MRI of bone and joints

Bone and joint MRI is the use of MRI to scan bones and joints for observation of intraosseous conditions and diagnosis of related diseases. The hip and shoulder joints were routinely taken from the coronal plane and the cross-sectional T1WI and T2WI. The hip joints were symmetrical when imaging, and the sagittal plane was added if necessary. The knee, upper arm and lower leg were routinely imaged on the coronal and sagittal planes T1WI, T2WI, paying attention to parallel with the limbs, and if necessary, sweeping the cross section. Basic Information Specialist classification: growth and development check classification: nuclear magnetic resonance Applicable gender: whether men and women apply fasting: not fasting Tips: Pregnant women should be examined carefully. If they are pregnant, please inform the doctor. Normal value Subcutaneous fat and bone marrow showed high signals on T1WI, T2WI and proton density images; cortical bone, air, ligament, tendon and fibrocartilage showed low signal; muscle and joint hyaline cartilage showed moderately low signal. Fluids, such as intra-articular fluid, inflammation or edema and tumor tissue, are low on T1WI and high on T2WI. The hematoma shows different signs of intensity depending on the length of the bleeding. Check for abnormal lumps and areas. Clinical significance Abnormal result (1) For bone marrow, muscle disease and bone contusion changes, fat suppression scanning has high sensitivity; (2) Sagittal imaging of the knee joint, the scanning plane and the sagittal plane of the knee joint are at an angle of 15° (outward rotation of the knee joint), which can better display the anterior and posterior cruciate ligaments; (3) T2WI imaging of the sagittal plane of the knee joint, in order to avoid the arterial pulsation artifact, the phase coding generally adopts the HF direction; (4) Knee joint scanning If the phase encoding takes the HF direction, oversampling techniques can be used to avoid curling artifacts; (5) Limb vascular imaging, 2D (3D) TOF method or PC vascular imaging technology can be used to enhance the contrast agent using 3D-CE-MRA technology. People who need to be examined for the elderly, fractures and other bone-related diseases. Precautions Taboo before inspection: no special contraindications. Requirements for inspection: Check the relaxed mood, follow the doctor's instructions to check, please bring the medical records, X-ray film, CT film, and previous MRI films along with the MRI room for reference. Inspection process 1, coil and body position: The hip joint uses a body array coil or a body-wound flexible coil and a body coil. The supine position is advanced, and the center of the coil is aligned with the upper edge of the pubic symphysis. The knee joint uses a wrapped surface soft coil or a head coil. The supine position is advanced, and the center of the coil is aligned with the lower edge of the humerus. The shoulder joint uses a shoulder-wound surface coil or a body array coil. The supine position is advanced, and the center of the coil is aligned with the humeral head. The upper arm, the lower leg and the small joint use a rectangular surface coil or a flexible coil, and the inspection portion is aligned with the center of the coil. 2. Conventional imaging orientation and sequence: The hip and shoulder joints were routinely taken from the coronal plane and the cross-sectional T1WI and T2WI. The hip joints were symmetrical when imaging, and the sagittal plane was added if necessary. The knee, upper arm and lower leg were routinely imaged on the coronal and sagittal planes T1WI, T2WI, paying attention to parallel with the limbs, and if necessary, sweeping the cross section. Small joints depend on the specific situation. Prosthetic structures are well displayed by proton imaging using quadrilateral joint scanning. The conventional layer has a thickness of 4 mm and a pitch of 20%. The phase encode direction: the cross section adopts the LR direction, the sagittal plane adopts the AP direction or the HF direction, and the coronal plane adopts the LR direction. 3. Contrast enhancer: Contrast agent: 0.5 mol/L (Gd-DTPA), 0.1 mmol/Kg, 0.5-1 ml/s intravenously. Scanning sequence: T1WI scan of the lesion with cross-section, coronal plane, and sagittal plane. Not suitable for the crowd Inappropriate crowd: 1. Those who install artificial heart pacemakers and nerve stimulators are forbidden to check. 2. It is forbidden to check if there is a silver clip in the skull and a metal foreign object in the eyeball. 3. The ECG monitor cannot enter the MRI examination room. Those who have undergone arterial surgery, have had heart surgery and have an artificial heart valve are forbidden to check. 4, a variety of critically ill patients: such as coma after trauma or accident, irritability, arrhythmia, respiratory insufficiency, constant blood loss and incontinence and so on. 5. Metal objects (such as internal fixed steel nails) cannot be inspected at the inspection site. 6. Pregnant women should be examined carefully. If they are pregnant, please inform the doctor. Adverse reactions and risks Nothing.