Table 1.

Overview of salient T₁ mapping sequences comparing building plans, strengths, and limitations^a

Sequence	Building plan: 3 integral parts			Strength	Limitation	Reference
	T1 preparation	Imaging readout	Respiratory motion compensation
Original MOLLI	IR pulse over multiple heartbeats	Single-shot end-diastolic bSSFP	Single breath-hold	– High-quality T1 maps – Good precision (noise resilience) – Widely available – High inter-center reproducibility	– T1 time dependence on T2, MT, and sequence parameters – HR dependence	[6]
Fixed-recovery MOLLI	IR pulse over multiple heartbeats	Single-shot end-diastolic bSSFP	Single 11-s breath-hold	– Little HR variability – Separate optimization allows precision for both native and post-GBCA regimes	– Requires different protocols for native and post-GBCA scans	[7]
ShMOLLI	IR pulse over multiple heartbeats	Single-shot end-diastolic bSSFP	Single short 9-s breath-hold	– Short breath-holds via short rest periods of 1 heartbeat – Incomplete magnetization recovery compensated for by conditional data fit – Unified sequence for pre-/post-GBCA scanning – Little HR variability	– Low number of fit images available for use especially in native mapping – Vulnerable to mistriggering as sampling sparse	[8]
FLASH-MOLLI	IR pulse over multiple heartbeats	Single-shot end-diastolic FLASH	Single 11-s breath-hold	– Avoids off-resonance artifacts (good for high-field strengths) – No T2 dependence – Tailored fitting compensates for disruption of relaxation by FLASH pulses improving accuracy compared to original MOLLI	– Decreased SNR compared to SSFP schemes – Elaborate post-processing limits availability	[9]
TRASSI	IR pulse over multiple heartbeats	Radial golden-angle FLASH	Single short 5-s breath-hold	– Inherent properties of the radial acquisition, short breath-hold, and HR-adaptable acquisition window provide high resilience to motion artifacts – Tailored fit improves accuracy	– Potential blurring due to view-sharing across heartbeats – Little baseline data – Elaborate post-processing limits availability	[10]
SASHA	SR preparation over multiple heartbeats	Single-shot bSSFP	Single 10-s breath-hold	– Excellent accuracy as invariant to T2, MT, and inversion efficiency – Alternative reconstruction scheme has been proposed to trade off accuracy against precision – High-contrast imaging scheme available for free-breathing applications	– Still low precision compared to MOLLI – Low SNR baseline images more prone to artifacts – Low blood-myocardial imaging contrast makes post-processing with image registration challenging	[11]
SMART1 MAP	A series of single-point SR experiments	Single-shot bSSFP	Single breath-hold (13 heartbeats)	– Intra-scan heart rate insensitivity by adapting recovery time to changing heart rates by measuring heartbeats in real time – Good accuracy compared to MOLLI	– Limited data on in vivo clinical applicability; has yet to be validated at scale and on other vendor platforms	[12, 13]
SAPPHIRE	Hybrid SR/IR over multiple heartbeats	Single-shot bSSFP	Single 10-s breath-hold	– Good accuracy compared to MOLLI – Improved precision compared to SASHA	– Lower precision compared to MOLLI – Low SNR images are prone to artifacts	[14]
STONE	IR pulse over multiple heartbeats	Single-shot bSSFP	Interleaved multi (5)-slice 55 s free-breathing + registration + real-time slice tracking	– No rest periods between breath-holds as free-breathing improves patient comfort – Improved accuracy due to slice-interleaved scanning	– Potential for slice-tracking failure in heavy breathing patients – Perturbation of blood T1 times due to crosstalk between slices	[15]
ANGIE	IR pulse over multiple heartbeats	Segmented bSSFP	41 s free-breathing + diaphragmatic navigator gating	– No rest periods between breath-holds as free-breathing improves patient comfort – Enables high-resolution scans – Motion compensation robust to heavy breathing	– Accuracy comparable to MOLLI (not superior) – Elaborate compressed sensing reconstruction needed before the fit which limits availability	[16]

ANGIE Accelerated and Navigator-Gated Look-Locker Imaging for cardiac T₁ Estimation, bSSFP balanced steady-state free precession, FLASH fast low-angle shot, GBCA gadolinium-based contrast agents, HR heart rate, IR inversion recovery, MOLLI MOdified Look-Locker Inversion Recovery, MT magnetization transfer, s second(s), SAPPHIRE SAturation Pulse Prepared Heart-Rate Independent Inversion REcovery Sequence, SASHA SAturation Recovery Single SHot Acquisition, ShMOLLI shortened MOLLI, SNR signal-to-noise ratio, SR saturation recovery, STONE slice-interleaved T₁ mapping

^aList of T₁ mapping sequences is not exhaustive—more variants exist in the published literature that may not be recapitulated here