**3. Imaging**

### **3.1 Radiography**

Every patient with suspected bone neoplasia should be initially evaluated by orthogonal radiography examination and, although the radiologist's report is of great value, the orthopedist must have the basic knowledge to recognize the information that the bone lesion can provide on radiography [10]. The correct diagnostic approach to a bone neoplasm cannot be adequately achieved without radiographic evaluation [14, 16, 17].

The radiographic findings provide important information about the nature of the bone lesion. We can observe if it is bone-forming (osteoblastic), if it promotes bone destruction (osteolytic) or if the lesion has areas of bone formation as well as areas of bone destruction (mixed). Second, the radiography will provide the lesion location (epiphysis, diaphysis, metaphysis, or surface), presence of periosteal reaction (spiculate, sunlight, onion skin, and Codman's triangle), presence of halo of sclerosis, presence of pathological fracture, extension to soft tissues (extra compartmental lesion), among other characteristics specific to each type of bone neoplasm that can even define the diagnosis (**Table 2**) [10, 11, 14, 18].

### **3.2 CT scan**

Computed tomography can better delineate the information obtained on radiography, especially in lesions of bone sites with more complex anatomy, such as the pelvis


*Perspective Chapter: Bone Tumors – How to Make a Diagnosis? DOI: http://dx.doi.org/10.5772/intechopen.106673*

> **Table 2.**

*Differential diagnosis by lesion location.*

### **Figure 1.**

*Examples of CT-scan of pulmonary metastases in patients with osteosarcoma, in general the lesions are found in the periphery of the lung.*

### **Figure 2.**

*(A) clinical aspect of the right knee, observing an increase in volume in the distal region of the femur, (B) radiographic appearance of aggressive bone lesion in the distal metaphysis of the femur, and (C) MRI demonstrating the full extent of the affected bone.*

and spine. CT scan can observe the presence or absence of intralesional calcifications; it can be useful in the assessment of the risk of fragility fracture and used to guide biopsies. For lesions suspected of malignancy, CT scan is mandatory for the investigation of pulmonary metastases [11, 19]. In relation to osteoid osteoma, it is the exam of choice to locate the lesion niche (**Figure 1**) [2, 20].
