Correlation of structural abnormalities of the wrist and metacarpophalangeal joints evaluated by high-resolution peripheral quantitative computed tomography, 3 Tesla magnetic resonance imaging and conventional radiographs in rheumatoid arthritis.

AIM: In rheumatoid arthritis (RA) hands, we applied high-resolution peripheral quantitative computed tomography (HR-pQCT) and 3 Tesla (3 T) magnetic resonance imaging (MRI), which are new methods for erosion detection and bone marrow edema (BME) quantification. We compared the erosion measurements between these techniques with conventional radiographs (CR) in order to examine their significance for evaluating structural abnormalities. METHODS: In 16 RA patients, HR-pQCT of metacarpophalangeal and wrist joints, 3 T MRI of wrist joints, as well as CR in both hands and feet were performed. Ten patients had 1-year follow-up CR. CRs were graded according to the modified Sharp score (MSS). Bone erosions were evaluated in HR-pQCT and MRI. BME pattern was quantified from MRI for volume, signal change and total burden. RESULTS: The erosion detection sensitivity of MRI was 85.7% and CR was 60.9% when HR-pQCT was considered as a reference method. The smallest dimensions of erosion detected by HR-pQCT, MRI and CR were 0.09, 0.14 and 0.66 cm, respectively. Baseline total MSS was correlated with HR-pQCT erosion measures, MRI erosion measures and MRI BME volume (P < 0.05). The mean difference between baseline and 1-year follow-up MSS (delta MSS) was 1.2. A trend was observed toward a correlation between delta MSS and MRI BME volume and burden. CONCLUSION: This study demonstrates that HR-pQCT detects more and smaller bone erosions compared to MRI and CR. In addition, 3 T MRI can provide quantitative measurement of BME. Combination of HR-pQCT and MRI modalities may provide powerful tools to evaluate joint inflammation and bone damage in RA.

MR T(1)ρ quantification of cartilage focal lesions in acutely injured knees: correlation with arthroscopic evaluation.

OBJECTIVE: Quantitative T1ρ MRI has been suggested as a promising tool to detect changes in cartilage composition that are characteristic of cartilage damage and degeneration. The objective of this study was to evaluate the capability of MR T1ρ to detect cartilage lesions as evaluated by arthroscopy in acutely ACL-injured knees and to compare with the Whole-Organ Magnetic Resonance Imaging Score (WORMS) using clinical standard MRI. METHOD: Ten healthy controls (mean age 35) with no ACL injury or history of osteoarthritis (OA) and 10 patients with acute ACL injuries (mean age 39) were scanned at 3 Tesla (3T). ACL patients underwent ACL reconstruction, where focal lesions were graded according to an Outerbridge grading system during arthroscopic evaluation. Normalized MR T1ρ values (T1ρ z-scores normalized to control values in matched regions) in full thickness, and superficial and deep layers of cartilage were compared between defined sub-compartments with and without focal lesions. Intraclass (ICC) correlation and the root mean square coefficient of variation (RMS-CV) were performed to evaluate the inter-observer reproducibility of T1ρ quantification. Sub-compartments of cartilage were also evaluated using WORMS scoring and compared to their Outerbridge score respectively. RESULTS: The inter-observer ICC and the RMS-CV of the sub-compartment T1ρ quantification were 0.961 and 3.9%, respectively. The average T1ρ z-scores were significantly increased in sub-compartments with focal lesions compared to those without focal lesions and to the control cohort (p<0.05). CONCLUSION: Our results indicate that T1ρ provided a better diagnostic capability than clinical standard MRI grading in detecting focal cartilage abnormalities after acute injuries. Quantitative MRI may have great potential in detecting cartilage abnormalities and degeneration non-invasively, which are occult with standard morphological MRI.

Bone marrow changes related to disuse.

OBJECTIVES: To evaluate bone marrow changes on knee magnetic resonance imaging (MRI) in patients with 3- to 6-week-long period of unloading. METHODS: MRI knee examinations were performed in 30 patients (14 men, 16 women; aged 20-53 years) at baseline and 5-10 weeks after immobilisation of the ipsilateral lower extremity; subsets of patients were examined at additional time-points. Ten volunteers (4 men, 6 women; aged 20-50 years) were studied as control cohort at two time-points. Bone marrow signal abnormalities were analysed according to: (1) severity, (2) signal alteration relative to hyaline cartilage, (3) morphology, (4) increased vascularity in the knee joint and (5) T1-signal alteration. Spearman's rank correlation test (SRC) and Kendall's tau (KT) were used to compare individual scores. RESULTS: All 30 patients presented abnormal bone marrow findings after unloading, which reached a peak at 10-25 weeks (P <0.001). These findings decreased within 1 year (P < 0.001). High scores of severity were associated with confluent and patchy patterns of bone marrow (SCR = 0.923, P < 0.001 and KT = 0.877, P <0.001). CONCLUSIONS: Signal abnormalities of the bone marrow related to unloading are consistent findings and most prominent 10-25 weeks following immobilisation when both confluent and patchy hyperintense patterns are present.

Lumbosacral transitional vertebrae: association with low back pain.

PURPOSE: To assess the prevalence and degree of lumbosacral transitional vertebrae (LSTV) in the Osteoarthritis Initiative (OAI) cohort, to assess whether LSTV correlates with low back pain (LBP) and buttock pain, and to assess the reproducibility of grading LSTV. MATERIALS & METHODS: Institutional review board approval was obtained, and informed consent documentation was approved for the study protocol. Standard standing pelvic radiographs that included the transverse processes of L5 were graded according to Castellvi classification of LSTV in 4636 participants (1992 men and 2804 women; aged 45-80 years) from the OAI cohort. These data were correlated with prevalence and severity of LBP and buttock pain. RESULTS: Prevalence of LSTV was 18.1% (841 of 4636), with a higher rate in men than in women (28.1% vs 11.1%, respectively; P<.001). Of the 841 individuals with LSTV, 41.72% were type I (dysplastic enlarged transverse process), 41.4% were type II (pseudoarticulation), 11.5% were type III (fusion), and 5.2% were type IV (one transverse process fused and one with pseudoarticulation). Of the participants without LSTV, 53.9% reported LBP, while the prevalence of LBP for types I, II, III, and IV was 46%, 73%, 40%, and 66%, respectively (P<.05, χ2 test). Types II and IV had higher prevalence and severity of LBP and buttock pain (P<.001). CONCLUSION: LSTV types II and IV positively correlate with prevalence and severity of LBP and buttock pain.

Association of magnetic resonance imaging-based knee cartilage T2 measurements and focal knee lesions with knee pain: data from the Osteoarthritis Initiative.

OBJECTIVE: To evaluate the association of magnetic resonance imaging (MRI)-based knee cartilage T2 measurements and focal knee lesions with knee pain in knees without radiographic osteoarthritis (OA) among subjects with OA risk factors. METHODS: We studied the right knees of 126 subjects from the Osteoarthritis Initiative database. We randomly selected 42 subjects ages 45-55 years with OA risk factors, right knee pain (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC] pain score ≥5), no left knee pain (WOMAC pain score 0), and no radiographic OA (Kellgren/Lawrence [K/L] score ≤1) in the right knee. We also selected 2 comparison groups: 42 subjects without knee pain in either knee and 42 with bilateral knee pain. Both groups were frequency matched to subjects with right knee pain only by sex, age, body mass index, and K/L score. All of the subjects underwent 3T MRI of the right knee. Focal knee lesions were assessed and cartilage T2 measurements were performed. RESULTS: Prevalences of meniscal, bone marrow, and ligamentous lesions and joint effusion were not significantly different between the groups (P > 0.05), while cartilage lesions were more frequent in subjects with right knee pain only compared to subjects without knee pain (P < 0.05). T2 values averaged over all of the compartments were similar in subjects with right knee pain only (mean ± SD 34.4 ± 1.8 msec) and in subjects with bilateral knee pain (mean ± SD 34.7 ± 4.7 msec), but were significantly higher compared to subjects without knee pain (mean ± SD 32.4 ± 1.8 msec; P < 0.05). CONCLUSION: These results suggest that elevated cartilage T2 values are associated with findings of pain in the early phase of OA, whereas among morphologic knee abnormalities only knee cartilage lesions are significantly associated with knee pain status.

Quantitative characterization of bone marrow edema pattern in rheumatoid arthritis using 3 Tesla MRI.

PURPOSE: To develop imaging techniques that provide quantitative characterization of bone marrow edema pattern (BME) in wrist joints of patients with rheumatoid arthritis (RA), including volume, signal intensity changes, and perfusion properties. MATERIALS AND METHODS: Fourteen RA patients and three controls were scanned using 3 Tesla MR. BME was semi-automatically segmented in water images obtained from iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL) sequences. BME perfusion parameters (enhancement and slope) were evaluated using three-dimensional (3D) dynamic enhanced MRI (DCE-MRI). Experimental reproducibility, inter- and intra-observer reproducibility of BME quantification were evaluated using root mean square coefficients of variation (RMS-CV) and intraclass correlation (ICC). RESULTS: The RMS-CV for BME volume quantification with repeated scans were 6.9%. The inter-observer ICC was 0.993 and RMS CV was 5.2%. The intra-observer ICC was 0.998 and RMS CV was 2.3%. Both maximum enhancement and slope during DCE-MRI were significantly higher in BME than in normal bone marrow (P < 0.001). No significant correlation was found between BME quantification and clinical evaluations. CONCLUSION: A highly reproducible semi-automatic method for quantifying BME lesion burden in RA was developed, which may enhance our capability of predicting disease progression and monitoring treatment response.

CT-guided biopsy of bone and soft-tissue lesions: role of on-site immediate cytologic evaluation.

PURPOSE: To assess the impact of on-site immediate cytologic assessment (ICA) on the diagnostic success rate of computed tomography (CT)-guided percutaneous needle biopsy (PNB) of musculoskeletal lesions and the long-term outcome in inconclusive PNB findings. MATERIALS AND METHODS: A total of 299 CT-guided PNBs of musculoskeletal lesions performed between January 1997 and December 2009 were retrospectively reviewed. The lesions were categorized by their morphology, location, and size, and by biopsy type. The diagnostic success rates, impact of ICA, and outcome in inconclusive PNBs were studied, with final histopathologic findings and/or clinical follow-up as a reference. RESULTS: The overall diagnostic success rate of PNBs was 72.9% (218 of 299). The success rate increased with larger lesions (> 2 cm to 4 cm; P = .009). Biopsies performed with ICA had a higher success rate (77.0% vs 63.3%; P = .015). PNBs had inconclusive results in 109 of 299 cases (36.5%). In 66 of these, repeat open biopsy or clinical follow-up demonstrated 19 malignant/aggressive lesions (28.8%) and 47 benign/nonaggressive lesions (71.2%). CONCLUSIONS: CT-guided PNB had a satisfactory success rate, which significantly increased when performed with ICA. Inconclusive results in PNB were most frequently associated with benign findings during further workup.

Osteoid osteoma of the femur in a 7-month-old infant treated with radiofrequency ablation.

Osteoid osteoma occurs most commonly in children, adolescents, and young adults between the ages of 5 and 30 years. In the preschool age group, it is quite uncommon, accounting for only 3-8% of all osteoid osteoma cases. We report a case of osteoid osteoma in a 7-month-old infant, who presented with decreased use of the right lower extremity due to pain. Magnetic resonance imaging (MRI) showed an atypical appearance. A biopsy of the lesion, with histopathological examination, confirmed the diagnosis of osteoid osteoma. Radiofrequency ablation (RFA) of the nidus under computed tomography (CT) guidance was performed. The patient developed a recurrence after 3 months, which was treated with a second RFA. On subsequent follow-up, the infant did not show signs of pain after 1 month. In summary, this case report shows that osteoid osteoma can present in early infancy and can be successfully treated with RFA at this age, however, recurrence after the procedure can occur and close follow-up is recommended.

Presacral fibrosarcoma in childhood: a case report.

Presacral fibrosarcoma is a rare malignant tumor in childhood. Because of its rarity in the presacral region, it is often missed from the differential diagnosis of presacral mass in childhood. The authors present a case of large presacral fibrosarcoma involving spinal canal, with an initial presentation of back pain and abnormal gaiting.

The prevalence of carotid artery calcifications detected on panoramic radiographs in patients with metabolic syndrome.

OBJECTIVES: The purpose of this study was to determine the prevalence of carotid artery calcifications (CAC) detected on panoramic radiographs in patients with metabolic syndrome (MetS). STUDY DESIGN: Eighty-five Thai subjects (29 men, 56 women) who had MetS according to the International Diabetes Federation definition were evaluated for CAC detected on panoramic radiographs. The confirmation of findings was done by ultrasonography. RESULTS: Carotid artery calcifications were detected in 19 subjects (22.4%) with a mean age of 64 years, range 48-74 years. These subjects included 12 men and 7 women. The CAC were significantly more common in men than in women (P = .002). There were 8 subjects (9.4%) with bilateral calcifications and 11 subjects (12.9%) with unilateral calcification. No significant difference between the right and left sides was found (P = .44). CONCLUSION: Thai people with MetS have high prevalence of radiographically detectable carotid artery calcifications.

Three-Tesla MRI diagnosis of meniscal tears of the knee.

OBJECTIVE: To study and diagnose meniscal tear of the knee using 3-Tesla (3-T) magnetic resonance imaging (MRI) compared with arthroscopy. MATERIAL AND METHOD: One hundred twenty eight consecutive patients who underwent MRI of the knee using a 3-T magnet between April 2007 and Nov 2008 were included in this study. The inclusion criteria were the patients who had (i) subsequent knee arthroscopy, (ii) available medical records, and (iii) no history of meniscal surgery. Their MR images were retrospectively reviewed by two radiologists with consensus agreement. The diagnostic values for diagnosing meniscal tears were evaluated and compared to the arthroscopic results. RESULTS: Thirty-two patients (64 menisci) were included; 26 males and 6 females, mean age was 36.4 years (range 19-62). The mean interval between MRI and arthroscopy was 93 days. To diagnose tear of medial, lateral, and both menisci; the sensitivity was 100%, 90%, 100%; the specificity was 77%, 73%, 50%; the accuracy was 91%, 78%, 84%; the positive predictive value (PPV) was 86%, 60%, 81%; and the negative predictive value (NPV) was 100%, 94%, 100%, respectively. False positive MR findings were found predominantly at the posterior horn and at the peripheral third of the menisci. By dividing the patients into 2 groups according to the mean MRI-arthroscopy interval (< 93 and > 93 days): increased sensitivity and NPV of detecting lateral meniscal tear; increased specificity, accuracy, and PPV of both meniscal tear was observed in the longer duration group, but there was no statistical significance in the present study. CONCLUSION: The present results with 3-T MRI revealed high sensitivity and NP V comparable to the literature, thus supporting previous studies that if a meniscal tear is not seen on 3-T MRI, it is highly unlikely to be present. False positive MR findings found predominantly at the posterior horn and at the peripheral third of the menisci. The longer the MRI-arthroscopy interval yielded increased diagnosing values of meniscal tear but there is no statistical significance in the present study