A geometric index to differentiate abnormal from normal septal wall motion on cardiac MRI.
BACKGROUND
The definition of abnormal septal wall motion (SWM) is usually performed on a subjective visual assessment with cardiac MR (CMR).


OBJECTIVE
To quantify SWM using a geometric index and to compare this index to the visual inspection in patients with or without abnormal SWM.


METHODS
Cine CMR images of 100 consecutive patients were retrospectively assessed for visual evaluation of SWM and calculation of a convexity septal index (CSI) on mid-ventricular short-axis images, defined as b/a (a = minimal distance from anterior to posterior ventricular junctions; b = maximal distance from septum to a), obtained in end-systole (ES) and end-diastole (ED). Cohen κ, Bland-Altman method, Kruskall-Wallis, Mann-Whitney U, Jonckheere-Terpstra, and Spearman statistics were used to compare the two methods.


RESULTS
At visual evaluation, 73 patients had normal SWM (group A), nine abnormal SWM at ES (group B), and 18 at ES and ED (group C). Median CSI for group A was significantly higher (ES = 0.23, ED = 0.25) than those for group B and C (0.10-0.15) (P < 0.001). Inter-reader reproducibility of visual evaluation was high (κ = 0.841, P < 0.001) while that for CSI was 77%. Average time for visual analysis was 3 min, for quantitative analysis 4 min.


CONCLUSIONS
CSI is a simple and reproducible way to quantify SWM. ED CSI seems to be sensitive in detecting abnormal SWM in patients with apparently normal SWM at visual evaluation.
IRCCS Policlinico San Donato, Radiology Unit, San Donato Milanese, Italy francesco.secchi@grupposandonato.it.
Francesco
F
Secchi
Università degli Studi di Milano, Scuola di Specializzazione in Radiodiagnostica, Milan, Italy.
Elda Chiara
EC
Resta
Università degli Studi di Milano, Scuola di Specializzazione in Radiodiagnostica, Milan, Italy.
Antonello
A
Giardino
IRCCS Policlinico San Donato, Radiology Unit, San Donato Milanese, Italy.
Giovanni
G
Di Leo
IRCCS Policlinico San Donato, Unit of Cardiology, San Donato Milanese, Italy.
Francesco
F
Bandera
IRCCS Policlinico San Donato, Unit of Cardiology, San Donato Milanese, Italy.
Marco
M
Guazzi
IRCCS Policlinico San Donato, Radiology Unit, San Donato Milanese, Italy Università degli Studi di Milano, Dipartimento di Scienze Biomediche per la Salute, Milan, Italy.
Francesco
F
Sardanelli
D000328:Adult; D003937:Diagnosis, Differential; D005260:Female; D006331:Heart Diseases / Q000175:diagnosis* / Q000503:physiopathology*; D006346:Heart Septum / Q000503:physiopathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D015203:Reproducibility of Results; D012189:Retrospective Studies
Cardiac MR (CMR); convexity septal index (CSI); septal wall motion (SWM)