STIR sequences (B). Myocardial mass in the anterior part of the interventricular septum---homogeneous and isointense (arrow) in the cine-MR sequence and hyperintense and heterogeneous (arrow heads) in T2-STIR sequences.
Imaging findings in cardiac masses: Part i Table 2
487
More characteristic findings of benign cardiac tumors.
Tumor
Localization
CT attenuation
T1 SI
T2 SI
Enhancement
Myxoma
LA Pedicle in interatrial septum RA LV
Heterogeneous (necrosis, calcifications, bleeding) Fat
Similar to myocardium Hypointense Hyperintense Hyperintense Hypointense With selective suppression of fat
Hyperintense
Minimal Heterogeneous
Absent
Aortic valve Mitral valve Pedicle Myocardium
Similar to myocardium
Similar to myocardium Hypointense Similar to myocardium Heterogeneous Hypointense Hyperintense
Hyperintense Hypointense with selective suppression of fat Similar to myocardium Hypointense Minimal hypersignal Heterogeneous Hypointense Hyperintense
Lipoma
Fibroelastoma
Rhabdomyoma Fibroma
Intraventricular septum LV
Paraganglioma
Pericardium
Similar to myocardium Similar to myocardium Calcifications (25%) Heterogeneous Central necrosis
Similar to myocardium Hypointense Hyperintense
Hyperintense
Absent
Minimal absent Minimal moderate
Intense periferal
RA: right atrium; LA: left atrium; SI: signal intensity; CT: computed tomography; LV: left ventricle.
Paraganglioma Paragangliomas are uncommon neuroendocrine neoplasms more common between 10 and 60 years of age.9 Its usual location is the pericardium. They can be isolated or associated with paragangliomas in other locations (20%) or with bone metastasis (5%).9,27 In the CT, they appear as heterogeneous masses with central necrosis and intense enhancement of peripheral predominance. They rarely calcify. In the MRI, they are usually iso-/hypointense in T1-weighted sequences and hyperintense in T2-weighted sequences. Occasionally, they are hyperintense in T1 due to intratumor bleeding. With IV contrast they usually show intense enhancement of peripheral predominance.9,28---30
Conclusion The location of being heart tumors guides the etiologic diagnosis in most cases. The densiometric characteristics of the CT and signal characteristics of the MRI help us establish the diagnosis and distinguish them from malignant neoplasms and pseudo-tumors (Table 2).
Ethical responsibilities Protection of people and animals. The authors declare that no experiments with human beings or animals have been performed while conducting this investigation.
Data confidentiality. The authors declare that in this article there are no data from patients. Right to privacy and informed consent. The authors declare that in this article there are no data from patients.
Authors 1. 2. 3. 4. 5. 6. 7. 8. 9.
Manager of the integrity of the study: CDA, RSF. Study idea: CMD, RSF, MMD. Study design: CMD, RSF, MMD. Data mining: CDA, ARS, CMD, ERG, RSF, MMD. Data analysis and interpretation: CMD, ERG, RSF. Statistical analysis: N/A. Reference search: CDA, ARS, RSF. Writing: CDA, ARS, CMD, ERG, RSF. Critical review of the manuscript with intellectually relevant remarks: CMD, ERG, RSF, MMD. 10. Approval of final version: CDA, ARS, CMD, ERG, RSF, MMD.
Conflict of interests The authors declare no conflict of interests.
References 1. Motwani M, Kidambi A, Herzog BA, Uddin A, Greenwood JP, Plein S. MR imaging of cardiac tumors and masses: a review of methods and clinical applications. Radiology. 2013;268:26---43.
488 2. Sparrow PJ, Kurian JB, Jones TR, Sivananthan MU. MR imaging of cardiac tumors. Radiographics. 2005;25:1255---76. 3. Hendel RC, Patel MR, Kramer CM, Poon M, Hendel RC, Carr JC, et al. ACCF/ACR/SCCT/SCMR/ASNC/NASCI/SCAI/SIR 2006 appropriateness criteria for cardiac computed tomography and cardiac magnetic resonance imaging: a report of the American College of Cardiology Foundation Quality Strategic Directions Committee Appropriateness Criteria Working Group, American College of Radiology, Society of Cardiovascular Computed Tomography, Society for Cardiovascular Magnetic Resonance, American Society of Nuclear Cardiology, North American Society for Cardiac Imaging, Society for Cardiovascular Angiography and Interventions, and Society of Interventional Radiology. J Am Coll Cardiol. 2006;48:1475---97. 4. Taylor AJ, Cerqueira M, Hodgson JM, Mark D, Min J, O’Gara P, et al. ACCF/SCCT/ACR/AHA/ASE/ASNC/NASCI/SCAI/SCMR 2010 appropriate use criteria for cardiac computed tomography. A report of the American College of Cardiology Foundation Appropriate Use Criteria Task Force, the Society of Cardiovascular Computed Tomography, the American College of Radiology, the American Heart Association, the American Society of Echocardiography, the American Society of Nuclear Cardiology, the North American Society for Cardiovascular Imaging, the Society for Cardiovascular Angiography and Interventions, and the Society for Cardiovascular Magnetic Resonance. J Cardiovasc Comput Tomogr. 2010;4:407---33. 5. Bukley O, Madan R, Kwong R, Rybick FJ, Hunsaker A, Cardiac Masses. Part 1: imaging strategies and technical considerations. AJR Am J Roentgenol. 2011;197:W837---41. 6. Kramer CM, Barkhausen J, Flamm SD, Kim RJ, Nagel E. Society for Cardiovascular Magnetic Resonance Board of Trustees Task Force on Standardized Protocols. Standardized cardiovascular magnetic resonance (CMR) protocols 2013 update. J Cardiovasc Magn Reson. 2013;15:91. 7. Pazos-López P, Pozo E, Siqueira ME, García-Lunar I, Cham M, Jacobi A, et al. Value of CMR for the differential diagnosis of cardiac masses. JACC Cardiovasc Imaging. 2014;7:896---905. 8. Butany J, Nair V, Naseemuddin A, Nair GM, Catton C, Yau T. Cardiac tumours: diagnosis and management. Lancet Oncol. 2005;6:219---28. 9. Araoz PA, Mulvagh SL, Tazelaar HD, Julsrud PR, Breen JF. CT and MR imaging of benign primary cardiac neoplasms with echocardiographic correlation. Radiographics. 2000;20:1303---19. 10. Masui T, Takahashi M, Miura K, Naito M, Tawarahara K. Cardiac myxoma: identification of intratumoral hemorrhage and calcification on MR images. AJR Am J Roentgenol. 1995;164:850---2. 11. Grebenc ML, Rosado-de-Christenson ML, Green CE, Burke AP, Galvin JR. Cardiac myxoma: imaging features in 83 patients. Radiographics. 2002;22:673---89. 12. Weinsaft JW, Kim RJ, Ross M, Krauser D, Manoushagian S, LaBounty TM, et al. Contrast-enhanced anatomic imaging as compared to contrast-enhanced tissue characterization for detection of left ventricular thrombus. JACC Cardiovasc Imaging. 2009;2:969---79. 13. Barkhausen J, Hunold P, Eggebrecht H, Schüler WO, Sabin GV, Erbel R, et al. Detection and characterization of intracardiac thrombi on MR imaging. AJR Am J Roentgenol. 2002;179:1539---44.
C. Díaz Angulo et al. 14. Randhawa K, Ganeshan A, Hoey ET. Magnetic resonance imaging of cardiac tumors: part 2, malignant tumors and tumor-like conditions. Curr Probl Diagn Radiol. 2011;40:169---79. 15. Burke A, Virmani R. Classification and incidence of cardiac tumors. In: Burke A, Virmani R, editors. Tumors of the heart and great vessels: atlas of tumor pathology, vol. 16, 3rd ed. Washington, DC: Armed Forces Institute of Pathology; 1996. p. 1---11. 16. Kim EK, Park SJ, Park PW, Byun KM, Lee SC, Park SW, et al. Popcorn-like appearance of papillary fibroelastoma of the aortic valve --- diagnosis on multimodality imaging; echocardiography, computed tomography and magnetic resonance imaging. Circ J. 2012;76:758---60. 17. Méndez C, Soler R, Rodríguez E, Pazos V, Romeu D, Rois A. Intracavitary left ventricular pedunculated lipoma; 2012 [Internet]. Available in http://www.eurorad.org/case.php?id=10097 [accessed 15.05.12]. 18. Ghadimi Mahani M, Lu JC, Rigsby CK, Krishnamurthy R, Dorfman AL, Agarwal PP. MRI of pediatric cardiac masses. AJR Am J Roentgenol. 2014;202:971---81. 19. Rodríguez E, Soler R, Gayol A, Freire R. Massive mediastinal and cardiac fatty infiltration in a young patient. J Thorac Imaging. 1995;10:225---6. 20. O’Sullivan PJ, Gladish GW. Cardiac tumors. Semin Roentgenol. 2008;43:223---33. 21. Habertheuer A, Andreas M, Wiedemann D, Rath C, Kocher A. A rare case of obstructive right atrial lipoma. Ann R Coll Surg Engl. 2014;96:e39---41. 22. Khalili A, Ghaffari S, Jodati A, Shokoohi B, Pourafkari L. Giant right atrial lipoma mimicking tamponade. Asian Cardiovasc Thorac Ann. 2013;23:317---9. 23. Kanemitsu S, Hirano K, Shimono T, Shimpo H. A case of a large cardiac lipoma with coronary artery disease. Asian Cardiovasc Thorac Ann. 2014;22:604---6. 24. Nir A, Tajik AJ, Freeman WK, Seward JB, Offord KP, Edwards WD, et al. Tuberous sclerosis and cardiac rhabdomyoma. Am J Cardiol. 1995;76:419---21. 25. Tao TY, Yahyavi-Firouz-Abadi N, Singh GK, Bhalla S. Pediatric cardiac tumors: clinical and imaging features. Radiographics. 2014;34:1031---46. 26. Berkenblit R, Spindola-Franco H, Frater RW, Fish BB, Glickstein JS. MRI in the evaluation and management of a newborn infant with cardiac rhabdomyoma. Ann Thorac Surg. 1997;63:1475---7. 27. Yadav PK, Baquero GA, Malysz J, Kelleman J, Gilchrist IC. Cardiac paraganglioma. Circ Cardiovasc Interv. 2014;7: 851---6. 28. Randhawa K, Ganeshan A, Hoey ET. Magnetic resonance imaging of cardiac tumors: part 1, sequences, protocols, and benign tumors. Curr Probl Diagn Radiol. 2011;40:158---68. 29. Soler R, Méndez C, Rodríguez E, Flores X. Synchronous pericardial paraganglioma and cystic adrenal pheochromocytoma; 2011 [Internet]. Available in http://www.eurorad.org/ case.php?id=9214 [accessed 04.04.11]. 30. Sook M, Hamoir E, De Leval L, Duquenne S, Larbuisson R, Joris J, et al. Cardiac paraganglioma: diagnostic work up and review of the literature. Acta Chir Belg. 2012;112:310---3.
www.elsevier.es/rx
RADIOLOGY THROUGH IMAGES
Imaging findings in cardiac masses (Part i): Study protocol and benign tumors夽 C. Díaz Angulo, C. Méndez Díaz, E. Rodríguez García, R. Soler Fernández∗ , A. Rois Siso, M. Marini Díaz na (CHUAC), A Coru˜ na, Spain Servicio de Radiodiagnóstico, Complejo Hospitalario Universitario A Coru˜ Received 12 November 2014; accepted 9 July 2015
KEYWORDS Cardiac masses; Myxoma; Fibroelastoma; Lipoma; Rhabdomyoma
PALABRAS CLAVE Masas cardíacas; Mixoma; Fibroelastoma; Lipoma; Rabdomioma
Abstract Cardiac masses represent a diagnostic challenge because decisions about treatment are based on imaging techniques. Echocardiography, magnetic resonance (MR) and computed tomography (CT) are fundamental for the detection, characterization, and staging of cardiac masses as well as for planning their treatment. Most primary cardiac tumors are benign; myxomas, papillary fibroelastomas, and lipomas are the most common. The location of the tumors and its characteristics on CT and MR orient the etiologic diagnosis in most cases. This article describes the protocols for CT and MR studies of cardiac masses as well as the morphologic findings, predominant locations, and most useful characteristics for characterizing benign cardiac masses and establishing the differential diagnosis with malignant cardiac tumors and non-neoplastic pseudotumors. © 2014 SERAM. Published by Elsevier España, S.L.U. All rights reserved.
Hallazgos de imagen de las masas cardíacas (parte i): protocolo de estudio y tumores benignos Resumen Las masas cardíacas son un reto diagnóstico porque las decisiones terapéuticas se basan en los hallazgos de las técnicas de imagen. La ecocardiografía, la resonancia magnética (RM) y la tomografía computarizada (TC) son fundamentales para la detección, caracterización, estadificación y planificación del tratamiento. La mayoría de los tumores primarios son benignos; los más frecuentes son el mixoma, el fibroelastoma papilar y el lipoma. La localización del tumor y sus características en la TC y la RM orientan el diagnóstico etiológico en la mayor parte de los casos.
夽
Please cite this article as: Díaz Angulo C, Méndez Díaz C, Rodríguez García E, Soler Fernández R, Rois Siso A, Marini Díaz M. Hallazgos de imagen de las masas cardíacas (parte I): protocolo de estudio y tumores benignos. Radiología. 2015;57:480---488. ∗ Corresponding author. E-mail address: [email protected] (R. Soler Fernández). 2173-5107/© 2014 SERAM. Published by Elsevier España, S.L.U. All rights reserved.
Imaging findings in cardiac masses: Part i
481
Se describen los protocolos de estudio de TC y RM de las masas cardíacas, así como los hallazgos morfológicos, las localizaciones preferentes y las características más útiles para caracterizar las masas cardíacas benignas y establecer el diagnóstico diferencial con los tumores cardíacos malignos y las lesiones pseudotumorales no neoplásicas. © 2014 SERAM. Publicado por Elsevier España, S.L.U. Todos los derechos reservados.
Introduction Primary heart tumors are uncommon (0.002---3%) and most are benign.1,2 Clinical manifestations are usually unspecific; they can simulate other cardiovascular diseases and can be potentially deadly due to their hemodynamic repercussion. Most of them are initially detected through ultrasound, the modality of choice due to its availability and innocuousness. However, magnetic resonance imaging (MRI) and computed tomography (CT) provide additional information for diagnosis, therapeutic decision and surgical planning.3,4 Image findings in cardiac masses are presented in two parts. In this first part, the CT and MRI study protocols are described and the findings in benign cardiac masses, and malignant tumors and pseudotumoral lesions are described in the second part.
Protocols of image acquisition Protocol with computed tomography General overview The CT is the complementary image modality in the study of cardiac masses in unstable patients who do not tolerate prolonged decubitus or cannot do apneas who have rhythm disorders that prevent electrocardiographic synchronization, and in patients with claustrophobia, since it is a quick technique that can be performed without cardiac synchronism.4 Also it is the modality of choice to detect calcifications, establish the relation between the masses and the coronary arteries and assess the primary tumor and its spread when suspicion of metastasis.5 Occasionally, cardiac masses are an incidental finding in examinations performed due to symptoms of unspecific thoracic pathology or during the staging of malignant neoplasms in which the study protocol is that of the suspected disease. Study acquisition The protocol includes the acquisition of a topogram on which the examination is planned from the cervico-thoracic union up to the diaphragm which allows assessing the vascular structures, the pulmonary parenchyma and the chest cavity; it is useful for pre-surgery planning and to analyze tumor spread to adjacent structures.4 A series is acquired without intravenous (IV) contrast followed by a second series at 60 s after the IV administration of 100---120 ml of iodized contrast
through an automatic injector, followed by a bolus of 40 ml of saline solution with a flow of 3---4 ml/s. The acquisition parameters depend on the characteristics of the machine. In a 64-detector machine, adequate images are obtained in patients weighing over 80 kg, with a collimation of 64 × 0.625, a rotation time of 500 ms, 300 mA and 80 or 100 kV. The studies can be performed with or without electrocardiographic synchronism.5
Magnetic resonance protocol General overview MRI is a complementary modality to ultrasound in the study of cardiac masses. It is an objective, reproducible, innocuous modality, with a high temporal and contrast resolution which allows us to use wide fields of vision to analyze the heart and the remaining thoracic structures.3,5 MRI examinations will be performed preferably in 1.5 or 3.0 T machines, with surface phase-coupled antennas and electrocardiographic synchronization. Study acquisition The usual study protocol consists of (Table 1): 1. Multiplanar locator with electrocardiographic synchronization and in respiratory apnea in order to know the position of the heart in the thorax. 2. Functional sequences, cine-MRI, of ‘‘white blood’’ based on gradient echo (GE) (fast imaging with steady-state precession, SSFP). They are sequences with mixed T2 and T1 weighting (T2/T1), with great differentiation in the signal intensity of the blood and the myocardium which facilitates the detection of intracavitary lesions. In addition, its high temporal resolution allows us to obtain cine-MR images with electrocardiographic synchronization in order to analyze the functional repercussions of the masses and quantify the ventricular function. 3. Morphological and tissue characterization sequences, of ‘‘black blood’’ based on turbo or fast spin echo (TSE), usually with double or triple inversion pulse to improve the intracavitary flow cancelation. T1- and T2weighted sequences will be obtained and optionally, fat-suppression sequences. 4. First-step perfusion during IV administration of gadolinium chelates. Ultrafast T1-weighted sequences in GE with high temporal resolution to analyze the arrival of the contrast bolus, and assess myocardial perfusion.6
482 Table 1
C. Díaz Angulo et al. Magnetic resonance (MR) protocol for the study of cardiac masses.
Sequence
Acquisition
Views
Other
Localizer
Multiplane
Transversal Coronal Sagittal Transversal 3 chambers 2 chambers 4 chambers Short axis Depending on the location of the mass Transversal or 4 chambers or short axis Depending on the location of the mass Transversal or 4 chambers or short axis Depending on the location of the mass 4 chambers or short axis
In mild breathing apnea
Cine-RM SSFP
TSE-T1
TSE-T2
Multicut-multiphase 1 multiphase cut 1 multiphase cut 1 multiphase cut Multicut-multiphase 2D multicut
2D multicut
First-step perfusion
2D or 3D multicut
Delayed enhancement
TEG-T1 with inversion pulse or 2D or 3D multicut PSIR
3 chambers 2 chambers 4 chambers Short axis
In In In In In In
mild mild mild mild mild mild
breathing breathing breathing breathing breathing breathing
apnea apnea apnea apnea apnea apnea
Optional, suppression of fat In mild breathing apnea Optional, suppression of fat, Gadolinium contrast. Dose: 0.05---0.1 mmol/kg Flow of 3---7 ml/s. Saline solution (30 ml in adults and twice as much contrast volume in children) Gadolinium contrast. Dose: 0.1---0.2 mmol/kg Delay time: 10 min. Inversion time: 150---300 ms. Diastolic synchronization.
PSIR: phase sensitive inversion-recovery.
5. Late enhancement sequences (black myocardium). T1weighted sequences with a 180◦ inversion pulse applied in a given time (inversion time) to cancel the signal of the healthy myocardium. They can be turbo or fast gradient echo (TGE) or phase-sensitive inversion-recovery (PSIR) sequences. The inversion time to cancel the myocardium ranges from 150 to 300 ms. However, a 500---550 ms inversion time in 1.5 T machines and 850---900 ms in 3 T machines is useful to differentiate tumor thrombi.6 The late enhancement sequences allow us to outline the tumor more clearly and they are essential to detect and characterize the thrombi.7 Planes/views of acquisition Cine-MR images are usually obtained on the transversal plane toward the thorax and on intrinsic cardiac planes on the long horizontal axis (three cameras), the long vertical axis (two cameras), four cameras and short axis. TSE-T1 and TSE-T2 sequences (with or without fat suppression) and the first-step perfusion sequences will be obtained on the plane from which the lesion is better observed.
It must be remembered that MRI is a complementary modality to ultrasound in the study of cardiac masses.
Benign tumors Primary tumors of the heart are usually benign. They can have an intracavitary location and be attached to the endocardium or the myocardium through a broad implantation base or a pedicle, or they can be intra-myocardial. The myxoma, the papillary fibroelastoma and the lipoma are the most frequent ones.
Myxoma The myxoma is the most frequent primary heart tumor (25---50%).1 The vast majority are sporadic and they affect women of between 40 and 70 years of age. They are usually asymptomatic or they occur with heart failure, embolism, syncope or sudden death, mainly when they prolapse through the mitral valve8 ; 7% is part of the Carney complex---autosomal dominant syndrome characterized by myxoma, hyperpigmentation and extracardiac tumors.9 They are more frequent in the left atrium (LA) (75%), they are usually attached by a pedicle to the interatrial septum, close to the fossa ovalis, and they can prolapse through the atrial-ventricular valves (Fig. 1). Other locations are the right atrium (RA) (Fig. 2), the right ventricle (RV), the left ventricle (LV), the aortic valve and the inferior vena cava.1 Myxomas kick in as intracavitary oval, heterogeneous masses of variable sizes (1---15 cm), due to the presence
Imaging findings in cardiac masses: Part i
483
We need to remember that myxomas are the most common heart tumors, they are usually located in the LA and they are attached to the interatrial septum by a pedicle. Its MRI signal is variable and its enhancement is heterogeneous.
The papillary fibroelastoma
Figure 1 Myxoma in a 53-year-old woman with dyspnea and weight loss. The CT with IV contrast shows a polylobulated mass (asterisk) in the left atrium attached to the interatrial septum with prolapse toward the left ventricle toward the mitral ring.
Papillary fibroelastomas account for 10% of primary heart tumors.14,15 They are often asymptomatic and do not usually cause valvular dysfunction14,16 ; 90% of them are located on the endocardial surface of the aortic (29%) or mitral (25%) valves.9 They are small (<1 cm), well-outlined lesions, showing soft-tissue attenuation in the CT and hypointense or intermediate signals in the T1-weighted sequences, intermediate signals in T2-weighted sequences and hypointense in cineMR SSFP sequences. They are not usually enhanced after the administration of contrast (Fig. 5).14,16 Differential diagnosis is established with the endocarditis warts that are usually associated with valvular destruction and insufficiency and intracavitary thrombi.
Lipoma of necrosis, calcifications, bleeding, cystic formations or fibrosis (Figs. 3 and 4).10 In the CT, most of them are of low attenuation (Fig. 1). In the MRI they show one iso/hypointense or hyperintense signal with respect to the myocardium in T1-weighted sequences and hyperintense in the T2-weighted sequences (Fig. 3). Enhancement in CT and MRI after the administration of contrast is usually scarce and heterogeneous.2,11 Differential diagnosis must be performed with the malignant intracavitary thrombi and neoplasms. The absence of enhancement with IV contrast is the most useful sign to differentiate an intracavitary thrombus from a myxoma.11---13
Lipomas (8% of the heart tumors)17 are more frequent in obese adults but they can be detected at any age. They are generally solitary, although multiple cases have been described associated to tuberous sclerosis and congenital heart conditions.18 They do not cause symptoms or show rhythm disorders or with clinical manifestations of hemodynamic affectation due to obstruction or compression of adjacent structures. The most frequent location is endocavitary in the RA and the LV; other locations are the cardiac valves, intramyocardial (25%) and pericardial (25%).17,19 In the CT and the MRI, endocavitary lipomas occur as small sessile homogeneous masses attached to the
Figure 2 Myxoma in a 63-year-old asymptomatic male. The cine-MR SSFP images in the four-chamber view, in systole (A) show one well-outlined and polylobulated intracavitary mass (arrows) in the right atrium with one pedicle anchored to the distal part of the interatrial septum that prolapses in the diastole (B) (arrow heads) through the triscuspid valve.
484
C. Díaz Angulo et al.
Figure 3 Myxoma in a 53-year-old woman with dyspnea of one year duration. (A) In the T1-TSE-weighted sequence in the transversal view one endocavitary mass can be identified in the left atrium well-outlined and of intermediate signal (asterisk). (B) In the first-step perfusion sequence after the administration of gadolinium contrast the mass is hypointense in early stages. Note the pedicle anchored to the interatrial septum (arrow head).
interatrial septum or the atrial roof; and the intramyocardial ones, as oval well-outlined, homogeneous masses. In CT without contrast, they are of low attenuation (−50 UH) and they do not enhance after the administration of contrast. In the MRI, they are hyperintense in T1-TSE weighted sequences and hypointense in specific fat suppression sequences, and they usually shoe one hypointense capsule (Fig. 6).2,9,19 Differential diagnosis in children must be performed with teratoma and in adults with lipomatous hypertrophy of the interatrial septum and with liposarcoma. Unlike intracavitary lipomas, lipomatous hypertrophy infiltrates the interatrial septum and respects the fossa ovalis in a peculiar way.20 Liposarcoma is a lipomatous tumor with attenuation and intensity of heterogeneous signal that is enhanced after
the administration of contrast and capable of infiltrating adjacent structures.20 Surgical resection will depend on its size, location and functional repercussion; CT is essential to establish the relation between the lipoma and the coronary arteries as well as to plan surgery.21---23
We need to remember that attenuation in the CT and signal characteristics in the MRI of lipomas are enough to establish diagnosis.
Rhabdomyoma Rhabdomyoma is the most frequent heart tumor in children. They are often diagnosed in the neonatal period, in isolation or associated with tuberous sclerosis2,18,24 and most relapse spontaneously.23 They are usually asymptomatic, but they can cause obstruction of the ventricular outflow tract or arrhythmias.18,25 Rhabdomyomas are usually multiple (90%) and intramyocardial. They are isointense in the MRI in T1-weighted sequences and slightly hyperintense in T2weighted sequences. With IV contrast, enhancement is minimal or absent (Fig. 7).2,18,26
We need to remember that rhabdomyomas are the most common tumors in children; they are often multiple and intramyocardial and most relapse spontaneously.
Figure 4 Myxoma in a 69-year-old woman with dyspnea. The TC with IV contrast shows one partially calcified mass in the left atrium (arrow) attached to the interatrial septum by a wide implantation base.
Fibroma The fibroma is the second most frequent benign heart tumor in children.25 It can be asymptomatic or occur with
Imaging findings in cardiac masses: Part i
485
Figure 5 Papillary fibroelastoma. (A) The TC with IV contrast identifies one small node of soft tissue attenuation (arrow heads) attached to the atrial surface of the tricuspid valve. (B) In the cine-MR images the node shows a hypointense signal (arrow).
arrhythmia or sudden death. There is increased prevalence in the Gorlin and Gardner syndromes.9,18 Fibromas are usually single, well-outlined tumors, often located in the interventricular septum and the lateral wall of the LV (Fig. 8).18 They show heterogeneous, hypointense
or hyperintense signals in T1- and T2-weighted sequences. In first-step perfusion they show hypointense and hyperintense signals in late enhancement sequences, occasionally with central hypointensity. Calcifications are frequent (25%) and easier to detect in CT studies without contrast.9,18
Figure 6 Lipoma in a 67-year-old woman with incidental finding of one mass in an ultrasound. The T1-TSE-weighted sequences in the transversal (A) and sagittal (B) views show one intracavitary mass (arrows) originating in the posterior wall if the left atrium of homogeneous and hyperintense signal. In the T1-TSE-weighted sequences with selective suppression of fat (C) the mass is hypointense (arrow head).
486
C. Díaz Angulo et al.
Figure 7 Rhabdomyoma in a newly born female baby with arryhtmia. The transversal TSE-T1 (A) and TSE-T1 (B) images show one large mass in the right ventricle (asterisk) of hyperintense, heterogeneous signal. The mass is similar to the myocardium (arrows) in the cine-MR SSFP sequences (C).
Figure 8 Fibroma in an asymptomatic 8-year-old girl. Cine-MR in the short axis view (A) and T2-STIR sequences (B). Myocardial mass in the anterior part of the interventricular septum---homogeneous and isointense (arrow) in the cine-MR sequence and hyperintense and heterogeneous (arrow heads) in T2-STIR sequences.
Imaging findings in cardiac masses: Part i Table 2
487
More characteristic findings of benign cardiac tumors.
Tumor
Localization
CT attenuation
T1 SI
T2 SI
Enhancement
Myxoma
LA Pedicle in interatrial septum RA LV
Heterogeneous (necrosis, calcifications, bleeding) Fat
Similar to myocardium Hypointense Hyperintense Hyperintense Hypointense With selective suppression of fat
Hyperintense
Minimal Heterogeneous
Absent
Aortic valve Mitral valve Pedicle Myocardium
Similar to myocardium
Similar to myocardium Hypointense Similar to myocardium Heterogeneous Hypointense Hyperintense
Hyperintense Hypointense with selective suppression of fat Similar to myocardium Hypointense Minimal hypersignal Heterogeneous Hypointense Hyperintense
Lipoma
Fibroelastoma
Rhabdomyoma Fibroma
Intraventricular septum LV
Paraganglioma
Pericardium
Similar to myocardium Similar to myocardium Calcifications (25%) Heterogeneous Central necrosis
Similar to myocardium Hypointense Hyperintense
Hyperintense
Absent
Minimal absent Minimal moderate
Intense periferal
RA: right atrium; LA: left atrium; SI: signal intensity; CT: computed tomography; LV: left ventricle.
Paraganglioma Paragangliomas are uncommon neuroendocrine neoplasms more common between 10 and 60 years of age.9 Its usual location is the pericardium. They can be isolated or associated with paragangliomas in other locations (20%) or with bone metastasis (5%).9,27 In the CT, they appear as heterogeneous masses with central necrosis and intense enhancement of peripheral predominance. They rarely calcify. In the MRI, they are usually iso-/hypointense in T1-weighted sequences and hyperintense in T2-weighted sequences. Occasionally, they are hyperintense in T1 due to intratumor bleeding. With IV contrast they usually show intense enhancement of peripheral predominance.9,28---30
Conclusion The location of being heart tumors guides the etiologic diagnosis in most cases. The densiometric characteristics of the CT and signal characteristics of the MRI help us establish the diagnosis and distinguish them from malignant neoplasms and pseudo-tumors (Table 2).
Ethical responsibilities Protection of people and animals. The authors declare that no experiments with human beings or animals have been performed while conducting this investigation.
Data confidentiality. The authors declare that in this article there are no data from patients. Right to privacy and informed consent. The authors declare that in this article there are no data from patients.
Authors 1. 2. 3. 4. 5. 6. 7. 8. 9.
Manager of the integrity of the study: CDA, RSF. Study idea: CMD, RSF, MMD. Study design: CMD, RSF, MMD. Data mining: CDA, ARS, CMD, ERG, RSF, MMD. Data analysis and interpretation: CMD, ERG, RSF. Statistical analysis: N/A. Reference search: CDA, ARS, RSF. Writing: CDA, ARS, CMD, ERG, RSF. Critical review of the manuscript with intellectually relevant remarks: CMD, ERG, RSF, MMD. 10. Approval of final version: CDA, ARS, CMD, ERG, RSF, MMD.
Conflict of interests The authors declare no conflict of interests.
References 1. Motwani M, Kidambi A, Herzog BA, Uddin A, Greenwood JP, Plein S. MR imaging of cardiac tumors and masses: a review of methods and clinical applications. Radiology. 2013;268:26---43.
488 2. Sparrow PJ, Kurian JB, Jones TR, Sivananthan MU. MR imaging of cardiac tumors. Radiographics. 2005;25:1255---76. 3. Hendel RC, Patel MR, Kramer CM, Poon M, Hendel RC, Carr JC, et al. ACCF/ACR/SCCT/SCMR/ASNC/NASCI/SCAI/SIR 2006 appropriateness criteria for cardiac computed tomography and cardiac magnetic resonance imaging: a report of the American College of Cardiology Foundation Quality Strategic Directions Committee Appropriateness Criteria Working Group, American College of Radiology, Society of Cardiovascular Computed Tomography, Society for Cardiovascular Magnetic Resonance, American Society of Nuclear Cardiology, North American Society for Cardiac Imaging, Society for Cardiovascular Angiography and Interventions, and Society of Interventional Radiology. J Am Coll Cardiol. 2006;48:1475---97. 4. Taylor AJ, Cerqueira M, Hodgson JM, Mark D, Min J, O’Gara P, et al. ACCF/SCCT/ACR/AHA/ASE/ASNC/NASCI/SCAI/SCMR 2010 appropriate use criteria for cardiac computed tomography. A report of the American College of Cardiology Foundation Appropriate Use Criteria Task Force, the Society of Cardiovascular Computed Tomography, the American College of Radiology, the American Heart Association, the American Society of Echocardiography, the American Society of Nuclear Cardiology, the North American Society for Cardiovascular Imaging, the Society for Cardiovascular Angiography and Interventions, and the Society for Cardiovascular Magnetic Resonance. J Cardiovasc Comput Tomogr. 2010;4:407---33. 5. Bukley O, Madan R, Kwong R, Rybick FJ, Hunsaker A, Cardiac Masses. Part 1: imaging strategies and technical considerations. AJR Am J Roentgenol. 2011;197:W837---41. 6. Kramer CM, Barkhausen J, Flamm SD, Kim RJ, Nagel E. Society for Cardiovascular Magnetic Resonance Board of Trustees Task Force on Standardized Protocols. Standardized cardiovascular magnetic resonance (CMR) protocols 2013 update. J Cardiovasc Magn Reson. 2013;15:91. 7. Pazos-López P, Pozo E, Siqueira ME, García-Lunar I, Cham M, Jacobi A, et al. Value of CMR for the differential diagnosis of cardiac masses. JACC Cardiovasc Imaging. 2014;7:896---905. 8. Butany J, Nair V, Naseemuddin A, Nair GM, Catton C, Yau T. Cardiac tumours: diagnosis and management. Lancet Oncol. 2005;6:219---28. 9. Araoz PA, Mulvagh SL, Tazelaar HD, Julsrud PR, Breen JF. CT and MR imaging of benign primary cardiac neoplasms with echocardiographic correlation. Radiographics. 2000;20:1303---19. 10. Masui T, Takahashi M, Miura K, Naito M, Tawarahara K. Cardiac myxoma: identification of intratumoral hemorrhage and calcification on MR images. AJR Am J Roentgenol. 1995;164:850---2. 11. Grebenc ML, Rosado-de-Christenson ML, Green CE, Burke AP, Galvin JR. Cardiac myxoma: imaging features in 83 patients. Radiographics. 2002;22:673---89. 12. Weinsaft JW, Kim RJ, Ross M, Krauser D, Manoushagian S, LaBounty TM, et al. Contrast-enhanced anatomic imaging as compared to contrast-enhanced tissue characterization for detection of left ventricular thrombus. JACC Cardiovasc Imaging. 2009;2:969---79. 13. Barkhausen J, Hunold P, Eggebrecht H, Schüler WO, Sabin GV, Erbel R, et al. Detection and characterization of intracardiac thrombi on MR imaging. AJR Am J Roentgenol. 2002;179:1539---44.
C. Díaz Angulo et al. 14. Randhawa K, Ganeshan A, Hoey ET. Magnetic resonance imaging of cardiac tumors: part 2, malignant tumors and tumor-like conditions. Curr Probl Diagn Radiol. 2011;40:169---79. 15. Burke A, Virmani R. Classification and incidence of cardiac tumors. In: Burke A, Virmani R, editors. Tumors of the heart and great vessels: atlas of tumor pathology, vol. 16, 3rd ed. Washington, DC: Armed Forces Institute of Pathology; 1996. p. 1---11. 16. Kim EK, Park SJ, Park PW, Byun KM, Lee SC, Park SW, et al. Popcorn-like appearance of papillary fibroelastoma of the aortic valve --- diagnosis on multimodality imaging; echocardiography, computed tomography and magnetic resonance imaging. Circ J. 2012;76:758---60. 17. Méndez C, Soler R, Rodríguez E, Pazos V, Romeu D, Rois A. Intracavitary left ventricular pedunculated lipoma; 2012 [Internet]. Available in http://www.eurorad.org/case.php?id=10097 [accessed 15.05.12]. 18. Ghadimi Mahani M, Lu JC, Rigsby CK, Krishnamurthy R, Dorfman AL, Agarwal PP. MRI of pediatric cardiac masses. AJR Am J Roentgenol. 2014;202:971---81. 19. Rodríguez E, Soler R, Gayol A, Freire R. Massive mediastinal and cardiac fatty infiltration in a young patient. J Thorac Imaging. 1995;10:225---6. 20. O’Sullivan PJ, Gladish GW. Cardiac tumors. Semin Roentgenol. 2008;43:223---33. 21. Habertheuer A, Andreas M, Wiedemann D, Rath C, Kocher A. A rare case of obstructive right atrial lipoma. Ann R Coll Surg Engl. 2014;96:e39---41. 22. Khalili A, Ghaffari S, Jodati A, Shokoohi B, Pourafkari L. Giant right atrial lipoma mimicking tamponade. Asian Cardiovasc Thorac Ann. 2013;23:317---9. 23. Kanemitsu S, Hirano K, Shimono T, Shimpo H. A case of a large cardiac lipoma with coronary artery disease. Asian Cardiovasc Thorac Ann. 2014;22:604---6. 24. Nir A, Tajik AJ, Freeman WK, Seward JB, Offord KP, Edwards WD, et al. Tuberous sclerosis and cardiac rhabdomyoma. Am J Cardiol. 1995;76:419---21. 25. Tao TY, Yahyavi-Firouz-Abadi N, Singh GK, Bhalla S. Pediatric cardiac tumors: clinical and imaging features. Radiographics. 2014;34:1031---46. 26. Berkenblit R, Spindola-Franco H, Frater RW, Fish BB, Glickstein JS. MRI in the evaluation and management of a newborn infant with cardiac rhabdomyoma. Ann Thorac Surg. 1997;63:1475---7. 27. Yadav PK, Baquero GA, Malysz J, Kelleman J, Gilchrist IC. Cardiac paraganglioma. Circ Cardiovasc Interv. 2014;7: 851---6. 28. Randhawa K, Ganeshan A, Hoey ET. Magnetic resonance imaging of cardiac tumors: part 1, sequences, protocols, and benign tumors. Curr Probl Diagn Radiol. 2011;40:158---68. 29. Soler R, Méndez C, Rodríguez E, Flores X. Synchronous pericardial paraganglioma and cystic adrenal pheochromocytoma; 2011 [Internet]. Available in http://www.eurorad.org/ case.php?id=9214 [accessed 04.04.11]. 30. Sook M, Hamoir E, De Leval L, Duquenne S, Larbuisson R, Joris J, et al. Cardiac paraganglioma: diagnostic work up and review of the literature. Acta Chir Belg. 2012;112:310---3.