Medical Imaging Analysis Report

I. Imaging Findings

Based on the provided ultrasound, CT, and MRI images, a cystic lesion can be observed either within the arterial wall or adjacent to it in the popliteal region behind the knee. Ultrasound examination shows a low-echoic or anechoic cystic structure in the outer arterial layer, with fluid signals inside; its size may vary depending on posture or activity. Color Doppler can reveal narrowing of the arterial lumen and help evaluate hemodynamic changes. On MRI (especially T2-weighted images), there is a focal or linear high-signal area within or near the popliteal arterial wall in a cystic shape, and in some cases, there may be signs of connection with the adjacent joint capsule. Overall, the imaging features are typical of a cystic adventitial disease.

II. Potential Diagnoses

1. Popliteal Artery Aneurysm: Can also present as an abnormal arterial dilation in the popliteal region, but it generally involves the actual arterial lumen. Ultrasound or MRI often shows blood flow signals or mural thrombosis within the aneurysm cavity, which differs from the cystic adventitial lesion found outside the arterial lumen in this case.
2. Cystic Adventitial Disease of the Popliteal Artery: Commonly seen in middle-aged men; the characteristic imaging finding is a cystic lesion on the arterial adventitia, which may connect to the joint capsule. The imaging findings in this case strongly suggest this diagnosis.
3. Baker’s Cyst (Popliteal Cyst): Typically located where the joint capsule herniates between the semimembranosus tendon and the joint, presenting as a cystic lesion in the popliteal region. However, it usually connects directly to the joint and does not often involve the arterial adventitia.
4. Arterial Thrombosis or Local Arteritis: When the arterial wall thickens or thrombosis forms, there can be arterial lumen narrowing. However, imaging usually shows inflammatory changes or occlusive thrombus, rather than a distinct cystic, fluid-filled lesion.

Considering the clinical presentation (intermittent claudication, male patient, lesion location) and the radiographic findings, cystic adventitial disease of the popliteal artery is the most likely diagnosis.

III. Final Diagnosis

Integrating the patient’s age, symptoms (intermittent claudication), imaging findings (cystic lesion in or around the arterial adventitia, possibly connecting to the joint), and the typical demographic and anatomical distributions of this condition, cystic adventitial disease of the popliteal artery is the most probable diagnosis.

IV. Treatment Plan and Rehabilitation Strategy

1. Treatment Strategy:
The primary treatment for this condition is surgical intervention, including excision of the cyst and closure of any potential connection to the joint capsule. If the cyst is large and causes significant arterial narrowing or occlusion, surgical indications are stronger. In early or mild cases, physical therapy and pain management may be considered while monitoring for progression.
If there is a high risk of vascular stenosis, an assessment for vascular reconstruction or stent placement might be needed. However, for cystic adventitial disease of the popliteal artery, priority is usually given to removing the lesion and blocking any joint capsule communication to reduce recurrence.

2. Rehabilitation and Exercise Prescription (FITT-VP Principle):

• Exercise Frequency: Start with low-intensity walking 3–4 times a week.
• Exercise Intensity: Primarily at light to moderate intensity (slightly increased breathing rate but still able to speak normally). After surgery or when symptoms are under control, intensity can be gradually increased under medical advice.
• Exercise Time: Initially 15–20 minutes per session. Increase gradually to 30 minutes or more based on individual tolerance.
• Exercise Type: Low-impact activities, such as walking on flat ground, elliptical training, swimming, or stationary cycling, to reduce high-pressure impact on the popliteal region.
• Exercise Progression: As rehabilitation progresses and joint range of motion and muscle strength improve, gradually increase exercise duration and intensity. Closely monitor for knee or popliteal pain or swelling changes and schedule regular check-ups.
• Exercise Volume and Plan: Aim for a small, weekly increase in exercise intensity or duration over 6–8 weeks, adapted to individual recovery. Avoid excessive load that could cause knee or vascular reinjury.

During rehabilitation training, if popliteal swelling, worsening pain, or abnormal lower limb perfusion (e.g., numbness, weakness) occurs, seek medical evaluation promptly.

Disclaimer: This report is for medical reference only and cannot replace the in-person consultation and diagnosis of a qualified physician. Specific treatment plans should be determined by a specialist based on the individual patient’s condition.