Motion

Regional left ventricular wall motion can be assessed in different ways: by visual assessment, regional strain, and the new Medis innovative parameter Inward Displacement. All methodologies aim to identify regional myocardial impairment before it becomes manifest.

More specifically, although ejection fraction and global strain have shown to be of great value for clinical diagnosis, assessing regional dysfunction remains a challenge, even with regional strain. To assess regional dysfunction in a more objective and quantitative manner, we have introduced “Inward Displacement”.

Early feedback confirms the method works very well in MR, CT as well as in Echocardiography. With the Medis Medical Imaging Solution, you can quickly and accurately quantify the left ventricular regional wall motion.

Wall Motion

Regional strain provides information on regional ventricular dysfunction by measuring the changes in parallel displacement along the left ventricular circumference. However, the sensitivity of regional strain has been shown to be relatively low. This is due to the fact, that small changes in the length of a subsegment along the perimeter of the left heart chamber are prone to large variabilities, depending on the definitions of these subsegments.

 

Over the years, various left ventricular wall motion models have been developed, the most well-known model is the centerline model [1]. This model is based on the changes in position of individual points along the LV perimeter from ED to ES and perpendicular to the centerline between the ED and ES contours. However, this is method not based on a solid wall motion model.

 

The feature tracking technology provides much more information about the actual displacement of the individual positions along the left ventricular boundary. Based on that solid technology, Medis has created an actual left ventricular wall motion model which shows that points along the endocardial border are moving towards well-defined “centers of contraction”. The new Inward Displacement model allows for an objective quantitative assessment of regional function. Figure 1 shows a graphical representation of the basic principles of the Inward Displacement model.

Figure 1: Basic principles of the Inward Displacement model

Pathologies

Over the years, strain has demonstrated its value for the function of the left ventricle in different cardiac disorders such as myocardial infarction, cardiac toxicity, and various cardiomyopathies. Some of the pathologies are highlighted below.

The value of strain keeps increasing by new evidence that is gathered through research highlighting the incremental prognostic value of strain in various cardiac disorders

Myocardial Infarct

To detect myocardial infarction, it is expected that changes in the regional strain and inward displacement are visible in multiple segments, in line with the associated coronary trajectories.

For example, the  CT-derived regional strain was significantly reduced in patients with significant disease in the LAD compared with healthy controls [2]. Also, with MR [3] and Ultrasound [4], the ability to detect myocardial infarcts based on regional wall motion technologies has been illustrated.

Recently, a case report was published demonstrating the use of Inward Displacement to objectively confirm regional dysfunction in a patient with a myocardial infarct [5]. Assessing left ventricular remodeling and defining therapeutic strategies could be done based on the regional wall motion results.

De La Pena-Almaguer et al. recently published a case report demonstrating the use of Inward Displacement to objectively confirm regional dysfunction in a patient with a myocardial infarct. From image a-c, one can see the 3-chamber view, the 2-chamber view and the 4-chamber view image acquired by CT. From d to f the corresponding ES and ED borders are demonstrated with the red lines in between illustrating Inward Displacement. From g, one can see the 3D model composed out of three different views and lastly h and j are 17 segment AHA models for Inward Displacement and longitudinal strain respectively.

Amyloidosis

Due to regional strain, cardiac amyloidosis can be diagnosed by the presence of relative apical sparing [6].  Regional strain by echocardiography can be measured quantitatively in which the apical regional strain shows normal values. This can also be seen in figure 2 in which normal apical regional strain values can be seen whereas basal and mid-regional strain values are reduced. Another article shows that regional strain quantification enables differentiating cardiac amyloidosis from other pathologies such as hypertrophic cardiomyopathy [7].

Figure 2: Bull's eye plots of speckle tracking longitudinal strain patterns in patients with amyloidosis [6]

Measuring motion using Medis

There has been a great need to describe accurately and quantitatively regional left ventricular wall motion along its actual motion trajectories, and not along the perimeter of the chamber, which does not describe the actual physiology. For that reason, Medis has, together with our KOLs, developed the Inward Displacement model as a new innovative methodology based on Speckle or Feature tracking, as well as a model that describes better the actual trajectories rather than the centerline method. Therefore, the Inward Displacement bull’s eye plots describe the regional impairment most in line with visual observations.

Our Medis Inward Displacement solution is feasible for the Left Ventricle and is available for MR, CT, and Ultrasound to further enhance insights for your patients’ cases. 

Inward Displacement across modalities

Understanding Ultrasound: Strain

Measuring motion using Medis

There has been a great need to describe accurately and quantitatively regional left ventricular wall motion along its actual motion trajectories, and not along the perimeter of the chamber, which does not describe the actual physiology. For that reason, Medis has, together with our KOLs, developed the Inward Displacement model as a new innovative methodology based on Speckle or Feature tracking, as well as a model that describes better the actual trajectories rather than the centerline method. Therefore, the Inward Displacement bull’s eye plots describe the regional impairment most in line with visual observations.

Our Medis Inward Displacement solution is feasible for the Left Ventricle and is available for MR, CT, and Ultrasound to further enhance insights for your patients’ cases. 

Inward Displacement across modalities

Understanding Ultrasound: Strain

Benefits of measuring strain using Medis

Based on Feature/Speckle Tracking

Medis’ tracking algorithms are created by the Founders of strain. Both the speckle and feature tracking algorithms are robust, vendor-independent, and proven algorithms. The algorithms have been optimized for each specific modality. Altogether, our tracking algorithms have been used in over 1700 scientific papers.

Workflow

The inward displacement measurement is based on Feature Tracking hence we have incorporated it in the Strain application. Once you have performed your strain analysis, you are one button click away from your Inward Displacement results presented in the Bull’s Eye plots. The values will be presented based on your regular cine images without any additional time or effort.

Multi-modality

Inward Displacement can be measured on Ultrasound, MRI, and CT images with Medis. This enables comparing data from one modality to another, as for all modalities the inward displacement is based on the same algorithm., Medis multimodality solution, ensures that very likely you will have inward displacement data for each patient, depending on at least one available modality

Deep Learning contours

Getting the long axis endocardial borders can be a time-consuming and repetitive task. For MR data deep learning contour detection has been embedded, for which we have had great feedback from our users. The Medis AI Deep learning algorithm, which has been trained on almost 900 datasets in various cases across different vendors and pathologies, increases reproducibility.

Based on Feature/Speckle Tracking

Medis’ tracking algorithms are created by the Founders of strain. Both the speckle and feature tracking algorithms are robust, vendor-independent, and proven algorithms. The algorithms have been optimized for each specific modality. Altogether, our tracking algorithms have been used in over 1700 scientific papers.

Workflow

The inward displacement measurement is based on Feature Tracking hence we have incorporated it in the Strain application. Once you have performed your strain analysis, you are one button click away from your Inward Displacement results presented in the Bull’s Eye plots. The values will be presented based on your regular cine images without any additional time or effort.

Multi-modality

Inward Displacement can be measured on Ultrasound, MRI, and CT images with Medis. This enables comparing data from one modality to another, as for all modalities the inward displacement is based on the same algorithm., Medis multimodality solution, ensures that very likely you will have inward displacement data for each patient, depending on at least one available modality

Deep Learning contours

Getting the long axis endocardial borders can be a time-consuming and repetitive task. For MR data deep learning contour detection has been embedded, for which we have had great feedback from our users. The Medis AI Deep learning algorithm, which has been trained on almost 900 datasets in various cases across different vendors and pathologies, increases reproducibility.

Using Inward Displacement
across different modalities

Inward Displacement can be measured in Ultrasound, MR and CT images. Medis multimodality solution ensures that very likely you will have inward displacement data for each patient, depending on at least one available modality

Medis Suite CT

Medis Suite MR

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