Health technology assessment of magnetic resonance imaging of the knee.

A search of the available literature was performed and the role of MR imaging of the knee is discussed. Based on this search the authors concluded that MR has a high sensitivity in detecting any abnormalities in the knee but it does not have the same diagnostic accuracy as a clinical investigation performed by a trained knee specialist when all knee injuries are taken together. It does lead to a decrease in the number of surgical interventions due to its high negative predictive value. For the detection of meniscal injury, MR has the same accuracy as arthroscopy and should be performed in order to avoid unnecessary surgical interventions. A negative MR also obviates further investigation in suspected cartilage damage. This is not true for anterior and posterior cruciate ligament problems where MRI is less accurate than clinical investigation.

Health technology assessment of magnetic resonance.

MR imaging has established itself as a reliable means of imaging pathology in many different regions of the body without the disadvantage of ionizing radiation. There was also hope that MRI might replace not only CT but also more invasive imaging techniques. Until now the substitution, especially that of CT has been less than expected. To evaluate the possible substitution of CT by MR imaging, it is paramount to have high quality evidence regarding the efficacy of MRI. This was collected by performing a systematic search of the available literature using Medical Subject Heading (MeSH) terms. The retrieved articles were classified according to the different levels of diagnostic efficacy as described by Fryback and Thornbury. Based on the available studies and the quality assessment, a level of evidence is attributed for the diagnostic efficacy of MRI in each indication.

Health technology assessment of magnetic resonance imaging of the spine and bone marrow.

The high spatial resolution and the lack of ionizing radiation, makes magnetic resonance imaging the method of choice for imaging most spinal pathology, especially if associated with neurological symptoms. However, due to the high sensitivity of MR imaging, careful correlation between imaging findings and clinical findings is important to ensure appropriate treatment. Substituting radiographic evaluations for rapid MRI in the primary care setting may offer little additional benefit to patients. It may even increase the costs of care but the decisions about the use of imaging depend on judgments concerning whether the small observed improvement in outcome justifies additional cost. Because the presence of an abscess is a major factor in deciding between conservative and surgical treatment, MRI plays an essential role in the decision-making process concerning the treatment of spondylodiscitis. MR is also the method of choice for quantitative evaluation of bone marrow in lymphoma patients when a crucial therapeutic decision has to be made or for the qualitative evaluation of the spinal cord if compression is suspected in primary spinal malignancy or metastatic disease.

Widening of the spinal canal and dural ectasia in Marfan's syndrome: assessment by CT.

We describe a method for diagnosing dural ectasia (DE) and spinal canal widening (SCW) using CT. We examined 23 patients with Marfan's syndrome (MFS), 17 with Ehlers-Danlos syndrome (EDS) and 29 normal subjects, using six axial slices at the level of the L1-S1 pedicles. Transverse diameters of the vertebral bodies, spinal canal and dural sac were measured and indices were defined to differentiate patients with DE and SCW from normal. Statistical significance was assessed using Student's t -test, chi (2)-test and Pearson's correlation coefficient. DE and SCW occurred in 69.6 % and 60.9 % of cases of MFS and in 23.5 % and 35.3 % of EDS respectively. In MFS, prevalence was significantly higher than in the control group. DE was significantly more frequent in MFS than in EDS. A strong correlation existed between DE and SCW in MFS and the control group, but not in EDS. Our system enables quantitative assessment of SCW and DE. The latter is particularly important in subjects suspected of having MFS, in whom it is a common and characteristic sign.

Traumatic lumbosacral nerve root meningoceles. The value of myelography, CT and MRI in the assessment of nerve root continuity.

A case of traumatic lumbar meningoceles at four levels in combination with total and partial nerve root avulsion and with preservation of a nerve root is reported. Several diagnostic imaging techniques (myelography, CT, myelo-CT and MRI) are compared and their value in demonstrating the continuity of the nerve roots is discussed. MRI could assess the continuity of a nerve root in a traumatic meningocele, not demonstrable by myelography or myelo-CT. The combination of myelography, myelo-CT and MRI is likely to provide a complete diagnostic evaluation of nerve root lesions.