Aix-Marseille University, CNRS, CRMBM, Marseille, France.
Department of Radiology, Timone University Hospital, Marseille, France.
J Cardiovasc Magn Reson. 2018 Oct 25;20(1):70. doi: 10.1186/s12968-018-0489-0.
The definition of left ventricular (LV) non-compaction is controversial, and discriminating between normal and excessive LV trabeculation remains challenging. Our goal was to quantify LV trabeculation on cardiovascular magnetic resonance (CMR) images in a genetic mouse model of non-compaction using a dedicated semi-automatic software package and to compare our results to the histology used as a gold standard.
Adult mice with ventricular non-compaction were generated by conditional trabecular deletion of Nkx2-5. Thirteen mice (5 controls, 8 Nkx2-5 mutants) were included in the study. Cine CMR series were acquired in the mid LV short axis plane (resolution 0.086 × 0.086x1mm) (11.75 T). In a sub set of 6 mice, 5 to 7 cine CMR were acquired in LV short axis to cover the whole LV with a lower resolution (0.172 × 0.172x1mm3). We used semi-automatic software to quantify the compacted mass (M), the trabeculated mass (M) and the percentage of trabeculation (M/M) on all cine acquisitions After CMR all hearts were sliced along the short axis and stained with eosin, and histological LV contouring was performed manually, blinded from the CMR results, and M, M and M/M were quantified. Intra and interobserver reproducibility was evaluated by computing the intra class correlation coefficient (ICC).
Whole heart acquisition showed no statistical significant difference between trabeculation measured at the basal, midventricular and apical parts of the LV. On the mid-LV cine CMR slice, the median M was 0.92 mg (range 0.07-2.56 mg), M was 12.24 mg (9.58-17.51 mg), M/M was 6.74% (0.66-17.33%). There was a strong correlation between CMR and the histology for M, M and M/ M with respectively: r = 0.94 (p < 0.001), r = 0.91 (p < 0.001), r = 0.83 (p < 0.001). Intra- and interobserver reproducibility was 0.97 and 0.8 for M; 0.98 and 0.97 for M; 0.96 and 0.72 for M/M, respectively and significantly more trabeculation was observed in the M Mutant mice than the controls.
The proposed semi-automatic quantification software is accurate in comparison to the histology and reproducible in evaluating M, M and M/ M on cine CMR.
左心室（LV）非致密化的定义存在争议，区分正常和过度 LV 小梁化仍然具有挑战性。我们的目标是使用专用的半自动软件包在非致密化的基因小鼠模型中对心血管磁共振（CMR）图像上的 LV 小梁化进行定量，并将我们的结果与作为金标准的组织学进行比较。
通过条件性小梁 Nkx2-5 删除生成心室非致密化的成年小鼠。共有 13 只小鼠（5 只对照，8 只 Nkx2-5 突变体）纳入研究。在 LV 短轴中部平面（分辨率 0.086×0.086x1mm）（11.75 T）上采集电影 CMR 系列。在 6 只小鼠的亚组中，使用较低的分辨率（0.172×0.172x1mm3）在 LV 短轴中采集 5 到 7 次电影 CMR 以覆盖整个 LV。我们使用半自动软件在所有电影采集上定量计算致密化质量（M）、小梁化质量（M）和小梁化百分比（M/M）。在 CMR 后，所有心脏都沿着短轴切片并用曙红染色，并在不了解 CMR 结果的情况下进行手动的 LV 轮廓组织学测量，并定量测量 M、M 和 M/M。通过计算组内相关系数（ICC）评估观察者内和观察者间的可重复性。
整个心脏采集显示 LV 基底部、中部和心尖部小梁化测量无统计学显著差异。在 LV 中部电影 CMR 切片上，M 的中位数为 0.92mg（范围 0.07-2.56mg），M 为 12.24mg（9.58-17.51mg），M/M 为 6.74%（0.66-17.33%）。CMR 与组织学在 M、M 和 M/M 方面具有很强的相关性，分别为：r=0.94（p<0.001）、r=0.91（p<0.001）、r=0.83（p<0.001）。观察者内和观察者间的可重复性分别为 0.97 和 0.8 用于 M；0.98 和 0.97 用于 M；0.96 和 0.72 用于 M/M，并且在 M 突变体小鼠中观察到的小梁化明显多于对照组。
与组织学相比，所提出的半自动定量软件在评估电影 CMR 上的 M、M 和 M/M 方面是准确且可重复的。
