Diagnostic quality and scoring of synovitis, tenosynovitis and erosions in low-field MRI of patients with rheumatoid arthritis: a comparison with conventional MRI

OBJECTIVE: To compare dedicated low-field MRI (lfMRI) with conventional MRI (cMRI) in the detection and scoring of synovitis, tenosynovitis and erosions in patients with rheumatoid arthritis. PATIENTS AND METHODS: The wrist and finger joints of 17 patients with rheumatoid arthritis (median (range) disease duration 8 years (7-12); Disease Activity Score 3.3 (2.6-4.5)) were examined by 0.2 T lfMRI and 1.5 TcMRI. The protocols comprised coronal spin-echo and three-dimensional gradient-echo sequences before and after contrast medium administration. Synovitis of the metacarpophalangeal and proximal interphalangeal joints 2-5 and the wrist joints was scored according to Outcome Measures in Rheumatology recommendations. Tenosynovitis and erosions were scored using 4-point and 6-point scales, respectively. The results were analysed by calculating kappa values and performing McNemar's test intra-individually on a joint-by-joint basis. RESULTS: Agreement between the two MRI techniques was good to excellent for synovitis and erosions, and moderate for tenosynovitis. Of the 306 joints evaluated, 245 and 200 joints showed synovitis in lfMRI and cMRI, respectively. Scoring of synovitis of the finger joints yielded kappa values from 0.69 to 0.94. Of the 68 flexor tendons evaluated, tenosynovitis was diagnosed by lfMRI in 24 and by cMRI in 33 instances. Of the 391 bones evaluated, 154 and 139 showed erosions in lfMRI and cMRI, respectively. kappa values for erosion scores were between 0.65 and 1. CONCLUSION: Dedicated, lfMRI shows high agreement with cMRI in diagnosing and scoring synovitis, tenosynovitis and erosions in rheumatoid arthritis when using standardised scoring systems.     

Erratum to: Accessory navicular bone: when ankle pain does not originate from the ankle

A young girl suffering from ankle pain occurring after gymnastics classes was referred to the rheumatology department by an orthopedic surgeon because a rheumatological condition was suspected to cause her symptoms. MRI was useful in pointing to the correct diagnosis of accessory navicular bone (AN). The morphological classification of ANs is discussed and the imaging modalities for diagnosis are presented.     

Low-field MRI for assessing synovitis in patients with rheumatoid arthritis. Impact of Gd-DTPA dose on synovitis scoring

OBJECTIVE: To investigate the impact of a double dose compared to a single dose of contrast material in low-field magnetic resonance imaging (MRI) on semi-quantitative scoring of synovitis in patients with rheumatoid arthritis (RA). METHODS: This prospective study included 38 RA patients (23 women and 15 men, mean age 51 years). All patients underwent low-field MRI of the hand before administration of contrast medium, after intravenous injection of 0.1 mmol/kg gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA), and after another dose of 0.1 mmol/kg Gd-DTPA. Two readers (A and B) blinded to dosage independently scored the single dose and double dose image sets for synovitis according to outcome measures in rheumatology (OMERACT) recommendations. Contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) were also calculated for each set. RESULTS: 149 metacarpophalangeal (MCP) joints were evaluated. There was good inter-reader agreement for each of the two sets (intra-class correlation coefficient of 0.75 for the single dose set and 0.83 for the double dose). Median CNR and SNR values were 5.4 and 15.9, respectively, for the single dose set and 8.5 and 16.6, respectively, for the double dose set (p<0.0001). Single dose set mean synovitis scores were 1.7 and 1.6 for readers A and B, respectively. Double dose set scores were 1.9 and 2.0, respectively. Thus, higher synovitis scores were recorded for the double dose sets than the single dose sets (p<0.005). CONCLUSION: In low-field MRI, when evaluating RA, the dose of the contrast material influences synovitis scoring. Therefore, dosage of contrast material should be taken into consideration when using extremity dedicated low-field MRI.     

Claustrophobia and premature termination of magnetic resonance imaging examinations

PURPOSE: To evaluate the incidence of MRI-related claustrophobia and prematurely terminated MRI (ptMRI) examinations due to claustrophobia in a large-scale cohort study. MATERIALS AND METHODS: The hospital's computerized radiology information system (RIS) was retrospectively analyzed for all 1.5-Tesla MRI examinations and reports during the year 2004. Data collected included demographic information, body part examined, known claustrophobia, and whether the examination was prematurely terminated. All information available on the MRI examinations and the patient-based data (i.e., excluding any additional examinations per patient) were analyzed. RESULTS: A total of 5798 MRI reports of 4821 patients were evaluated. A total of 95 patients (1.97%) suffered from claustrophobia and 59 (1.22%) prematurely terminated the examination due to claustrophobia. The incidence of ptMRI was higher in women than men (no statistical significance). The majority of patients with ptMRI were between 20 and 80 years old. Patients undergoing head MRI showed the highest incidence of ptMRI and those undergoing extremity, breast, or pelvic MRI had the lowest. Prone compared to supine positioning results in the lowest ptMRI incidence (P < 0.05). CONCLUSION: Claustrophobic reactions cause a relatively low incidence of ptMRI and are influenced by sex, body part examined, and positioning within the MR scanner. Sedation and prone positioning might help overcome these reactions.     

Primary hyperparathyroidism in young adults.

OBJECTIVES: The purpose of this study was to compare the incidence of multiglandular disease and rate of treatment failure between younger and older patients with primary hyperparathyroidism. STUDY DESIGN AND SETTING: The medical charts of patients who underwent surgery for primary hyperparathyroidism at our tertiary-care institution between 1995 and 2001 were reviewed. RESULTS: Three hundred nineteen patients were identified, of whom 33 were aged 40 years or less. There were no statistically significant differences between the younger and older groups in the incidence of multiglandular disease (9.1% for both, P = 1.00) or in the treatment failure rate (12.1% and 8%, respectively, P = 0.43). Sonography was significantly more sensitive than technetium Tc-sestamibi in the younger group (96% vs 57%, P < 0.05). Parathyroid hormone level and gland weight were significantly higher in the older group (P = 0.004). CONCLUSION: Our results suggest that the same treatment strategy should be applied to all patients with primary hyperparathyroidism. Ultrasound appears to be the localization procedure of choice in younger patients.     

Osteoid osteoma—the CT vessel sign

Objective  

To evaluate whether the presence of a feeding vessel in proximity to osteoid osteomas of long bones on multidetector CT (MDCT) can be an adjuvant clue for the diagnosis of osteoid osteoma.     

Correlation between MRI and double-balloon urethrography findings in the diagnosis of female periurethral lesions

This study aims to evaluate the correlation of MRI findings with double-balloon urethrography (DBU) in diagnosing female urethral diverticula and other periurethral lesions.     

Diagnostic value of CT-guided biopsy of indeterminate renal masses

AIM: To evaluate the role of percutaneous core biopsies in the diagnosis of renal masses that could not be classified as benign or malignant based upon imaging alone. MATERIALS AND METHODS: We retrospectively analysed core biopsies of indeterminate renal masses of 23 patients who were referred to us for computed tomography (CT)-guided biopsy from 1996-2001. Follow-up ranged from 1-5 years. Analysis was based on indications for biopsy, size and characteristics of the lesion and accuracy of biopsy results. RESULTS: There was one technical failure in 22 patients included in the analysis. Fifteen core biopsies revealed malignancies that were confirmed either clinically or surgically. Seven were benign, one of which was false-negative. The sensitivity was 93%, specificity 100%, positive predictive value 100% and negative predictive value 75%. The results in tumours <==3 cm were similar to those in larger lesions. CONCLUSIONS: We recommend the use of core biopsy as a diagnostic tool for indeterminate renal masses, regardless of mass size. Renal core biopsy can influence the management of lesions: primary renal lesions are resected, while treatment for metastatic disease is tailored to the primary tumour. Tumours with benign biopsy results should be re-evaluated and either referred for resection of the mass or followed up closely with clinical observation and of imaging studies.     

Modifications of cellulose synthase confer resistance to isoxaben and thiazolidinone herbicides in Arabidopsis Ixr1 mutants

In many higher plants, cellulose synthesis is inhibited by isoxaben and thiazolidinone herbicides such as 5-tert-butyl-carbamoyloxy-3-(3-trifluromethyl) phenyl-4-thiazolidinone. Semidominant mutations at the IXR1 and IXR2 loci of Arabidopsis confer isoxaben and thiazolidinone resistance. Isolation of the IXR1 gene by map-based cloning revealed that it encodes the AtCESA3 isoform of cellulose synthase. The two known mutant alleles contain point mutations that replace glycine 998 with aspartic acid, and threonine 942 with isoleucine, respectively. The mutations occur in a highly conserved region of the enzyme near the carboxyl terminus that is well separated from the proposed active site. Although the IXR1 gene is expressed in the same cells as the structurally related RSW1 (AtCESA1) cellulose synthase gene, these two CESA genes are not functionally redundant.