In: Anatomy and Physiology
Give five Differential diagnosis of deep vein thrombosis and their differentiating features on ultrasound
1.Cellulitis
The findings in ultrasound varies with site and severity of the infection.Some of them are
*Diffused thickening and increased echogenicity of skin and subcutaneous tissues
*Hypoechoic fluid that traverse between the hyperechoic fat and connective tissue.This occurs in the later stages of cellulitis and is called cobblestone appearance.
2.Calf muscle tear/Achilles tendon tear
No DVT seen on ultrasound
*Full thickness tear shows tendinous gap filled with edema or blood
*Complete rupture shows retraction of tendon ends
*Partial thickness or interstitial tears show high signal on long TR and tendon swelling to >7 mm AP.
In ultrasonography, it is difficult to visualise the calf veins due to edema associated with muscle tear.Also extreme tenderness associated with the muscle tear makes it difficult to compress with the ultrasound probe
3.Calf muscle hematoma
Venous ultrasound shows no thrombosis.Evidence of hematoma(hyperechoic areas) seen in ultrasound.
4.Large or ruptured popliteal cyst(Baker's cyst)
*Ultrasound shows fluid in the soft tissues of calf.
*Popliteal cystic lesion with a fluid containing neck between the tendon of semimembranosus and medial head of gastrocnemius.
5.Pelvic/thigh mass compressing venous outflow from the leg
Ultrasound shows obstructing mass which impinges on the iliac,femoral or venacava vessels