MR DIAGNOSTICS OF MUSCLE TRAUMA Ivo Nikolov, M.D., Radiologist - Spectar Imaging Centre, Sofia
Мyofibrils Сonnective tissue Fibers - Endomysium Fascicle - Permysium Мuscle - Еpimysium
Question of the orthopedic surgeon Anatomy Sport Trauma mechanism Pain location
Flexed elbow Abducted shoulder Supinated forearm FABS
Short head Long head
Muscle strain: Indirect injury to muscle caused by excessive stretch and overuse resulting in microtrauma, muscle, and myotendinous tearing.
Pearls and Pitfalls MTU is the weakest biomechanical link and therefore is more often the location of muscle fiber failure. Infection or deep venous thrombosis may be mistaken for a muscle strain. Grade I muscle injuries are associated with a feathery edema pattern of muscle fibers.
Edema Thinning or discontinuation of the injured section Avulsion and/or avulsion fracture in origin or insertion Retraction Hematoma Hemosiderin deposits
Commonly strained muscles 1. Undergo eccentric contraction; 2. Cross two joints; 3. Have a high proportion of fast twitch fibers. Hamstrings /biceps femoris, semitendinosus, semimembranosus/ Quadriceps femoris /rectus femoris / Adductors Triceps surae /medial gastrocnemius / Pectoralis major Biceps brachii Internal oblique abdominal muscle /tennis players/ Paravertebral musculature /windsurfers/
Muscle Tendon Bone Chain Children physeal /growth plate/ - apophyseal avulsion fractures Young adults MTU classic site for strains Old adults tendinosis fiber tearing at sites that are weakened by tendon degeneration
Report checklist: 1. The name of the injured muscle/s/; 2. The site/s/of injury; 3. Extend of injury /grade, length on long axis, amount of retracted torn fibers/; 4. Focal fluid collection, haematoma, heterotopic ossification; 5. Age.
Grade I /Mild/ Grade II /Moderate/ Grade III /Severe/ edema, small hematoma, preserved muscle morphology big hematoma, disruption up to 50% of muscle fibers complete tearing or avulsion with or without muscle retraction
Grade I - edema in MTU of soleus and gastrocnemius muscles
Grade I - proximal long head of biceps femoris muscle /MTU/
Grade II - distal tendon of iliopsoas muscle
Avulsion of adductor longus muscle with partial tear of adductor brevis and pectineus muscles
supraspinatus muscle
Muscle contusions are caused by compressive or concussive direct trauma to the tissue with a blunt object.
Pearls and Pitfalls Contusions involve the deep muscle belly fibers. Muscle edema and hematoma contribute to an increase in muscle girth without architectural disruption. Myositis ossificans is associated with both myonecrosis and hematoma.
Contusion of rectus femoris, vastus lateralis and vastus intermedius muscles
Interstitial haemorrhage is bleeding that occurs between the connective tissues, whereas a hematoma is a blood collection confined to a restricted location.
Haemorrhage in the epimysium after Grade I strain of rectus femoris muscle
References: Distal Biceps Tendon Rupture Elbow, M. Stadnic, www.radsource.us, MRI Web Clinic, Jan, 2015 Hypertrophy vs Hyperplasia, What s The Difference, Brandon s Blueprint, www.musclebiology.wordpress.com, Nov, 2015 Imaging of Lower Limb Muscle Injury, J, Lee, J. Healy, www.aspetar.com, Aspetar Sports Medicine Journal, Aug, 2012 Magnetic Resonance Imaging in Orthopaedics and Sports Medicine, D. Stoller, Lippincott/Williams & Wilkins Magnetic Resonance Imaging in Orthopaedic Sports Medicine, R. Pedowitz, C. Chung, D. Resnick, Springer Muscle MR Traumatic Changes, M. Pathria, J. Bradshaw, The Radiology Assistant, Oct, 2009 Radiology Key of Muscle Injuries, www.radiologykey.com Skeletal Muscle Disease: Patterns of MRI Appearances, D. Theodorou et al., PMC, Br J Radiol, Dec.;85/1020/: e1298-e1308
Thank you for your attention!