This trial studies the accuracy of a magnetic resonance imaging (MRI) scan in imaging the inside of the chest in patients with thymoma that is newly diagnosed or has come back. An MRI scan may be able to detect if and how far the tumor has spread more accurately than a standard computed tomography (CT) scan.

PRIMARY OBJECTIVES:

I. To determine whether thymoma staging by MRI is as accurate as staging by CT as compared to surgical staging.

SECONDARY OBJECTIVES:

I. To determine whether evaluation of phrenic nerve paralysis by functional MRI is as accurate as the fluoroscopic "sniff test" as compared to surgical evaluation of phrenic nerve involvement.

II. To determine whether fast novel MRI sequences are as accurate as conventional MRI sequences for staging thymoma, when comparing to surgical staging.

OUTLINE:

Patients undergo an MRI scan over 45-60 minutes and a diaphragm fluoroscopy 30 days before surgery.

Inclusion Criteria:

• All adult patients scheduled to meet with a thoracic surgeon from MD Anderson Cancer Center (ACC) for resection of newly diagnosed thymoma or thymoma recurrence in the chest and scheduled for surgery

Exclusion Criteria:

• Children, defined as individuals younger than 18 years old on the preoperative visit with the thoracic surgeon
• Pregnant patients
• Patients unable to understand the consent form
• Patients with metal within the chest and pacemakers
• Patients with a known allergic reaction to gadolinium, who will have their MRI performed without contrast
• Patients with glomerular filtration rate (GFR) < 60 ml/min, who will have their MRI performed without contrast
• Patients with an allergy to iodinated contrast material will follow departmental routine policy, that is those with anaphylaxis will have their CT performed without intravenous contrast and others will be prepped as for departmental guidelines for routine chest CT
• Patients with abnormal renal function will have their CT study perform as per DI's iodinated contrast administration guidelines, and no contrast will be administered with GFR lower than 30 ml/min