The history of magnetic resonance imaging and its reflections in Acta Radiologica

The first reports in Acta Radiologica on magnetic resonance imaging (MRI) were published in 1984, four years after the first commercial MR scanners became available. For the first two years, all MR papers originated from the USA. Nordic contributions started in 1986, and until 2020, authors from 44 different countries have published MR papers in Acta Radiologica. Papers on MRI have constituted, on average, 30%-40% of all published original articles in Acta Radiologica, with a high of 49% in 2019. The MR papers published since 1984 document tremendous progress in several areas such as magnet and coil design, motion compensation techniques, faster image acquisitions, new image contrast, contrast-enhanced MRI, functional MRI, and image analysis. In this historical review, all of these aspects of MRI are discussed and related to Acta Radiologica papers.

Low-Field MR Imaging (0.1 T) in Patients with Clinically Suspected Acute Spinal Block

The diagnostic usefulness of a 0.1 T MR unit in patients with clinical suspicion of acute spinal block was studied in 59 patients who were referred to acute MR investigation. The records were reviewed retrospectively 1 month after the MR for assessing the clinical impact of the examination. Ninety-eight per cent had a true-positive examination confirmed by surgery (21%) or observation (77%). In 60% of the patients the MR imaging had a therapeutic consequence. In only one patient did the level of visualised pathology at the MR examination not correlate with the clinical findings; the patient subsequently refused surgical treatment. We conclude that a low-field MR unit is excellent for acute examination of patients clinically suspected of acute spinal block.

Metastasis to nervous system: spinal epidural and intramedullary metastases

Spinal cord epidural metastasis (SEM) is a common complication of systemic cancer with an increasing incidence. Prostate, breast and lung cancer are the most common offenders. Metastasis usually arises in the posterior aspect of vertebral body with later invasion of epidural space. Pathophysiologically, vascular insufficiency is more important than direct spinal cord compression. The most common complaint is pain, and two thirds of patients with SEM have motor signs at initial diagnosis. Currently magnetic resonance imaging is the most sensitive diagnostic tool. The optimal management of SEM is still arguable, but recent advances in surgical management of SEM and higher complication rate of surgery following radiotherapy should persuade clinicians to consider de novo surgery where possible. Radiotherapy has an important role, particularly in treatment of radiosensitive tumors and in patients who are not candidates for surgery. Novel approaches such as stereotactic radiosurgery are promising; however, response to chemotherapy depends on inherent properties of primary tumor. Recurrent SEM is a substantial problem for which surgery or repeat radiotherapy may be options. Intramedullary metastasis is rare but should be considered in patients with systemic malignancy and asymmetrical presentation of myelopathic symptoms. The prognosis is usually poor and preferred modality of treatment is radiotherapy.

The osteoporotic spine

With an aging population, osteoporotic vertebral collapse is an increasingly common condition in both the Western and Eastern hemispheres. This review looked into the situation in Hong Kong with the aim of highlighting the major differences in data from the Western. Between 1989 and 1994, 497 patients with osteoporotic vertebral collapse, aged 65 to 94 years old, were admitted under the authors' care, with a female to male ratio of 5:1. More than 1/3 of the patients had fracture involving 1 single vertebra. The mean hospital stay was 5 days, with an additional 6 to 23 days in a convalescent hospital. Complication of spinal cord compression is uncommon and occurred in only 10 patients (2%) in this series who were treated mostly with anterior decompression and iliac crest graft with varying degrees of neurologic recovery. Despite the general benign nature of the problem, the high morbidity and the long hospital stays undoubtedly are significant drains on health care resources.

MRI of spinal epidural lymphoma

We reviewed the MRI features in eight patients with spinal epidural lymphoma (clinically primary in 4 patients); one patient had multiple lesions. The cervical spine was involved in one patient, the thoracolumbar spine in 5 and the sacrum in two. Mean longitudinal extension of the epidural lesion was 2.6 vertebral segments. The tumours were homogeneously isointense with the spinal cord on T1-weighted images and isointense or hyperintense on proton-density and T2-weighted images. The spinal cord was compressed in four patients but showed signal changes in only one. In five patients the lesions communicated through the intervertebral foramina with paravertebral soft tissue masses. In all but one of the patients diffuse signal changes in the vertebral body marrow consistent with osteolytic or osteoblastic changes were identified adjacent to or at distance from the epidural lesion. Vertebral collapse was observed in two patients.

Metastatic epidural spinal cord compression: current concepts and treatment

Metastatic epidural spinal cord compression (MESCC) is a medical emergency complicating the course of 5-10% of patients with cancer [1]. When diagnosis and treatment is early with the patient ambulatory prognosis for continued ambulation is good [2]. If the patient is nonambulatory or paraplegic, prognosis for meaningful recovery of motor and bladder function is markedly decreased. In the last decade, significant advances in the understanding, management and treatment of metastatic epidural spinal cord compression have occurred. Recent pathophysiological and pharmacological animals studies have afforded insights into disease mechanisms [3-9]. The audit of standard methods of investigation and magnetic resonance imaging have resulted in revision of guidelines for patient evaluation [10-17]. Finally, new surgical philosophies and technical advances have generated interest and controversy [18-25]. With improved clinical awareness, new imaging modalities will help us diagnose epidural spinal cord compression earlier and institute appropriate treatment.

Case report: spinal cord compression due to metastatic hepatocellular carcinoma

Hepatocellular carcinoma is an uncommon cancer in the United States. Its initial presentation as spinal cord compression due to vertebral metastasis is rare. This article reports a case of radiculopathy and rapidly developing spinal cord compression because of bony metastasis from this form of liver cancer. This article also reviews pertinent literature and discusses the diagnostic modalities for early detection.