Add dataset card

README.md

@@ -1,25 +1,87 @@
 ---
-dataset_info:
-  features:
-  - name: image
-    dtype: image
-  - name: mask
-    dtype: image
-  - name: class_label
-    dtype: string
-  - name: image_id
-    dtype: string
-  - name: has_multifocal_lesion
-    dtype: bool
-  splits:
-  - name: train
-    num_bytes: 167665177
-    num_examples: 780
-  download_size: 167488624
-  dataset_size: 167665177
-configs:
-- config_name: default
-  data_files:
-  - split: train
-    path: data/train-*
+license: other
+task_categories:
+  - image-segmentation
+tags:
+  - medical
+  - ultrasound
+  - breast
+  - segmentation
+  - busi
+size_categories:
+  - n<1K
 ---
+
+# BUSI — Breast Ultrasound Images Dataset
+
+Re-hosted mirror of the Breast Ultrasound Images Dataset (Al-Dhabyani et al., 2020),
+collected at Baheya Hospital, Cairo, Egypt and originally distributed via the
+Cairo University Scholar page of co-author Aly Fahmy.
+
+This mirror is intended for use with [EasyMedSeg](https://github.com/) and provides:
+
+- A single canonical source (the original Cairo Univ. URL has unstable TLS).
+- Parquet schema with one row per image and a single binary mask.
+- For images with multifocal lesions, the multiple `_mask_N.png` files in the
+  original release are merged into one binary mask via per-pixel logical OR
+  (the convention adopted by the paper and by BUS-Set / Thomas et al. 2023).
+
+## Composition
+
+| Class       | Images | Multifocal cases |
+|-------------|-------:|-----------------:|
+| benign      | 437    | 16               |
+| malignant   | 210    | 1                |
+| normal      | 133    | 0                |
+| **Total**   | **780**| **17**           |
+
+Image dimensions are variable (~190–719 px, average ~500×500 px). Source release
+is from 2018; 600 female patients, ages 25–75; GE LOGIQ E9 / E9 Agile B-mode.
+
+## Splits
+
+BUSI has **no official train/val/test split**. This release ships a single
+`train` split. Downstream code is expected to define its own splits
+(BUS-Set provides reproducible ones).
+
+## Schema
+
+| Column                   | Type      | Description                                                |
+|--------------------------|-----------|------------------------------------------------------------|
+| `image`                  | `Image`   | Source PNG (RGB)                                           |
+| `mask`                   | `Image`   | Binary mask (`L` mode, 0/255) — OR-merged across all mask files |
+| `class_label`            | `string`  | `"benign"` / `"malignant"` / `"normal"`                    |
+| `image_id`               | `string`  | e.g., `"benign (100)"`                                     |
+| `has_multifocal_lesion`  | `bool`    | `True` if the source had >1 mask file                      |
+
+## Known data-quality caveats
+
+Per Pawłowska et al. (2023, *Data in Brief*, [PMC10293973](https://pmc.ncbi.nlm.nih.gov/articles/PMC10293973/)):
+- ~235 duplicated images (~19%); 8 lesions appear in both benign and malignant folders (label leakage).
+- ~70 axilla (non-breast) images mis-categorized as breast.
+- 295 images with overlaid annotations (calipers, doppler markers, text) intersecting the lesion ROI.
+- ≥7 images contain a visible biopsy needle.
+
+This mirror **does not modify** the source files (other than mask merging) — the
+above issues are inherited as-is. Cite Pawłowska et al. when reporting cleanups.
+
+## License
+
+The original authors do not state an explicit license on the Cairo Univ. page or
+in the *Data in Brief* paper. Treat as **research use, with required citation**.
+Kaggle uploaders have tagged copies as CC BY 4.0 (uploader-asserted, not
+author-confirmed). Do not assume redistribution rights beyond research.
+
+## Citation
+
+```bibtex
+@article{Aldhabyani2020BUSI,
+  title   = {Dataset of breast ultrasound images},
+  author  = {Al-Dhabyani, Walid and Gomaa, Mohammed and Khaled, Hussein and Fahmy, Aly},
+  journal = {Data in Brief},
+  volume  = {28},
+  pages   = {104863},
+  year    = {2020},
+  doi     = {10.1016/j.dib.2019.104863}
+}
+```