Top 3 Differentials in Musculoskeletal Imaging

Part 1: Trauma

1 Shoulder dislocation

2 Distal clavicular erosion

3 Widening of acromioclavicular (AC) joint

4 Fracture dislocation of forearm

5 Carpal dislocation

6 Avulsion fracture of finger

7 Avulsion fracture of the pelvis

8 Widened pubic symphysis

9 Pelvic ring disruption

10 Avulsion fracture at the knee

11 Distal fibular fracture

12 Calcaneal avulsion fracture

13 Fracture at the base of the fifth metatarsal

Part 2: Bone Tumors

14 Aggressive periosteal reaction

15 Focal cortical thickening

16 Epiphyseal equivalent lucent lesion

17 Solitary focal sclerotic lesion

18 Lesion with permeative or moth-eaten pattern

19 Osseous lesion with fluid-fluid levels

20 Osseous lesion with chondroid matrix

21 Osseous lesion with osteoid matrix

22 Polyostotic lesions-looks like a syndrome

23 Surface lesion of bone

24 Multiple lytic lesions

25 Multiple sclerotic lesions

26 Expansile lytic lesion of rib

27 Ivory vertebral body

28 Lytic lesion of distal phalanx

29 Anterior tibial cystic appearing lesion

30 Lucent lesion in calcaneus

31 Diffusely increased bone density

32 Well-marginated ossific mass projecting off the surface of the bone (without full-thickness cortical disruption or overlying soft-tissue mass)

33 Long lesion in a long bone with ground glass matrix-Roentgen classic

34 Bony projection with continuation of cortex and medullary cavity of host bone-Roentgen classic

35 Fractured lytic lesion with a fallen fragment-Roentgen classic

Part 3: Upper Extremity

36 Abnormal/variant appearance of anterosuperior labrum

37 Abnormality of inferior glenohumeral ligament

38 Abnormality of proximal long head of biceps tendon

39 Tear of the anteroinferior labrum

40 Bursa or cyst around the shoulder

41 Rotator cuff abnormality

42 Rotator interval abnormality

43 Posterior glenoid labral abnormality

44 Nerve entrapment at shoulder

45 Nerve entrapment at elbow

46 Distal biceps tendon abnormality

47 Radial-sided, soft-tissue injury at elbow on MRI

48 Osteochondral lesion of elbow

49 Ulnar-sided, stabilizer injury at elbow on MRI

50 Numerous tiny T2 hyperintense subcutaneous nodules

Part 4: Lower Extremity

51 Variant sciatic nerve anatomy

52 Ischiofemoral space narrowing and quadratus femoris muscle edema in a patient with chronic ischial tuberosity avulsion (nonunion)

53 Small smoothly marginated depression ("fossa") at the mid-acetabular roof

54 Focal subchondral bone edema in the femoral head

55 Low-grade tearing of the iliotibial band (ITB), with soft-tissue edema along the fascia

56 Focal periphyseal edema

57 Curvilinear signal separating the patella into two fragments

58 Frond-like lobules of fatty tissue in the suprapatellar recess, with effusion

59 Cystic-appearing lesion centered inferior to the medial joint line of the knee

60 Accessory muscle around ankle

61 Accessory ossicle around ankle

62 Achilles tendon abnormality

63 Impingement syndrome at ankle

64 Ankle sprain

65 Medial tendon abnormality at ankle

66 Nerve entrapment around ankle and foot

67 Plantar fascial abnormality

68 Peroneal tendon disease at the ankle

69 Midfoot ligamentous or osseous injury

70 Hallux sesamoid abnormality

71 Subchondral crescent sign-Roentgen classic

72 Fluid collection at the inferomedial aspect of hip-Roentgen classic

73 Cleft of T2 hyperintense signal at the attachment of rectus abdominis-adductor aponeurosis-Roentgen classic

74 Hamstring tendon discontinuity with subacute hematoma-Roentgen classic

Part 5: Arthropathies

75 Intense, diffuse, nontraumatic bone and soft-tissue edema centered at the midfoot

76 Polyarticular arthritis in an adolescent, with "blooming" intraarticular hemosiderin

77 Bilateral sacroiliitis

78 Contour defect at the posterolateral humeral head

79 Proximal arthropathy affecting primarily the metacarpophalangeal joints.

80 Distal arthropathy affecting primarily the interphalangeal joints

81 Erosive arthropathy involving the foot

82 Acro-osteolysis

83 Loose bodies

84 Articular cartilage thinning, subchondral cyst formation and dorsal subluxation of the metacarpal base-Roentgen classic

Part 6: Infection

85 Penumbra sign

86 Sequestrum

87 Fluid collection with edema at metaphyseal-equivalent location (prior to skeletal maturity)

88 Space occupying lesion posterior to olecranon

89 Unilateral sacroiliitis

90 Epitrochlear lymphadenopathy

91 Aggressive, cortically-based osteolysis and periosteal reaction at the diaphysis of an adult long bone

92 Abscesses in bone and adjacent to bone, with thin perforations in cortex-Roentgen classic

Part 7: Soft Tissue Tumors

93 Fusiform mass, with longitudinal "tail" entering and exiting eccentrically

94 Complex fluid collection in the bicipitoradial bursa

95 Infiltrative intra-articular mass of low-T2 signal intensity, with erosions

96 Non-mineralized soft-tissue mass with an infiltrative border ("tail sign") that responds favorably to non-operative treatment

97 Post-traumatic fluid-like collection in the deep subcutaneous tissue along the superficial aspect of the fascia

98 Large, pendulous mass at the inner thigh in a morbidly obese patient

99 Leg, ankle, and foot edema, with prominent thickening and increased density of the subcutaneous fat layer

100 Triad of key findings: Pretibial varices, linear cortical defect in mid tibia, and prominent nutrient vein within the mid tibia

101 Multiple T2-hypointense masses in the subcutaneous fat layer of the foot

102 Large subfascial soft-tissue mass with heterogeneous signal on T1, T2, and post-contrast images

103 Rim enhancing mass in iliopsoas

104 Infrascapular soft-tissue mass containing diffuse streaks of fatty tissue-Roentgen classic

Part 8: Metabolic Musculoskeletal Conditions

105 Frayed metaphyses

106 Generalized periosteal reaction

107 Periarticular calcified mass

108 Long bone sclerosis

109 Multiple bone infarcts

110 Osteoporosis

111 Widespread soft tissue calcifications

112 Rugger jersey spine

Part 9: Spine

113 Vertebral body fusion

114 Odontoid fracture

115 Hyperflexion Injury

116 Midline sacral lesion

117 Posterior vertebral body scalloping

118 Anterior vertebral body scalloping

119 Lytic lesion of posterior elements of spine

120 Epidural mass

121 Diffuse marrow T1 and T2 low signal

122 Focal T1 signal increase

123 Intradural extramedullary mass

124 Intradural intramedullary spinal cord mass

125 End plate irregularity

Part 10: Pediatric or Developmental Musculoskeletal Conditions

126 Short rib skeletal dysplasia

127 Abnormal epiphyses

128 Limb deficiency

129 Genu varum

130 Lucent metaphyses

131 Dense metaphyses

132 Dislocated hip

133 Physeal widening

134 Hip effusion

135 Infrapatellar soft tissue swelling

136 Foot deformity

137 Soft tissue mass in an infant

138 Large soft tissue mass in an older child

139 Periosteal reaction in a newborn/infant

140 Wormian bones

141 Madelung deformity

142 Tarsal coalition

143 Well-corticated ossific density at the lateral aspect of acromion-Roentgen classic

144 Osteoporosis, bowing deformities, and multilevel spine fractures-Roentgen classic

145 Decreased lower lumbar interpediculate distances, "tombstone" iliac bones, "champagne glass" pelvic inlet, and rhizomelic limb shortening-Roentgen classic

146 Multiple rib fractures in various stages of healing-Roentgen classic