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[The MRT of scaphoid pseudarthrosis with Gd-DTPA. Its staging and clinical correlation]
Abstract:
During a period of two years, 134 patients with pseudo-arthrosis of the scaphoid were examined by conventional radiography and by MRI in the course of a prospective study. The aim of the study was to define radiological staging using contrast enhanced MRI in order to improve the prognostic criteria. All MRI examinations were carried out with a 1.5 tesla scanner (SP63) using a surface coil and T1 weighted spin echo sequences in sagittal and frontal projection and frontal FLASH T2 sequences and axial spin echo T2 sequences. The T1 weighted SE sequences in frontal projection were carried out before and after iv contrast (0.1 mmol Gd-DTPA/kg KG). All sequences were compared with conventional radiographs and the operative findings. Eight patients in stage 0 showed high signal intensity of both fragments in T1 weighted SE sequences and at surgery there was good vascularisation. In 22 cases there was reduced signal intensity in at least one fragment (stage I). 45 patients with scaphoid pseudo-arthrosis showed complete signal loss but marked contrast uptake with still vital nuclei at surgery (stage II). In 22 patients, there was no increase in signal intensity after contrast and complete loss of vitality of the fragments at surgery. Staging was not possible in 37 patients because of previous operative intervention. The use of contrast enhanced MRI provides additional information compared with conventional radiography or plain MRI.
Insights
Contrast-enhanced MRI improves prognostic criteria for scaphoid pseudoarthrosis. This advanced imaging technique offers superior diagnostic information compared to conventional radiography or non-enhanced MRI for scaphoid bone healing assessment.
Area of Science:
- Orthopedic Surgery
- Radiology
- Medical Imaging
Background:
- Scaphoid pseudoarthrosis, a non-union of the scaphoid bone, presents diagnostic challenges.
- Accurate prognostic criteria are essential for effective treatment planning.
- Conventional radiography and standard MRI have limitations in assessing vascularity and vitality.
Purpose of the Study:
- To define a radiological staging system for scaphoid pseudoarthrosis using contrast-enhanced MRI.
- To improve prognostic accuracy by incorporating contrast-enhanced MRI findings.
- To compare the diagnostic value of contrast-enhanced MRI with conventional radiography and non-enhanced MRI.
Main Methods:
- Prospective study of 134 patients with scaphoid pseudoarthrosis over two years.
- Conventional radiography and MRI (1.5 tesla, T1-weighted SE, FLASH T2, axial T2 sequences) performed.
- Contrast-enhanced T1-weighted SE sequences (gadolinium-DTPA) used to assess fragment vascularity; findings correlated with operative results.
Main Results:
- Stage 0 (n=8): High signal intensity on T1-weighted MRI, good vascularization at surgery.
- Stage I (n=22): Reduced signal intensity in at least one fragment.
- Stage II (n=45): Complete signal loss but marked contrast uptake, vital fragments; no contrast uptake and non-vital fragments observed.
- Staging was not possible in 37 patients due to prior surgery.
Conclusions:
- Contrast-enhanced MRI provides significant additional information for staging scaphoid pseudoarthrosis.
- This technique enhances prognostic accuracy compared to conventional radiography or non-enhanced MRI.
- The proposed radiological staging using contrast-enhanced MRI aids in evaluating fragment vitality and predicting healing potential.