Perspective Projection-Based 3D CT Reconstruction from Biplanar X-rays
Daeun Kyung*, Kyungmin Jo*, Jaegul Choo, Joonseok Lee, Edward Choi
ICASSP 2023 (Best Student Paper Awards)
X-ray computed tomography (CT) is one of the most common imaging techniques used to diagnose various diseases in the medical field. Its high contrast sensitivity and spatial resolution allow the physician to observe details of body parts such as bones, soft tissue, blood vessels, etc. As it involves potentially harmful radiation exposure to patients and surgeons, however, reconstructing 3D CT volume from perpendicular 2D X-ray images is considered a promising alternative, thanks to its lower radiation risk and better accessibility. This is highly challenging though, since it requires reconstruction of 3D anatomical information from 2D images with limited views, where all the information is overlapped. In this paper, we propose PerX2CT, a novel CT reconstruction framework from X-ray that reflects the perspective projection scheme. Our proposed method provides a different combination of features for each coordinate which implicitly allows the model to obtain information about the 3D location. We reveal the potential to reconstruct the selected part of CT with high resolution by properly using the coordinate-wise local and global features. Our approach shows potential for use in clinical applications with low computational complexity and fast inference time, demonstrating superior performance than baselines in multiple evaluation metrics.

Clone the repository and navigate into the directory:

$ git clone https://github.com/dek924/PerX2CT.git
$ cd PerX2CT

Create a conda environment, activate it, and install the required packages:

$ conda create -n perx2ct python=3.8
$ conda activate perx2ct
$ pip install --upgrade pip
$ pip install -r requirement.txt

• We are currently utilizing the LIDC-IDRI dataset. You can download the original dataset here. Follow the instructions in prepare_datasets.md to preprocess the dataset.

• We've provided the pretrained weights used for our paper's experiments. You can download these weights here.

To train PerX2CT, run main.py with the hyper-parameters provided below:

python main.py --train True --gpus <gpu_ids> --name <exp_name> --base <path_to_base_config>

Note: The hyperparameters used in our paper's experiments are set as default. Note: The configuration for training the PerX2CT model without zoom-in is configs/PerX2CT.yaml, while the configuration for training the PerX2CT_global model with zoom-in is configs/PerX2CT_global_w_zoomin.yaml.

To evaluate PerX2CT, run main_test.py with hyperparameters below.

python main_test.py --ckpt_name <checkpoint_name> --path <checkpoint_dir> --val_test <target_test_set (val or test)>

To evaluate PerX2CT for zoom-in task, run main_test_zoom.py with hyperparameters below.

python main_test_zoom.py --ckpt_name <checkpoint_name> --path <checkpoint_dir> --val_test <target_test_set (val or test)> --zoom_size <target_zoomin_patch_size>

This implementation uses code from following repositories:

• Official X2CT-GAN implementation
• Official Taming Transformers implementation

We thank the authors for their open-sourced code.

@INPROCEEDINGS{10096296,
  author={Kyung, Daeun and Jo, Kyungmin and Choo, Jaegul and Lee, Joonseok and Choi, Edward},
  booktitle={ICASSP 2023 - 2023 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)}, 
  title={Perspective Projection-Based 3d CT Reconstruction from Biplanar X-Rays}, 
  year={2023},
  volume={},
  number={},
  pages={1-5},
  doi={10.1109/ICASSP49357.2023.10096296}}

For any questions or concerns regarding this code, please contact to us ([email protected] or [email protected]).