> This page is for MAISI, version 1.0.1 (Latest) (default).
> For other versions, use one of these documentation indexes:
> - 1.0.1 (Latest) (default): https://docs.nvidia.com/nim/medical/maisi/1.0.1/llms.txt
> - 1.0.0: https://docs.nvidia.com/nim/medical/maisi/1.0.0/llms.txt

> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://docs.nvidia.com/nim/medical/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs.nvidia.com/nim/medical/_mcp/server.

# API Reference

MAISI NIM provides following API endpoints:

* `GET`: /v1/health/live - Check if service is alive (might not be ready yet)
* `GET`: /v1/health/ready - Check if service is ready and model is ready for inference
* `GET`: /v1/license - Return the license for the NIM
* `GET`: /v1/maisi/info - Fetch detailed information about the model such as version and labels
* `POST`: /v1/maisi/run - Generate CT images with paired segmentation masks

## Payload Options

| Parameter | Required | Type | Description | Options/Range |
|-----------|----------|------|-------------|---------------|
| `num_output_samples` | Yes | Integer | Number of images to generate | Positive integer |
| `body_region` | Yes | List of Strings | Target body regions | ["head", "chest", "thorax", "abdomen", "pelvis", "lower"] |
| `anatomy_list` | No | List of Strings | Specific anatomical structures | See Supported Anatomy section |
| `output_size` | No | List of 3 Integers | Image dimensions (x, y, z) | x, y: 256, 384, 512<br />z: 128, 256, 384, 512, 640, 768 |
| `spacing` | No | List of 3 Floats | Voxel spacing | Each value: 0.5 to 5.0 |
| `controllable_anatomy_size` | No | List of Tuples (String, Float) for organ name and size | Organ size control (max 10) | Organs: ["liver", "gallbladder", "stomach", "pancreas", "colon", "lung tumor", "bone lesion", "hepatic tumor", "colon cancer primaries", "pancreatic tumor"]<br />Size: 0.0 to 1.0, or -1 (remove) |
| `pre_signed_url` | No | String | URL for result upload | - |
| `local_working_dir` | No | String | If specified, the generated images will be saved in the provided directory. | - |
| `image_output_ext` | No | String | Output file extension | Supported extensions: ".nrrd", ".nii", ".nii.gz", ".dcm". Default: ".nii.gz" |
| `label_output_ext` | No | String | Output file extension | Supported extensions: ".nrrd", ".nii", ".nii.gz", ".dcm". Default: ".nii.gz" |

## Supported Anatomy

You can find all of the classes available in the model in the [MAISI label_dict.json](https://raw.githubusercontent.com/Project-MONAI/tutorials/1c942f49693131c53365359a7b11153a563a97a6/generation/maisi/configs/label_dict.json).  

## Recommended `output_size` and `spacing` Values

Based on the statistics of the training data, we recommend the following input parameters for the body regions included in the training data. The recommended `output_size` is the median value of the training data, and the recommended `spacing` is calculated as the median Field of View (FOV) divided by the recommended `output_size`.

| `body_region`                         |  `output_size`  |    `spacing` [mm]     |
| ------------------------------------- | :-------------: | :-------------------: |
| ['chest', 'abdomen']                  | [512, 512, 128] | [0.781, 0.781, 2.981] |
| ['chest']                             | [512, 512, 128] | [0.684, 0.684, 2.422] |
| ['chest', 'abdomen', 'lower']         | [512, 512, 256] | [0.793, 0.793, 1.826] |
| ['lower']                             | [512, 512, 384] | [0.839, 0.839, 0.728] |
| ['abdomen', 'lower']                  | [512, 512, 384] | [0.808, 0.808, 0.729] |
| ['head', 'chest', 'abdomen']          | [512, 512, 384] | [0.977, 0.977, 2.103] |
| ['abdomen']                           | [512, 512, 128] | [0.723, 0.723, 1.182] |
| ['head', 'chest', 'abdomen', 'lower'] | [512, 512, 384] | [1.367, 1.367, 4.603] |
| ['head', 'chest']                     | [512, 512, 128] | [0.645, 0.645, 2.219] |

If users want to try different `"output_size"`, please adjust `"spacing"` to ensure a reasonable FOV, which is the product of `"output_size"` and `"spacing"`.

Please refer to [Getting Started](/nim/medical/maisi/getting-started) for more examples.