Rapid Fire Session

Session: Rapid Fire Session 5: CMR - Analysis (including machine learning) (Monitor 6)

Phenomics Based CMR Characterization of Muscular Dystrophy Subtypes With Comparison to Healthy Cohorts

Saturday, February 7, 2026

10:29 AM - 10:36 AM

Location: Galapagos / Aruba / Ilhabela (2nd Lower Level)

Presenting Author(s)

Malcolm L. Serran, BSc

MD Student
University of Toronto
Toronto, Ontario, Canada

Primary Author(s)

Malcolm L. Serran, BSc

MD Student
University of Toronto
Toronto, Ontario, Canada

Co-Author(s)

RM

Rylan Marianchuk, BSc

Masters Student
University of Calgary
Calgary, Alberta, Canada
Justin J. Tse, PhD, MSc, BSc

Research Associate
University of Calgary
Calgary, Alberta, Canada
ES

Eric P. Seidlitz, PhD

Assistant Professor
McMaster University, Ontario, Canada
KM

Kim L. McBride, MD

Department Head
University of Calgary, Canada
TB

Talia A. Beckie, BEng

Cardiac Imaging Systems Engineer
Libin cardiovascular Institute, University of Calgary
Calgary, Alberta, Canada
SR

Sandra Rivest, RN

Research Coordinator
Libin Cardiovascular Institute; University of Calgary
Calgary, Alberta, Canada
JF

Jacqueline Flewitt, MSc

Manager of Strategic Partnerships
Libin Cardiovascular Institute; University of Calgary
Calgary, Alberta, Canada
NM

Noelle Mahon, RN

Research Nurse
University of Calgary, Canada
YF

Yuanchao Feng, PhD

Senior AHS analyst
Libin Cardiovascular Institute; University of Calgary
Calgary, Alberta, Canada
JN

Julian B. Neves, MSc

Junior Data Engineer
Libin Cardiovascular Institute, University of Calgary, Canada
AA

Augustine Amakiri, PhD

Data Analyst
University of Calgary, Canada
MK

Melanie King, PhD

Director, Program Development and Implementation
Libin Cardiovascular Institute, University of Calgary, Canada
OK

Omid B. Kiamanesh, MD

Director
University of Calgary, Canada
James A. White, MD

Professor
Libin Cardiovascular Institute; University of Calgary
Calgary, Alberta, Canada
Dina Labib, MD, PhD, FSCMR

Associate Scientific Director, Personalized Diagnostics Program; Adjunct Assistant Professor
University of Calgary
Calgary, Alberta, Canada

Background: Cardiac involvement is a leading cause of morbidity and mortality in patients with muscular dystrophy (MD). CMR-based phenotyping presents unique opportunities to characterize the expression of disease across unique genetic sub-types. In this study we performed comprehensive CMR analyses, inclusive of 4D chamber modelling, to compare global and regional structural, tissue, and deformation features across four common MD subtypes with comparison to healthy volunteers (HV).

Methods: A total of 120 MD patients and 100 HV were prospectively recruited by the Cardiovascular Imaging Registry of Calgary (CIROC). The study cohort consisted of 41 patients with dystrophinopathies (Dys), 42 with type 1 myotonic dystrophy (DM1), 17 with type 2 myotonic
dystrophy (DM2), and 20 with limb-girdle muscular dystrophy. Standardized CMR protocols were performed inclusive of routine 2D cine and late gadolinium enhancement (LGE) imaging. Conventional CMR analyses were performed using commercially available software (cvi42). This was followed by automated (no user interaction) processing of routinely acquired cines using the 4Deep analysis package, delivering spatially registered bi-layer 4D mesh models of the LV across 480 hexahedral elements. For each element, maximal wall thickness, 3D mass, and 3D principal strain (3DPS) markers were calculated, then collated for each AHA segment. Global and regional CMR markers for each MD group were compared in context of HV reference values using one-way ANOVA or Kruskal-Wallis test.

Results: The median age of MD patients was 37.0 (IQR, 26.0–53.0) vs. 46.0 (IQR, 30.0–54.0) in HV with females comprising 34% and 54%, respectively. CMR characteristics are shown in Table 1. Conventional CMR analysis showed a significant reduction of LV ejection fraction (EF) across all MD subgroups vs HV, the worst being for Dys. A high prevalence of abnormal LGE was observed across patient groups, with highest burden in Dys (prevalence of 76%, mainly subepicardial and mid-wall patchy). 4Deep analyses showed global reductions in 3D maximum principal strain (3DmaxPS) amplitude across all patient groups except for DM2 with trend towards lower height-indexed 3D LV mass in DM1. Regional analyses showed significant reductions in height-indexed 3D mass for the basal inferolateral segment in DM1 (Figure 1). Segmental 3DmaxPS was significantly lower in the Dys and DM1 versus HV and versus the 2 other MD subgroups, localizing to the septal, inferior, and inferolateral segments. End-diastolic meshes for a representative HV and patient with Dys are shown in Figure 2.

Conclusion: In this study we explored a range of CMR markers, inclusive of 3D shape and deformation, to discriminate phenotypic differences in a large group of patients with MD. We identified significant heterogeneity in disease expression across the four MD subtypes, supporting ongoing need for genotype-specific approaches surrounding the diagnosis, surveillance and risk management of patients with MD.

Table 1. CMR characteristics of healthy volunteers and muscular dystrophy subgroups

Characteristic	HVN = 100	Dystrophinopathies N = 41	DM1 N = 42	DM2 N = 17	LGMD N = 20	p-value
Age, y	46.0 (30.0, 54.0)	27.0 (20.0, 36.0)	40.5 (31.0, 55.0)	52.0 (42.0, 60.0)	50.0 (31.5, 56.5)	< 0.001
Male sex	46 (46%)	41 (100%)	18 (43%)	7 (41%)	13 (65%)	< 0.001
Conventional CMR measures
LV EDV Indexed to Height, mL/m	88.1 (78.0, 99.7)	96.6 (72.4, 111.8)	77.9 (70.2, 93.6)	69.2 (59.5, 100.0)	82.1 (65.5, 104.4)	0.075
LV ESV Indexed to Height, mL/m	31.4 (26.6, 38.2)	47.6 (32.6, 58.0)	33.1 (25.6, 39.0)	27.0 (24.4, 45.0)	35.0 (26.4, 51.5)	0.001
LV EF, %	63.0 (61.0, 67.0)	54.0 (46.5, 58.9)	58.8 (53.8, 63.7)	59.0 (57.4, 62.1)	56.4 (51.0, 61.4)	< 0.001
LV Mass Indexed to Height, g/m	50.8 (42.5, 62.9)	55.5 (48.4, 60.9)	44.8 (37.6, 56.5)	46.5 (38.7, 62.0)	54.5 (40.3, 65.7)	0.10
RV EDV Indexed to Height, mL/m	96.9 (85.6, 108.8)	84.7 (60.0, 93.2)	82.2 (67.5, 92.6)	73.9 (65.6, 106.7)	80.1 (63.9, 99.3)	< 0.001
RV ESV Indexed to Height, mL/m	41.6 (33.6, 49.3)	39.3 (25.8, 43.9)	34.4 (28.1, 42.8)	31.5 (25.1, 53.9)	38.9 (29.4, 45.8)	0.042
RV EF	57.0 (53.5, 62.0)	54.1 (52.2, 59.4)	56.0 (52.2, 59.6)	56.4 (52.5, 61.5)	55.3 (49.1, 58.8)	0.23
LA Volume Indexed to Height, mL/m	38.6 (32.7, 46.8)	31.2 (21.3, 40.5)	30.1 (21.7, 35.6)	35.4 (25.2, 40.0)	38.2 (33.9, 48.2)	< 0.001
LGE imaging
Any LGE Pattern	-	31 (76%)	12 (29%)	6 (35%)	10 (50%)	< 0.001
Sub-Endocardial	-	3 (8%)	0 (0%)	0 (0%)	0 (0%)	0.15
Mid-wall Striae	-	9 (23%)	2 (5%)	1 (7%)	3 (15%)	0.092
RV Insertion Site	-	3 (8%)	6 (14%)	3 (21%)	3 (15%)	0.50
Mid-wall Patchy	-	15 (38%)	3 (7%)	2 (14%)	2 (10%)	0.003
Sub-Epicardial	-	25 (63%)	2 (5%)	2 (14%)	6 (30%)	< 0.001
Diffuse LGE	-	0 (0%)	1 (2%)	0 (0%)	0 (0%)	>0.99
Fibrosis/scar %	-	7.4 (0.0, 16.2)	0.0 (0.0, 0.0)	0.0 (0.0, 1.5)	0.0 (0.0, 7.4)	< 0.001
4Deep CMR Measures
LV EDV Indexed to Height, mL/m	108.6 (91.3, 125.8)	127.8 (84.8, 145.3)	101.2 (79.3, 124.4)	85.6 (75.0, 95.1)	103.0 (91.1, 132.8)	0.050
LV ESV Indexed to Height, mL/m	45.6 (35.6, 53.0)	57.8 (40.9, 77.6)	47.7 (34.9, 61.2)	33.3 (29.8, 41.4)	58.8 (36.0, 80.9)	0.003
LV EF, %	59.6 (55.9, 62.6)	50.2 (41.3, 56.3)	53.8 (49.7, 58.9)	57.3 (52.8, 60.2)	49.9 (41.0, 61.4)	< 0.001
LV mass Indexed to Height, g/m	49.8 (43.4, 61.1)	51.5 (46.7, 58.4)	44.4 (38.4, 53.5)	47.7 (37.8, 58.1)	51.7 (42.9, 62.1)	0.059
Maximum Wall Thickness, mm	11.0 (9.8, 13.1)	11.8 (9.4, 12.4)	10.7 (10.0, 12.7)	11.4 (9.7, 12.9)	11.9 (9.9, 14.2)	0.93
Mean Maximum Principal Strain, %	67.2 (59.2, 78.4)	54.3 (44.6, 70.1)	53.9 (45.4, 65.7)	71.6 (63.3, 80.5)	64.9 (41.9, 79.9)	< 0.001
Mean Minimum Principal Strain, %	-22.8 (-24.6, -20.6)	-21.0 (-22.5, -17.6)	-20.9 (-25.0, -18.9)	-21.9 (-23.0, -21.3)	-22.4 (-24.2, -20.1)	0.005

Values are represented as median (Q1, Q3) or counts (%)

LV denotes left ventricle; EDV, end diastolic volume; ESV, end systolic volume; EF, ejection fraction; RV, right ventricle; LA, left atrial; and LGE, late gadolinium enhancementTable 1. CMR characteristics of healthy volunteers and muscular dystrophy subgroups

Characteristic	HVN = 100	Dystrophinopathies N = 41	DM1 N = 42	DM2 N = 17	LGMD N = 20	p-value
Age, y	46.0 (30.0, 54.0)	27.0 (20.0, 36.0)	40.5 (31.0, 55.0)	52.0 (42.0, 60.0)	50.0 (31.5, 56.5)	< 0.001
Male sex	46 (46%)	41 (100%)	18 (43%)	7 (41%)	13 (65%)	< 0.001
Conventional CMR measures
LV EDV Indexed to Height, mL/m	88.1 (78.0, 99.7)	96.6 (72.4, 111.8)	77.9 (70.2, 93.6)	69.2 (59.5, 100.0)	82.1 (65.5, 104.4)	0.075
LV ESV Indexed to Height, mL/m	31.4 (26.6, 38.2)	47.6 (32.6, 58.0)	33.1 (25.6, 39.0)	27.0 (24.4, 45.0)	35.0 (26.4, 51.5)	0.001
LV EF, %	63.0 (61.0, 67.0)	54.0 (46.5, 58.9)	58.8 (53.8, 63.7)	59.0 (57.4, 62.1)	56.4 (51.0, 61.4)	< 0.001
LV Mass Indexed to Height, g/m	50.8 (42.5, 62.9)	55.5 (48.4, 60.9)	44.8 (37.6, 56.5)	46.5 (38.7, 62.0)	54.5 (40.3, 65.7)	0.10
RV EDV Indexed to Height, mL/m	96.9 (85.6, 108.8)	84.7 (60.0, 93.2)	82.2 (67.5, 92.6)	73.9 (65.6, 106.7)	80.1 (63.9, 99.3)	< 0.001
RV ESV Indexed to Height, mL/m	41.6 (33.6, 49.3)	39.3 (25.8, 43.9)	34.4 (28.1, 42.8)	31.5 (25.1, 53.9)	38.9 (29.4, 45.8)	0.042
RV EF	57.0 (53.5, 62.0)	54.1 (52.2, 59.4)	56.0 (52.2, 59.6)	56.4 (52.5, 61.5)	55.3 (49.1, 58.8)	0.23
LA Volume Indexed to Height, mL/m	38.6 (32.7, 46.8)	31.2 (21.3, 40.5)	30.1 (21.7, 35.6)	35.4 (25.2, 40.0)	38.2 (33.9, 48.2)	< 0.001
LGE imaging
Any LGE Pattern	-	31 (76%)	12 (29%)	6 (35%)	10 (50%)	< 0.001
Sub-Endocardial	-	3 (8%)	0 (0%)	0 (0%)	0 (0%)	0.15
Mid-wall Striae	-	9 (23%)	2 (5%)	1 (7%)	3 (15%)	0.092
RV Insertion Site	-	3 (8%)	6 (14%)	3 (21%)	3 (15%)	0.50
Mid-wall Patchy	-	15 (38%)	3 (7%)	2 (14%)	2 (10%)	0.003
Sub-Epicardial	-	25 (63%)	2 (5%)	2 (14%)	6 (30%)	< 0.001
Diffuse LGE	-	0 (0%)	1 (2%)	0 (0%)	0 (0%)	>0.99
Fibrosis/scar %	-	7.4 (0.0, 16.2)	0.0 (0.0, 0.0)	0.0 (0.0, 1.5)	0.0 (0.0, 7.4)	< 0.001
4Deep CMR Measures
LV EDV Indexed to Height, mL/m	108.6 (91.3, 125.8)	127.8 (84.8, 145.3)	101.2 (79.3, 124.4)	85.6 (75.0, 95.1)	103.0 (91.1, 132.8)	0.050
LV ESV Indexed to Height, mL/m	45.6 (35.6, 53.0)	57.8 (40.9, 77.6)	47.7 (34.9, 61.2)	33.3 (29.8, 41.4)	58.8 (36.0, 80.9)	0.003
LV EF, %	59.6 (55.9, 62.6)	50.2 (41.3, 56.3)	53.8 (49.7, 58.9)	57.3 (52.8, 60.2)	49.9 (41.0, 61.4)	< 0.001
LV mass Indexed to Height, g/m	49.8 (43.4, 61.1)	51.5 (46.7, 58.4)	44.4 (38.4, 53.5)	47.7 (37.8, 58.1)	51.7 (42.9, 62.1)	0.059
Maximum Wall Thickness, mm	11.0 (9.8, 13.1)	11.8 (9.4, 12.4)	10.7 (10.0, 12.7)	11.4 (9.7, 12.9)	11.9 (9.9, 14.2)	0.93
Mean Maximum Principal Strain, %	67.2 (59.2, 78.4)	54.3 (44.6, 70.1)	53.9 (45.4, 65.7)	71.6 (63.3, 80.5)	64.9 (41.9, 79.9)	< 0.001
Mean Minimum Principal Strain, %	-22.8 (-24.6, -20.6)	-21.0 (-22.5, -17.6)	-20.9 (-25.0, -18.9)	-21.9 (-23.0, -21.3)	-22.4 (-24.2, -20.1)	0.005

Values are represented as median (Q1, Q3) or counts (%)

LV denotes left ventricle; EDV, end diastolic volume; ESV, end systolic volume; EF, ejection fraction;

RV, right ventricle; LA, left atrial; and LGE, late gadolinium enhancement Figure 1. AHA segmental distribution of height indexed LV mass and max principal strain in HV and the MD subgroups. DM1 denotes type 1 myotonic dystrophy; DM2, type 2 myotonic dystrophy; Dys, dystrophinoapthy; HV, healthy volunteers; and LGMD, limb girdle muscular dystrophy.
Figure 2. End-diastolic meshes from a representative HV (left panel; 49 Y female) and a patient with Becker muscular dystrophy (right panel; 37 Y male). The patient shows significant left ventricular dilatation, globular shape, and marked reduction in 4Deep LV ejection fraction (21%).