Muscle weakness is associated with non-contractile muscle tissue of the vastus medialis muscle in knee osteoarthritis.

BACKGROUND: Quadriceps weakness is assumed to be associated with compositional properties of the vastus medialis muscle in patients with knee osteoarthritis (OA). METHODS: The aim was to determine the association of non-contractile muscle tissue in the vastus medialis muscle, measured with routine MRI, with muscle extensor strength in patients with knee OA. Sagittal T1-weighted 3T MRI of 94 patients with knee OA, routinely acquired in clinical practice were used for analysis. Using the MRI's, the amount of non-contractile muscle tissue in the vastus medialis muscle was measured, expressed as a percentage of (non)-contractile tissue, dichotomized into a low and a high non-contractile percentage group. Muscle strength was assessed by isokinetic measurement of knee extensors and by conduction of the Get-Up and Go (GUG) test. In regression analyses, associations of percentage of non-contractile muscle tissue with muscle strength and GUG time were determined and controlled for sex, age, BMI and radiographic severity. RESULTS: A high percentage of non-contractile muscle tissue (> 11.2%) was associated with lower muscle strength (B = -0.25, P = 0.006) and with longer GUG time (B = 1.09, P = 0.021). These associations were specifically confounded by sex and BMI, because these two variables decreased the regression coefficient (B) with > 10%. CONCLUSIONS: A high percentage of non-contractile muscle tissue in the vastus medialis muscle measured by clinical T1-weighted 3T MRI is associated with muscle weakness. The association is confounded by sex and BMI. Non-contractile muscle tissue seems to be an important compositional property of the vastus medialis muscle underlying quadriceps weakness.

Computer-aided detection (CAD) for breast MRI: evaluation of efficacy at 3.0 T.

OBJECTIVE: The purpose of the study was to evaluate the accuracy of 3.0-T breast MRI interpretation using manual and fully automated kinetic analyses. MATERIAL AND METHODS: Manual MRI interpretation was done on an Advantage Workstation. Retrospectively, all examinations were processed with a computer-aided detection (CAD) system. CAD data sets were interpreted by two experienced breast radiologists and two residents. For each lesion automated analysis of enhancement kinetics was evaluated at 50% and 100% thresholds. Forty-nine malignant and 22 benign lesions were evaluated. RESULTS: Using threshold enhancement alone, the sensitivity and specificity of CAD were 97.9% and 86.4%, respectively, for the 50% threshold, and 97.9% and 90%, respectively, for the 100% threshold. Manual interpretation by two breast radiologists showed a sensitivity of 84.6% and a specificity of 68.8%. For the same two radiologists the mean sensitivity and specificity for CAD-based interpretation was 90.4% (not significant) and 81.3% (significant at p < 0.05), respectively. With one-way ANOVA no significant differences were found between the two breast radiologists and the two residents together, or between any two readers separately. CONCLUSION: CAD-based analysis improved the specificity compared with manual analysis of enhancement. Automated analysis at 50% and 100% thresholds showed a high sensitivity and specificity for readers with varying levels of experience.

Direct Comparison of the Thickness Of The Parietal Peritoneum Using Peritoneal Biopsy and Ultrasonography of the Abdominal Wall in Patients Treated with Peritoneal Dialysis.

Background:Long-term treatment with peritoneal dialysis (PD) results in peritoneal fibrosis. Peritoneal biopsies have been used to determine the severity of fibrosis. Ultrasonography (US) of the abdominal wall has been used to measure peritoneal thickness non-invasively. However, direct comparison of both methods in the same patient has never been done. Furthermore, the validity of US to measure peritoneal thickness has not been investigated.Methods:We performed 3 studies: 1) a human biopsy study to compare US measurement of peritoneal thickness with histological examination; 2) a human cadaver study to investigate the effect of removing the peritoneum on US results; and 3) a phantom study in which we used US to measure the thickness of membrane-like structures with a known thickness to investigate the influence of different US settings.Results:The median thickness in biopsies of the peritoneum was 113 µm (interquartile range [IQR] 72 -129 µm), while this was 370 µm (IQR 324 - 458 µm) when measured by US (p < 0.0001). The mean difference between the 2 measures was -257 µm (limits of agreement -4.6 and -511 µm). In the cadaver study, removal of the peritoneum did not have an effect on the presence or thickness of the hyperechoic line reported to represent the peritoneum. In the phantom study, results were highly dependent on frequency of the transducer, scan depth, and gain settings.Conclusions:Ultrasonography results differ markedly from histological measurement using peritoneal biopsies. However, the hyperechoic line generated by US represents the interface between 2 neighboring tissues and not a separate morphological structure. Moreover, its thickness is greatly influenced by user-defined US settings.

Multiple fiber laser-induced thermotherapy for ablation of large intrahepatic tumors.

OBJECTIVE: The aim of this study was to test three techniques used simultaneously to increase lesion size. BACKGROUND DATA: Laser-induced thermotherapy (LITT) is a method of local tumor ablation, which may prolong survival in patients with unresectable liver metastases. The main limitation has been the production of lesions with sufficient tumor-free margin. METHODS: LITT treatment was performed with water-cooled, multiple fiber application and hepatic blood flow occlusion in six patients with unresectable intrahepatic metastases. Response was measured by computed tomography scan. RESULTS: In all patients, tumors were effectively ablated. In two patients with colorectal metastases, lesions up to 8.6 cm could be created. CONCLUSION: The use of watercooled multiple fiber application and hepatic inflow occlusion makes LITT an effective ablative method, expanding the treatment options for patients with large intrahepatic masses.

Interobserver variability of clinical target volume delineation of glandular breast tissue and of boost volume in tangential breast irradiation.

BACKGROUND AND PURPOSE: To determine the interobserver variability of clinical target volume delineation of glandular breast tissue and of boost volume in tangential breast irradiation. PATIENTS AND METHODS: Eighteen consecutive patients with left sided breast cancer treated by breast conserving surgery agreed to participate in our study. Volumes of the glandular breast tissue (CTV breast) and of the boost (CTV boost) were delineated by five observers. We determined 'conformity indices' (CI) and the ratio between the volume of each CTV and the mean volume of all CTVs (CTV ratio). Subsequently we determined the most medial, lateral, anterior, posterior, cranial and caudal extensions both of CTV breast and CTV boost for all observers separately. RESULTS: The mean CI breast was 0.87. For one observer we noted the highest CTV ratio in 17 out of 18 cases. No association was noted between CI breast and menopausal status. The mean CI boost was 0.56. We did not find a relation between the presence or absence of clips and the CI boost. For another observer we noted the lowest CTV boost ratio in 10 out of 17 cases. CONCLUSIONS: We recommend that each institute should determine its interobserver variability with respect to CTV breast and CTV boost before implementing the delineation of target volumes by planning CT in daily practice.

Fine-needle aspiration of thyroid tumors: identifying factors associated with adequacy rate in a large academic center in the Netherlands.

The goal of our study was to evaluate, and identify factors associated with, the adequacy rate of fine-needle aspiration (FNA) cytology of thyroid tumors to improve the quality of the procedure. We reviewed 1,611 cytological pathology reports of thyroid tumors of 871 patients between January 1998 and August 2008. The overall cytological adequacy rate was 53.9%. The freehand technique had significantly higher adequacy rates than the ultrasound (US)-guided technique (P < 0.001) regardless of size, tumor type, multinodularity, or location. Aspiration, performing specialist (endocrinologist versus radiologist), and size were the factors associated with adequacy rates. US-guided FNA is recommended in previous articles, but results in our clinic were in favor of freehand FNA. US guidance is a way to improve adequacy rates, but we would like to stress the importance of other factors like operator experience, education, and quality control in one's own institution before implementing techniques.

[A patient with bilateral microcalcifications on mammography]. / Bilaterale microcalcificaties op het mammogram.

A 25-year-old woman with systemic lupus erythematosus presented with multiple palpable masses in both breasts. On mammography multiple, coarse, heterogeneous, microcalcificatons were seen. Histopathologic examination showed inflammation, fibrosis, fat necrosis and dystrophic microcalcifications. Based on these findings the patient was diagnosed with lupus mastitis.

Long-term symptomatic outcome and radiologic assessment of laparoscopic hiatal hernia repair.

BACKGROUND: The long-term durability of laparoscopic repair of paraesophageal hiatal herniation is uncertain. This study focuses on the long-term symptomatic and radiologic outcome of laparoscopic paraesophageal herniation repair. METHODS: Between 2000 and 2007, 70 patients (49 females, mean age +/- standard deviation 60.6 +/- 10.9 years) undergoing laparoscopic repair of paraesophageal herniation were studied prospectively. After a mean follow-up of 45.6 +/- 23.8 months, symptomatic (65 patients, 93%) and radiologic follow-up (60 patients, 86%) was performed by standardized questionnaires and esophagograms. RESULTS: The symptomatic outcome was successful in 58 patients (89%), and gastroesophageal anatomy was intact in 42 patients (70%). The addition of a fundoplication was the only significant predictor of an unfavorable radiologic outcome in the univariate analysis (odds ratio .413; 95% confidence interval, .130 to 1.308; P = .125). CONCLUSIONS: The long-term symptomatic outcome of laparoscopic repair of paraesophageal hiatal herniation was favorable in 89% of patients, and 70% had successful anatomic repair. The addition of a fundoplication did not prevent anatomic herniation.