Medical Imaging Analysis Report

I. Imaging Findings

From the provided CT and MRI images of both thighs, the following findings are noted:

• Muscle Edema and Abnormal Signals: There is visible soft tissue swelling in the bilateral thigh muscle groups, with decreased muscle intensity on T1WI. On T2WI and fat-suppression sequences (such as STIR or T2 fat suppression), the muscles show markedly high signal, indicating significant inflammation or edema.
• Potential Fluid/Pus Collection: Irregular fluid-density or fluid-signal areas can be observed locally. They appear hypodense on CT and hyperintense on MRI, suggesting possible pus or exudate.
• Surrounding Soft Tissue Changes: The fascial plane is blurred, and adjacent soft tissue is swollen, implying possible involvement of the fascia or subcutaneous tissue.
• No Obvious Bone Destruction: Currently, there is no sign of cortical disruption or fracture on the imaging.

II. Potential Diagnoses

Based on the patient’s young age, acute onset, significant bilateral leg swelling, and multiple organ failure, the following differential diagnoses should be strongly considered:

1. Streptococcal Myositis:
   • A severe muscle infection caused by Group A streptococci, clinically presenting with high fever, severe pain, and rapid progression, often accompanied by sepsis, shock, and multiple organ dysfunction.
   • Imaging may reveal extensive muscle inflammation, abscess, or necrosis, which can appear highly aggressive.
2. Pyomyositis or Other Bacterial Infections:
   • Commonly caused by Staphylococcus aureus or other frequent bacterial strains, but may also be due to hemolytic streptococci.
   • Radiologic findings are similar to those of streptococcal myositis; differentiation requires pathogen identification and clinical blood culture results.
3. Necrotizing Fasciitis:
   • A severe bacterial infection of the muscles and fascia, often related to streptococci or polymicrobial organisms.
   • There may be an overlap with myositis. Surgical exploration can help clarify whether both fascia and muscle layers are extensively necrotic.

III. Final Diagnosis

Considering the patient’s background as a young female, previous healthy status, multiple organ failure, imaging findings, and clinical symptoms (such as severe bilateral leg pain, fever, shock, and respiratory failure), the most likely diagnosis is Streptococcal Myositis, i.e., an invasive muscle infection caused by Group A streptococci.

Given the aggressive nature of this condition, if necrosis or more extensive muscle involvement is suspected, further confirmation through surgical exploration and pathogen analysis (bacterial culture, pathology) is necessary.

IV. Treatment Plan and Rehabilitation Program

Once Streptococcal Myositis/Pyomyositis is confirmed or highly suspected, comprehensive treatment must begin without delay:

1. Surgical Intervention:
   • For patients presenting with abscesses or necrotic tissue, prompt surgical drainage or debridement is required to remove the infectious focus and relieve pressure.
2. Antimicrobial Therapy:
   • Intravenous penicillins or cephalosporins sensitive to Group A streptococci are preferred; broader-spectrum antibiotics can be used initially until the pathogen is definitively identified.
   • The treatment course typically lasts at least 2–3 weeks, adjusted according to clinical response and inflammatory markers.
3. Supportive Care:
   • Closely monitor vital signs and organ function. If needed, employ extracorporeal blood purification (dialysis or hemofiltration) or mechanical ventilation.
   • Maintain electrolyte and acid-base balance as well as provide nutritional support.

Rehabilitation and Exercise Prescriptions can gradually be introduced once the acute phase of infection has passed and inflammatory markers have stabilized or decreased significantly. It is advisable to create a stepwise recovery program based on the patient’s muscle strength and cardiopulmonary function:

• Early Stage (Bed Rest or Restricted Activity)
  • Focus on protecting the lower limb muscles, avoiding excessive weight bearing and stretching.
  • Begin with passive range-of-motion exercises or isometric muscle training for the distal joints of the affected limb to prevent muscle atrophy.
• Middle Stage (Ambulation and Gradual Weight-Bearing)
  • Once infection and inflammation are controlled, introduce short-distance assisted walking exercises to prevent joint stiffness.
  • Exercise frequency can be 3–4 times a week, with each session gradually increasing in duration from 10 to 30 minutes.
  • Based on muscle recovery, light to moderate lower limb resistance training (e.g., resistance bands or low-weight dumbbells) can be introduced.
• Late Stage (Fitness Recovery and Enhancement)
  • Gradually transition to more intense strength and endurance training, such as jogging or low-impact aerobic exercises (elliptical, cycling, etc.).
  • Continuously monitor hip and knee joint stability, muscle strength, and cardiopulmonary function.
  • Exercise frequency can increase to 4–5 times a week, with a total duration of 30–45 minutes each time at a moderate intensity.

Throughout the rehabilitation process, personalized adjustment is crucial. If new pain, swelling, or discomfort arises, the training plan should be reassessed and modified immediately.

Disclaimer:
This report is based solely on the current imaging and clinical information for reference and does not substitute for an in-person consultation or professional medical advice. If any abnormalities or worsening of the condition occur, please consult a medical professional or contact a specialized medical institution promptly.