# Usage Questions **URL:** https://pytomography.discourse.group/c/usage-questions/5.md [Latest](https://pytomography.discourse.group/latest.md) · [Categories](https://pytomography.discourse.group/categories.md) · [Tags](https://pytomography.discourse.group/tags.md) --- ## [About the Usage Questions category](https://pytomography.discourse.group/t/about-the-usage-questions-category/8)
**Author:** [@lukepolson](https://pytomography.discourse.group/u/lukepolson)\ **Replies:** 0
--- ## [Question about PET scanner \`info\` parameters](https://pytomography.discourse.group/t/question-about-pet-scanner-info-parameters/108)
**Author:** [@ml-w](https://pytomography.discourse.group/u/ml-w)\ **Replies:** 1\ **Last updated:** [January 13, 2026, 2:56am UTC](https://pytomography.discourse.group/t/question-about-pet-scanner-info-parameters/108 "2026-01-13T02:56:04Z")
I am trying to follow the reconstruction tutorial but encounter some issues with setting up the info parameter: GATE (Listmode Reconstruction; Without Time of Flight) — PyTomography 3.4.0 documentation I wonder if there… --- ## [How to acquire delay coincidences from GATE root output?](https://pytomography.discourse.group/t/how-to-acquire-delay-coincidences-from-gate-root-output/94)
**Author:** [@halveluve](https://pytomography.discourse.group/u/halveluve)\ **Replies:** 1\ **Last updated:** [March 27, 2025, 3:40pm UTC](https://pytomography.discourse.group/t/how-to-acquire-delay-coincidences-from-gate-root-output/94 "2025-03-27T15:40:15Z")
Hi there, I have been recently trying to reconstruct images from my own GATE-simulated dataset based on the GATE listmode TOF tutorial for PET image reconstruction. However, while the data you provided in the tutorial d… --- ## [Issue when using a double gaussian operator](https://pytomography.discourse.group/t/issue-when-using-a-double-gaussian-operator/78)
**Author:** [@akippen](https://pytomography.discourse.group/u/akippen)\ **Replies:** 3\ **Last updated:** [November 19, 2024, 11:00am UTC](https://pytomography.discourse.group/t/issue-when-using-a-double-gaussian-operator/78 "2024-11-19T11:00:39Z")
Hi there, We are trying to perform a SPECT reconstruction using our own PSF operator. We have fit the PSF response to a double gaussian mixture in order to better account for the tails. This fitting has given results fo… --- ## [XCAT Simulation](https://pytomography.discourse.group/t/xcat-simulation/66)
**Author:** [@Chi](https://pytomography.discourse.group/u/Chi)\ **Replies:** 2\ **Last updated:** [October 2, 2024, 10:06am UTC](https://pytomography.discourse.group/t/xcat-simulation/66 "2024-10-02T10:06:24Z")
Hi everyone, I was wondering if anyone could help me. I am running an XCAT phantom（128 ×128 ×128 pixel width = 0.300 (cm/pixel) slice width = 0.1500 (cm/pixel)） SPECT simulation in SIMIND. The attenuation，projec… --- ## [Missing files in the PET-GATE tutorial (Listmode Reconstruction with Time of Flight)](https://pytomography.discourse.group/t/missing-files-in-the-pet-gate-tutorial-listmode-reconstruction-with-time-of-flight/38)
**Author:** [@Jack001](https://pytomography.discourse.group/u/Jack001)\ **Replies:** 7\ **Last updated:** [September 29, 2024, 5:58am UTC](https://pytomography.discourse.group/t/missing-files-in-the-pet-gate-tutorial-listmode-reconstruction-with-time-of-flight/38 "2024-09-29T05:58:29Z")
Hi everyone, I am running the PET-GATE tutorial (Listmode Reconstruction with Time of Flight). I am unable to find some of the files listed below: PET scanner geometry file (mMR\_Geometry.mac) fdg\_pet\_phantom\_umap.nii.… --- ## [Simind.get\_psfmeta\_from\_header may not work?](https://pytomography.discourse.group/t/simind-get-psfmeta-from-header-may-not-work/65)
**Author:** [@Chi](https://pytomography.discourse.group/u/Chi)\ **Replies:** 4\ **Last updated:** [September 27, 2024, 7:37am UTC](https://pytomography.discourse.group/t/simind-get-psfmeta-from-header-may-not-work/65 "2024-09-27T07:37:36Z")
Hello everyone When I run the tutorial ,SIMIND-Tutorials/tutorial3 at master · lukepolson/SIMIND-Tutorials · GitHub About PSF psf\_meta = simind.get\_psfmeta\_from\_header(‘test\_tot\_w2.h00’) psf\_transform = SPECTPSFTrans… --- ## [OSEM reconstruction for SPECT using SIMIND](https://pytomography.discourse.group/t/osem-reconstruction-for-spect-using-simind/64)
**Author:** [@Haruki](https://pytomography.discourse.group/u/Haruki)\ **Replies:** 2\ **Last updated:** [September 27, 2024, 6:29am UTC](https://pytomography.discourse.group/t/osem-reconstruction-for-spect-using-simind/64 "2024-09-27T06:29:40Z")
Hello, everyone. I have a trouble, about OSEM reconstruction. I was doing OSEM with pytomography, but the image after reconstruction dose not work. I was using a cylindrical homogeneous phantom with a diameter of 18cm,… --- ## [SPECT/SIMIND TEW & Attenuation map](https://pytomography.discourse.group/t/spect-simind-tew-attenuation-map/43)
**Author:** [@Haruki](https://pytomography.discourse.group/u/Haruki)\ **Replies:** 0\ **Last updated:** [June 27, 2024, 7:44am UTC](https://pytomography.discourse.group/t/spect-simind-tew-attenuation-map/43 "2024-06-27T07:44:27Z")
Hello everyone! I’m trying to solve two errors (TEW & Attenuation map). I want to TEW, but when I enter the following code I get an error . And ,I want to create an attenuation map, but I get the following error. … --- ## [Projection data of special size runtime error](https://pytomography.discourse.group/t/projection-data-of-special-size-runtime-error/33)
**Author:** [@json](https://pytomography.discourse.group/u/json)\ **Replies:** 2\ **Last updated:** [May 24, 2024, 8:44am UTC](https://pytomography.discourse.group/t/projection-data-of-special-size-runtime-error/33 "2024-05-24T08:44:24Z")
For SPECT reconstruction, when the projection matrix size is 160x128x240，if attenuation correction is performed based on CT, an error will occur, if don’t do attenuation correction, it will work correctly. If projection … --- ## [Guidance for attenuation map from CT](https://pytomography.discourse.group/t/guidance-for-attenuation-map-from-ct/29)
**Author:** [@jakopbsf](https://pytomography.discourse.group/u/jakopbsf)\ **Replies:** 2\ **Last updated:** [April 23, 2024, 6:10pm UTC](https://pytomography.discourse.group/t/guidance-for-attenuation-map-from-ct/29 "2024-04-23T18:10:32Z")
Hello everyone, I was wondering if I could receive some guidance in terms of CT attenuation correction. I went through the reconstruction tutorials without any issues but when I wanted to try it myself with some Lu-177… --- ## [Scatter estimation using 2 energy windows](https://pytomography.discourse.group/t/scatter-estimation-using-2-energy-windows/24)
**Author:** [@pearsonm](https://pytomography.discourse.group/u/pearsonm)\ **Replies:** 2\ **Last updated:** [April 18, 2024, 12:04am UTC](https://pytomography.discourse.group/t/scatter-estimation-using-2-energy-windows/24 "2024-04-18T00:04:54Z")
Hello, I want to reconstruct files using Tc99m from a GE850 SPECT/CT with 2 energy windows: emission 126 - 155Kev scatter 114 - 126 Kev If I run the following line will the scatter tensor be correct? scatter = dico… --- ## [Comparison with vendors reconstructions](https://pytomography.discourse.group/t/comparison-with-vendors-reconstructions/16)
**Author:** [@ludovic](https://pytomography.discourse.group/u/ludovic)\ **Replies:** 1\ **Last updated:** [March 22, 2024, 4:39am UTC](https://pytomography.discourse.group/t/comparison-with-vendors-reconstructions/16 "2024-03-22T04:39:31Z")
Hi Pytomo team! Thank you for this nice Python tool. I have a question regarding the dicom notebook you provided. At some point, to compare the reconstruction with the one offered by the vendor, you used Pydicom to lo… --- ## [PyTomography GATE tutorial and object\_meta](https://pytomography.discourse.group/t/pytomography-gate-tutorial-and-object-meta/21)
**Author:** [@robsol90](https://pytomography.discourse.group/u/robsol90)\ **Replies:** 1\ **Last updated:** [March 1, 2024, 4:33pm UTC](https://pytomography.discourse.group/t/pytomography-gate-tutorial-and-object-meta/21 "2024-03-01T16:33:05Z")
Hello, First of all thank you very much for this great piece of software! I am trying to follow the GATE tutorial (Reconstructing GATE Data — PyTomography 1.3.5 documentation) which works fine. However, if I change the … --- ## [Anthropomorphic Phantom Reconstruction](https://pytomography.discourse.group/t/anthropomorphic-phantom-reconstruction/12)
**Author:** [@Niamh\_McArdle](https://pytomography.discourse.group/u/Niamh_McArdle)\ **Replies:** 3\ **Last updated:** [February 12, 2024, 3:31pm UTC](https://pytomography.discourse.group/t/anthropomorphic-phantom-reconstruction/12 "2024-02-12T15:31:02Z")
Hi everyone, I was wondering if anyone could help me with a reconstruction problem I am having please. I am running an XCAT phantom SPECT simulation in SIMIND. I have simulated activity in the lungs and liver of the XCAT…