Are magnetic resonance flexion views useful in evaluating the cervical spine of patients with rheumatoid arthritis?

Objective. To determine whether MR imaging in flexion adds value relative to imaging in the neutral position with respect to displaying involvement of the subarachnoid space, brainstem and spinal cord. Design and patients. T1-weighted MR images of the cervical spine in 42 rheumatoid arthritis patients with cervical spine involvement were obtained and analyzed prospectively. We assessed changes between images obtained in the neutral position and following active flexion, especially horizontal atlantoaxial and subaxial motion, presence or absence of brainstem compression, subarachnoid space involvement at the atlantoaxial and subaxial level and the cervicomedullary angle. Vertical atlantoaxial subluxation and the amount of pannus were correlated with motion and change in subarachnoid space. Results. The flexion images showed horizontal atlantoaxial motion in 21 patients and subaxial motion in one patient. The flexion view displayed brainstem compression in only one patient. Involvement of the subarachnoid space increased at the atlantoaxial level in eight (19%) patients (P=0.004) and at the level below C2 in five (12%) patients (P=0.03). There were no patients with a normal subarachnoid space in neutral position and compression in the flexed position. The cervicomedullary angle changed significantly with flexion. Vertical atlantoaxial subluxation and the amount of pannus did not show a significant correlation with motion or subarachnoid space involvement. Conclusion. MR imaging in the flexed position shows a statistically significant narrowing of the subarachnoid space at the atlantoaxial level and below C2. Cord compression is only observed on flexion views if the subarachnoid space in neutral position is already decreased. MR imaging in the flexed position might be useful, since subarachnoid space involvement may be an indicator for the development of neurologic dysfunction. Received: 15 June 1999 Revision requested: 29 July 1999, 20 September 1999 Revision received: 2 October 1999 Accepted: 26 October 1999     

Musculoskeletal imaging: what information is important to the orthopedic oncologist?

Imaging of a suspected musculoskeletal lesion is critical for proper treatment of the patient. Specific information from imaging studies is essential to the clinician. The most critical question is "What is the potential for the lesion to be malignant?" The opinion of the radiologist regarding the potential for malignancy will influence the clinician regarding referral of the patient to an orthopedic oncologist. Decisions regarding the type of biopsy and how the procedure should be performed are best made by collaborative discussion between the treating orthopedic oncologist and the radiologist. The orthopedic oncologist requires specific information from imaging studies focusing on the location and extent of tumor involvement to determine the appropriate surgical treatment for the patient and to perform an adequate resection of the tumor.     

Herniation pits in the femoral neck: a radiographic indicator of femoroacetabular impingement?

The purpose was to assess the significance of herniation pits in the femoral neck for radiographic diagnosis of femoroacetabular impingement (FAI). Eighty hips in 62 patients (bilateral in 18) with neutral pelvic orientation were enrolled. Herniation pits were diagnosed when they were located at the anterosuperior femoral neck, close to the physis, and with a diameter of >3 mm. The five radiographic signs of FAI were used: lateral center edge angle (LCE) >39°, acetabular index (AI) ≤0, extrusion index (EI) <25%, acetabular retroversion, and pistol-grip deformity. Patients with radiographs suggesting FAI were retrospectively correlated with their clinical symptoms. Positive radiographic signs were observed in 7 hips with LCE, 7 with AI, and 80 with EI criteria. Only 3 hips out of 80 (3.8%) showed all of the signs. The acetabular retroversion and pistol-grip deformity were seen in 12/80 and 3/80 hips, respectively. The total number of hips that met radiographic criteria for FAI, including pincer type and cam type, was 18 (23%). However, none of these hips were clinically diagnosed with FAI. All symptomatic hips (11/80) presented only with nonspecific pain, and 2 hips out of 11 showed radiographic signs of FAI. The low frequency of positive radiographic signs suggesting FAI with related symptoms among patients with herniation pits suggests that herniation pits have limited significance in the diagnosis of FAI. Therefore it can be concluded that an incidental finding of herniation pits does not necessarily imply a correlation with FAI.     

Three-dimensional phase-contrast magnetic resonance angiography: a useful clinical adjunct to gadolinium-enhanced three-dimensional renal magnetic resonance angiography?

OBJECTIVE: To assess the value of three-dimensional (3D) phase-contrast (PC) magnetic resonance angiography (MRA) after gadolinium (Gd)-enhanced 3D MRA for renal artery imaging. METHODS: Twenty-one patients with suspected renal artery hypertension were reviewed. All studies included Gd-enhanced 3D MRA and 3D PC MRA. Blinded interpretation of the images was performed for each technique independently and in combination. Conventional X-ray angiography was used for diagnostic correlation when available. RESULTS: Renal artery stenosis was present in 7 (16.3%) of 43 renal arteries, confirmed by X-ray angiography. MRA images demonstrated 100% sensitivity and 74% specificity for Gd-enhanced 3D MRA and 100% sensitivity and 94% specificity for 3D PC MRA. All vessels were diagnosed correctly when both image sets were viewed. CONCLUSION: 3D PC MRA can improve the specificity of renal MRA by decreasing the number of false-positive Gd-enhanced 3D MRA interpretations.     

Delayed gadolinium‐enhanced magnetic resonance imaging (dGEMRIC) of hip joint cartilage in femoroacetabular impingement (FAI): Are pre‐ and postcontrast imaging both necessary?

The purpose of this study was to assess if delayed gadolinium MRI of cartilage using postcontrast T₁ (T_1Gd) is sufficient for evaluating cartilage damage in femoroacetabular impingement without using noncontrast values (T₁₀). T_1Gd and ΔR₁ (1/T_1Gd ? 1/T₁₀) that include noncontrast T₁ measurements were studied in two grades of osteoarthritis and in a control group of asymptomatic young‐adult volunteers. Differences between T_1Gd and ΔR₁ values for femoroacetabular impingement patients and volunteers were compared. There was a very high correlation between T_1Gd and ΔR₁ in all study groups. In the study cohort with Tonnis grade 0, correlation (r) was ?0.95 and ?0.89 with Tonnis grade 1 and ?0.88 in asymptomatic volunteers, being statistically significant (P < 0.001) for all groups. For both T_1Gd and ΔR₁, a statistically significant difference was noted between patients and control group. Significant difference was also noted for both T_1Gd and ΔR₁ between the patients with Tonnis grade 0 osteoarthritis and those with grade 1 changes. Our results prove a linear correlation between T_1Gd and ΔR₁, suggesting that T_1Gd assessment is sufficient for the clinical utility of delayed gadolinium MRI of cartilage in this setting and additional time‐consuming T₁₀ evaluation may not be needed. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.     

Low field-low cost: can low-field magnetic resonance systems replace high-field magnetic resonance systems in the diagnostic assessment of multiple sclerosis patients?

As low-field MR imaging is becoming a widely used imaging technique, we aimed at a prospective assessment of differences in imaging quality between low- and high-field MR imaging in multiple sclerosis patients possibly interfering with diagnostic or therapeutic decision making. Twenty patients with clinically proven multiple sclerosis were examined with optimized imaging protocols in a 1.5- and a 0.23-T MR scanner within 48 h. Images were assessed independently by two neuroradiologists. No statistically significant interrater discrepancies were observed. A significantly lower number of white matter lesions could be identified in low-field MR imaging both on T1- and on T2-weighted images (T2: high field 700, low field 481; T1: high field 253, low field 177). A total of 114 enhancing lesions were discerned in the high-field MR imaging as opposed to 45 enhancing lesions in low-field MR imaging. Blood-brain barrier disruption was identified in 11 of 20 patients in the high-field MR imaging, but only in 4 of 20 patients in low-field MR imaging. Since a significantly lower lesion load is identified in low-field MR imaging than in high-field MR imaging, and blood-brain barrier disruption is frequently missed, caution must be exercised in interpreting a normal low-field MR imaging scan in a patient with clinical signs of multiple sclerosis and in interpreting a scan without enhancing lesions in a patient with known multiple sclerosis and clinical signs of exacerbation.     

Is impingement the cause of jumper's knee? Dynamic and static magnetic resonance imaging of patellar tendinitis in an open-configuration system

BACKGROUND: Chronic overload is considered the main cause of patellar tendinitis, but it has been postulated that impingement of the inferior patellar pole against the patellar tendon during knee flexion could be responsible. HYPOTHESIS: The role of the patellar pole in patellar tendinitis can be determined by dynamic magnetic resonance imaging. STUDY DESIGN: Case-control study. METHODS: We compared 19 knees with patellar tendinitis and 32 asymptomatic knees of age-matched subjects using an open-configuration magnetic resonance imaging system. Dynamic sagittal images were obtained from full extension to 100 degrees of flexion with and without activation of the quadriceps muscle. The following measurements were made from the images: tendon-patella angle, anteroposterior diameter of the tendon, signal difference-to-noise ratio, the shape of the inferior patellar pole, and the location of the patellar tendon insertion. RESULTS: The tendon-patella angle was not significantly different between groups at any flexion angle, with or without quadriceps muscle activation. The insertion site of the patellar tendon differed significantly but not the shape of the inferior pole of the patella. The volume and the signal difference-to-noise ratio of zones of increased intratendinous signal as well as the anteroposterior diameter of the proximal patellar tendon were increased in symptomatic knees. CONCLUSIONS: The relationship between the patella and the patellar tendon was identical in both groups; therefore, chronic overload seems to be a major cause of patellar tendinitis.     

MRI of the cervical spine with neck extension: is it useful?

Objectives

Standard MRI of the cervical spine is performed in a different anatomical position to that utilised for traditional contrast myelography. Those well practised in myelography are familiar with the considerable changes in configuration of the bony and soft tissues of the cervical spine that may occur with changes in the degree of neck flexion and extension. We set out to compare the findings in a select group of patients with myeloradiculopathy who had undergone myelography and MRI in both standard and neck-extended positions. These findings were correlated with the clinical status.

Methods

29 patients underwent myelography with CT (CTM) and MRI in neutral and neck-extended positions. The imaging was assessed for the degree of cord compression and neural foraminal narrowing, quantified using a simple grading scheme suitable for routine clinical practice. The degree of neck extension was assessed using an angular measurement.

Results

For both CTM and MRI, scanning with the neck extended significantly increases the severity of cord compression compared with the standard supine position, to a degree similar to that shown during conventional prone myelography. The degree of perceived cord compression is related to the degree of neck extension achieved. Correlation of standard MRI findings and the clinical level of radiculopathy is poor. This correlation improves when the neck is extended.

Conclusions

The most appropriate position for routine MRI of the cervical spine in degenerative disease remains unknown, but in selected patients imaging with the neck extended may provide important additional information.With the introduction of spinal surface coil technology and gradient echo sequences in the late 1980s, MRI rapidly replaced intrathecal contrast myelography as the standard imaging method for assessment of the cervical spinal cord and nerve roots. The two investigations are performed in very different anatomical positions. Standard cervical spine MRI is performed in a coil that is designed to make the patient comfortable, to minimise movement-related artefacts. This generally results in a position of mild extension of the neck. On the other hand, the majority of images for plain cervical myelography are obtained with the patient prone and the neck hyperextended so as to retain myelographic contrast within the cervical lordosis. CT myelography (CTM) is typically performed with the patient supine and with the neck straight or mildly flexed; however, CT myelography can also be performed in the prone position with the neck extended [1].For a number of years we continued to use plain myelography, with CTM as a second-line investigation in patients with cervical myelopathy and/or radiculopathy, when the results of standard MRI were inconsistent with symptoms and signs. More recently we have also performed MRI with neck extension, predominantly in patients with myelopathic features but inconclusive supine MRI. We have been unsure how extended MRI compares with myelography and whether it is able to produce the same degree of extension as myelography. We have performed CT in the prone extended position as well, but have also been unsure how that relates to standard supine CT imaging or to extended MRI. We therefore wished to compare these various modalities in a heterogeneous group of clinically problematic patients.     

Late gadolinium enhancement on cardiac magnetic resonance imaging: is it associated with a higher incidence of nonsustained ventricular tachycardia in patients with idiopathic dilated cardiomyopathy?

Purpose  

Late gadolinium enhancement (LGE) during cardiac magnetic resonance imaging (MRI) can be seen in patients with myocardial fibrosis accompanied by myocardial infarction and cardiomyopathy. Some idiopathic dilated cardiomyopathy (DCM) patients have fibrosis in the myocardium and show LGE during cardiac MRI. The purpose of this study was to investigate the clinical significance of LGE in patients with DCM.     

Complete written/oral information about dose exposure in CT: is it really useful to guarantee the patients’ awareness about radiation risks?

Aims and objectives

According to the European directive 2013/59/Euratom, starting from February 2018, the information relating to patient exposure will be part of computed tomography (CT) reports, but the impact of this information on patients has not been deeply evaluated. Aim of our study was to evaluate patients’ perception of radiation exposure related to routine CT and their understanding after communication of their dose exposure.

Materials and methods

A survey, investigating patient’s knowledge of radiation dose, was given to all adult patients (>?18 years) undergoing a CT examination both before and after CT scan. The first survey was the same for all patients. After CT scan, a second questionnaire was administered (after receiving the CT dose bill report and medical written and/or explanation about ionizing radiation risk). Results of the pre- and post-CT questionnaires responses were compared according to demographics characteristics and among the four post-CT groups.

Results

For some questions, statistically significant differences were found between the two centres. Seventy per cent of the patients answered that the presence of CT parameters in the report is considered useful. Even if not always statistically significant there was a slight increase in awareness of ionizing radiation risk comparing the pre- and post-CT surveys. The group that had both written and oral explanations had a better comprehension of CT dose bill (group III vs. I, p?=?0.002).

Conclusion

The way of communication of ionizing radiation risks did not affect the results of the post-CT survey. Indeed, the interest in the topic did not rise in the post-CT survey in any of the group. Adequate information about ionizing radiation risks provided together with dose exposure information may be useful. However, there is not a standardized better way of communicating information on ionizing radiation risks due to CT.

     

Mid-term outcomes of exercise therapy for the non-surgical management of femoroacetabular impingement syndrome: are short-term effects persisting?

ObjectivesTo investigate the mid-term outcomes of exercise therapy in patients with femoroacetabular impingement syndrome (FAIS).DesignFollow-up study.SettingClinical setting.ParticipantsTwenty-six patients with FAIS who completed a 12-week semi-standardized, progressive exercise therapy program.Main outcome measuresAt a mid-term follow-up of 4.6 years, therapy outcome was assessed using (i) the Global Treatment Outcome questionnaire for hip pain, (ii) the Hip Outcome Score (HOS) for hip pain and function in activities of daily living (ADL) and Sport and (iii) the Hip Sports Activity Scale (HSAS) for sport activity level. Mid-term outcomes were compared to pre-symptomatic, pre-therapy, as well as to short-term follow ups (18 weeks).ResultsIn patients who completed the exercise program and did not undergo hip surgery (N = 19), mid-term HOS ADL and HOS Sport (P = 0.002) were higher than pre-therapy, and comparable to the 18-week follow-up. Mid-term HSAS was lower than the pre-symptomatic status (P = 0.022), but comparable to the 18-week follow-up.ConclusionAt a mid-term follow-up of 4.6 years, FAIS patients with no subsequent hip surgery maintained the good exercise therapy outcomes and the level of sport activity achieved at short term.