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Focal caseous mitral annular calfication: Evaluation with cardiac MRI
European Journal of Radiology Extra 73 (2010) e53–e55
Contents lists available at ScienceDirect
European Journal of Radiology Extra journal homepage: intl.elsevierhealth.com/journals/ejrex
Focal caseous mitral annular calfication: Evaluation with cardiac MRI Laura Jimenez-Juan a,1 , Andrew Crean b,2 , David Latter c,3 , Andrew Yan d,4 , Anish Kirpalani a,∗ a
Medical Imaging, St. Michael’s Hospital and University of Toronto, 30 Bond Street, Toronto, Ontario M5B 1W8, Canada Medical Imaging and Cardiology, Toronto General Hospital, 585 University Avenue, Toronto, Ontario M5G, Canada c Cardiovascular Surgery, St. Michael’s Hospital, 30 Bond Street, Toronto, Ontario M5B 1W8, Canada d Cardiology, St. Michael’s Hospital, 30 Bond Street, Toronto, Ontario M5B 1W8, Canada b
a r t i c l e
i n f o
Article history: Received 3 November 2009 Accepted 26 November 2009
Keywords: Mitral annular calcification CMR
a b s t r a c t We present a case of a 63-year-old male with an early caseous form of mitral annular calcification, which was incidentally found on a routine echocardiogram and initially suspicious for a malignant cardiac tumor. We show the relevance of using cardiac MRI in the workup of this important differential diagnosis of cardiac tumors. © 2009 Elsevier Ireland Ltd. All rights reserved.
1. Case report A 63-year-old asymptomatic male presented to his cardiologist with an elevated potassium and creatinine. A transthoracic echocardiogram (TTE), performed as part of the workup, showed an incidental left atrial mass measuring 3 cm. The patient was referred for coronary angiography, which revealed normal coronary arteries and no evidence of a tumor blush. Left ventriculogram suggested a large radio-opaque structure near the basal aspect of the left ventricle, appearing larger than described on TTE. Contrast-enhanced chest CT demonstrated a dense intracardiac mass that was initially interpreted to be homogeneously enhancing. This raised the suspicion of a malignant tumor and a referral to our institution for a cardiac surgery consultation was initiated. Shortly after transfer, repeat TTE demonstrated an echogenic mass attached to the posterior mitral annulus with mild mitral regurgitation. The patient underwent ECG-gated cardiac magnetic resonance imaging (CMR) for further evaluation with the following sequences: cine steady-state free precession (SSFP), T1- and T2weighted black blood imaging, and T1-weighted gradient echo first pass contrast-enhanced imaging following IV injection of gadobenate dimeglumine, a gadolinium-based contrast agent (GBCA). The
∗ Corresponding author. Tel.: +1 416 864 6060x6497. E-mail addresses: [email protected] (L. Jimenez-Juan), [email protected] (A. Crean), [email protected] (D. Latter), [email protected] (A. Yan), [email protected] (A. Kirpalani). 1 Tel.: +1 416 864 6060x6103. 2 Tel.: +1 416 340 4710. 3 Tel.: +1 416 864 5366. 4 Tel.: +1 416 864 5159. 1571-4675/$ – see front matter © 2009 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ejrex.2009.11.001
CMR confirmed a circumscribed 4.5 cm × 3.4 cm hypointense mass attached to the posterior leaflet of the MV on the left ventricular surface. CMR signal properties followed calcium on all pulse sequences (Fig. 1). This mass moderately restricted excursion of the posterior MV leaflet compared to the anterior leaflet (Fig. 2), and there was mild mitral regurgitation. There was no evidence of attachment to the left ventricular myocardium. There was no evidence of fat or soft tissue within the mass. Left ventricular global and regional systolic function was normal. On first pass imaging following GBCA administration, the mass did not demonstrate contrast enhancement (Fig. 3). An ECG-gated unenhanced 64-detector CT study then confirmed the presence of calcification (Fig. 4). Because the CMR and CT findings were concordant and suggestive of a focal caseous form of mitral annular calcification (MAC), without any embolic phenomena, the patient was managed conservatively. 2. Discussion MAC is a fibrous, benign degenerative calcification of the MV ring. It is usually an incidental finding in asymptomatic patients on chest X-ray or CT. When the calcification is well defined, rounded, dense and localized to the posterior leaflet, it is termed caseous MAC. This focal form often, but not always, contains a less calcified central area resembling liquefaction. It is usually composed of a mixture of cholesterol, calcium and fatty acids, yielding a toothpaste-like texture at pathology [2]. Caseous MAC is a rare finding which, in the two largest published echocardiographic series of MAC, was found in about 0.6% of all cases of MAC [1,2]. In these two series, all 32 cases of caseous MAC were found on the posterior leaflet of the MV [1,2]. Its precise pathogenic mechanism remains
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L. Jimenez-Juan et al. / European Journal of Radiology Extra 73 (2010) e53–e55
Fig. 1. T2-weighted black blood fat suppressed transverse MR image showing a low signal intensity circumscribed mass attached to the posterior leaflet of the mitral valve on the left ventricular surface, following properties of calcium on all pulse sequences.
Fig. 3. T1-weighted fast gradient echo 4-chamber image following GBCA injection for first pass perfusion. No enhancement was demonstrated.
controversial. On echocardiography, caseous MAC can mimic a mass and can be initially misinterpreted as a neoplasm, thrombus or abscess, as it was in our case. Therefore, it should be included in the differential diagnosis of intracardiac masses. For this reason, further investigation with another imaging modality such as CMR or ECG-gated CT is justified for better characterization of the lesion. Thus far, the majority of reported cases of this rare variant of MAC have been imaged with echocardiography [2–4], and relatively few with CT [5,6]. There is limited information on the CMR appearance of caseous MAC [7]. While our case demonstrates homogeneous calcification, transformation over time into a more heterogeneous liquefactive form has been reported [6]. Our case demonstrates hypointensity of the mass on all standard CMR pulse sequences. In addition, we have shown its lack of enhancement
Fig. 4. Unenhanced transverse images from ECG-gated cardiac CT performed on the same day as CMR. There is a well defined, rounded and homogeneously calcified mass related to the posterior leaflet of the mitral valve, consistent with caseous MAC.
with GBCA. While CT and CMR can both confirm the calcified nature of caseous MAC and demonstrate its anatomic relationship to the LV myocardium, CMR may allow superior evaluation of its anatomic relationship to the MV leaflets and the function of the MV apparatus. The presence of severe mitral valve dysfunction may be an indication for surgical resection of caseous MAC, but otherwise, conservative management is usually appropriate [8]. Conflict of interest All authors declare no conflicts of interest. Fig. 2. Single diastolic image from a cine SSFP 3-chamber MR series, demonstrating the well-defined hypointense mass attached to the posterior leaftlet of the mitral valve (short arrow), which is open. Motion of the posterior leaflet of the MV is somewhat restricted as compared with the anterior leaflet (long arrow). Note is made of the papillary muscle attached to the posterior leaflet (arrowhead).
References [1] Deluca G, Correale M, Ieva R, Del Salvatore B, Gramenzi S, Di Biase M. The incidence and clinical course of caseous calcification of the mitral annu-
L. Jimenez-Juan et al. / European Journal of Radiology Extra 73 (2010) e53–e55
[2]
[3] [4]
[5]
lus: a prospective echocardiographic study. J Am Soc Echocardiogr 2008;21: 828–33. Harpaz D, Auerbach I, Vered Z, Motro M, Tobar A, Rosenblatt S. Caseous calcification of the mitral annulus: a neglected, unrecognized diagnosis. J Am Soc Echocardiogr 2001;14:825–31. Marcu CB, Ghantous AE, Prokop EK. Caseous calcification of the mitral valve ring. Heart Lung Circ 2006;15:187–8. Minardi G, Manzara C, Pulignano G, et al. Caseous calcification of the mitral annulus with mitral regurgitation and impairment of functional capacity: a case report. J Med Case Rep 2008;2:205. Lubarsky L, Jelnin V, Marino N, Hecht HS. Images in cardiovascular medicine caseous calcification of the mitral annulus by 64-detector-row computed
e55
tomographic coronary angiography: a rare intracardiac mass. Circulation 2007;116:e114–5. [6] Blankstein R, Durst R, Picard MH, Cury RC. Progression of mitral annulus calcification to caseous necrosis of the mitral valve: complementary role of multi-modality imaging. Eur Heart J 2009;30: 304. [7] Arora H, Madan P, Simpson L, Stainback RF. Caseous calcification of the mitral annulus. Tex Heart Inst J 2008;35:211–3. [8] Fernandes RM, Branco LM, Galrinho A, et al. Caseous calcification of the mitral annulus. A review of six cases. Rev Port Cardiol 2007;26: 1059–70.
Contents lists available at ScienceDirect
European Journal of Radiology Extra journal homepage: intl.elsevierhealth.com/journals/ejrex
Focal caseous mitral annular calfication: Evaluation with cardiac MRI Laura Jimenez-Juan a,1 , Andrew Crean b,2 , David Latter c,3 , Andrew Yan d,4 , Anish Kirpalani a,∗ a
Medical Imaging, St. Michael’s Hospital and University of Toronto, 30 Bond Street, Toronto, Ontario M5B 1W8, Canada Medical Imaging and Cardiology, Toronto General Hospital, 585 University Avenue, Toronto, Ontario M5G, Canada c Cardiovascular Surgery, St. Michael’s Hospital, 30 Bond Street, Toronto, Ontario M5B 1W8, Canada d Cardiology, St. Michael’s Hospital, 30 Bond Street, Toronto, Ontario M5B 1W8, Canada b
a r t i c l e
i n f o
Article history: Received 3 November 2009 Accepted 26 November 2009
Keywords: Mitral annular calcification CMR
a b s t r a c t We present a case of a 63-year-old male with an early caseous form of mitral annular calcification, which was incidentally found on a routine echocardiogram and initially suspicious for a malignant cardiac tumor. We show the relevance of using cardiac MRI in the workup of this important differential diagnosis of cardiac tumors. © 2009 Elsevier Ireland Ltd. All rights reserved.
1. Case report A 63-year-old asymptomatic male presented to his cardiologist with an elevated potassium and creatinine. A transthoracic echocardiogram (TTE), performed as part of the workup, showed an incidental left atrial mass measuring 3 cm. The patient was referred for coronary angiography, which revealed normal coronary arteries and no evidence of a tumor blush. Left ventriculogram suggested a large radio-opaque structure near the basal aspect of the left ventricle, appearing larger than described on TTE. Contrast-enhanced chest CT demonstrated a dense intracardiac mass that was initially interpreted to be homogeneously enhancing. This raised the suspicion of a malignant tumor and a referral to our institution for a cardiac surgery consultation was initiated. Shortly after transfer, repeat TTE demonstrated an echogenic mass attached to the posterior mitral annulus with mild mitral regurgitation. The patient underwent ECG-gated cardiac magnetic resonance imaging (CMR) for further evaluation with the following sequences: cine steady-state free precession (SSFP), T1- and T2weighted black blood imaging, and T1-weighted gradient echo first pass contrast-enhanced imaging following IV injection of gadobenate dimeglumine, a gadolinium-based contrast agent (GBCA). The
∗ Corresponding author. Tel.: +1 416 864 6060x6497. E-mail addresses: [email protected] (L. Jimenez-Juan), [email protected] (A. Crean), [email protected] (D. Latter), [email protected] (A. Yan), [email protected] (A. Kirpalani). 1 Tel.: +1 416 864 6060x6103. 2 Tel.: +1 416 340 4710. 3 Tel.: +1 416 864 5366. 4 Tel.: +1 416 864 5159. 1571-4675/$ – see front matter © 2009 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ejrex.2009.11.001
CMR confirmed a circumscribed 4.5 cm × 3.4 cm hypointense mass attached to the posterior leaflet of the MV on the left ventricular surface. CMR signal properties followed calcium on all pulse sequences (Fig. 1). This mass moderately restricted excursion of the posterior MV leaflet compared to the anterior leaflet (Fig. 2), and there was mild mitral regurgitation. There was no evidence of attachment to the left ventricular myocardium. There was no evidence of fat or soft tissue within the mass. Left ventricular global and regional systolic function was normal. On first pass imaging following GBCA administration, the mass did not demonstrate contrast enhancement (Fig. 3). An ECG-gated unenhanced 64-detector CT study then confirmed the presence of calcification (Fig. 4). Because the CMR and CT findings were concordant and suggestive of a focal caseous form of mitral annular calcification (MAC), without any embolic phenomena, the patient was managed conservatively. 2. Discussion MAC is a fibrous, benign degenerative calcification of the MV ring. It is usually an incidental finding in asymptomatic patients on chest X-ray or CT. When the calcification is well defined, rounded, dense and localized to the posterior leaflet, it is termed caseous MAC. This focal form often, but not always, contains a less calcified central area resembling liquefaction. It is usually composed of a mixture of cholesterol, calcium and fatty acids, yielding a toothpaste-like texture at pathology [2]. Caseous MAC is a rare finding which, in the two largest published echocardiographic series of MAC, was found in about 0.6% of all cases of MAC [1,2]. In these two series, all 32 cases of caseous MAC were found on the posterior leaflet of the MV [1,2]. Its precise pathogenic mechanism remains
e54
L. Jimenez-Juan et al. / European Journal of Radiology Extra 73 (2010) e53–e55
Fig. 1. T2-weighted black blood fat suppressed transverse MR image showing a low signal intensity circumscribed mass attached to the posterior leaflet of the mitral valve on the left ventricular surface, following properties of calcium on all pulse sequences.
Fig. 3. T1-weighted fast gradient echo 4-chamber image following GBCA injection for first pass perfusion. No enhancement was demonstrated.
controversial. On echocardiography, caseous MAC can mimic a mass and can be initially misinterpreted as a neoplasm, thrombus or abscess, as it was in our case. Therefore, it should be included in the differential diagnosis of intracardiac masses. For this reason, further investigation with another imaging modality such as CMR or ECG-gated CT is justified for better characterization of the lesion. Thus far, the majority of reported cases of this rare variant of MAC have been imaged with echocardiography [2–4], and relatively few with CT [5,6]. There is limited information on the CMR appearance of caseous MAC [7]. While our case demonstrates homogeneous calcification, transformation over time into a more heterogeneous liquefactive form has been reported [6]. Our case demonstrates hypointensity of the mass on all standard CMR pulse sequences. In addition, we have shown its lack of enhancement
Fig. 4. Unenhanced transverse images from ECG-gated cardiac CT performed on the same day as CMR. There is a well defined, rounded and homogeneously calcified mass related to the posterior leaflet of the mitral valve, consistent with caseous MAC.
with GBCA. While CT and CMR can both confirm the calcified nature of caseous MAC and demonstrate its anatomic relationship to the LV myocardium, CMR may allow superior evaluation of its anatomic relationship to the MV leaflets and the function of the MV apparatus. The presence of severe mitral valve dysfunction may be an indication for surgical resection of caseous MAC, but otherwise, conservative management is usually appropriate [8]. Conflict of interest All authors declare no conflicts of interest. Fig. 2. Single diastolic image from a cine SSFP 3-chamber MR series, demonstrating the well-defined hypointense mass attached to the posterior leaftlet of the mitral valve (short arrow), which is open. Motion of the posterior leaflet of the MV is somewhat restricted as compared with the anterior leaflet (long arrow). Note is made of the papillary muscle attached to the posterior leaflet (arrowhead).
References [1] Deluca G, Correale M, Ieva R, Del Salvatore B, Gramenzi S, Di Biase M. The incidence and clinical course of caseous calcification of the mitral annu-
L. Jimenez-Juan et al. / European Journal of Radiology Extra 73 (2010) e53–e55
[2]
[3] [4]
[5]
lus: a prospective echocardiographic study. J Am Soc Echocardiogr 2008;21: 828–33. Harpaz D, Auerbach I, Vered Z, Motro M, Tobar A, Rosenblatt S. Caseous calcification of the mitral annulus: a neglected, unrecognized diagnosis. J Am Soc Echocardiogr 2001;14:825–31. Marcu CB, Ghantous AE, Prokop EK. Caseous calcification of the mitral valve ring. Heart Lung Circ 2006;15:187–8. Minardi G, Manzara C, Pulignano G, et al. Caseous calcification of the mitral annulus with mitral regurgitation and impairment of functional capacity: a case report. J Med Case Rep 2008;2:205. Lubarsky L, Jelnin V, Marino N, Hecht HS. Images in cardiovascular medicine caseous calcification of the mitral annulus by 64-detector-row computed
e55
tomographic coronary angiography: a rare intracardiac mass. Circulation 2007;116:e114–5. [6] Blankstein R, Durst R, Picard MH, Cury RC. Progression of mitral annulus calcification to caseous necrosis of the mitral valve: complementary role of multi-modality imaging. Eur Heart J 2009;30: 304. [7] Arora H, Madan P, Simpson L, Stainback RF. Caseous calcification of the mitral annulus. Tex Heart Inst J 2008;35:211–3. [8] Fernandes RM, Branco LM, Galrinho A, et al. Caseous calcification of the mitral annulus. A review of six cases. Rev Port Cardiol 2007;26: 1059–70.