MRI Open or Closed? Differences and the Best Choice.
The Open Magnetic Resonance consists of a low-field magnet that was created for the study of musculoskeletal pathology with the aim of containing the purchase, installation and maintenance costs which are considerably lower than traditional Magnetic Resonance. high field closed (Table 1).
The main limitations of low-field Open Magnetic Resonance derive from the structural characteristics of these devices which have a low signal / noise ratio which determines images of modest quality.
In these devices, in order to improve the quality of the images, it is necessary to increase the thickness of the section under examination, which reduces the possibility of detecting fine findings and therefore making accurate diagnoses and increasing the number of acquisitions, which inevitably increases the execution time of the examinations (1).
Furthermore, with low-field magnetic resonances it is not possible to use sophisticated techniques such as spectroscopy, perfusion, diffusion and fat subtraction techniques which are now indispensable in clinical practice in most body areas. These techniques require a high field, homogeneous with powerful gradient systems that open low field luminaires cannot have by definition.
Studies comparing open (low-field) and closed (high-field) magnetic resonance imaging on the diagnostic performance of musculoskeletal pathology are conflicting (1,2,3), but most authors agree on the greater accuracy of the devices at high field in the identification and characterization of fine musculoskeletal lesions.
On the other hand, there are no comparative studies regarding other body districts, such as the study of the brain, head-neck, mediastinum, abdomen and pelvis for the overwhelming superiority of high-field Closed Magnetic Resonance.
In addition, open field magnetic resonance cannot perform vascular studies and the study of the heart.
In any case, Open MRI has the undeniable advantage of greater comfort for the claustrophobic patient, which can be easily overcome even with high-field and high-sensitivity Closed MRIs.
The new Salvator Mundi Diagnostic Imaging Center, Imaging SMIH, for a more effective and specific diagnostic purpose has chosen to install one of the best 1.5 Tesla high field Closed Magnetic Resonances.
Patients may request, during the booking phase, to carry out the examination in light sedation in spontaneous breathing.
1. Tavernier T, Cotten A. High- Versus Low-Field MR Imaging. Radiol Clin N Am 2005; 43: 673–6812. Sanal HT, Cardoso F, Chen L, et al. Office-based Versus High-field Strength MRI Diagnostic and Technical Considerations. Sports Med Arthrosc Rev Volume 2009; 17 (1): 31-393. Magee T, Shapiro M, Williams D. Comparison of high-field strength versus low-field-strength MRI of the shoulder. AJR Am J Roentgenol. 2003 Nov;181(5):1211-5.
Table 1. Characteristics Open low-field magnetic resonance Vs Closed high-field magnetic resonance
- Low Magnetic Field 0.2-0.3 Tesla
- Medium spatial resolution
- Quality body, neuro, cardio and vascular exams cannot be performed
- Long exam times
- Greater comfort for claustrophobic patients
- High Magnetic Field 1-3 Tesla
- Excellent spatial resolution
- All body districts can be studied
- Short exam times
- Claustrophobic patients can perform any examination under deep anesthesia, sedation or with the assistance of qualified personnel