**Core Concept**
Occult fractures of the neck of femur are a type of hip injury where there is a non-displaced or minimally displaced fracture of the femoral neck, which can be difficult to diagnose clinically. These fractures are often associated with osteoporosis, particularly in elderly women. The diagnosis of occult fractures requires a combination of clinical evaluation, imaging studies, and laboratory tests.

**Why the Correct Answer is Right**
The best diagnostic tool for occult fractures of the neck of femur is the **radiograph** of the affected hip, specifically the AP and lateral views of the femoral neck. A **normal radiograph** does not rule out the possibility of an occult fracture, and therefore, a high index of suspicion is required in patients with hip pain and a history of trauma. In some cases, **MRI** may be used to confirm the diagnosis, especially if the radiographs are inconclusive.

**Why Each Wrong Option is Incorrect**
* **Option A:** Stress radiographs are not the best diagnostic tool for occult fractures of the neck of femur. While stress radiographs can be used to evaluate for stress fractures, they are not as sensitive as radiographs for diagnosing occult fractures.
* **Option B:** CT scans are not typically used as the initial imaging modality for occult fractures of the neck of femur. While CT scans can provide more detailed information than radiographs, they are not as readily available or as cost-effective.
* **Option D:** Bone scans are not the best diagnostic tool for occult fractures of the neck of femur. While bone scans can be used to evaluate for osteoblastic activity, they are not as sensitive or specific as radiographs for diagnosing occult fractures.

**Clinical Pearl / High-Yield Fact**
In patients with hip pain and a history of trauma, a normal radiograph does not rule out the possibility of an occult fracture of the neck of femur. A high index of suspicion and further imaging studies, such as MRI, may be necessary to confirm the diagnosis.

**Correct Answer:** C.