A CT scan acquires multiple X‑ray slice images displayed as 2D cross‑sections for diagnosis. A 3D CT is a post‑processed reconstruction of those slices into a volumetric, rotatable image or multiplanar views, improving spatial understanding for surgical planning, dental and orthopedic assessments. 3D reconstruction uses the same scan data (usually no extra radiation) but requires additional processing and interpretation.

A CT of the left shoulder is typically performed with the patient supine, head‑first into the scanner, and the left arm positioned alongside the body in neutral or slight external rotation. The arm is immobilized for comfort and repeatability. Acquisition is axial with multiplanar reformats (coronal and sagittal) to assess the glenohumeral joint, acromion, surrounding bones, and soft tissues.

CT scans are excellent for detecting shoulder bone problems—fractures, joint alignment, bone spurs, calcifications, arthritis, and complex anatomy—making them useful for surgical planning. They are less sensitive than MRI for soft-tissue injuries (rotator cuff, labrum), though CT arthrography can improve detection of labral or cuff tears. CT involves ionizing radiation, so clinicians weigh benefits versus risks when choosing imaging.

A 3D CT scan’s actual image acquisition is very quick—often seconds to a few minutes. Allow 10–20 minutes for a routine non‑contrast exam (positioning and scanning). If IV contrast or time‑dependent imaging is needed, the visit can take 30–60 minutes to include consent, IV placement, injection and observation. Reconstruction/3D processing may add a short processing interval but usually doesn’t extend your appointment.

A 3D CT scan starts with patient positioning on the scanner table; removal of metal and sometimes fasting. An IV contrast injection may be given. The scanner acquires multiple thin cross‑sectional X‑ray slices while the table moves through the gantry. Computer software reconstructs these slices into 3D volume‑rendered images for review. The exam is quick, noninvasive, and involves ionizing radiation.

A 3D CT scan exposes you to ionizing radiation, slightly increasing lifetime cancer risk. If contrast dye is used, you may have warmth, nausea, allergic reactions (rarely severe), or contrast-related kidney injury, especially with pre-existing kidney disease. Other effects include discomfort from lying still and anxiety or claustrophobia. Pregnant patients should avoid CT unless strongly indicated due to fetal radiation risk.