Diffusion-weighted imaging in musculoskeletal radiology-clinical applications and future directions

Diffusion-weighted imaging (DWI) is an established diagnostic tool with regards to the central nervous system (CNS) and research into its application in the musculoskeletal system has been growing. It has been shown that DWI has utility in differentiating vertebral compression fractures from malignant ones, assessing partial and complete tears of the anterior cruciate ligament (ACL), monitoring tumor response to therapy, and characterization of soft-tissue and bone tumors. DWI is however less useful in differentiating malignant vs. infectious processes. As of yet, no definitive qualitative or quantitative properties have been established due to reasons ranging from variability in acquisition protocols to overlapping imaging characteristics. Even with these limitations, DWI can still provide clinically useful information, increasing diagnostic accuracy and improving patient management when magnetic resonance imaging (MRI) findings are inconclusive. The purpose of this article is to summarize recent research into DWI applications in the musculoskeletal system.

Simultaneous multi-slice readout-segmented echo planar imaging for accelerated diffusion-weighted imaging of the breast

OBJECTIVES Readout-segmented echo planar imaging (rs-EPI) significantly reduces susceptibility artifacts in diffusion-weighted imaging (DWI) of the breast compared to single-shot EPI but is limited by longer scan times. To compensate for this, we tested a new simultaneous multi-slice (SMS) acquisition for accelerated rs-EPI. MATERIALS AND METHODS After approval by the local ethics committee, eight healthy female volunteers (age, 38.9±13.1 years) underwent breast MRI at 3T. Conventional as well as two-fold (2× SMS) and three-fold (3× SMS) slice-accelerated rs-EPI sequences were acquired at b-values of 50 and 800s/mm(2). Two independent readers analyzed the apparent diffusion coefficient (ADC) in fibroglandular breast parenchyma. The signal-to-noise ratio (SNR) was estimated based on the subtraction method. ADC and SNR were compared between sequences by using the Friedman test. RESULTS The acquisition time was 4:21min for conventional rs-EPI, 2:35min for 2× SMS rs-EPI and 1:44min for 3× SMS rs-EPI. ADC values were similar in all sequences (mean values 1.62×10(-3)mm(2)/s, p=0.99). Mean SNR was 27.7-29.6, and no significant differences were found among the sequences (p=0.83). CONCLUSION SMS rs-EPI yields similar ADC values and SNR compared to conventional rs-EPI at markedly reduced scan time. Thus, SMS excitation increases the clinical applicability of rs-EPI for DWI of the breast.

Owner-perceived, weighted quality-of-life assessments in dogs with spinal cord injuries.

OBJECTIVE To evaluate changes over time in owner-perceived, weighted quality-of-life assessments in dogs with spinal cord injuries and determine whether scores were associated with underlying etiology or with veterinarian-assigned scores for severity of neurologic dysfunction. DESIGN Cohort study. ANIMALS 100 dogs with spinal cord injury. PROCEDURES Duration of dysfunction, modified Frankel neurologic injury score, and etiology were recorded. At initial and recheck (4- to 6-week) evaluations, owners were asked to identify 5 areas or activities they believed had the most influence on their dogs' quality of life, assess their dogs' current status in each area, and provide a weighting for the importance of each area; results were used to construct a weighted quality-of-life score. Owners were also asked to provide a quality-of-life score with a visual analog scale (VAS). RESULTS At initial and recheck evaluations, weighted quality-of-life scores were higher for ambulatory than for nonambulatory dogs. However, scores did not differ among groups when dogs were grouped on the basis of underlying etiology or duration of injury. Dogs with an increase in Frankel score between the initial and recheck evaluations had a significant increase in weighted quality-of-life score, whereas for dogs that did not have any change in Frankel score, initial and recheck weighted quality-of-life scores were not significantly different. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that owner-assigned, weighted quality-of-life scores for dogs with spinal cord injuries did not vary significantly on the basis of underlying etiology or duration of injury but were higher for ambulatory than for nonambulatory dogs.

Evaluation of a questionnaire for obtaining owner-perceived, weighted quality-of-life assessments for dogs with spinal cord injuries.

OBJECTIVE To evaluate a questionnaire for obtaining owner-perceived, weighted quality-oflife assessments for dogs with spinal cord injuries. DESIGN Evaluation study. Animals-100 dogs with spinal cord injuries and 48 healthy control dogs. PROCEDURES The questionnaire was adapted from a questionnaire (the schedule for the evaluation of individual quality of life-direct weighting) used for human patients. Specifically, owners were asked to identify 5 areas or activities they believed had the most influence on their dogs' quality of life, assess their dogs' current status in each of those areas, and provide a weighting for the importance of each area. Results were used to construct a weighted quality-of-life score ranging from 0 to 100 for each dog. Owners were also asked to provide a quality-of-life score with a visual analog scale (VAS). RESULTS A good correlation was found between weighted and VAS quality-of-life scores. Dogs with spinal cord injuries had weighted quality-of-life scores that were significantly lower than scores for control dogs. Quality-of-life areas and activities provided by owners of dogs with spinal cord injuries were similar to areas and activities provided by owners of healthy control dogs and could mostly be encompassed by 5 broader domains: mobility, play or mental stimulation, health, companionship, and other. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that the questionnaire could be used to obtain owner-perceived, weighted quality-of-life assessments for dogs with spinal cord injuries. Obtaining owner-perceived quality-of-life assessments for individual dogs should allow veterinarians to better address quality-of-life concerns and expectations of owners.

Vegetation shift and laurophyllisation: the possible role of forest fires

Southern Switzerland is a fire prone area where fire has to be considered as a natural environmental factor. In the past decades, fire frequency has tended to increase due to changes in landscape management. The most common type of fire is surface fire which normally breaks out during the vegetation resting period. Usually this type of fire shows short residence time (rapid spread), low to medium fire intensity and limited size. South-facing slopes are particularly fire-prone, so that very high fire frequency is possible: under these conditions passive resistant species and postfire resprouting species are favoured, usually leading to a reduction in the number of surviving species to a few fire adapted sprouters. Evergreen broadleaves are extremely sensitive to repeated fires. A simulation of the potential vegetation of southern Switzerland under climatic changed conditions evidenced the coincidence of the potential area of spreading forests rich in evergreen broad-leaved species with the most fire-prone area of the region. Therefore, in future, wildfires could play an important regulating role: most probably they will not stop the large-scale laurophyllisation of the thermophilous forests of southern Switzerland, but at sites with high fire frequency the vegetation shift could be slowed or even prevented by fire-disturbances.

Surgical Treatment of Recurrent Endometrial Cancer: Time for a Paradigm Shift.

BACKGROUND Although surgery represents the cornerstone treatment of endometrial cancer at initial diagnosis, scarce data are available in recurrent setting. The purpose of this study was to review the outcome of surgery in these patients. METHODS Medical records of all patients undergoing surgery for recurrent endometrial cancer at NCI Milano between January 2003 and January 2014 were reviewed. Survival was determined from the time of surgery for recurrence to last follow-up. Survival was estimated using Kaplan-Meier methods. Differences in survival were analyzed using the log-rank test. The Fisher's exact test was used to compare optimal versus suboptimal cytoreduction against possible predictive factors. RESULTS Sixty-four patients were identified. Median age was 66 years. Recurrences were multiple in 38 % of the cases. Optimal cytoreduction was achieved in 65.6 %. Median OR time was 165 min, median postoperative hemoglobin drop was 2.4 g/dl, and median length hospital stay was 5.5 days. Eleven patients developed postoperative complications, but only four required surgical management. Estimated 5-year progression-free survival (PFS) was 42 and 19 % in optimally and suboptimally cytoreduced patients, respectively. At multivariate analysis, only residual disease was associated with PFS. Estimated 5-year overall survival (OS) was 60 and 30 % in optimally and suboptimally cytoreduced patients, respectively. At multivariate analysis, residual disease and histotype were associated with OS. At multivariate analysis, only performance status was associated with optimal cytoreduction. CONCLUSIONS Secondary cytoreduction in endometrial cancer is associated with long PFS and OS. The only factors associated with improved long-term outcome are the absence of residual disease at the end of surgical resection and histotype.

Motion-insensitive determination of B1+ amplitudes based on the bloch-siegert shift in single voxels of moving organs including the human heart.

PURPOSE To reliably determine the amplitude of the transmit radiofrequency ( B1+) field in moving organs like the liver and heart, where most current techniques are usually not feasible. METHODS B1+ field measurement based on the Bloch-Siegert shift induced by a pair of Fermi pulses in a double-triggered modified Point RESolved Spectroscopy (PRESS) sequence with motion-compensated crusher gradients has been developed. Performance of the sequence was tested in moving phantoms and in muscle, liver, and heart of six healthy volunteers each, using different arrangements of transmit/receive coils. RESULTS B1+ determination in a moving phantom was almost independent of type and amplitude of the motion and agreed well with theory. In vivo, repeated measurements led to very small coefficients of variance (CV) if the amplitude of the Fermi pulse was chosen above an appropriate level (CV in muscle 0.6%, liver 1.6%, heart 2.3% with moderate amplitude of the Fermi pulses and 1.2% with stronger Fermi pulses). CONCLUSION The proposed sequence shows a very robust determination of B1+ in a single voxel even under challenging conditions (transmission with a surface coil or measurements in the heart without breath-hold). Magn Reson Med, 2015. © 2015 Wiley Periodicals, Inc.

No Routine Postoperative Head CT following Elective Craniotomy - A Paradigm Shift?

INTRODUCTION Patient management following elective cranial surgery often includes routine postoperative computed tomography (CT). We analyzed whether a regime of early extubation and close neurological monitoring without routine CT is safe, and compared the rate of postoperative emergency neurosurgical intervention with published data. METHODS Four hundred ninety-two patients were prospectively analyzed; 360 had supra- and 132 had infratentorial lesions. Extubation within one hour after skin closure was aimed for in all cases. CT was performed within 48 hours only in cases of unexpected neurological findings. RESULTS Four-hundred sixty-nine of the 492 patients (95.3%) were extubated within one hour, 20 (4.1%) within 3 hours, and three (0.6%) within 3 to 10 hours. Emergency CT within 48 hours was performed for 43/492 (8.7%) cases. Rate of recraniotomy within 48 hours for patients with postoperative hemorrhage was 0.8% (n = 4), and 0.8% (n = 4) required placement of an external ventricular drain (EVD). Of 469 patients extubated within one hour, 3 required recraniotomy and 2 required EVD placements. Of 23 patients with delayed extubation, 1 recraniotomy and 2 EVDs were required. Failure to extubate within one hour was associated with a significantly higher risk of surgical intervention within 48 hours (rate 13.0%, p = 0.004, odds ratio 13.9, 95% confidence interval [3.11-62.37]). DISCUSSION Early extubation combined with close neurological monitoring is safe and omits the need for routine postoperative CT. Patients not extubated within one hour do need early CT, since they had a significantly increased risk of requiring emergency neurosurgical intervention. TRIAL REGISTRATION ClinicalTrials.gov NCT01987648.

An Activity Theoretical Approach to Designing Curriculum and Instruction That Shift the Means and Ends of History Education

Reformers want history education to help students learn to engage in historical inquiry, read critically across conflicting sources, and engage in civil discussion of controversial issues. How can we help teachers and students shift the roles, norms, and activity in history classrooms to achieve these aims? An activity-theoretical framework suggests the value of explicitly attending to multiple aspects of human activity when designing and presenting reform-oriented pedagogies or curricula. Such attention increases the odds that teachers who implement new approaches or curriculum will achieve significant shifts in the means and ends of history education.

Analysis of the LIFO inventory valuation method during the onset of IFRS

I propose that the Last in, First out (LIFO) inventory valuation method needs to be reevaluated. I will evaluate the impact of the LIFO method on earnings of publically traded companies with a LIFO reserve over the past 10 years. I will begin my proposal with the history of how the LIFO method became an acceptable valuation method and discuss the significance of LIFO within the accounting profession Next I will provide a description of LIFO, the First in, First out (FIFO), and the weighted average inventory valuation methods and explore the differences among each. More specifically, I will explore the arguments for and against the use of the LIFO method and the potential shift towards financial standards that do not allow LIFO (a standard adopted and influenced by the International Financial Accounting Standards Board). Data will be collected from Compustat for publicly traded companies (with a LIFO Reserve) for the past 10 years. I will document which firms use LIFO, analyze trends relating to LIFO usage and LIFO reserves (the difference in the cost of inventory between using LIFO and FIFO), and evaluate the effect on earnings. The purpose of this research is to evaluate the accuracy of LIFO in portraying earnings and to see how much tax has gone uncollected over the years because of the use of LIFO. Moreover, I will provide an opinion as to whether U.S. GAAP should adopt a standard similar to IFRS and ban the LIFO method.

The effect of the shift from HMO to PPO plans on the prevalence of hospital bad debt in the insured population: A case study in two Houston-area hospitals

In spite of the dramatic increase and general concern with U.S. hospital bad debt expense (AMNews, January 12, 2004; Philadelphia Business Journal, April 30, 2004; WSJ, July 23, 2004), there appears to be little available analysis of the precise sources and causes of its growth. This is particularly true in terms of the potential contribution of insured patients to bad debt expense in light of the recent shift in managed care from health maintenance organization (HMO) plans to preferred provider organization (PPO) plans (Kaiser Annual Survey Report, 2003). This study examines and attempts to explain the recent dramatic growth in bad debt expense by focusing on and analyzing data from two Houston-area hospital providers within one healthcare system. In contrast to prior studies in which self-pay was found to be the primary source of hospital bad debt expense (Saywell, R. M., et al., 1989; Zollinger, T. W., 1991; Weissman, Joel S., et al., 1999), this study hypothesizes that the growing hospital bad debt expense is mainly due to the shifting trend away from HMOs to PPOs as a conscious decision by employers to share costs with employees. Compared to HMO plans, the structure of PPOs includes higher co-pays, coinsurance, and deductibles for the patient-pay portion of medical bills, creating the potential for an increase in bad debt for hospital providers (from a case study). This bad debt expense has a greater impact in the community hospital than in the Texas Medical Center hospital. ^

The multiple location time weighted index: Using patient activity spaces to calculate primary care service areas

Geographic health planning analyses, such as service area calculations, are hampered by a lack of patient-specific geographic data. Using the limited patient address information in patient management systems, planners analyze patient origin based on home address. But activity space research done sparingly in public health and extensively in non-health related arenas uses multiple addresses per person when analyzing accessibility. Also, health care access research has shown that there are many non-geographic factors that influence choice of provider. Most planning methods, however, overlook non-geographic factors influencing choice of provider, and the limited data mean the analyses can only be related to home address. This research attempted to determine to what extent geography plays a part in patient choice of provider and to determine if activity space data can be used to calculate service areas for primary care providers. ^ During Spring 2008, a convenience sample of 384 patients of a locally-funded Community Health Center in Houston, Texas, completed a survey that asked about what factors are important when he or she selects a health care provider. A subset of this group (336) also completed an activity space log that captured location and time data on the places where the patient regularly goes. ^ Survey results indicate that for this patient population, geography plays a role in their choice of health care provider, but it is not the most important reason for choosing a provider. Other factors for choosing a health care provider such as the provider offering "free or low cost visits", meeting "all of the patient's health care needs", and seeing "the patient quickly" were all ranked higher than geographic reasons. ^ Analysis of the patient activity locations shows that activity spaces can be used to create service areas for a single primary care provider. Weighted activity-space-based service areas have the potential to include more patients in the service area since more than one location per patient is used. Further analysis of the logs shows that a reduced set of locations by time and type could be used for this methodology, facilitating ongoing data collection for activity-space-based planning efforts. ^

Relative phase shift and oscillation observations at moorings in the Filchner Depression area

Properties of the dense ice shelf water plume emerging from the Filchner Depression in the southwestern Weddell Sea are described, using available current meter records and CTD stations. A mean hydrography, based on more than 300 CTD stations gathered over 25 yr points to a cold, relatively thin and vertically well-defined plume east of the two ridges cross-cutting the continental slope about 60 km from the Filchner sill, whereas the dense bottom layer is warmer, more stratified and much thicker west of these ridges. The data partly confirm the three major pathways suggested earlier and agree with recent theories on topographic steering by submarine ridges. A surprisingly high mesoscale variability in the overflow region is documented and discussed. The variability is to a large extent due to three distinct oscillations (with periods of about 35 h, 3 and 6 d) seen in both temperature and velocity records on the slope. The oscillations are episodic, barotropic and have a horizontal scale of ~20-40 km across the slope. They are partly geographically separated, with the longer period being stronger on the lower part of the slope and the shorter on the upper part of the slope. Energy levels are lower west of the ridges, and in the Filchner Depression. The observations are discussed in relation to existing theories on eddies, commonly generated in plumes, and continental shelf waves.