Demonstration of a Human Color Vision Mimic in the Infrared.

Color vision results from the interaction of retinal photopigments with reflected or transmitted visible light. The International Commission on Illumination (CIE) developed the CIE color-matching chart, which separates colors on the basis of the interaction of their spectral profiles with three retinal photopigments in the human eye. We report the development of an infrared chromaticity (CIE-IR) chart, which mimics the CIE chart, in order to discriminate between different chemicals on the basis of the interactions of their IR signatures with three different IR optical filters, instead of the retinal photopigments in the human eye. Our results demonstrate that the CIE-IR chart enables separation of different classes of chemicals, as the visible CIE chart does with color, except for those in the IR spectral region. Such results clearly show that the biomimetic sensing method based on human color vision is in fact a true analogue to color vision and that the proposed CIE-IR chart can be used as a classification method unique to this biomimetic sensing modality.

Analytical procedure to assess the performance characteristics of a non-spectroscopic infrared optical sensor for discrimination of chemical vapors.

An optical-filter-based sensor that was designed to mimic human color vision was recently developed. This sensor uses three mid-infrared optical filters to discriminate between chemicals with similar, strongly overlapping mid-infrared absorption bands. This non-spectroscopic technique requires no spectral scanning. This paper defines the selectivity and specificity of this biomimetic sensor. Receiver operating characteristic curves are presented for each target chemical. These results demonstrate that the sensor is highly selective and can provide discrimination with no false positives for three similar target chemicals-acetone, hexane, and fuel oil-while rejecting potential interferents.

Biomimetic Optical-Filter Detection System for Discrimination of Infrared Chemical Signatures.

Optical-filter-based chemical sensors have the potential to dramatically alter the field of hazardous materials sensing. Such devices could be constructed using inexpensive components, in a small and lightweight package, for sensing hazardous chemicals in defense, industrial, and environmental applications. Filter-based sensors can be designed to mimic human color vision. Recent developments in this field have used this approach to discriminate between strongly overlapping chemical signatures in the mid-infrared. Reported work relied on using numerically filtered FTIR spectra to model the infrared biomimetic detection methodology. While these findings are encouraging, further advancement of this technique requires the collection and evaluation of directly filtered data, using an optical system without extensive numerical spectral analysis. The present work describes the design and testing of an infrared optical breadboard system that uses the biomimetic mammalian color-detection approach to chemical sensing. The set of chemicals tested includes one target chemical, fuel oil, along with two strongly overlapping interferents, acetone and hexane. The collected experimental results are compared with numerically filtered FTIR spectral data. The results show good agreement between the numerically filtered data model and the data collected using the optical breadboard system. It is shown that the optical breadboard system is operating as expected based on modeling and can be used for sensing and discriminating between chemicals with strongly overlapping absorption bands in the mid-infrared.

Optical filter selection for high confidence discrimination of strongly overlapping infrared chemical spectra.

Optical filter-based chemical sensing techniques provide a new avenue to develop low-cost infrared sensors. These methods utilize multiple infrared optical filters to selectively measure different response functions for various chemicals, dependent on each chemical's infrared absorption. Rather than identifying distinct spectral features, which can then be used to determine the identity of a target chemical, optical filter-based approaches rely on measuring differences in the ensemble response between a given filter set and specific chemicals of interest. Therefore, the results of such methods are highly dependent on the original optical filter choice, which will dictate the selectivity, sensitivity, and stability of any filter-based sensing method. Recently, a method has been developed that utilizes unique detection vector operations defined by optical multifilter responses, to discriminate between volatile chemical vapors. This method, comparative-discrimination spectral detection (CDSD), is a technique which employs broadband optical filters to selectively discriminate between chemicals with highly overlapping infrared absorption spectra. CDSD has been shown to correctly distinguish between similar chemicals in the carbon-hydrogen stretch region of the infrared absorption spectra from 2800-3100 cm(-1). A key challenge to this approach is how to determine which optical filter sets should be utilized to achieve the greatest discrimination between target chemicals. Previous studies used empirical approaches to select the optical filter set; however this is insufficient to determine the optimum selectivity between strongly overlapping chemical spectra. Here we present a numerical approach to systematically study the effects of filter positioning and bandwidth on a number of three-chemical systems. We describe how both the filter properties, as well as the chemicals in each set, affect the CDSD results and subsequent discrimination. These results demonstrate the importance of choosing the proper filter set and chemicals for comparative discrimination, in order to identify the target chemical of interest in the presence of closely matched chemical interferents. These findings are an integral step in the development of experimental prototype sensors, which will utilize CDSD.

Measurement of the Optical Constants of Sand Samples Using Ellipsometry on Sand-Adhesive Composites.

In order to model the propagation of light through a sand cloud, it is critical to have accurate data for the optical constants of the sand particles that comprise it. The same holds true for modeling propagation through particles of any type suspended in a medium. Few methods exist, however, to measure these quantities with high accuracy. In this paper, a characterization method based on spectroscopic ellipsometry (SE) that can be applied to a particulate material is presented. In this method, a polished disc of an adhesive compound is prepared, and its optical constants are measured. Next, a mixture of the adhesive and a sand sample is prepared and processed into a polished disc, and SE is performed. By treating the mixture as a Bruggeman effective medium, the optical constants of the particulate material are extracted. For verification of the proposed method, it is first applied to pure silica powder, demonstrating good agreement between measured optical constants and literature values. It is then applied to Arizona road dust, a standard reference material, as well as real desert sand samples. The resulting optical constant data is input into a rigorous scattering model to predict extinction coefficients for various types of sand. Modeling results are compared to spectroscopic measurements on static sand samples, demonstrating good agreement between predicted and measured spectral properties including the presence of a Christiansen feature near a wavelength of 8 µm.

Spectral Considerations for Standoff Infrared Detection of RDX on Reflective Aluminum.

This paper examines infrared spectroscopic effects for the standoff detection of an explosive material, hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), inkjet printed on an aluminum surface. Results of a spectroscopic study are described, using multiple optical setups. These setups were selected to explore how variations in the angles of incidence and collection from the surface of the material result in corresponding variations in the spectral signatures. The goal of these studies is to provide an understanding of these spectral changes since it affects standoff detection of hazardous materials on a reflective substrate. We demonstrate that variations in spectral effects are dependent on the relative surface concentration of the deposited RDX. We also show that it is reasonable to use spectroscopic data collected in a standard laboratory infrared spectrometer outfitted with a variable angle reflectometer set at 0° as reference spectra for data collected in a standoff configuration. These results are important to provide a systematic approach to understanding infrared (IR) spectra collection using standoff systems in the field, and to allow for comparison between such data, and data collected in the laboratory. Although the precise results are constrained to a specific material system (thin layers on a reflective substrate), the approach and general discussion provided are applicable to a broad range of IR standoff sensing techniques and applications.

Vertebral artery ostium atherosclerotic plaque as a potential source of posterior circulation ischemic stroke: result from borgess medical center vertebral artery ostium stenting registry.

BACKGROUND AND PURPOSE: Although atherosclerotic plaque in the carotid and coronary arteries is accepted as a cause of ischemia, vertebral artery ostium (VAO) atherosclerotic plaque is not widely recognized as a source of ischemic stroke. We seek to demonstrate its implication in some posterior circulation ischemia. METHODS: This is a nonrandomized, prospective, single-center registry on consecutive patients presenting with posterior circulation ischemia who underwent VAO stenting for significant atherosclerotic stenosis. Diagnostic evaluation and imaging studies determined the likelihood of this lesion as the symptom source (highly likely, probable, or highly unlikely). Patients were divided into 4 groups in decreasing order of severity of clinical presentation (ischemic stroke, TIA then stroke, TIA, asymptomatic), which were compared with the morphological and hemodynamic characteristics of the VAO plaque. Clinical follow-up 1 year after stenting assessed symptom recurrence. RESULTS: One hundred fourteen patients underwent stenting of 127 lesions; 35% of the lesions were highly likely the source of symptoms, 53% were probable, and 12% were highly unlikely. Clinical presentation correlated directly with plaque irregularity and presence of clot at the VAO, as did bilateral lesions and presence of tandem lesions. Symptom recurrence at 1 year was 2%. CONCLUSIONS: Thirty-five percent of the lesions were highly likely the source of the symptoms. A direct relationship between some morphological/hemodynamic characteristics and the severity of clinical presentation was also found. Finally, patients had a very low rate of symptom recurrence after treatment. These 3 observations point strongly to VAO plaque as a potential source of some posterior circulation stroke.

Behavior of the Reststrahlen Band in the 17-25 µm Spectral Region in the Diffuse Reflection Spectra of Sand and Silt Mixtures.

Studies on the reflectance spectra of different mixtures of sand and silt were performed in the infrared spectral region of 7-25 µm to explore the behavior of a second reststrahlen band occurring between 17 and 25 µm with respect to different mixtures of sand and silt. The reflectance spectrum of all samples exhibited reststrahlen bands within both the long wavelength infrared (LWIR) and the very long wavelength infrared (VLWIR) regions of the reflectance spectrum. Results demonstrate that both LWIR and VLWIR reststrahlen bands increase in area as the fraction of sand increases to 80%. More importantly, the data demonstrate that the VLWIR reststrahlen band, like that in LWIR, exhibits a significant and reproducible decrease in reflectivity for mixed soil versus weathered soil.

Infrared Reflectance Spectroscopic Evaluation of Inkjet Printed Standards of Cyclotrimethylenetrinitramine (RDX) on Aluminum Substrates.

The Department of Defense (DOD) and first responder communities are evaluating and developing optical systems for the detection and identification of explosives and components used for assembling homemade explosives (HMEs). Emerging detection technologies must be evaluated with authentic hazard material concentrations to ensure their accurate and reliable use in the field. In this work, infrared (IR) reflectance spectra over the spectral rage of 1000-1700 cm-1 were collected for different concentrations of inkjet-printed RDX (cyclotrimethylenetrinitramine) samples deposited onto aluminum substrates. A plot of the integrated area of both the symmetric and asymmetric NO2 vibrational bands for RDX on aluminum exhibited good linearity over the concentration range 20-500 µg/cm2. Detection limits for RDX on an aluminum surface were calculated to be 10.7 µg/cm2 for the symmetric NO2 vibrational band and 1.4 µg/cm2 for the asymmetric NO2 vibrational band. Evaluation of the NO2 vibrational band areas at different locations of the RDX array demonstrated that the samples exhibited good homogeneity across the surface. The concentration of an unknown sample of RDX on aluminum was determined using the fitted equations; results showed good agreement between the calculated and actual RDX surface concentration. The lot-to-lot variation of RDX on the aluminum surface was compared using the long wavelength infrared (LWIR) spectral band areas for two different lots of standards printed at the same RDX surface concentration. Results showed excellent lot-to-lot agreement indicating good reproducibility of the standards for RDX.

Discrimination Between Explosive Materials and Isomers Using a Human Color Vision-Inspired Sensing Method.

This paper describes the application of a human color vision approach to infrared (IR) chemical sensing for the discrimination between multiple explosive materials deposited on aluminum substrates. This methodology classifies chemicals using the unique response of the chemical vibrational absorption bands to three broadband overlapping IR optical filters. For this effort, Fourier transform infrared (FT-IR) spectroscopy is first used to computationally examine the ability of the human color vision sensing approach to discriminate between three similar explosive materials, 1,3,5,-Trinitro-1,3,5-triazinane (RDX), 2,2-Bis[(nitrooxy)methyl]propane-1,3,-diyldinitrate (PETN), and 1,3,5,7-Tetranitro-1,3,5,7-tetrazocane (HMX). A description of a laboratory breadboard optical sensor designed for this approach is then provided, along with the discrimination results collected for these samples using this sensor. The results of these studies demonstrate that the human color vision approach is capable of high-confidence discrimination of the examined explosive materials.

Laparotomy for visceral ischemia and gangrene.

In the six centuries since mesenteric ischemia was first described, multiple factors have been investigated as predictors of bowel viability with little consensus. We retrospectively examined all cases of exploratory laparotomy for suspected bowel ischemia over an 8.5-year period. Patients were grouped into those who had a "positive laparotomy" with findings of bowel ischemia, bowel gangrene, or both (PL) and those who had a "negative laparotomy" with no evidence of compromised bowel (NL). Of the 114 patients, 86 (75%) were in the PL group and 28 (25%) in the NL group. The significant differences between the two groups were the higher prevalence of females in the PL group versus the NL group [71% vs. 50% (P = 0.04)] and the younger age in the NL group versus the PL group [64 +/- 19 vs. 76 +/- 14 (P = 0.0002)]. The groups did not significantly differ with respect to preoperative comorbidities and results of laboratory studies. Two patients in NL group had pneumatosis intestinalis on abdominal CT. One patient in PL group had a negative visceral angiogram. There was no difference in mortality between the groups. No single preoperative study reliably predicted positive findings at laparotomy in our series.

Current trends in the management of iatrogenic cervical carotid artery injuries.

This study was undertaken to elicit the opinion of experts regarding the management of iatrogenic injury to the carotid artery. A text questionnaire was transmitted by electronic mail to members of the Western Vascular Society concerning management of iatrogenic injury to the cervical carotid artery. Participants were asked to submit information regarding practice status and their preferred choices for the management of different clinical scenarios. The scenarios were: (1) large bore sheath (> 8.5F) cannulation of the carotid artery in anesthetized patients, (2) large bore sheath cannulation of the carotid artery in an awake patient, (3) delayed recognition of a misplaced sheath by > 4 hours, and (4) arterial puncture was recognized after only the entry needle (16-gauge) was introduced but before sheath insertion. Finally, the members were asked to comment on the management of abnormal findings on duplex scanning, such as intimal flap or pseudoaneurysm. A response rate of 42% was obtained (45/106 active members). Eighty-two percent of respondents had been in practice for longer than 10 years. Eighty-nine percent had seen this complication and 29% had cared for patients in whom subsequent neurologic deficit developed. The institutional incidence of such injury was 1-5 cases per year for 82% of respondents. Sixteen-gauge needle injury was managed by immediate removal and applied pressure by 98% of respondents. When large-bore sheath injury is recognized within 1 hour of insertion, 62% of respondents would remove the sheath and hold pressure, with or without obtaining a duplex ultrasound examination. However, if injury recognition was delayed for > 4 hours, 82% would proceed to surgery. Only 26% operated on asymptomatic carotid flap found on ultrasound, while the remaining 74% would base their decision on size and flow characteristics on ultrasound. The management of pseudoaneurysm differed significantly. Whereas 31% of respondents would manage this finding expectantly, 69% would proceed to surgery regardless of size or symptoms. Despite awareness of iatrogenic injury to the cervical carotid artery, the institutional incidence remains high. Two thirds of respondents would manage a misplaced sheath in the carotid artery nonoperatively if the injury was recognized immediately. However, if injury recognition was delayed for > 4 hours, the majority of respondents would remove the sheath surgically. While the management of intimal flap largely depended on size and flow characteristics, 69% of respondents would operate on a pseudoaneurysm regardless of size or symptoms. The results of this survey may serve as a guideline for the management of this potentially devastating injury.

Attitudes regarding surgeons' attire.

BACKGROUND: No studies to date exist regarding the attire of physicians on a surgical service. The objective of this study was to determine patient, surgeon, and nonhospitalized public (NHP) attitudes and preferences regarding surgeons' attire and mannerisms. METHODS: A questionnaire was developed to survey each group. The Internet was used as a novel avenue to survey the NHP. Eight questions were presented to each group, and each question had three possible responses: agree, disagree, or no opinion. Total responses and percentages were determined for each group's answers, and statistical analysis was performed using chi-square test. RESULTS: Thirty-eight surgical inpatients, 38 surgeons, and 334 NHP participated in the study. All groups agreed that surgeons should wear nametags while they are seeing patients. Inpatients agreed with surgeons that surgeons should wear white coats while seeing patients (P > .05). Surgeons considered scrubs and clogs to be acceptable attire, which differed from all other groups (P < .05). Although 31% of the NHP considered blue jeans acceptable, only 10% of surgeons (P < .05) and 22% of patients (P > .05) considered them acceptable. All groups believed that a surgeon's appearance influences their perceptions and impressions regarding the quality of medical care they received (P < .05). CONCLUSIONS: Based on the agreement of all groups that a surgeon's appearance and mannerisms affects perceptions of the quality of medical care received, surgeons should respond to these perceptions and dress accordingly while seeing surgical patients.

Comparative discrimination spectral detection method for the identification of vapors using overlapping broad spectral filters.

We present a comparative discrimination spectral detection approach for the identification of chemical vapors using broad spectral filters. We applied the method to flowing vapors of as-received and non-interacting mixtures for the detection of the volatile components of a target chemical in the presence of interferents. The method is based on measurements of the overall spectral signature of the vapors, where the interferent spectrum largely overlaps the target spectrum. In this work we outline the construction of a set of abstract configuration-space vectors, generated by the broadband spectral components from sampled chemical vapors, and the subsequent vector-space operations between them, which enable the detection of a target chemical by comparative discrimination from interferents. The method was applied to the C-H vibrational band from 2500 to 3500 cm(-1), where there is large spectral signal overlap between the chosen target chemical and two interferents. Our results show clear detection and distinction of the target vapors without ambiguity.

Outcome of elderly patients with appendicitis: effect of computed tomography and laparoscopy.

HYPOTHESIS: Elderly patients who have appendicitis have a greater morbidity and mortality rate when compared with younger patients. We hypothesized that recent changes in the diagnosis and management of appendicitis in elderly patients might affect the outcome. DESIGN: Retrospective review. SETTING: Large metropolitan teaching hospital. PATIENTS: All patients aged 70 years and older who underwent appendectomy for appendicitis between January 1, 1991, and December 31, 2000, were divided into groups 1 (those treated from January 1, 1991, through December 31, 1995) and 2 (those treated from January 1, 1996, through December 31, 2000). MAIN OUTCOME MEASURES: Age, sex, preoperative evaluation, operative duration and findings, postoperative course, duration of hospital stay, and mortality rate. Continuous and categorical variables were analyzed using t and chi(2) tests, respectively. RESULTS: Ninety-five patients met inclusionary criteria. The mean age (78 years), sex, preoperative suggestion of appendicitis (group 1, 39 [83%] of 47 patients; group 2, 45 [94%] of 48 patients), and duration of the preoperative hospitalization over 24 hours (group 1, 11 patients [23%]; group 2, 9 patients [19%]) were similar in both groups. There was an increasing use of diagnostic computed tomography (group 1, 13 patients [28%]; group 2, 32 patients [67%]; P<.001) and laparoscopy (group 1, 14 patients [30%]; group 2, 23 patients [48%]; P =.02) between the 2 study periods associated with no significant difference in the duration of hospitalization, frequency of appendiceal perforation or abscess, occurrence of complications, or mortality. The length of operating time increased in the second period (ie, January 1, 1996, through December 31, 2000). CONCLUSIONS: Appendicitis in elderly patients continues to be a challenging surgical problem. While computed tomography may represent a useful diagnostic tool and laparoscopic appendectomy may be appropriate therapy for selected patients, neither has affected outcome when measured for morbidity and mortality rates. Overall results might improve with earlier consideration of the diagnosis in elderly patients with abdominal pain, followed by prompt surgical consultation and operation.

Objective indications for early tracheostomy after blunt head trauma.

BACKGROUND: Early tracheostomy has been shown to be beneficial after trauma; however, there are few objective data to identify early in the recovery period which patients will ultimately require tracheostomy after blunt head trauma. METHODS: The charts of all patients admitted to the surgical intensive care unit intubated at a level 1 urban trauma center, over a 5-year period with a primary admission diagnosis of blunt head trauma were retrospectively reviewed. RESULTS: Sixty-four patients met inclusion and exclusion criteria and were divided into two groups: those extubated and those that required tracheostomy. By day 3 the Glasgow Coma Scores for the two groups were significantly different and on day 4 the Simplified Acute Physiology (SAPS) Scores were significantly different. CONCLUSIONS: Calculating objective scores such as GCS and SAPS can aid in identifying those patients who will ultimately require a tracheostomy for prolonged airway protection after blunt head trauma with high positive predictive value.

Wireless clinical alerts and patient outcomes in the surgical intensive care unit.

Errors in medicine have gained public interest since the Institute of Medicine published its 1999 report on this subject. Although errors of commission are frequently cited, errors of omission can be equally serious. A computerized surgical intensive care unit (SICU) information system when coupled to an event-driven alerting engine has the potential to reduce errors of omission for critical intensive care unit events. Automated alerts and patient outcomes were prospectively collected for all patients admitted to a tertiary-care SICU for a 2-year period. During the study period 3,973 patients were admitted to the SICU and received 13,608 days of care. A total of 15,066 alert pages were sent including alerts for physiologic condition (6,163), laboratory data (4,951), blood gas (3,774), drug allergy (130), and toxic drug levels (48). Admission Simplified Acute Physiology Score and Acute Physiology and Chronic Health Evaluation II score, SICU lengths of stay, and overall mortality rates were significantly higher in patients who triggered the alerting system. Patients triggering the alert paging system were 49.4 times more likely to die in the SICU compared with patients who did not generate an alert. Even after transfer to floor care the patients who triggered the alerting system were 5.7 times more likely to die in the hospital. An alert page identifies patients who will stay in the SICU longer and have a significantly higher chance of death compared with patients who do not trigger the alerting system.

The value of laparoscopy in management of abdominal trauma.

The role of laparoscopy (LS) in abdominal trauma is controversial. Concerns remain regarding missed injuries and safety. Our objective for this study was to determine the safety and better define the role of LS in abdominal trauma victims. We performed a retrospective review of all patients who sustained abdominal trauma and underwent LS in a level I trauma center. The main outcome measures were age, gender, mechanism of injury (MOI), indication for laparoscopy, presence of intra-abdominal injury (IA), therapeutic laparoscopy (TxLS), need for laparotomy, length of hospital stay (LOS), missed injuries, complications, and deaths. Forty-eight patients underwent LS (62 per cent male; average age, 28 years; MOI, 35 (85%) penetrating, 7 (15%) blunt; mean ISS, 8). At laparoscopy, 58 per cent of patients had no intra-abdominal injury. IA injury was treated with laparotomy in 14 (29%) and TxLS in 6 (13%). One patient had a negative laparotomy (2%). No injuries were missed. No patients required reoperation. There was one complication: a pneumothorax. There were no deaths. LS was most valuable in penetrating trauma, avoiding laparotomy in more than two-thirds of patients with suspected intra-abdominal injury. LS can serve as a useful adjunct for the evaluation of blunt trauma. In a level I trauma center with LS readily available, the procedure is associated with a low rate of complications and missed injury.

The incidence of thromboembolism in the surgical intensive care unit.

The clinical diagnosis of deep venous thrombosis (DVT) is unreliable. Studies have been performed examining the utility of frequent duplex scans. However, these studies included patients outside of the intensive care unit. The incidence of venous thromboembolism and the effect of a less intense surveillance protocol was prospectively examined at a level-1 urban trauma center for a 6 month period. During the study period there were 726 admission to the surgical intensive care unit. Sequential compression devices (SCDs) were used for DVT prophylaxis in 93 per cent of the admissions. A total of 114 duplex scans were ordered: 42 per cent for surveillance and the rest for evaluation of a clinical indication. Twelve DVTs were discovered (11% overall DVT rate). No patient on subcutaneous heparin or low-molecular-weight heparin developed a DVT or pulmonary embolism (PE). Four patients suffered a PE; however, none were found to have a lower extremity DVT on duplex ultrasound and all received SCD prophylaxis. Overall, proper use of DVT prophylaxis for intensive care unit days 1-14 was 77 per cent. The incidence of venous thromboembolism in a group of patients at overall high risk was low. A program of DVT surveillance with duplex ultrasound was not cost-effective.

The capillary index score: rethinking the acute ischemic stroke treatment algorithm. Results from the Borgess Medical Center Acute Ischemic Stroke Registry.

BACKGROUND: Despite increased recanalization rates in the treatment of acute ischemic stroke, the percentage of patients with a good clinical outcome of all those treated has not risen above 50%. This 50% barrier may be broken by improving the criteria for treatment selection. This study investigated the addition of the capillary index score (CIS), a new index for assessing remaining viable tissue in the ischemic area, to the existing criteria. METHODS: The Borgess Medical Center Ischemic Stroke Registry is a non-randomized single-center single-operator registry of consecutive subjects admitted for intra-arterial treatment of acute ischemic stroke. The CIS was calculated from a pre-intervention catheter cerebral angiogram in subjects with internal carotid artery (ICA) or middle cerebral artery (MCA) (M1) occlusion. Thrombolysis In Myocardial Infarction (TIMI) 2 or 3 was considered successful recanalization. A modified Rankin Scale (mRS) of 0-2 at 3 months was considered a good outcome. RESULTS: ICA or MCA (M1) occlusion was found in 46 of 58 consecutive patients treated by the same operator. Recanalization was successful in 72% of patients and 27% had a good outcome. CIS was available for 26 patients; 42% were favorable (2 or 3) and 58% were poor (0 or 1). A good outcome was found only in the favorable CIS group (p=0.0148). Successful recanalization (p=0.0029) and time from ictus to revascularization (p=0.0039) predicted a good outcome. Of patients with favorable CIS and TIMI 3, 83% had a good outcome. CONCLUSIONS: Favorable CIS and recanalization were strong predictors of a good outcome. By using this new index as an adjunct to other criteria, the CIS may improve patient selection and help break the 50% barrier.