Adiabatic Mapping Research Articles

Detection of early metaphyseal changes in a piglet model of Legg-Calvé-Perthes disease using quantitative mapping of MRI relaxation times.

Legg-Calvé-Perthes disease (LCPD) is a childhood hip disorder characterized by ischemic injury to the epiphysis of the femoral head, but changes to the metaphysis have also been implicated in its pathogenesis. Quantitative magnetic resonance imaging (MRI) relaxation time mapping techniques are potentially useful to detect injury in LCPD, but studies to date have focused on the epiphysis. The purpose of this study was to assess whether T2, T1ρ, adiabatic T1ρ, and adiabatic T2ρ relaxation times can detect early metaphyseal changes in an LCPD piglet model. Complete epiphyseal ischemia of one femoral head was surgically induced and confirmed using contrast-enhanced MRI in n = 10 6-week-old piglets; the contralateral side was unoperated. The bilateral hips were imaged 1 week after surgery in vivo at 3T MRI using relaxation time mapping and contrast-enhanced MRI. Relaxation times and thicknesses of the metaphyseal primary and secondary spongiosa were measured and compared between the ischemic and contralateral-control femoral heads using paired t-tests. In the ischemic femoral heads, T2 relaxation times were significantly increased in the primary spongiosa (6.7 ± 9.8 ms, p = 0.029), and T2, T1ρ, adiabatic T1ρ, and adiabatic T2ρ relaxation times were significantly decreased in the secondary spongiosa (respectively: -13.3 ± 9.3 ms, p = 0.013; -32 ± 23 ms, p < 0.001; -43 ± 41 ms, p = 0.009; and -39 ± 13 ms, p < 0.001). The secondary spongiosa thickness was also significantly decreased in the ischemic femoral heads (p < 0.001). In conclusion, T2, T1ρ, adiabatic T1ρ, and adiabatic T2ρ relaxation time mapping techniques can detect early changes in the metaphysis following ischemic injury to the epiphysis of the femoral head in a piglet model of LCPD.

Anisotropy of T2 and T1ρ relaxation time in articular cartilage at 3 T.

The anisotropy of R2 and R1ρ relaxation rates in articular cartilage contains information about the collagenous structure of the tissue. Here we determine and study the anisotropic and isotropic components of T2 and T1ρ relaxation parameters in articular cartilage with a clinical 3T MRI device. Furthermore, a visual representation of the topographical variation in anisotropy is given via anisotropy mapping. Eight bovine stifle joints were imaged at 22 orientations with respect to the main magnetic field using T2, continuous-wave (CW) T1ρ, and adiabatic T1ρ mapping sequences. Relaxation rates were separated into isotropic and anisotropic relaxation components using a previously established relaxation anisotropy model. Pixel-wise anisotropy values were determined from the relaxation-time maps using Michelson contrast. The relaxation rates obtained from the samples displayed notable variation depending on the sample orientation, magnetization preparation, and cartilage layer. R2 demonstrated significant anisotropy, whereas CW-R1ρ (300 Hz) and CW-R1ρ (500 Hz) displayed a low degree of anisotropy. Adiabatic R1ρ was largely isotropic. In the deep cartilage regions, relaxation rates were generally faster and more anisotropic than in the cartilage closer to the tissue surface. The isotropic relaxation rate components were found to have similar values regardless of measurement sequence. The fitted relaxation model for T2 and T1ρ demonstrated varying amounts anisotropy, depending on magnetization preparation, and studied the articular cartilage layer. Anisotropy mapping of full joints showed varying amounts of anisotropy depending on the quantitative MRI parameter and topographical location, and in the case of T2, showed systematic changes in anisotropy across cartilage depth.

CMR 4-140 - Adiabatic T2ρ Mapping in the Human Myocardium at 3T

CMR 4-140 - Adiabatic T2ρ Mapping in the Human Myocardium at 3T

Robust cardiac mapping at 3T using adiabatic spin-lock preparations.

The aim of this study is to develop and optimize an adiabatic ( ) mapping method for robust quantification of spin-lock (SL) relaxation in the myocardium at 3T. Adiabatic SL (aSL) preparations were optimized for resilience against and inhomogeneities using Bloch simulations. Optimized -aSL, Bal-aSL and -aSL modules, each compensating for different inhomogeneities, were first validated in phantom and human calf. Myocardial mapping was performed using a single breath-hold cardiac-triggered bSSFP-based sequence. Then, optimized preparations were compared to each other and to conventional SL-prepared maps (RefSL) in phantoms to assess repeatability, and in 13 healthy subjects to investigate image quality, precision, reproducibility and intersubject variability. Finally, aSL and RefSL sequences were tested on six patients with known or suspected cardiovascular disease and compared with LGE, , and ECV mapping. The highest preparation efficiency was obtained in simulations for modules comprising 2 HS pulses of 30 ms each. In vivo maps yielded significantly higher quality than RefSL maps. Average myocardial values were 183.28 25.53 ms, compared with 38.21 14.37 ms RefSL-prepared . maps showed a significant improvement in precision (avg. 14.47 3.71% aSL, 37.61 19.42% RefSL, p < 0.01) and reproducibility (avg. 4.64 2.18% aSL, 47.39 12.06% RefSL, p < 0.0001), with decreased inter-subject variability (avg. 8.76 3.65% aSL, 51.90 15.27% RefSL, p < 0.0001). Among aSL preparations, -aSL achieved the better inter-subject variability. In patients, -aSL preparations showed the best artifact resilience among the adiabatic preparations. times show focal alteration colocalized with areas of hyper-enhancement in the LGE images. Adiabatic preparations enable robust in vivo quantification of myocardial SL relaxation times at 3T.

Map of suprathermal onto nonextensive parameters describing Langmuir waves

We propose a polytropic-like index that depends on the concentration and number of degrees of freedom of a gas of charged particles following a nonextensive distribution. An equation of state of the gas is obtained and a dispersion relation describing Langmuir waves is derived. Comparison of the acquired dispersion relation with a previous one, recently deduced in the realm of the Kappa distribution, provides an adiabatic map of suprathermal onto nonextensive parameters. In the isothermal limit, the map recovers a well-known relation between those quantities. The results presented here may be useful for investigating the physics of coupled and weakly interacting systems in the nonextensive framework.

Accelerated Quantitative 3D UTE-Cones Imaging Using Compressed Sensing.

In this study, the feasibility of accelerated quantitative Ultrashort Echo Time Cones (qUTE-Cones) imaging with compressed sensing (CS) reconstruction is investigated. qUTE-Cones sequences for variable flip angle-based UTE T1 mapping, UTE adiabatic T1ρ mapping, and UTE quantitative magnetization transfer modeling of macromolecular fraction (MMF) were implemented on a clinical 3T MR system. Twenty healthy volunteers were recruited and underwent whole-knee MRI using qUTE-Cones sequences. The k-space data were retrospectively undersampled with different undersampling rates. The undersampled qUTE-Cones data were reconstructed using both zero-filling and CS reconstruction. Using CS-reconstructed UTE images, various parameters were estimated in 10 different regions of interests (ROIs) in tendons, ligaments, menisci, and cartilage. Structural similarity, percentage error, and Pearson’s correlation were calculated to assess the performance. Dramatically reduced streaking artifacts and improved SSIM were observed in UTE images from CS reconstruction. A mean SSIM of ~0.90 was achieved for all CS-reconstructed images. Percentage errors between fully sampled and undersampled CS-reconstructed images were below 5% for up to 50% undersampling (i.e., 2× acceleration). High linear correlation was observed (>0.95) for all qUTE parameters estimated in all subjects. CS-based reconstruction combined with efficient Cones trajectory is expected to achieve a clinically feasible scan time for qUTE imaging.

Simple approach to characterizing band topology in bosonic pairing Hamiltonians

We revisit the problem of characterizing band topology in dynamically-stable quadratic bosonic Hamiltonians that do not conserve particle number. We show this problem can be rigorously addressed by a smooth and local adiabatic mapping procedure to a particle number conserving Hamiltonian. In contrast to a generic fermionic pairing Hamiltonian, such a mapping can always be constructed for bosons. Our approach shows that particle non-conserving bosonic Hamiltonians can be classified using known approaches for fermionic models. It also provides a simple means for identifying and calculating appropriate topological invariants. We also explicitly study dynamically stable but non-positive definite Hamiltonians (as arise frequently in driven photonic systems). We show that in this case, each band gap is characterized by two distinct invariants.

Endogenous assessment of myocardial injury with single-shot model-based non-rigid motion-corrected T1 rho mapping

BackgroundCardiovascular magnetic resonance T1ρ mapping may detect myocardial injuries without exogenous contrast agent. However, multiple co-registered acquisitions are required, and the lack of robust motion correction limits its clinical translation. We introduce a single breath-hold myocardial T1ρ mapping method that includes model-based non-rigid motion correction.MethodsA single-shot electrocardiogram (ECG)-triggered balanced steady state free precession (bSSFP) 2D adiabatic T1ρ mapping sequence that collects five T1ρ-weighted (T1ρw) images with different spin lock times within a single breath-hold is proposed. To address the problem of residual respiratory motion, a unified optimization framework consisting of a joint T1ρ fitting and model-based non-rigid motion correction algorithm, insensitive to contrast change, was implemented inline for fast (~ 30 s) and direct visualization of T1ρ maps. The proposed reconstruction was optimized on an ex vivo human heart placed on a motion-controlled platform. The technique was then tested in 8 healthy subjects and validated in 30 patients with suspected myocardial injury on a 1.5T CMR scanner. The Dice similarity coefficient (DSC) and maximum perpendicular distance (MPD) were used to quantify motion and evaluate motion correction. The quality of T1ρ maps was scored. In patients, T1ρ mapping was compared to cine imaging, T2 mapping and conventional post-contrast 2D late gadolinium enhancement (LGE). T1ρ values were assessed in remote and injured areas, using LGE as reference.ResultsDespite breath holds, respiratory motion throughout T1ρw images was much larger in patients than in healthy subjects (5.1 ± 2.7 mm vs. 0.5 ± 0.4 mm, P < 0.01). In patients, the model-based non-rigid motion correction improved the alignment of T1ρw images, with higher DSC (87.7 ± 5.3% vs. 82.2 ± 7.5%, P < 0.01), and lower MPD (3.5 ± 1.9 mm vs. 5.1 ± 2.7 mm, P < 0.01). This resulted in significantly improved quality of the T1ρ maps (3.6 ± 0.6 vs. 2.1 ± 0.9, P < 0.01). Using this approach, T1ρ mapping could be used to identify LGE in patients with 93% sensitivity and 89% specificity. T1ρ values in injured (LGE positive) areas were significantly higher than in the remote myocardium (68.4 ± 7.9 ms vs. 48.8 ± 6.5 ms, P < 0.01).ConclusionsThe proposed motion-corrected T1ρ mapping framework enables a quantitative characterization of myocardial injuries with relatively low sensitivity to respiratory motion. This technique may be a robust and contrast-free adjunct to LGE for gaining new insight into myocardial structural disorders.

A Methodology for Measuring Turbocharger Adiabatic Maps in a Gas-Stand and Its Usage for Calibrating Control Oriented and One-Dimensional Models at Early ICE Design Stages

Abstract In this work, a methodology is proposed to standardize turbochargers testing based on measuring the maps twice: in close to adiabatic and in diathermal conditions. Along the paper, it is discussed with special detail the impact of the procedure followed to achieve said quasi-adiabatic conditions in both the energy balance of the turbocharger and the testing complexity. As a conclusion, the paper proposes a methodology which combines quasi-adiabatic tests (cold and hot gas flow) with diathermal tests (hot gas flow) in order to extract from a turbocharger gas-stand all information needed by engine designers interested in controlling or one-dimensional-modeling the internal combustion engine (ICE). The methodology is completed with a guide for calibrating said control-oriented turbocharger models in order to separate aerodynamic efficiency (adiabatic) from heat transfer (HT) losses and from friction losses in the analysis of the turbocharger performance. The outsourced calibration of the turbocharger model allows avoiding uncertainties in the global ICE model calibration, what is very interesting for turbochargers benchmarking at early ICE-turbo matching stages or for global system analysis at early control design stages.

A holistic consideration of turbocharger heat transfer analysis and advanced turbocharging modeling methodology in a 1D engine process simulation context

The focus on transient engine operation will increase to fulfill future emission requirements in the commercial vehicle sector. Accordingly, the transient turbocharger matching process is becoming increasingly important. The one-dimensional fluid dynamics (1D-CFD) simulation is established as an important development tool for matching the exhaust gas turbocharger to a combustion engine. The optimization of the modeling methodology of the combustion process and the turbocharger modeling are two key parameters to improve the reliability of the dynamic engine process simulation. In this paper, the advanced turbocharger (TC) methodology is described. This includes the determination of the adiabatic turbocharger performance from conventional hot gas test stand (HGS) measurement data, the derivation of an one-dimensional (1D) turbocharger heat transfer model and a method to physically extend the turbine map range. The adiabatic efficiencies of the turbocharger are determined with a model-based heat transfer correction of the conventional measured efficiencies from HGS measurement data. These adiabatic efficiency maps were used as a baseline to extend the conventional TC model with a heat transfer model taking into account of the engine boundary conditions in terms of temperature, pressure and mass flow rate. To assess the temperature distribution and the thermal inertia of the TC main components, in both stationary and transient engine operations, the variable geometry turbine (VGT) turbocharger hardware, installed on a medium-duty diesel engine, was equipped with several thermocouples on all accessible surfaces to make comprehensive surface temperature surveys. A 1D lumped capacitance heat transfer model (HTM) of the VGT TC was developed and validated against the experimental data from the engine test bench. To complete the advanced TC modeling, the turbine map is extended using experimental measurement data, based on extended HGS measurements, in combination with mathematically supported extrapolation. The results from the advanced turbocharger simulation methodology significantly improves the prediction of the temperature drop over the turbine in comparison to the conventional adiabatic TC simulation methodology. The validated heat transfer model also allows the analysis of the heat flow breakdown of the turbocharger. Based on the advanced turbocharger model, a tool for the improved transient turbocharger-engine matching process is given.

In Silico Insight into the Reductive Nitrosylation of Ferric Hemeproteins.

A combination of in silico methods was used to extend the experimental description of the reductive nitrosylation mechanism in ferric hemeproteins with the molecular details of the role of surrounding amino acids. The computational strategy consisted in the estimation of potential energy profiles for the transition process associated with the interactions of the coordinated N(NO) moiety with O(H2O) or O(OH-) as nucleophiles, and with distal amino acids as proton acceptors or affecting the stability of transition states. We inspected the reductive nitrosylation in three representative hemeproteins -sperm whale metmyoglobin, α subunit of human methemoglobin and nitrophorin 4 of Rhodnius prolixus. For each case, classical molecular dynamics simulations were performed in order to obtain relevant reactive conformations, and a potential energy profile for the reactive step was obtained using adiabatic mapping or nudged elastic band approaches at the QM/MM level. Specifically, we report the role of a charged Arg45 of myoglobin in destabilizing the transition state when H2O acts as nucleophile, differently to the neutral Pro43 of the hemoglobin subunit. The case of the nitrophorin is unique in that the access of the required water molecules is scarce, thus, preventing the reaction.

Ramachandran conformational energy maps for disaccharide linkages found in Burkholderia multivorans biofilm polysaccharides

Ramachandran conformational energy maps have been prepared for all of the glycosidic linkages found in the C1576 exopolysaccharide that constitutes the biofilms of the bacterial species Burkholderia multivorans, a member of the Burkholderia cepacian complex that was isolated from a cystic fibrosis patient. This polysaccharide is a rhamnomannan with a tetrasaccharide repeat unit containing two mannose residues and two rhamnose residues, –[3-α-d-Man-(1→2)-α-d-Man-(1→2)-α-d-Rha-(1→3)-α-d-Rha-(1→]n–, where approximately 50% of the rhamnoses are randomly methylated on their O3 hydroxyl groups, further increasing the overall hydrophobicity of the chains. Because of the methylation, the tetrasaccharide repeat unit actually contains six possible linkages. The conformational energy maps are fully adiabatic relaxed maps in which the energy for each (ϕ,ψ) grid point on the map represents the lowest possible energy for the molecule in that conformation, considering all the combinations of the other degrees of freedom, such as hydroxyl orientations. Molecular dynamics simulations were used to verify that these maps indeed describe the conformational dynamics of these linkages. All six linkages were found to be quite restricted in possible ϕ angles, but to exhibit several possible low-energy ψ angles, suggesting that these chains could be quite flexible.

Finding Reactive Configurations: A Machine Learning Approach for Estimating Energy Barriers Applied to Sirtuin 5.

Sirtuin 5 is a class III histone deacetylase that, unlike its classification, mainly catalyzes desuccinylation and demanoylation reactions. It is an interesting drug target that we use here to test new ideas for calculating reaction pathways of large molecular systems such as enzymes. A major issue with most schemes (e.g., adiabatic mapping) is that the resulting activation barrier height heavily depends on the chosen educt conformation. This makes the selection of the initial structure decisive for the success of the characterization. Here, we apply machine learning to a large number of molecular dynamics frames and potential energy barriers obtained by quantum mechanics/molecular mechanics calculations in order to identify (1) suitable start-conformations for reaction path calculations and (2) structural features relevant for the first step of the desuccinylation reaction catalyzed by Sirtuin 5. The latter generally aids the understanding of reaction mechanisms and important interactions in active centers. Using our novel approach, we found eleven key features that govern the reactivity. We were able to estimate reaction barriers with a mean absolute error of 3.6 kcal/mol and identified reactive configurations.

Condensation two-phase flow patterns for zeotropic mixtures of tetrafluoromethane/ethane in a horizontal smooth tube

Mixed-refrigerant Joule-Thomson refrigeration (MJTR) systems have distinct advantages in the temperature range from 80 to 230 K. Tetrafluoromethane (R14) and ethane (R170) are essential components of mixed-refrigerants. In this paper, the adiabatic flow pattern map for R14/R170 mixtures was firstly developed based on previous flow pattern data. Then an experimental investigation on condensation two-phase flow patterns for R14/R170 mixtures (0.193/0.0.807, 0.437/0.563, 0.632/0.368 and 0.799/0.201 by mole) in a horizontal smooth tube with inner diameter of 4 mm was presented. Experiments were carried out at mass fluxes from 100 to 350 kg m−2s−1, saturation pressures from 1.5 to 2.5 MPa and heat fluxes from 8.4 to 42.2 kW m−2 over the entire range of vapor quality. The effects of mass flux, saturation pressure, heat flux and concentration on flow pattern evolutions were discussed and presented. Analysis results indicated that mass transfer resistance and heat flux account for the nonequilibrium effects of zeotropic mixture condensation, which leads to the different evolutionary trends between condensation and adiabatic two-phase flow. Finally, a new condensation flow pattern map was deduced by containing nonequilibrium effects into adiabatic flow pattern map.

Geometrical Conversion of the EGFR Extracellular Domain by Adiabatic Mapping Combining Normal Mode Analysis of the Elastic Network Model and Energy Optimization.

The activation of epidermal growth factor receptor (EGFR) involves the geometrical conversion of the extracellular domain (ECD) from the tethered to the extended forms with the dynamic rearrangement of the relative positions of four subdomains (SDs); however, this conversion process has not yet been thoroughly understood. We compare the two different forms of the X-ray crystal structures of ECD and simulate the ECD conversion process using adiabatic mapping that combines normal mode analysis of the elastic network model (ENM-NMA) and energy optimization. A comparison of the crystal structures reveals the rigidity of the intradomain geometry of the SD-I and -III backbone regardless of the form. The forward mapping from the tethered to the extended forms retains the intradomain geometry of the SD-I and -III backbone and reveals the trends to rearrange the relative positions of SD-I and -III and to dissociate the C-terminal tail of SD-IV from the hairpin loop in SD-II. The reverse mapping from the extended to the tethered forms complements the promotion of ECD conversion in the presence of epidermal growth factor (EGF).

A holistic methodology to correct heat transfer and bearing friction losses from hot turbocharger maps in order to obtain adiabatic efficiency of the turbomachinery

Turbocharger performance maps provided by manufacturers are usually far from the assumption of reproducing the isentropic performance. The reason being, those maps are usually measured using a hot gas stand. The definition of the effective turbocharger efficiency maps include the mechanical losses and heat transfer that has occurred during the gas stand test for the turbine maps and only the heat transfer for the compressor maps. Thus, a turbocharger engine model that uses these maps provides accurate results only when simulating turbocharger operative conditions similar to those at which the maps are recorded. However, for some critical situations such as Worldwide harmonized Light vehicles Test Cycles (WLTC) driving cycle or off-design conditions, it is difficult to ensure this assumption. In this article, an internal and external heat transfer model combined with mechanical losses model, both previously developed and calibrated, has been used as an original tool to ascertain a calculation procedure to obtain adiabatic maps from diabatic standard turbocharger maps. The turbocharger working operative conditions at the time of map measurements and geometrical information of the turbocharger are necessary to discount both effects precisely. However, the maps from turbocharger manufacturers do not include all required information. These create additional challenges to develop the procedure to obtain approximated adiabatic maps making some assumptions based on SAE standards for non-available data. A sensitivity study has been included in this article to check the validity of the hypothesis proposed by changing the values of parameters which are not included in the map data. The proposed procedure becomes a valuable tool either for Original Equipment Manufacturers (OEMs) to parameterize turbocharger performance accurately for benchmarking and turbocharged engine design or to turbocharger manufacturers to provide much-appreciated information of their performance maps.

Improved Heat Transfer Correction Method for Turbocharger Compressor Performance Measurements

The compressor adiabatic performance map is important for turbocharger matching with engine. Its accuracy was affected by the heat transfer phenomenon in the turbocharger. The corrected method for compressor performance measurement which affected by heat transfer was widely investigated by some authors. The aim of this work was to measure compressor adiabatic efficiency by simplified method, and estimated the effects of internal heat transfer on compressor efficiency. This approach only added five temperature sensors on the turbocharger based on the standard instruments and doesn’t need other special instruments, and the heat transfer properties of turbocharger and compressor adiabatic efficiency could be calculated by lumped model. This method was validated by other experiments. Finally, the heat absorbed by compressor under different operating conditions was analyzed by this method. The results showed water-cooling was main influenced factor, and water-cooling was a barrier for heat transfer from turbine to compressor.

QM/MM molecular modelling on mutation effect of chorismate synthase enzyme catalysis

Chorismate synthase (CS) catalyzes the conversion of 5-enolpyruvylshikimate-3-phosphate (EPSP) to chorismate which is a key intermediate in the biosynthesis of aromatic amino acids. CS enzyme is a new target for antibacterial drugs. Even though several reaction mechanisms have been proposed, the catalytic mechanism is still unclear. QM/MM adiabatic mapping calculations were performed in order to investigate roles of this enzyme. High-accuracy SCS-MP2/aVDZ/CHARMM27 calculations indicated that the reaction pathway has three steps; (i) proton transfer from reduced flavin mononucleotide (FMNH2) to D339, (ii) proton transfer from EPSP to FMNH– and (iii) phosphate elimination. Adiabatic mapping calculations indicated that H110 and R48 residues play essential catalyst roles for CS enzyme catalysis by transition state (TS) and product stabilizations via charge polarization and hydrogen bonding to EPSP and/or FMNH2. A high accuracy calculation - SCS-MP2/aVDZ/CHARMM27 method was employed to obtain the accurate reaction mechanism pathway and to evaluate the effect of amino acid residues in the active site on the enzyme catalysis. The potential energy barriers of the reactions of H110A and R48A were found to increase. The CS catalysis was consequently slowed down due to missing the TS and product stabilizations.

New adiabatic and condensation two-phase flow pattern maps of R14 in a horizontal tube

Heat transfer and pressure drop for two-phase flow are closely related to corresponding flow patterns. In this work, an experimental investigation on adiabatic and condensation two-phase flow patterns and their transitions of tetrafluoromethane (R14) in a horizontal tube with inner diameter of 4 mm was conducted. Experiments were implemented at mass fluxes from 200 to 650 kg/(m2 s), saturation pressures from 1 to 3 MPa and heat fluxes from 8.2 to 28.2 kW/m2. The observed adiabatic flow patterns were compared with six well-known flow pattern maps, none of them can predict all the transition lines accurately. Therefore, a new dimensionless number S1, which takes account of inertia force, gravity force, shear force and surface tension force, was proposed to develop the new adiabatic flow pattern transition criteria. Eight groups of data were compared with the new adiabatic flow pattern map, most of the flow pattern data can be accurately predicted. What’s more, in order to explain the effect of heat flux on condensation flow pattern transitions, another new dimensionless number S2 was proposed by combining the dimensionless number S1 and boiling number together. Finally, a condensation flow pattern map was proposed based on the dimensionless number S2.

Photodissociation dynamics in the first absorption band of pyrrole. II. Photofragment distributions for the 1A2(πσ*)←X̃1A1(ππ) transition.

The analysis of the total kinetic energy release (TKER) of the photofragments pyrrolyl + H-atom formed in the photodissociation of pyrrole in the low-lying state 1A2(πσ*) is presented. The TKER distributions contain complementary and often more precise information on the fragmentation process than the broad diffuse absorption spectra. The distributions are calculated quantum mechanically for the diabatic state 1A2(πσ*) either isolated or coupled to the ground electronic state at an exit channel conical intersection. The calculations use the novel ab initio quasi-diabatic potential energy matrix constructed in the work of Picconi and Grebenshchikov [J. Chem. Phys. 148, 104103 (2018)]. The approximate overlap integral-based adiabatic mapping approach is introduced with which the quantum mechanical TKER distributions can be efficiently and accurately reproduced. Finally, the calculated TKERs are compared with the experimental results. The main features of the measured vibrationally resolved distributions are reproduced, and the spectral peaks are assigned and interpreted in detail.