# Data Cleaning Report
**Generated**: 2026-02-07 19:13:04
**Updated**: 2026-02-07 (removed 3 patients with incomplete MRI channels)

## 1. Dataset Overview

| Group | Folder | Patients | Label |
|-------|--------|----------|-------|
| Normal | `normal/` | 40 | 0 |
| Lateral Ventricular Megaly (LVM) | `LVM/` | 39 | 1 |
| Periventricular Leukomalacia (PVL) | `PVL/` | 40 | 2 |
| LVM + PVL | `LVM_PVL/` | 38 | 3 |

**Total patients**: 157

## 2. Data Cleaning Actions

| Action | Details |
|--------|---------|
| Removed PII | `姓名` (patient name), `住院号` (hospital ID) |
| Column translation | `编号`→`patient_id`, `检查描述`→`exam_description`, `检查结果`→`diagnosis` |
| Added columns | `group`, `group_label` (0-3), `group_name_en` |
| Format conversion | `.xlsx` → `.csv` (UTF-8) |
| Folder renaming | Chinese → English (see below) |
| Text cleaning | Removed non-breaking spaces (`\xa0`), stripped whitespace |
| Removed incomplete | 3 patients missing T2-SAG: `100-21` (LVM), `110-14`, `110-52` (LVM_PVL) |

### Folder Renaming

| Original (Chinese) | New (English) |
|-------------------|---------------|
| `正常 2026-2-6` | `normal` |
| `扩张 2026-2-6` | `LVM` |
| `软化 2026-2-6` | `PVL` |
| `扩张+软化 2026-2-7` | `LVM_PVL` |

## 3. MRI Channel Integrity

**Target channels**: FLAIR, T1WI, T2-SAG, T2WI

### normal (Normal)

- Patients: 40
- Total target-channel DCM files: 2661
- Average DCM per patient (4 channels): 66.5
- All patients have complete target channels

### LVM (Lateral Ventricular Megaly (LVM))

- Patients: 39
- Total target-channel DCM files: 2,625
- Average DCM per patient (4 channels): 67.3
- All patients have complete target channels
- Extra channels present (not used): 3D-SWI, ADC, DWI, SWI

### PVL (Periventricular Leukomalacia (PVL))

- Patients: 40
- Total target-channel DCM files: 2,662
- Average DCM per patient (4 channels): 66.5
- All patients have complete target channels

### LVM_PVL (LVM + PVL)

- Patients: 38
- Total target-channel DCM files: 2,520
- Average DCM per patient (4 channels): 66.3
- All patients have complete target channels
- Extra channels present (not used): ADC, DWI, SWI, T1+C

## 4. Output File Structure

```
feng_dataset/
├── clinical_data_all.csv          # Combined dataset (all groups)
├── clean_data.py                  # This cleaning script
├── cleaning_report.md             # This report
├── normal/                        # Normal controls
│   ├── clinical_data.csv
│   └── 001-441/                   # Patient folders
│       ├── FLAIR/  (*.DCM)
│       ├── T1WI/   (*.DCM)
│       ├── T2-SAG/ (*.DCM)
│       └── T2WI/   (*.DCM)
├── LVM/                           # Lateral Ventricular Megaly
│   ├── clinical_data.csv
│   └── 100-xxx/ ...
├── PVL/                           # Periventricular Leukomalacia
│   ├── clinical_data.csv
│   └── 010-xxx/ ...
└── LVM_PVL/                       # LVM + PVL
    ├── clinical_data.csv
    └── 110-xxx/ ...
```

## 5. CSV Column Description

| Column | Type | Description |
|--------|------|-------------|
| `patient_id` | string | Unique patient identifier (e.g., `001-441`) |
| `group` | string | Group folder name: `normal`, `LVM`, `PVL`, `LVM_PVL` |
| `group_label` | int | Numeric label: 0=Normal, 1=LVM, 2=PVL, 3=LVM+PVL |
| `group_name_en` | string | Full English group name |
| `exam_description` | string | Radiologist's MRI examination description (Chinese) |
| `diagnosis` | string | Final diagnosis conclusion (Chinese) |

## 6. Notes

- **Medical text** (`exam_description`, `diagnosis`) is kept in the original Chinese to preserve clinical accuracy. Machine translation of specialized medical radiology reports may introduce errors.
- **Original xlsx files** are retained in each folder as backup.
- **Removed patients**: 3 patients (`100-21`, `110-14`, `110-52`) were excluded due to missing T2-SAG channel. Both their DICOM folders and CSV records have been removed.
- **Disease description document**: `新生儿侧脑室扩张+脑白质软化疾病描述 AI+医生审核版本.docx` is preserved as-is (reference document, not patient data).