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(SMEs add content and update the text below. Thank you.)

Parametric Mapping is a way to measure relaxation time for longitudinal and transverse relaxation time along with extracellular volume. The Native T1 mapping or longitudinal (T1)  relaxation time is the time constant which determines the rate at which excited protons return to equilibrium. It is a measure of the time taken for spinning protons to realign with the external magnetic field. The Native T1 mapping or transverse (T2) relaxation time constant which determines the rate at which excited protons reach equilibrium or go out of phase with each other. It is a measure of the time taken for spinning protons to lose phase coherence among the nuclei spinning perpendicular to the main field.

"T1 mapping stands for registering the course of recovery of longitudinal magnetism", this means the relaxation time after either the preparation step (saturation or inversion prepulse) followed by the acquisition of images at several time points during the T1 recover/relaxation. T1 value represents the time when recovery of magnetism has reached a percentage of its original state (63%). The recovery rate relates to the myocardial tissue properties that may be altered by pathological tissue presence (https://www.ahajournals.org/doi/10.1161/circresaha.116.307974). T1 mapping values increase with disease, and decrease post contrast.

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For extracellular volume - use percent. Normal is under 28.5%; Abnormal is in the mid 30%; mid 20% 

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Post contrast longitudinal relaxation time is 400s to 500s

Post contrast transverse relaxation time is not done

Stopped here -

1. Do we need timepoints for the T1 measurement or just the point in time of the final assessment? Not applicable
   
2. Does Cardiac Motion correction need to be indicated? If yes, does the type need to be indicated (such as the modified LL (MOLLI) sequence)?  If yes, should this be reflected on each result? (Alana/Jon/Diane - I am considering a "Cardiac Motion Correction Indicator" NSV if this is important)- MOLLI shMOLLI, SHASHA, too much in the weeds. not applicable.
3. Three is a "gold" standard noted as the "T1 mapping based on the acquisition of single images by a T1 turbo spin-echo sequence". It is noted as the ultimate T1 mapping method. Does the method need to be called out by what kind of acquisition sequence was used? NA
   
4. For the location does the intracellular compartment need to be noted? (myocytes, fibroblasts, endothelial cells, smooth muscle cells)
5. Does the cardiac phase for the specific T1 segment need to be noted? (atrial systole-diastole; isovolumentric contraction-diastole; rapid ejection-systole; reduced ejection-systole; isovolumetric relaxation-diastole; rapid ventricular filling-diastole) - NA, done in diastole
6. Is it important to record the "MRI scanner type" (Avanto, Siemens; Best, Philips; Acheiva, Philips), the "reception coil" (16-channel; 32-channel), "the T1 mapping sequence" (MOLLI; ShMOLLI)

The following example shows the parametric mapping (T1 mapping, T2 mapping, and extracellular volume) results for USUBJID 301. For brevity, after contrast a limited sample of tests were shown in this example.

The PR dataset shows the procedure of cardiac magnetic resonance imaging using the device associated with SPDEVID ABC001 and the PRREFID of 12345678. This information shows what CMR device is used for the procedure and the This example Procedures (PR) dataset includes the SPDEVID variable to show what device was used and the PRREFID variable to represent the accession number or procedure reference identifier associated with the specific procedure for USUBJID 301. The SPDEVID variable is was used to relate records by the device (in this case, the CMR machine). The Device Identifier (DI) dataset holds the device information details, the Device Properties (DO) dataset holds characteristics of the device that do not vary over the between subjects. The Device-In-Use (DU) dataset holds settings that are set on a device when it is used and may vary between participants.link this PR record to the device records.

The Cardiovascular System Findings This example cardiovascular system findings (CV) dataset contains physiological and morphological findings related to the cardiovascular system so it holds the assessments from the parametric mapping. The CV dataset below shows how to represent longitudinal relaxation time, transverse relaxation time, and extracellular volume findings from CMR imaging. This example includes records for an unreadable image and an unperformed test. For these records, CVSTAT was populated with "NOT DONE" and CVREASND was populated with the reason the result was not provided or the procedure was not done. An NSV was used to represent image quality.