DOI:10.2214/AJR.06.5087
AJR 2006; 187:W662
© American Roentgen Ray Society
Incidence of Myocardial Bridging Observed on MDCT
Takeshi Nakaura,
Kazuo Awai and
Yasuyuki Yamashita
Graduate School of Medical Science Kumamoto University Kumamoto,
Japan
WEBThis is a Web exclusive article.
We read the study of Dr. Kantarci et al.
[1] with great interest, and we
wish to make the following comments. The authors reported that the incidence
of myocardial bridging on MDCT in their study was 3.5% and that this finding
is in agreement with the results of some angiography studies. On the other
hand, we have noted that higher incidences and a variety of incidences have
been reported in the pathology literature, with incidences between 15% and 85%
and an average incidence of about one third of adults
[2]. Thus, the incidence of
myocardial bridging reported in a pathology study appears to contradict those
observed in conventional coronary angiography and MDCT coronary angiography
studies. The low incidence on angiography can be explained by minimal or no
compression by thin bridges or by the presence of an atherosclerotic lesion
that results in physiologic stenosis proximal to the bridge.
We believe that the incidence of myocardial bridging on MDCT coronary
angiography might differ according to diagnostic criteria, although Dr.
Kantarci et al. [1] did not
submit diagnostic criteria for myocardial bridging in detail. Ferreira et al.
[3] reported that 75% of
myocardial bridging cases are superficial bridgesthat is, not fully
covered by myocardial fibers but by a thin layer of connective tissue, nerves,
and fatty tissue. These superficial myocardial bridges may not be included in
the study by Kantarci et al. because distinguishing between such a thin
myocardial bridge and the coronary arterial wall is difficult due to the
limited spatial resolution of MDCT coronary angiography.
Recently, we retrospectively reviewed the records and images of 92 patients
who underwent MDCT coronary angiography on a 40-MDCT scanner and calculated
the incidence of myocardial bridging. Our diagnostic criteria of myocardial
bridging on MDCT were "a segment of coronary artery travels in
myocardium and the thickness of the overlying soft tissue is more than 1.5
mm." Among the 92 patients, 22 cases (23.9%) of myocardial bridging were
detected.
If the appropriate diagnostic criteria are selected, the incidence of
myocardial bridging on MDCT may be higher than those in angiographic studies
and similar to those in pathology studies. We are not disputing the results
Dr. Kantarci and colleagues reported by
[1], but rather, we suggest
that a comparative study between pathologic and MDCT findings is needed to
define the diagnostic criteria of myocardial bridging on MDCT.
References
- Kantarci M, Duran C, Durur I, et al. Detection of myocardial
bridging with ECG-gated MDCT and multiplanar reconstruction.
AJR 2006; 186(6
suppl 2): S391-S394[Abstract/Free Full Text]
- Mohlenkamp S, Hort W, Ge J, Erbel R. Update on myocardial bridging.
Circulation 2002;206
: 2616-2622
- Ferreira AG Jr, Trotter SE, Konig B Jr, Decourt LV, Fox K, Olsen
EG. Myocardial bridges: morphological and functional aspects. Br
Heart J 1991; 66:364
-367[Abstract/Free Full Text]

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