Early MRI Scans Research Articles

Long‐term safety of cardiac magnetic resonance imaging performed in the first few days after bare‐metal stent implantation

To investigate the long-term safety of cardiac magnetic resonance imaging (CMR) performed one to seven days after coronary artery stent (bare metal) implantation. We analyzed 119 consecutive patients with acute myocardial infarction (MI) who underwent emergency coronary stent implantation with a bare-metal stent. CMR using a 1.5T scanner was performed on 51 patients (42.9%) at a mean of 2.7+/-3.1 days after stent implantation (CMR+ group), and the remaining 68 patients (57.1%) served as controls (CMR- group). The patients were followed up to six months for major adverse cardiac events. The average stent size was 3.3+/-0.5x18.4+/-6.7 mm, and 86% of the stents were made of 316L stainless steel. There were no significant differences between the CMR+ and CMR- groups in terms of infarct features, angiographic findings, or stent characteristics. Over a mean follow-up of 4.4+/-2.1 months, 12 patients (10.1%) had 16 events (13.4%). Two patients had adverse events after early MRI scan (4.3%), a rate that is lower than the event rate in the patients who did not undergo MRI (16%, P=0.04), and one of the two events was clearly not MRI related. CMR on a 1.5T scanner can be safely performed within one to seven days after coronary bare-metal stent implantation and is not associated with an increased risk of adverse clinical cardiac outcomes. In the light of accumulating data, the guidelines by stent manufacturers should be revised.

Photodynamic therapy using meso tetra hydroxy phenyl chlorin (mTHPC) in early prostate cancer

Prostate cancer is increasing in incidence, but current treatments including surgery and radiotherapy have significant side effects. This pilot study was designed to assess the potential of photodynamic therapy (PDT) using meso tetra hydroxy phenyl chlorin (mTHPC) for organ confined prostate cancer. Six men with organ confined prostate cancer were photosensitised with mTHPC (0.15 mg/kg). Between 2 and 5 days later, red light (652 nm) was delivered to areas of biopsy proven cancer via fibres inserted through transperineal needles (50-100 J per site). After 8 of 10 PDT sessions, the prostate specific antigen (PSA) fell by up to 67%. Early MRI scans showed oedema and patchy necrosis, which resolved over 2 months. Biopsies of treated areas revealed necrosis and fibrosis at 1-2 months. PDT for primary prostate cancer appears safe and can reduce PSA levels. As this was a phase I study, no attempt was made to treat the whole prostate; this or targeted tumour ablation could be attempted in a phase II study with an increased number of fibres. This technique merits further investigation in early prostate cancer.

Patterns of injury in patients with radiographic occult fracture of neck of femur as determined by magnetic resonance imaging.

The purpose of the present study was to review retrospectively our experience with MRI in patients over the age of 50 who present to the emergency department with inability to weight bear following a fall and whose initial radiographs were normal. The study was designed to establish the incidence and pattern of bone and soft tissue injuries in these patients and to determine whether MRI could provide predictive information regarding length of hospital stay. The present study demonstrated the practicality of a protocol using MRI to obtain rapid definitive diagnosis in patients with occult fractures of the pelvic ring and neck of femur. The present study also suggests that significant prognostic information with regard to length of hospital stay can be obtained from an early MRI scan.

Surgical management of traumatic lesions of the axillary nerve: 83 cases

Axillary nerve injuries still go undiagnosed far too often despite their frequency. However the quality of the outcome depends on expert management and prompt surgery. To optimise the latter, we re-examined 83 operated cases of traumatic lesions of the axillary nerve. We analysed the neurological and functional recovery of these patients by means of a follow-up evaluation at 6 years postop. The results were classified by age, mechanism of injury, delay to surgery and the presence or otherwise of associated neurological or osteo-articular lesions. We highlighted that a high index of suspicion ought to exist in all cases of trauma to the shoulder in a patient aged more than 40, any injury associated with palsy of the long head of triceps and in the case of an osteo-articular lesion due to high-velocity trauma. A complete lack of shoulder abduction must always prompt a search for a lesion of the axillary nerve as well as a suprascapular nerve palsy or rotator cuff lesion. There are few literature reports of surgical management of this particular nerve injury. An early MRI scan as part of the management should improve results by a reduction in the delay before surgery. As a result of our investigation we conclude that a lesion of the axillary nerve without signs of recovery at 3 months should be referred to a centre specialized in peripheral nerve surgery.

Imaging the problem scaphoid

Scaphoid fractures can be difficult to diagnose on X-ray, even at 2 weeks. We have compared prospectively bone scanning versus MRI scanning in 22 patients with persistent signs and symptoms suggestive of a scaphoid fracture at 2 weeks and found both methods to be sensitive, but MRI to be more specific, particularly in diagnosing soft tissue injuries like scapho-lunate ligament ruptures and triangular fibrocartilage tears. An early MRI scan at 2 weeks allows the clinician to make the appropriate decision in this group of patients whose diagnoses include; occult scaphoid fractures, other occult carpal and radial fractures, ligamentous injuries and those without apparent injuries. MRI has also been useful in defining the group of injuries which may imitate a clinically occult scaphoid fracture.