Presentation Format: Oral presentation.
Purpose or Learning Objective: Magnetic resonance imaging (MRI) diagnosis of the phalanges is challenging because the finger rays and the thumb are oriented differently in space. Furthermore, the tendons run obliquely, especially the extensor pollicis longus, flexor pollicis longus, and extensor digiti minimi tendons.
Methods or Background: We analyzed the imaging results of > 1,200 MRI examinations of the fingers and thumb using 1.5- or 3-T scanners and multichannel phased-array coils. Our experience is reviewed in this presentation.
Results or Findings: These recommendations for both hands contribute to optimized finger MRI: (1) In two-dimensional (2D) fast spin-echo (FSE) sequences, geometry can be best assessed if only one finger ray is scanned. The thumb, in particular, should be examined separately. (2) Isotropic three-dimensional (3D) sequences are advantageous for imaging tendons because they allow oblique, double-oblique, and curved planes during postprocessing. A coronal acquisition slab is recommended covering several finger rays. (3) For coronal and sagittal assessment of an entire ray, the longitudinal field of view (FOV) should be 130 mm and slice thickness 1.5 mm without a gap. For focal lesions, the longitudinal FOV can be reduced to 80 mm. (4) The coronal plane is preferred for lesions of the joints and the collateral ligaments; the sagittal plane is preferred for lesions of the flexor and extensor tendons and the palmar plate. (5) The transaxial plane should be scanned with fat-saturated proton-density FSE sequences, and in tenosynovial giant cell tumors and bone tumors also with T2*-weighted gradient-echo sequences and a slice thickness of 2.5 mm. (6) Conventional 2D FSE sequences depict soft tissue tumors with high contrast. (7) Intravenous contrast agent is required for nonganglionic tumors and all synovial diseases.
Conclusion: With a focused request, geometric scan parameters can be optimized in MRI of the fingers. We recommend 3D sequences to assess lesions of the tendons.
