Effect of epidural corticosteroid injection on magnetic resonance imaging findings

BACKGROUND: Magnetic resonance imaging (MRI) of the spine is the preferred diagnostic tool for pathologic conditions affecting the spine. However, in patients receiving epidural corticosteroid injection (ESI) for treatment of spinal diseases, there is a possibility of misreading of MR images because of air or fluid in the epidural space after the injection. Therefore, we defined the characteristics of abnormal changes in MRI findings following an ESI in patients with low back pain. METHODS: We reviewed the medical records of 133 patients who underwent MRI of the lumbar spine within 7 days after ESI between 2006 and 2015.All patients were administered an ESI using a 22-gauge Tuohy needle at the lumbar spine through the interlaminar approach. The epidural space was identified by the loss of resistance technique with air. RESULTS: The incidences of abnormal changes in MRI findings because of ESI were 54%, 31%, and 25% in patients who underwent MRI at approximately 24 h, and 2 and 3 days after ESI, respectively. Abnormal MRI findings included epidural air or fluid, needle tracks, and soft tissue changes. Epidural air, the most frequent abnormal finding (82%), was observed in 41% of patients who underwent MRI within 3 days after injection. Abnormal findings due to an ESI were not observed in MR images acquired 4 days after ESI or later. CONCLUSIONS: Pain physicians should consider the possibility of abnormal findings in MR images acquired after epidural injection using the interlaminar approach and the loss of resistance technique with air at the lumbar spine.

Dynamic CT Perfusion Imaging for the Detection of Crossed Cerebellar Diaschisis in Acute Ischemic Stroke

OBJECTIVE: Although the detection of crossed cerebellar diaschisis (CCD) by means of different imaging modalities is well described, little is known about its diagnosis by computed tomography perfusion (CTP) imaging. We investigated the detection rate of CCD by CTP imaging and the factors related to CCD on CTP images in patients with acute ischemic stroke. MATERIALS AND METHODS: CT perfusion maps of cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT), and time-to-peak (TTP) obtained from 81 consecutive patients affected by an acute ischemic stroke were retrospectively reviewed. Whole-brain perfusion maps were obtained with a multichannel CT scanner using the toggling-table technique. The criteria for CCD was a unilateral supratentorial ischemic lesion and an accompanying decrease in perfusion of the contralateral cerebellar hemisphere on the basis of CTP maps by visual inspection without a set threshold. Maps were quantitatively analyzed in CCD positive cases. RESULTS: The criteria for CCD were fulfilled in 25 of the 81 cases (31%). Detection rates per CTP map were as follows: MTT (31%) > TTP (21%) > CBF (9%) > CBV (6%). Supratentorial ischemic volume, degree of perfusion reduction, and infratentorial asymmetry index correlated strongly (R, 0.555-0.870) and significantly (p < 0.05) with each other in CCD-positive cases. CONCLUSION: It is possible to detect CCD on all four of the CTP-based maps. Of these maps, MTT is most sensitive in detecting CCD. Our data indicate that CTP imaging is a valid tool for the diagnosis of CCD in patients affected by an acute hemispheric stroke.

The Brachioradialis Muscle Flap for Resurfacing of Sort Tissue Defect in the Hand and Forearm

The provision of adequate soft tissue cover for a complex hand and forearm wound-dirty, infected and exposed bone can be a challenging problem. Conventionally, a distant flap or free flap have been used, but these have been associated with several problems such as joint stiffness, risk of microsurgical procedures, negligible donor site morbidity, prolonged operation time and economic restriction. As well, fasciocutaneous flap has been the limitation of infection control. In these situations, the ipsilateral muscle flap provides the ideal cover with its rich blood supply and single operative field. Previously described by Lendrum(1980), by Lae et al.(1981), and later by McGeorge(1991), the brachioradilis muscle is the most superficial muscle on the radial side of the forearm. Its flap is based on the radial artery and venae comitantes. From August 1996 to October 1997, we performed branchioradialis muscle flap in seven patients. Despite the sacrifice of the major hand artery, brachioradialis muscle flap has many advantages including the reliability of flap survival, easy dissection, early mobilization and absence of functional and aesthetic problems at the donor site. It is a relatively simple and rapid method for resurfacing soft tissue defect in the hand and forearm. We obtained satisfactory and reliable results.