Objectives
To compare imaging and clinical features of fungal and
Staphylococcus aureus
discitis-osteomyelitis (DO) for patients presenting for CT-guided biopsies.
Methods
Our study was IRB-approved ...and HIPAA-compliant. A group of 11 fungal DO (FG) with MRI within 7 days of the biopsy and a control group (CG) of 19
Staphylococcus aureus
DO were evaluated. Imaging findings (focal vs diffuse paravertebral soft tissue abnormality, partial vs complete involvement of the disc/endplate), biopsy location, pathology, duration of back pain, immune status, history of intravenous drug, history of prior infection, current antibiotic treatment, and history of invasive intervention. Differences were assessed using the Fisher exact test and Kruskal-Wallis test. Naïve Bayes predictive modeling was performed.
Results
The most common fungal organisms were Candida species (9/11, 82%). The FG was more likely to have focal soft tissue abnormality (
p
= 0.040) and partial disc/endplate involvement (
p
= 0.053). The clinical predictors for fungal DO, in order of importance, back pain for 10 or more weeks, current antibiotic use for 1 week or more, and current intravenous drug use. History of invasive instrumentation within 1 year was more predictive of
Staphylococcus aureus
DO.
Conclusion
MRI features (focal partial soft tissue abnormality and partial involvement of the disc/endplate) in combination with clinical features may help to predict fungal species as a causative organism for DO.
Key Points
• MRI features of discitis-osteomyelitis (focal partial soft tissue abnormality and partial involvement of the disc/endplate) in combination with clinical features may help to predict fungal species as a causative organism for DO.
Introduction
Fatty degeneration of the gluteal muscles on metal artefact reduction sequence (MARS) MRI has been shown to correlate with poor functional outcomes, particularly in patients with total ...hip arthroplasty (THA). Standardized, reliable classification systems that permit assessment of fatty gluteal infiltration are needed for clinical decision making. This study aimed to compare the reproducibility and accuracy of commonly used MRI classification systems for fatty gluteal atrophy in THA patients.
Methods
MARS magnetic resonance images of 82 patients with unilateral THA were analysed by three independent trained observers. The readers evaluated fatty degeneration of the gluteus minimus, gluteus medius, and gluteus maximus according to 3 widely used classification systems: Goutallier, Quartile, and Bal and Lowe. Interobserver and intraobserver repeatability were determined using the weighted Kappa test. Quantitative evaluation of the proportion of intramuscular fat based on MR signal intensities was obtained and represented the gold standard.
Results
Mean interobserver agreement for the Quartile classification system (0.93) was higher compared with Goutallier classification system (0.87) and the Bal and Lowe classification system (0.83; range 0.79–0.88;
p
= 0.04). Intraobserver repeatability was significantly higher for the Quartile classification system (weighted kappa 0.91, 0.89, 0.85) compared with the Bal and Lowe classification system (weighted kappa 0.83, 0.77, 0.75;
p
< 0.01) and Goutallier classification system (weighted kappa 0.83, 0.77, 0.75;
p
= 0.04). Agreement with the gold standard measurements was significantly higher in the Quartile classification system (0.88, 0.84, 0.81) compared with the Goutallier classification system (0.80, 0.77, 0.78;
p
= 0.02) and Bal and Lowe classification system (0.76, 0.74, 0.73;
p
< 0.01).
Discussion
This study directly compared three clinically used MRI classification systems for fatty gluteal muscle atrophy in THA patients. Our findings demonstrate that although all three classification systems demonstrate good reproducibility and accuracy, the Quartile classification system is superior to the others in terms of intraobserver reliability and accuracy to quantify fatty gluteal degeneration in THA patients.
ANTARES: The first undersea neutrino telescope Ageron, M.; Anghinolfi, M.; Ardid, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/2011, Letnik:
656, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The ANTARES Neutrino Telescope was completed in May 2008 and is the first operational Neutrino Telescope in the Mediterranean Sea. The main purpose of the detector is to perform neutrino astronomy ...and the apparatus also offers facilities for marine and Earth sciences. This paper describes the design, the construction and the installation of the telescope in the deep sea, offshore from Toulon in France. An illustration of the detector performance is given.
Objective
There is surging interest in using dual‐energy computed tomography (DECT) to identify cardiovascular monosodium urate (MSU) deposits in patients with gout. We sought to examine the ...prevalence and characterization of cardiovascular DECT artifacts using non–electrocardiogram (EKG)‐gated DECT pulmonary angiograms.
Methods
We retrospectively reviewed non–EKG‐gated DECT pulmonary angiograms performed on patients with and without gout at a single academic center. We noted the presence and locations of vascular green colorization using the default postprocessing two‐material decomposition algorithm for MSU. The high‐ and low‐energy grayscale images and advanced DECT measurements were used to determine whether they were true findings or artifacts. We classified artifacts into five categories: streak, contrast medium mixing, misregistration due to motion, foreign body, and noise.
Results
Our study included CT scans from 48 patients with gout and 48 age‐ and sex‐matched controls. The majority of patients were male with a mean age of 67 years. Two independent observers attributed all areas of vascular green colorization to artifacts. The most common types of artifacts were streak (56% vs 57% between patients and controls, respectively) and contrast medium mixing (51% vs 65%, respectively). Whereas some of the default DECT measurements of cardiovascular green colorization were consistent with values reported for subcutaneous tophi, advanced DECT measurements were not consistent with that of tophi.
Conclusion
Artifacts that could be misconstrued as cardiovascular MSU deposits were commonly identified in patients with and without gout on non–EKG‐gated DECT pulmonary angiograms. These artifacts can inform future vascular DECT studies on patients with gout to minimize false‐positive findings.
Objective
To compare rotator cuff (RC) muscle cross-sectional areas (CSA) in subjects with adhesive capsulitis (AC) to age- and sex-matched controls.
Materials and methods
We retrospectively analyzed ...97 shoulder MRIs or MR arthrography studies, of which 42 were clinically diagnosed with AC (27 female, 15 male) and 55 were age- and sex-matched controls (38 female, 17 male). All AC subjects underwent imaging ≥ 6 months after symptom onset. All imaging was examined to exclude RC full-thickness tears and prior surgery. A standardized T1 sagittal MR image was segmented in each subject to obtain the CSA of subscapularis (SSC), supraspinatus (SSP), and infraspinatus (ISP) muscles. Differences in CSAs between AC and control subjects were analyzed by sex (females and males separately) and all subjects combined.
Results
AC females had significantly decreased SSC (
P
= 0.002) and total (
P
= 0.006) CSAs compared to controls. Male AC subjects showed decreased SSC (
P
= 0.044), SSP (
P
= 0.001), and total (
P
= 0.005) CSAs. Across all subjects, male and female, the AC cohort had significantly decreased SSC (
P
= 0.019) and total (
P
= 0.029) CSAs compared to controls.
Conclusion
Decreased RC muscle CSAs were present in AC subjects with ≥ 6 months of symptom duration, with decreased SSC and total CSAs in male and female subjects, and decreased SSP CSA in males.
Purpose
To determine the added value of computed tomography (CT) to identify severe hip osteoarthritis (OA).
Materials and methods
A retrospective query of all cases of hip or knee arthroplasty ...planning CTs between January 2018 and March 2022 was performed. Age, sex, and symptoms were collected from the medical record. CTs were evaluated for the degree of osteoarthritis and classified using an adapted Kellgren-Lawrence (KL) grading system in the anterior, posterior, superior, and superomedial hip. Frontal hip or pelvis radiographs within 1 year of the CT were also graded.
Results
There were 265 eligible hips in 178 subjects, age 66 ± 11 (range 31–93) years, with 85/178 (48%) males and 93/178 (52%) females, and 127/265 (48%) right and 138/265 (52%) left hips. The posterior hip joint was the most common location for grade 2/3 OA (20%), followed by superior hip joint (14%). Anterior or posterior grade 2/3 OA occurred concurrently with superior or superomedial grade 2/3 OA in 32/68 (47%) of hips. Grade 2/3 OA was detected on CT more commonly than on XR both in the superior (14 vs 8.6%,
P
= 0.0016) and superomedial (8.7 vs 4.8%,
P
= 0.016) hip joint.
Of the 71 symptomatic hips, 22 (31%) hips demonstrated either anterior and/or posterior grade 2/3 OA on CT, and 9 (9/22, 41%) of these hips had superior or superomedial grade 0/1 OA.
Conclusion
CT may be warranted when the patient has pain suggestive of osteoarthritis not detected on radiographs.
The purpose of this study was to determine whether CT attenuation thresholds can be used to distinguish untreated osteoblastic metastases from enostoses.
The study group comprised 62 patients with ...279 sclerotic bone lesions found at CT (126 enostoses in 37 patients and 153 metastases in 25 patients). The cause of sclerotic lesions was assessed histologically or by clinical and imaging follow-up. None of the patients had undergone prior treatment for the metastases. The mean and maximum attenuation were measured in Hounsfield units. ROC analysis was performed to determine sensitivity, specificity, AUC, 95% CIs, and cutoff values of CT attenuation to differentiate metastases from enostoses. Interreader reproducibility was assessed using an intraclass correlation coefficient with 95% CI.
The mean and maximum CT attenuation values of enostoses were 1190 ± 239 HU and 1323 ± 234 HU, respectively, and those of osteoblastic metastases were 654 ± 176 HU and 787 ± 194 HU, respectively. Using a cutoff of 885 HU for mean attenuation, the AUC was 0.982, sensitivity was 95%, and specificity was 96%. Using a cutoff of 1060 HU for maximum CT attenuation, the AUC was 0.976, sensitivity was 95%, and specificity was 96%. The mean attenuation intraclass correlation coefficient was 0.987 for enostoses and 0.81 for metastases. The maximum attenuation intraclass correlation coefficient was 0.814 for enostoses and 0.980 for metastases.
CT attenuation measurements can be used to distinguish untreated osteoblastic metastases from enostoses. A mean attenuation of 885 HU and a maximum attenuation of 1060 HU provide reliable thresholds below which a metastatic lesion is the favored diagnosis.
Objective
To assess the readability of patient-targeted online information on musculoskeletal radiology procedures.
Methods
Eleven common musculoskeletal radiology procedures were queried in three ...online search engines (Google, Yahoo!, Bing). All unique patient-targeted websites were identified (
n
= 384) from the first three pages of search results. The reading grade level of each website was calculated using 6 separate validated metrics for readability assessment. Analysis of word and sentence complexity was also performed. Results were compared between academic vs. non-academic websites and between websites found on different pages of the search results. Statistics were performed using a
t
test.
Results
The mean reading grade level across all procedures was 10th–14th grade. Webpages for nerve block were written at a higher reading grade level on non-academic websites (
p
= 0.025). There was no difference in reading grade levels between academic and non-academic sources for all other procedures. There was no difference in reading grade levels between websites found on the first page of search results compared with the second and third pages. Across all websites, 16–22% of the words used had 3+ syllables and 31–43% of the words used had 6+ characters (complex words); 13–24% of the sentences used had 22+ words (complex sentences).
Conclusion
Patient-targeted online information on musculoskeletal radiology procedures are written at the 10th–14th grade reading level, which is well beyond the AMA and NIH recommendation. Readability can be lowered by decreasing text complexity through limitation of high-syllable words and reduction in word and sentence length.
It is of great interest to physicians and patients/patients' families to be able to predict the amount of growth decrement after craniospinal irradiation (CSI). Little data exist on the effect of ...proton CSI. Our aim was to determine the effect of proton CSI on vertebral body (VB) growth retardation, and to identify factors associated with growth delay.
We performed a retrospective outcome data analysis of 80 patients <16 years old with central nervous system tumors who received proton radiation therapy (PRT) at the Massachusetts General Hospital between 2002 and 2010 with available spinal magnetic resonance imaging. Forty-eight patients received CSI, and 32 patients with brain tumors who received focal cranial irradiation served as controls. VB height was measured midline using sagittal T1-weighted contrast or noncontrast enhanced magnetic resonance imaging of the spine. Measurements were repeated at multiple levels (C3, C3-C4, T4, T4-T5, C3-T6, T4-T7, L3, L1-L5) on available scans for the duration of follow-up. Data were fitted using a mixed-effects multivariable regression model, including follow-up time, CSI dose, age at CSI, and pretreatment VB percentile as parameters.
Median follow-up was 69.6 months for patients treated with proton CSI and 52.9 months for the control group. There was a significant association of CSI dose, follow-up time, age at treatment, and pretreatment VB percentile with VB growth retardation. Growth retardation was shown to be independent of gender or growth hormone deficiency.
Although the current practice of PRT CSI delivery allows for sparing of the organs anterior to the spine, the vertebral column receives radiation therapy because of its close proximity to the targeted spinal canal. In growing children, the whole VB has generally been included so that growth impairment is even across the VB. We present a quantitative model predicting the growth retardation of patients treated with PRT CSI based on age at treatment, CSI dose, follow-up time, and pretreatment growth percentile.
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