Medical Analysis Report

I. Imaging Findings

Based on the provided pelvic MRI scans, the following findings are observed:

• In the sacroiliac joint region (particularly on the left side or bilaterally), abnormal signals are noted, which present as high signal changes on T2/STIR sequences, suggesting local edema or inflammatory infiltration.
• In some images, the articular surfaces appear blurred, with joint space narrowing or partial structural destruction, indicating a possible inflammatory or infectious lesion of the sacroiliac joint.
• The surrounding soft tissues show a certain degree of inflammatory signal changes, with high signal in the local muscle fascia, suggesting possible soft tissue involvement or abscess formation.
• No obvious fracture lines or extensive bone collapse are observed, but there are signs of bone destruction (decreased continuity and clarity of the trabecular structure).

Combining the patient's clinical symptoms (persistent lower back pain) with laboratory findings indicating sites of high metabolic activity, there is a high likelihood that the lesions involve both left and right sacroiliac joint areas.

II. Potential Diagnoses

Based on imaging findings, the patient’s medical history (including MALT lymphoma treatment and autoimmune hemolytic anemia), and clinical symptoms, the following differential diagnoses should be considered:

• Tuberculous Sacroiliitis (Sacroiliac Joint Tuberculosis)
  Reason: The patient presents with chronic lumbosacral pain and MRI demonstrates joint destruction with surrounding soft tissue inflammatory response. According to previous reports, sacroiliac joint tuberculosis can manifest as atypical persistent pain, with early X-ray or ultrasound findings often inconspicuous, while MRI typically reveals noticeable edema and enhancement, which is consistent with the imaging findings in this case.
• Bacterial (Suppurative) Sacroiliitis
  Reason: Similar local joint destruction and inflammatory infiltration can occur, such as in Staphylococcus aureus infection. However, the patient does not present with significant acute fever or markedly elevated white blood cell counts, and assessment of clinical inflammatory markers (e.g., CRP, ESR) is required for comprehensive analysis.
• Tumor-Related Lesions (e.g., lymphoma recurrence or bone metastasis)
  Reason: Given the history of MALT lymphoma, despite successful chemotherapy, the possibility of skeletal lymphoma or other metastatic lesions involving the sacroiliac joint must be ruled out.
• Other Granulomatous Inflammation or Fungal Infection
  Reason: In cases of immunocompromise or other systemic diseases, fungal or granulomatous infections can also present with similar imaging findings, though they are less common. Further investigation by microbiological or pathological biopsy is needed.

III. Final Diagnosis

Taking into account the patient’s medical history (including malignancy, radiotherapy, chemotherapy, etc.), clinical presentation (chronic lower back/sacroiliac region pain), laboratory findings (possible spinal/joint tuberculosis), and characteristic MRI changes, the most likely diagnosis is:

Tuberculosis of the Sacroiliac Joint (Tuberculous Sacroiliitis)

Because a definitive diagnosis still requires etiological or pathological evidence, sacroiliac joint aspiration/biopsy can be performed for confirmation if there is a high clinical and MRI suspicion. Bacterial culture and related molecular tests (such as PCR) can further confirm the diagnosis.

IV. Treatment Plan and Rehabilitation Program

1. Treatment Strategy

• Anti-Tuberculosis Therapy:
  If the diagnosis is confirmed, a standard anti-tuberculosis regimen of six to nine months is recommended (commonly including isoniazid, rifampin, pyrazinamide, ethambutol, etc.). Specific medication use should be guided by infectious disease/tuberculosis specialists. Regular monitoring of liver and kidney function, as well as potential adverse drug reactions, is necessary.
• Surgical Intervention:
  If there is extensive joint destruction, significant abscess formation, or failure of conservative treatment, imaging-guided drainage or surgical debridement may be considered to reduce the infectious burden and improve functional prognosis.
• Supportive Care:
  This includes pain management, nutritional support, and correction of potential immunological or hematological disorders (such as the patient’s autoimmune hemolytic anemia).

2. Rehabilitation/Exercise Prescription Recommendations

On the basis of anti-tuberculosis treatment and stabilized condition, functional rehabilitation should be gradually introduced to prevent joint stiffness and muscle atrophy. Adhering to the FITT-VP principle, the basic approach is as follows:

• Frequency (Frequency): 3–5 times a week, depending on pain severity and joint tolerance.
• Intensity (Intensity): Start with low-intensity exercises (e.g., bed stretches, leg lifts). If pain and local swelling subside, gradually increase the intensity.
• Time (Time): Begin with 10–15 minutes per session and gradually extend to 20–30 minutes, dividing into segments to avoid fatigue.
• Type (Type): Initially, isometric exercises for the lower back and hip joints can be performed in a supine or seated position. Later, depending on recovery, low-impact exercises such as walking or swimming can be tried.
• Progression (Progression): As pain and inflammation subside, gradually introduce small equipment (e.g., resistance bands, light dumbbells) to strengthen the lumbar and hip muscles and enhance core stability.

During rehabilitation, closely monitor changes in the patient’s pain. If significant discomfort or acute inflammatory reactions occur, suspend the relevant exercises and promptly re-evaluate. For patients with fragile bones or severe joint destruction, progression in activity should be more cautious.

Disclaimer

This report is a reference analysis based on the available imaging and historical information. It cannot replace in-person consultation or the final opinion of a qualified physician. If there are any questions or changes in condition, please seek prompt medical attention and follow the advice of specialized physicians.