Given a context passage, generate a question from the passage such that its answer is shortest continous span from the passage.

Example input: In 1582 the united provinces invited francis, duke of anjou to lead them; but after a failed attempt to take antwerp in 1583, the duke left the netherlands again. after the assassination of william of orange (10 july 1584), both henry iii of france and elizabeth i of england declined the offer of sovereignty. however, the latter agreed to turn the united provinces into a protectorate of england (treaty of nonsuch, 1585), and sent the earl of leicester as governor-general. this was unsuccessful and in 1588 the provinces became a confederacy. the union of utrecht is regarded as the foundation of the republic of the seven united provinces, which was not recognized by the spanish empire until the peace of westphalia in 1648.
Example output: In what year did francis, duke of anjou leave the netherlands?
Example explanation: The generated question is perfect. Because the question is based on second sentence of the input passage and its answer is 1583.
Q: Magnetic resonance imaging (MRI) has a higher sensitivity and specificity (90% and 79%) than plain radiography (54% and 68%) for diagnosing diabetic foot osteomyelitis. MRI performs somewhat better than any of several common tests--probe to bone (PTB), erythrocyte sedimentation rate (ESR) >70 mm/hr, C-reactive protein (CRP) >14 mg/L, procalcitonin >0.3 ng/mL, and ulcer size >2 cm--although PTB has the highest specificity of any test and is commonly used together with MRI. No studies have directly compared MRI with a combination of these tests, which may assist in diagnosis.
A:
Which disease can be diagnosed with the "probe to bone" test?