Medical Imaging Analysis Report

I. Radiological Findings

From the provided CT and MRI 3D reconstruction images of the pelvis and lumbosacral region, the following can be observed:

• Multiple erosive or osteolytic lesions in the pelvic and sacral regions, with some lesions involving the vertebral endplates and adjacent soft tissues.
• On CT reconstruction, extensive bone destruction is visible, showing irregular low-density areas, partially resembling cystic cavities or areas with heterogeneous densities.
• MRI sequences reveal multifaceted cystic or honeycomb-like lesion signals within the sacroiliac joints, paravertebral soft tissues, and bone. The lesion boundaries are unclear, and thick walls or septations can be seen locally.
• Some lesions are surrounded by thickened soft tissues with heterogeneous signals. No obvious central enhancement is noted, though mild or ring-enhancing features may be present at the lesion edges or along septations.
• Lesion-like masses can also be seen around the lumbosacral nerve pathways, suggesting possible involvement of the perineural tissue.

Considering the patient’s past surgical history (cranial and sacral surgery), previous wound debridement, and persistent lower back pain, a chronic invasive lesion of the pelvis and vertebral bodies must be highly suspected.

II. Potential Diagnoses

1. Echinococcosis (Hydatid Disease, especially alveolar echinococcosis): The patient has a confirmed previous diagnosis, and current imaging findings are consistent with a parasitic infestation leading to multifocal osteolysis and soft tissue spread. Features include multiple septated cystic changes, adherence to surrounding tissues, poorly defined borders, and potential vertebral involvement.
2. Bone metastases: Malignant lesions commonly appear as osteolytic or mixed destructive lesions in the pelvic region, often accompanied by more pronounced soft tissue masses and faster progression or enhancement. However, no typical primary malignancy history is noted in the patient data (further evaluation would be required if unknown).
3. Tuberculosis or other chronic infections (e.g., spinal tuberculosis with psoas or iliac abscess): These can also present with osteolytic destruction and soft tissue abscesses (“cold abscess”). However, given the patient’s established history of echinococcosis, expansion of an existing parasitic infection is more likely.
4. Paget’s disease: Commonly presents with bone deformities and enlargement, and may exhibit osteolytic areas. However, imaging usually shows the “lytic–mixed–sclerotic” phases. In this case, the local osteolysis with invasive characteristics is more suggestive of an invasive parasitic or neoplastic process.

III. Final Diagnosis

Considering the 10-year history of alveolar echinococcosis (multilocular echinococcosis), imaging findings, and clinical presentation, the most likely diagnosis is “Alveolar Echinococcosis (involvement of the pelvis and sacral vertebrae)”. Given its diffuse infiltrative nature and chronic course, close specialty follow-up is essential, along with serological tests and pathological confirmation (e.g., biopsy when necessary) to refine diagnosis and assessment.

IV. Treatment Plan and Rehabilitation Program

4.1 Treatment Plan

• Long-term anti-parasitic medication:
  For chronic cases of alveolar echinococcosis, benzimidazole drugs (such as albendazole or mebendazole) are typically recommended for prolonged, even lifelong treatment to suppress lesion progression.
• Surgical treatment:
  If the lesion is localized and can be completely resected, surgery may help alleviate local compression and improve prognosis. However, for severe bone destruction or extensive infiltration, complete resection is often challenging. A multidisciplinary approach (orthopedics, infectious diseases, general surgery) is necessary for evaluation.
• Symptom and complication management:
  For patients with neurological symptoms, pain, or secondary infections, targeted anti-inflammatory, analgesic, and, if necessary, nerve decompression measures should be employed.

4.2 Rehabilitation and Exercise Prescription

Because of significant bone destruction in the lumbosacral region, rehabilitation and exercise should focus on protecting the bones and joints, preventing further fractures or nerve damage.

• Early recovery phase (FITT-VP principle):
  • Frequency: 3–4 times per week;
  • Intensity: Low-intensity, non-weight-bearing or partial weight-bearing exercises, such as simple core workouts or range-of-motion activities in a bed or seated position.
  • Time: 20–30 minutes per session, progressing gradually based on tolerance.
  • Type: Low-load isometric exercises for back and core muscles, leg raises, range-of-motion activities, and breathing exercises within a safe range.
  • Volume/Progression: Gradually increase session duration and repetitions based on pain or fatigue, avoiding any exercise that provokes new pain or discomfort.
• Intermediate to later stages:
  If the condition stabilizes and imaging shows the lesion is under control, low-load weight-bearing exercises may be introduced. Under the guidance of a physician or physical therapist, short-distance, low-speed walking with assistive devices can be considered. Water-based therapy may be used to reduce weight-bearing stress.
• Individualization and safety:
  Pain, fatigue, and local status should be monitored before and after each session. Discontinue exercise and consult a doctor or therapist if significant discomfort arises. Any vigorous twisting, bending, or high-impact movements should be avoided.

V. Disclaimer

This report is based solely on the provided medical history and imaging data for reference and does not replace professional, in-person clinical diagnosis and treatment recommendations. Patients must complete further examinations under the guidance of a specialist and obtain an individualized treatment plan.