Metal artifact suppression at the hip: diagnostic performance at 3.0 T versus 1.5 Tesla

PurposeThis work aimed to compare the diagnostic performance of a metal artifact suppression sequence (MAVRIC-SL) for imaging of hip arthroplasties (HA) at 1.5 and 3 Tesla (T) field strength.MethodsEighteen patients (10 females; aged 27-74) with HA were examined at 3.0 and 1.5 T within 3 weeks. The sequence protocol included 3D-MAVRIC-SL PD (coronal), 3D-MAVRIC-SL STIR (axial), FSE T1, FSE PD and STIR sequences. Anatomical structures and pathological findings were assessed independently by two radiologists. Artifact extent and technical quality (image quality, fat saturation and geometric distortion) were also evaluated. Findings at 1.5 and 3.0 T were compared using a Wilcoxon signed rank test.ResultsWhile image quality was better at 1.5 T, visualization of anatomic structures and clinical abnormalities was not significantly different using the two field strengths (p > 0.05). Fat suppression and amount of artifacts were significantly better at 1.5 T (p  < 0.01). Inter- and intra-reader agreement for different anatomic details, image quality and visualization of abnormalities ranged from k = 0.62 to k = 1.00.ConclusionMAVRIC-SL at 1.5 T had a comparable diagnostic performance when compared MAVRIC-SL at 3.0 T; however, the higher field strength was associated with larger artifacts, limited image quality and worse fat saturation

Magnetic resonance arthrography of the hip: technique and spectrum of findings in younger patients

Magnetic resonance(MR) imaging is the reference imaging technique in the evaluation of hip abnormalities. However, in some pathological conditions—such as lesions of the labrum, cartilaginous lesions, femoroacetabular impingement, intra-articular foreign bodies, or in the pre-operative work-up of developmental dysplasia of the hip—intra-articular injection of a contrast medium is required to obtain a precise diagnosis. This article reviews the technical aspects, contraindications, normal appearance and potential pitfalls of MR arthrography, and illustrates the radiological appearance of commonly encountered conditions

Retro-trochanteric sciatica-like pain: current concept

The aim of this manuscript is to review the current knowledge in terms of retro-trochanteric pain syndrome, make recommendations for diagnosis and differential diagnosis and offer suggestions for treatment options. The terminology in the literature is confusing and these symptoms can be referred to as ‘greater trochanteric pain syndrome’, ‘trochanteric bursitis’ and ‘trochanteritis’, among other denominations. The authors focus on a special type of sciatica, i.e. retro-trochanteric pain radiating down to the lower extremity. The impact of different radiographic assessments is discussed. The authors recommend excluding pathology in the spine and pelvic area before following their suggested treatment algorithm for sciatica-like retro-trochanteric pain. Level of evidence II

Gait adaptations in low back pain patients with lumbar disc herniation: Trunk coordination and arm swing

Patients with chronic non-specific low back pain (LBP) walk with more synchronous (in-phase) horizontal pelvis and thorax rotations than controls. Low thorax-pelvis relative phase in these patients appears to result from in-phase motion of the thorax with the legs, which was hypothesized to affect arm swing. In the present study, gait kinematics were compared between LBP patients with lumbar disc herniation and healthy controls during treadmill walking at different speeds and with different step lengths. Movements of legs, arms, and trunk were recorded. The patients walked with larger pelvis rotations than healthy controls, and with lower relative phase between pelvis and thorax horizontal rotations, specifically when taking large steps. They did so by rotating the thorax more in-phase with the pendular movements of the legs, thereby limiting the amplitudes of spine rotation. In the patients, arm swing was out-of phase with the leg, as in controls. Consequently, the phase relationship between thorax rotations and arm swing was altered in the patients. © The Author(s) 2010