Multidetector CT presentation of a parachute-like asymmetric by jlhd32


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									                                                                            The British Journal of Radiology, 81 (2008), e266–e268


Multidetector CT presentation of a parachute-like asymmetric
mitral valve
 O UCAR, MD, 2M VURAL,             MD,
                                         H CICEKCIOGLU,           MD,
                                                                        L PASAOGLU,         MD,
                                                                                                  S AYDOGDU,           MD     and

Departments of 1Cardiology and 2Radiology, Ankara Numune Education and Research Hospital, Talatpasa Bulvari, 06430,
Sihhiye, Ankara, Turkey

ABSTRACT. A 24-year-old man with a complaint of exertional dyspnoea had a Grade III/
VI apical pansystolic murmur on physical examination. He underwent a transthoracic
echocardiogram, which revealed a funnel-shaped mitral valve with moderately thick
leaflet tissue and an eccentric orifice, as well as a bicuspid aortic valve. The mitral valve
was mildly stenotic and severely regurgitant. Although demonstration of a single
                                                                                                          Received 25 February 2007
papillary muscle in the parasternal short axis view suggested a parachute mitral valve,                   Revised 1 July 2007
the diagnosis was uncertain owing to poor echocardiographic acoustic quality. 16-row                      Accepted 17 September
multidetector CT (MDCT) clearly demonstrated two papillary muscles and the patient                        2007
was diagnosed as having a parachute-like asymmetric mitral valve. In conclusion, MDCT
                                                                                                          DOI: 10.1259/bjr/20218809
can be used as a complementary imaging technique for the evaluation of subvalvular
mitral apparatus and papillary muscles, especially in patients with poor                                  ’ 2008 The British Institute of
echocardiographic acoustic quality.                                                                       Radiology

   A 24-year-old man presented with exertional dyspnoea.            apparatus. The MDCT was performed using a 16-slice
He had a non-documented history of rheumatic valvular               Toshiba multidetector Aquilion system (Toshiba Medical
heart disease. His vital signs were stable and he had no            Systems, Otawara, Japan). 120 ml of non-ionic contrast
signs of pulmonic disease. On cardiac auscultation, the             material was injected in the antebrachial vein with a flow
patient had a Grade III/VI pansystolic murmur best heard            rate of 4.5 ml s21. The imaging and reconstruction
at the apex. His electrocardiogram was normal except for            parameters were as follows: detector collimation 16 6
a biphasic P-wave with terminal negativity in lead V1,              0.75 mm, voltage 120 kV, current 350 mA, rotation time
suggesting left atrial abnormality. His physician ordered           0.42 s, reconstruction slice width 1 mm and increment
an echocardiogram. On transthoracic echocardiography,               0.5 mm. Retrospective electrocardiographic gating was
left ventricular ejection fraction and peak systolic pul-           used to eliminate cardiac motion artefacts, and sagittal
monary artery pressure were within normal limits. The               coronal multiplanar reformats were reconstructed on a
mitral valve was funnel-shaped with moderately thick                Vitrea post-processing workstation. Image reconstruction
leaflet tissue and an eccentric orifice (Figure 1). There was       was performed in 10% steps through the entire R–R
a prominent systolic prolapse of the anterior mitral leaflet.       interval, and 0–90% phase cine displays were evaluated in
Severe mitral regurgitation was seen with colour Doppler,           the short- and long-axis of the heart. MDCT clearly
and the left atrium was enlarged. The mean diastolic                demonstrated two seperate papillary muscles settled
gradient between the left atrium and left ventricle was             abnormally close to each other. The posteromedial
detected as 5 mmHg by continuous wave Doppler. The                  papillary muscle had two heads and the anterolateral
aortic valve was bicuspid with normal function. Although            papillary muscle seemed to be dominant (Figure 3).
the morphological characteristics of the mitral valve               Abnormal disorientation and asymmetry of the papillary
resembled those of rheumatic valvular heart disease,                muscles caused valvular dysfunction similar to PMV,
demonstration of a single posteromedial papillary muscle            with both stenosis and prolapse (Figure 4). The bicuspid
with multiple heads in the parasternal short axis view,             aortic valve was also displayed on MDCT (Figure 5). The
together with the bicuspid aortic valve, suggested a                patient was diagnosed as having ‘‘parachute-like asym-
diagnosis of ‘‘parachute mitral valve’’ (PMV) (Figure 2).           metric mitral valve’’ with bicuspid aortic valve. Exclusion
However, owing to poor echocardiographic acoustic                   of rheumatic valvular heart disease aborted the need for
quality, a definite diagnosis could not be made. The                long-term penicillin prophylaxis.
patient refused a transoesophageal echocardiographic
examination and underwent 16-row multidetector CT
(MDCT) in order to evaluate the subvalvular mitral                  Discussion
Address correspondence to: Ozgul Ucar, Keklikpinari Mah, 463/7,       PMV is a congenital abnormality characterized by a
06450, Dikmen, Ankara, Turkey. E-mail:       single centrally located papillary muscle that receives all

    e266                                                                         The British Journal of Radiology, November 2008
Case report: MDCT presentation of a parachute-like asymmetric mitral valve

Figure 1. Transthoracic echocardiogram demonstrating a
funnel-shaped mitral valve with a moderately thick leaflet
tissue and an eccentric orifice in a modified apical four-
chamber view. LA, left atrium; LV, left ventricle.

chordae [1]. The leaflets and chordae are also abnormal,      Figure 3. Oblique coronal multiplanar reformatted image
                                                              demonstrating abnormally close papillary muscles. The
with variable degrees of thickening and shortening. The
                                                              posteromedial papillary muscle has two heads and the
mitral valve can be stenotic and regurgitant. PMV             anterolateral papillary muscle appears to be dominant.
usually appears as a part of the Shone complex (PMV,
supravalvular mitral ring, subaortic stenosis and coarc-
tation of the aorta) [2]. In one study, a bicuspid aortic     muscles. However, in cases of poor echocardiographic
valve was present in 50% of patients with PMV [3]. A          acoustic quality, transthoracic echocardiography may
differential diagnosis of PMV should be made from a           not yield a definite diagnosis. In such situations, MRI is a
parachute-like asymmetric mitral valve and rheumatic          reasonable alternative with which to evaluate the mitral
mitral disease. In contrast to true PMV, a parachute-like     valve. However, owing to technical insufficiencies, we
asymmetric mitral valve has two separate papillary            continued to use MDCT. Although MDCT of the heart is
muscles, with one being more dominant. The dominant           used largely to evaluate the coronary arteries, there is
papillary muscle is usually located higher in the left        accumulating evidence for its utility in the evaluation of
ventricle and is attached to the ventricular wall from        heart valves and chambers [5–7]. In our case, MDCT
both the base and the lateral side [4]. The papillary         gave complementary information about the papillary
muscle anatomy is normal in rheumatic valvular heart          muscle anatomy of the mitral valve and helped in the
disease, in which the leaflets and subvalvular apparatus      final diagnosis.
are thickened and fused. Transthoracic echocardiogra-
phy is the primary tool used in the differential diagnosis.
A parasternal short axis view is the main window for
evaluation of the number and orientation of papillary

Figure 2. Transthoracic echocardiogram showing a single       Figure 4. Oblique short-axis image of the papillary muscles;
posteromedial papillary muscle with multiple heads in the     abnormally close papillary muscles and systolic prolapse of
parasternal short-axis view. LV, left ventricle.              the anterior mitral leaflet are seen.

The British Journal of Radiology, November 2008                                                                   e267
                                                                               O Ucar, M Vural, H Cicekcioglu et al

                                                        papillary muscles, especially in patients with poor
                                                        echocardiographic acoustic quality.

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  MDCT can be a complementary imaging technique for        valve assessment with MR imaging and 64-section multi-
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