Multi-institutional quantitative evaluation and clinical validation of Smart Probabilistic Image Contouring Engine (SPICE) autosegmentation of target structures and normal tissues on computer tomography images in the head and neck, thorax, liver, and male pelvis areas.

PURPOSE: Clinical validation and quantitative evaluation of computed tomography (CT) image autosegmentation using Smart Probabilistic Image Contouring Engine (SPICE). METHODS AND MATERIALS: CT images of 125 treated patients (32 head and neck [HN], 40 thorax, 23 liver, and 30 prostate) in 7 independent institutions were autosegmented using SPICE and computational times were recorded. The number of structures autocontoured were 25 for the HN, 7 for the thorax, 3 for the liver, and 6 for the male pelvis regions. Using the clinical contours as reference, autocontours of 22 selected structures were quantitatively evaluated using Dice Similarity Coefficient (DSC) and Mean Slice-wise Hausdorff Distance (MSHD). All 40 autocontours were evaluated by a radiation oncologist from the institution that treated the patients. RESULTS: The mean computational times to autosegment all the structures using SPICE were 3.1 to 11.1 minutes per patient. For the HN region, the mean DSC was >0.70 for all evaluated structures, and the MSHD ranged from 3.2 to 10.0 mm. For the thorax region, the mean DSC was 0.95 for the lungs and 0.90 for the heart, and the MSHD ranged from 2.8 to 12.8 mm. For the liver region, the mean DSC was >0.92 for all structures, and the MSHD ranged from 5.2 to 15.9 mm. For the male pelvis region, the mean DSC was >0.76 for all structures, and the MSHD ranged from 4.8 to 10.5 mm. Out of the 40 autocontoured structures reviews by experts, 25 were scored useful as autocontoured or with minor edits for at least 90% of the patients and 33 were scored useful autocontoured or with minor edits for at least 80% of the patients. CONCLUSIONS: Compared with manual contouring, autosegmentation using SPICE for the HN, thorax, liver, and male pelvis regions is efficient and shows significant promise for clinical utility.

Inferior vena cava filters for recurrent thrombosis: current evidence.

Inferior vena cava filters are often used as alternatives to anticoagulant therapy for the prevention of pulmonary embolism. Many of the clinical data that support the use of these devices stem from relatively limited retrospective studies. The dual purpose of this review is to examine the incidence of thrombotic complications associated with inferior vena cava filters and to discuss the role of anticoagulant therapy concurrent with filter placement. Device-associated morbidity and overall efficacy can be considered only in the context of rates of vena cava thrombosis, insertion-site thrombosis, recurrent deep venous thrombosis, and recurrent pulmonary embolism.

Fractures of the proximal femur: correlates of radiological evidence of osteoporosis.

OBJECTIVE: Fractures of the proximal femur are common sequelae of osteoporosis, and are responsible for significant morbidity and mortality in elderly patients worldwide. Plain film radiographic assessment methods to assess for fracture risk may be of particular value. DESIGN AND PATIENTS: The authors present the results of biomechanical testing, radiographic imaging, and histologic exam of 20 embalmed human bone specimens, with implications for clinical correlation of radiologic findings. Authors assessed bone architecture using the Singh Index, using a blinded 3-rater system to reduce bias and measure intra-observer reliability. After loading to failure with ultimate tensile strength (UTS), bone specimens were assessed by fracture location type and by trabecular bone volume (TBV). RESULTS: Singh scoring was performed with Inter-Class Correlation of 0.80 (F=0.24, by ICC Portney Model 2). A statistically-significant difference among the UTS distributions was noted for UTS by Fracture Site (F=4.49, p=0.026, by ANOVA). No significant association of Singh Index with TBV, or TBV with UTS, was observed, although a trend toward greater UTS with higher Singh grade was observed. CONCLUSIONS: The authors propose that the Singh Index is a valuable and reliable indicator which may reflect structural integrity in trabecular bone. Fracture site along the femur is associated with tensile strength. The authors, in the light of these findings, address the promise and potential impact of prophylactic hip augmentation in populations at risk for femoral neck pathology.

Present and future challenges in medical data management: economics, ethics, and the law.

Electronically-linked knowledge plays an increasingly central role in the delivery of health services worldwide. Medical data collection, archival, and analysis are all increasing in both rate and volume; large, cohesive collections of personal health information are emerging rapidly. Factors driving this integration include value-added methods of diagnosis and therapy, interest in evidence-based practices, safety concerns, and increased consumer demand for personalized, comprehensive medical services. Practitioners, businesses, patients, and the public at large would be well-served to develop and sustain a dialogue addressing these phenomena, including assessments their of economic, ethical, legal implications.

Characterization of N200 and P300: selected studies of the Event-Related Potential.

The Event-Related Potential (ERP) is a time-locked measure of electrical activity of the cerebral surface representing a distinct phase of cortical processing. Two components of the ERP which bear special importance to stimulus evaluation, selective attention, and conscious discrimination in humans are the P300 positivity and N200 negativity, appearing 300 ms and 200 ms post-stimulus, respectively. With the rapid proliferation of high-density EEG methods, and interdisciplinary interest in its application as a prognostic, diagnostic, and investigative tool, an understanding of the underpinnings of P300 and N200 physiology may support its application to both the basic neuroscience and clinical medical settings. The authors present a synthesis of current understanding of these two deflections in both normal and pathological states.

Camellia sinensis: historical perspectives and future prospects.

As the source of brewed tea preparations, Camellia sinensis has operated for centuries at the interface of agriculture, politics, and biology. The purpose of this review is to present an inter-disciplinary survey of issues surrounding cultivation, processing, and consumption of the tea plant. Particular attention is given to the biologic effects of tea: first, assessing at the level of human physiology its value as a chemopreventive and chemotherapeutic agent; second, examining effects of production upon local ecosystems, due to resource demands and industrial farming practices. In sum, C. sinensis emerges as a potentially powerful contributor to both public health and economic growth if its role is managed from a prospective, sustainable, and evidence-based vantage.

Pain encoding in the human forebrain: binary and analog exteroceptive channels.

The neuronal system signaling pain has often been characterized as a labeled line consisting of neurons in the pain-signaling pathway to the brain [spinothalamic tract (STT)] that respond only to painful stimuli. It has been proposed recently that the STT contains a series of analog labeled lines, each signaling a different aspect of the internal state of the body (interoception) (e.g., visceral-cold-itch sensations). In this view, pain is the unpleasant emotion produced by disequilibrium of the internal state. We now show that stimulation of an STT receiving zone in awake humans (66 patients) produces two different responses. The first is a binary response signaling the presence of painful stimuli. The second is an analog response in which nonpainful and painful sensations are graded with intensity of the stimulus. Compared with the second pathway, the first was characterized by higher pain ratings and stimulus-evoked sensations covering more of the body surface (projected fields). Both painful responses to stimulation were described in terms usually applied to external stimuli (exteroception) rather than to internal or emotional phenomena, which were infrequently evoked by stimulation of either pathway. These results are consistent with those of functional imaging studies that have identified brain regions activated in a binary manner by the application of a specific, painful stimulus while increases in stimulus intensity do not produce increased activation. Such binary pain functions could be involved in pain-related alarm-alerting functions, which are independent of stimulus amplitude.

Impact of instructed relevance on the visual ERP.

Event-related potentials have been used to study the distinction between attention to novelty and effortful orienting to task-relevant items. However, effects due to stimulus frequency, response production, and instructed task-relevance have not been fully separated. The current study used a visual oddball design in which two stimuli were presented, one frequently (P = 0.8) and one infrequently (P = 0.2). Subjects (n = 21) participated in 4 blocks, two in which the infrequent stimulus was the instructed target and two in which the frequent stimulus was the instructed target. This was crossed with two blocks in which subjects were instructed to respond to the targets with a keypress and two blocks in which subjects were instructed to press a key to the ignored non-targets and respond to the targets by withholding a keypress. The results showed N1 effects for instruction, suggesting enhancement due to an attentional set established prior to stimulus delivery, and for frequency, suggesting orienting to the infrequent stimuli. A prefrontal positivity (P2a) was enhanced to instructed targets, but instruction only entered as an interactive factor on the posterior N2 at the same latency, suggesting interaction between frontal areas of evaluation and posterior areas of perceptual representation in identification of task-relevant stimuli. The P300 was enhanced to the infrequent stimuli, but there was no main effect for target instruction, although instruction did impact a higher-order interaction.

Serum prostate-specific antigen screening for prostate cancer: application of current evidence to model criteria.

Prostatic carcinoma, particularly in younger men, carries a significant possibility of morbidity and mortality, although authoritative diagnosis and treatment itself is not without associated risks. Controversy still looms with respect to the actual implementation of routine serum prostate-specific antigen (PSA) screening for the general public. A brief summary of indications for screening programmes is presented, and these concepts are applied specifically to the body of research surrounding prostate cancer screening with PSA testing. Due to the slowly-progressive natural history of prostate cancer and the high morbidity associated with confirmation biopsy and definitive treatment, periodic general screening with insensitive and nonspecific PSA secrum testing emerges as an inefficient allocation of health care capital. The possible effectiveness of targeted screening practices for selected high-risk individuals, however, is considered.

Unusual migration of the distal catheter of a ventriculoperitoneal shunt into the heart: case report.

OBJECTIVE AND IMPORTANCE: Placement of a ventriculoperitoneal (VP) shunt is the most common form of treatment for hydrocephalus. Thoracic complications with VP shunts are rare, but we present the second documented case of the distal migration of the distal catheter of a VP shunt into the heart. CLINICAL PRESENTATION: A 14-year-old boy, who underwent placement of a right occipital VP shunt at another institution after closed-head injury, presented with hypertension. Plain chest x-rays and computed tomography revealed the distal catheter to be in the right ventricle of the heart. INTERVENTION: A joint surgical procedure was performed with the cardiac surgery team. The cardiac surgeons created a pericardial window through a subxyphoid incision. Simultaneously, a right occipital incision was made to access the distal catheter, which was then slowly pulled out with the pericardium under direct visualization. No hemorrhage or change in the pericardium was observed, and, therefore, the need for a thoracotomy was eliminated. A new distal catheter was placed into the peritoneal cavity. CONCLUSION: The migration of the distal catheter probably occurred during the initial VP shunt placement. The internal jugular vein probably was perforated by the tunneler during the creation of the distal catheter tract. Slow venous flow and negative inspiratory pressure may have gradually pulled the catheter up into the right atria and ventricle. As demonstrated by our case report, the catheter can be extracted safely in a joint procedure with cardiac surgeons, and a thoracotomy is not always necessary. The patient did not experience postoperative complications, and his hypertension was alleviated.