FIGURE 10-1 Patterns of bone destruction—geographic. (A) Lateral radiograph of the calcaneus showing a well-defined geographic lytic lesion (arrows). T1-weighted (B) and T2-weighted (C) magnetic resonance (MR) images showing homogeneous fluid signal caused by a benign unicameral bone cyst.

FIGURE 10-2 Moth-eaten. Lateral view of the femur showing a destructive lesion with poorly defined margins and a pathologic fracture anteriorly (arrowhead) as the result of metastasis.

FIGURE 10-3 Permeative. Poorly defined lytic lesion in the proximal humerus with permeative cortical changes attributable to Ewing sarcoma.

FIGURE 10-4 Matrix calcifications. Axial CT image of the distal tibial epiphysis showing a well-defined geographic lesion with calcifications. Appearance and location characteristic of chondroblastoma.

FIGURE 10-5 Periosteal response. Osteogenic sarcoma with bone sclerosis and cortical break: a triangular elevation (arrow) (Codman triangle) seen with aggressive lesions.

FIGURE 10-6 Patient with a knee sarcoma and midfemoral skip lesion. The knee coil would be optimal for knee imaging, but the skip lesion would not be identified unless the larger body coil was used to evaluate the entire femur.

FIGURE 10-7 Optimal image planes. (A,B) Sarcoma in the proximal femur with level of excision for limb salvage marked on coronal images. At least 5 to 7 cm of normal marrow usually is included in the resection. (C) Optimal sagittal image in a different patient showing the entire area of interest on one image. Line marks planned resection.

FIGURE 10-8 Intracapsular osteoid osteoma. Coronal T1-weighted (A) and fluid-sensitive (B) weighted images showing a large area of signal abnormality in the right femoral neck. (C) Axial T2-weighted image shows fluid in the joint with a small high signal intensity nidus (arrowhead) and surrounding edema. (D) Axial CT image demonstrates the lucent nidus (arrowhead) more clearly.

FIGURE 10-9 Tibial osteoid osteoma. (A) Posterior image from a bone scan showing increased tracer in the medial tibia. (B) CT scan clearly defines the nidus (arrow) and surrounding bone sclerosis.

FIGURE 10-10 Osteoblastoma. Sagittal (A) and axial (B) contrast-enhanced T1-weighted images showing a large enhancing lesion that appears to involve the body and neural arch with spinal cord compression. Axial (C), sagittal (D), and coronal (E) CT images demonstrate matrix calcification or ossification with a thin cortical rim characteristic of osteoblastoma.

FIGURE 10-11 Anteroposterior (AP) (A) and lateral (B) radiographs of an osteochondroma. Coronal T1-weighted (C) and axial T2-weighted (D) images showing marrow extending into the lesion (arrow) and a thin high signal intensity cartilaginous cap (arrowheads).

FIGURE 10-12 Axial CT of an osteochondroma arising from the upper tibia.

FIGURE 10-13 AP (A) and lateral (B) radiographs of a phalangeal enchondroma. There is cortical expansion and a pathologic fracture (arrow).

FIGURE 10-14 Enchondroma in a 52-year-old woman. (A) Routine radiograph of the shoulder showing a focus of calcifications in the marrow of the humeral neck with no endosteal scalloping. Coronal T1-weighted (B) and T2-weighted (C) MR images showing areas of low and high intensity in the enchondroma as the result of calcifications. There is no marrow edema, cortical destruction, or soft tissue mass.

FIGURE 10-15 Chondroblastoma. (A) AP radiograph demonstrates a proximal tibial lesion with sclerotic margins and calcifications. There is subtle periosteal reaction (arrow). Coronal T1- (B) and T2-weighted (C) images demonstrate a well-defined lesion with marrow edema pattern.

FIGURE 10-16 Chondromyxoid fibroma in a 45-year-old woman. (A) Oblique radiograph of the knee showing a lytic lesion with sclerotic margins (arrows). (B) Axial CT showing the well-defined sclerotic margins with no matrix calcifications. Axial T1-weighted (C), axial enhanced T1-weighted (D), and T2-weighted coronal (E) images showing the lesion to be low signal intensity on T1 (D) with peripheral enhancement.

FIGURE 10-17 Nonossifying fibromas in the tibia and femur of a 15-year-old boy. AP (A) and lateral (B) radiographs showing lucent lesions in the tibia and femur (arrowheads) with well-defined sclerotic margins. There also is osteochondritis dissecans in the medial femoral condyle. (C,D) Sagittal T2-weighted MR images showing high signal intensity with low intensity at the margin of the lesions.

FIGURE 10-18 Unicameral bone cyst. AP radiograph of the humerus with a bone cyst and pathologic fracture with the “fallen fragment sign” (arrows).

FIGURE 10-19 Unicameral bone cyst. Sagittal T1-weighted (A) and STIR (5300/30/150) (B) images showing low intensity on T1-weighted (A) and high intensity on STIR (B) consistent with a fluid-filled cyst.

FIGURE 10-20 Aneurysmal bone cyst. (A) AP radiograph showing a lytic expanding lesion in the upper tibia. Coronal T1-weighted (B) and axial T2-weighted (C) MR images showing a cystic lesion with fluid–fluid levels.

FIGURE 10-21 Thirteen year old male with polyostotic fibrous dysplasia. (A) AP radograph of the pelvis demonstrates lucent lesions in the ilium and femur. (B) Radionuclide bone scan shows multiple lesions on the left involving the pelvis, femur, and tibia. Coronal T1- (C) and T2-weighted (D) images demonstrate abnormal signal intensity in the involved bones with expansion of the femoral neck.

FIGURE 10-22 Giant cell tumor. (A) AP radiograph demonstrates a poorly defined lesion involving the epiphysis and metaphysis. Coronal T1- (B) and postcontrast T1-weighted (C) images show low signal intensity on the T1-weighted image (B) and contrast enhancement (C). Coronal (D) and axial (E) CT images showing low attenuation with no calcified matrix.