Myocardial Cut-off Sign is a Sensitive and Specific Cardiac Computed Tomography and Magnetic Resonance Imaging Sign to Distinguish Left Ventricular Pseudoaneurysms From True Aneurysms

PURPOSE

The purpose of this study was to describe the myocardial cut-off sign, assess its ability to distinguish left ventricular pseudoaneurysms (LV PSAs) from true aneurysms (LVAs), and compare its performance with other imaging findings and quantitative measurements used to differentiate LV PSAs from LVAs.

MATERIALS AND METHODS

This retrospective single-center study identified patients with preoperative cardiac computed tomography (CT) or magnetic resonance imaging (MRI) and surgically confirmed LVAs or LV PSAs over a 10-year period. Seventeen LV PSAs (11 MRI, 6 CT) and 18 LVAs (10 MRI, 8 CT) were included. The myocardial cut-off sign was objectively a >50% decrease in aneurysm sac wall thickness measured at 1 cm from the aneurysmal neck (measurements at 2 cm were also assessed) and subjectively an abrupt "cut-off" of myocardium for the aneurysm sac for PSA compared with a gradual tapering of sac wall thickness for LVA. Two radiologists independently evaluated images for the subjective presence of this sign.

RESULTS

The myocardial cut-off sign was 91% sensitive and 97% specific when measured 1 cm from the aneurysm neck. When measured at 2 cm from the neck, the sign was 100% sensitive and 69% specific. Subjective analysis of whether the myocardium appeared "cut-off" was 94% to 100% sensitive and 78% to 94% specific with excellent agreement for both PSA (κ=0.94) and LVA (κ=0.83).

CONCLUSIONS

The myocardial cut-off sign on cardiac CT and MRI is a sensitive and specific finding of LV PSA. Specificity is improved with objective measurements compared with subjective assessment (97% vs. 78% to 94%). This sign may help radiologists distinguish between LV PSAs and LVAs.

Thrombolysis is an Independent Risk Factor for Poor Outcome After Carotid Revascularization

BACKGROUND

Thrombolysis is the standard of care for acute ischemic stroke patients presenting in the appropriate time window. Studies suggest that the risk of recurrent ischemia is lower if carotid revascularization is performed early after the index event. The safety of early carotid revascularization in this patient population is unclear.

OBJECTIVE

To evaluate the safety of carotid revascularization in patients who received thrombolysis for acute ischemic stroke.

METHODS

The Nationwide Inpatient Sample database was queried for patients admitted through the emergency room with a primary diagnosis of carotid stenosis and/or occlusion. Each patient was reviewed for administration of thrombolysis, carotid endarterectomy, (CEA) or carotid angioplasty and stenting (CAS). Primary endpoints were intracerebral hemorrhage (ICH), postprocedural stroke (PPS), poor outcome, and in-hospital mortality. Potential risk factors were examined using univariate and multivariate analyses.

RESULTS

A total of 310 257 patients were analyzed. Patients who received tissue plasminogen activator (tPA) and underwent either CEA or CAS had a significantly higher risk of developing an ICH or PPS than patients who underwent either CEA or CAS without tPA administration. The increased risk of ICH or PPS in tPA-treated patients who underwent carotid revascularization diminished with time, and became similar to patients who underwent carotid revascularization without tPA administration by 7 d after thrombolysis. Patients who received tPA and underwent CEA or CAS also had higher odds of poor outcome and in-hospital mortality.

CONCLUSION

Thrombolysis is a strong risk factor for ICH, PPS, poor outcome, and in-hospital mortality in patients with carotid stenosis/occlusion who undergo carotid revascularization. The increased risk of ICH or PPS due to tPA declines with time after thrombolysis. Delaying carotid revascularization in these patients may therefore be appropriate. This delay, however, will expose these patients to the risk of recurrent stroke. Future studies are needed to determine the relative risks of these 2 adverse events.

Epidemiology of Hepatic Steatosis at a Tertiary Care Center: An MRI-based Analysis

RATIONALE AND OBJECTIVES

Little is known about the frequency and risk factors of hepatic steatosis in the tertiary care setting. Such knowledge is essential to clinicians making decisions about testing for this condition. Thus, our aim was to describe the epidemiology of hepatic steatosis, as captured by magnetic resonance imaging (MRI), at a tertiary care center.

MATERIALS AND METHODS

A near-consecutive cohort of 1006 adult patients underwent standard-of-care liver MRIs. Images were retrospectively processed to derive proton density fat fraction (PDFF) maps. Data from three spatially distinct regions of interest (ROIs) were aggregated to derive overall hepatic PDFF values. Demographic, anthropometric, clinical, and laboratory variables were included in a multivariate analysis to determine predictors of hepatic steatosis grades (based on established PDFF cutoffs). Hepatic steatosis grades derived from single vs aggregated ROIs were compared.

RESULTS

Hepatic steatosis was observed in 25% of patients (19% grade 1; 3% grade 2; 3% grade 3). Controlling for all other variables, the odds of hepatic steatosis increased by 7%-9% (P <.001) for each whole point increase in body mass index (BMI), whereas elevated serum bilirubin was associated with lower odds of hepatic steatosis (P = .002). Race, diabetes mellitus, dyslipidemia, and metabolic syndrome were not independently predictive of hepatic steatosis when controlling for other variables (eg, BMI). Employing single ROIs (rather than three aggregated ROIs) resulted in incorrect steatosis grading in up to 8.0% of patients.

CONCLUSION

Many adult patients undergoing liver MRI at a tertiary care center have hepatic steatosis, with larger BMIs as the only independent predictor of higher grades. This information can be used by clinicians at such centers to make evidence-based decisions about when to test for hepatic steatosis in their patients.

Intravenous tissue-type plasminogen activator therapy is an independent risk factor for symptomatic intracerebral hemorrhage after carotid endarterectomy

BACKGROUND

Carotid endarterectomy (CEA) for symptomatic carotid artery stenosis and intravenous tissue-type plasminogen activator (IV-tPA) for acute ischemic stroke are proven therapies; however, the safety of CEA in stroke patients who recently received IV-tPA has not been established.

OBJECTIVE

To evaluate the safety of CEA in stroke patients who recently received IV-tPA.

METHODS

A retrospective review of patients who underwent CEA for symptomatic carotid artery stenosis was performed. The primary end point was postoperative symptomatic intracerebral hemorrhage (sICH). A univariate analysis of potential risk factors for sICH, including IV-tPA therapy, timing of CEA, degree of stenosis, and stroke severity, was performed. Factors with a value of P < .1 on univariate analysis were tested further.

RESULTS

Among 142 patients, 3 suffered sICH after CEA: 2 of 11 patients treated with IV-tPA (18.2%) and 1 of 131 patients not treated with IV-tPA (0.8%). Both IV-tPA patients suffering sICH underwent CEA within 3 days of tPA administration. On univariate analysis, IV-tPA (P = .02), female sex (P = .09), shorter time between ischemic event and CEA (P = .06), and lower mean arterial pressure during the first 48 hours of admission (P = .08) were identified as risk factors for sICH. On multivariate analysis, IV-tPA was the only significant risk factor (P = .002 by stepwise logistic regression; P = .03 by nominal logistic regression).

CONCLUSION

This study indicates that IV-tPA is an independent risk factor for sICH after CEA. This suggests that CEA should be pursued cautiously in patients who recently received IV-tPA. Early surgery may be associated with an increased risk for sICH.

ABBREVIATIONS

CEA, carotid endarterectomyIV-tPA, intravenous recombinant tissue-type plasminogen activatorMAP, mean arterial pressureNASCET, North American Symptomatic Carotid Endarterectomy TrialNIHSS, National Institutes of Health Stroke ScaleNINDS, National Institute of Neurological Disorders and StrokesICH, symptomatic intracerebral hemorrhageTIA, transient ischemic attack.

Borden-Shucart Type I dural arteriovenous fistulas: clinical course including risk of conversion to higher-grade fistulas

Object

The goal of this study was to determine the clinical course of Borden-Shucart Type I cranial dural arteriovenous fistulas (DAVFs) and to calculate the annual rate of conversion of these lesions to more aggressive fistulas that have cortical venous drainage (CVD).

Methods

A retrospective chart review was conducted of all patients harboring DAVFs who were seen at the authors' institution between 1997 and 2009. Twenty-three patients with Type I DAVFs who had available clinical follow-up were identified. Angiographic and clinical data from these patients were reviewed. Neurological outcome and status of presenting symptoms were assessed during long-term follow-up.

Results

Of the 23 patients, 13 underwent endovascular treatment for intolerable tinnitus or ophthalmological symptoms, and 10 did not undergo treatment. Three untreated patients died of unrelated causes. In those who were treated, complete DAVF obliteration was achieved in 4 patients, and palliative reduction in DAVF flow was achieved in 9 patients. Of the 19 patients without radiographic cure, no patient developed intracranial hemorrhage or nonhemorrhagic neurological deficits (NHNDs), and no patient died of DAVF-related causes over a mean follow-up of 5.6 years. One patient experienced a spontaneous, asymptomatic obliteration of a partially treated DAVF in late follow-up, and 2 patients experienced a symptomatic conversion of their DAVF to a higher-grade fistula with CVD in late follow-up. The annual rate of conversion to a higher-grade DAVF based on Kaplan-Meier cumulative event-free survival analysis was 1.0%. The annual rate of intracranial hemorrhage, NHND, and DAVF-related death was 0.0%.

Conclusions

A small number of Type I DAVFs will convert to more aggressive DAVFs with CVD over time. This conversion to a higher-grade DAVF is typically heralded by a change in patient symptoms. Follow-up vascular imaging is important, particularly in the setting of recurrent or new symptoms.

Renal measurements on CT angiograms: correlation with graft function at living donor renal transplantation

PURPOSE

To determine which measurement of donor renal size on computed tomographic (CT) angiograms has the greatest correlation with renal function preoperatively in the donor and postoperatively in the transplant recipient.

MATERIALS AND METHODS

Informed consent was waived for this retrospective HIPAA-compliant study approved by the institutional review board. Renal length, total volume, and cortical volume were measured on renal donor CT angiograms in 111 patients. Preoperative serum creatinine values for donors and postoperative creatinine values for recipients at hospital discharge and 6, 12, 24, and 36 months after transplant were collected, and estimated glomerular filtration rate (eGFR) was calculated. Correlation coefficients with 95% confidence intervals (CIs) were obtained for renal measures and donor eGFR and for renal measures adjusted to recipient body habitus and posttransplant creatinine level in the recipient. Thresholds were set for adjusted length and volumes, and the odds ratio (OR) for creatinine level less than 1.5 mg/dL at 36 months was calculated.

RESULTS

Renal volumes and length were correlated with donor eGFR (r=0.58 [95% CI: 0.44, 0.69] for cortical volume, 0.56 [95% CI: 0.42, 0.68] for total volume, and 0.43 [95% CI: 0.27, 0.57] for renal length). All three measures, adjusted to recipient body habitus, were correlated with recipient renal function from discharge (r=-0.41 to -0.43) up to 36 months after transplantation (r=-0.33 to -0.41). By using a threshold of 1.5 for cortical volume to recipient weight, 2.25 for total volume to recipient weight, and 0.175 for renal length to recipient weight, the odds of creatinine level greater than 1.5 mg/dL were four times as great for smaller kidney-to-recipient weight ratios, a statistically significant pattern for cortical volume (OR, 4.07; 95% CI: 1.10, 15.09) but not total volume (OR, 4.24; 95% CI: 0.90, 20.01) or renal length (OR, 4.08; 95% CI: 0.48-34.29).

CONCLUSION

Renal length and volumes correlated with recipient renal function up to 36 months after transplant. A low ratio of cortical volume to recipient weight was associated with diminished renal function at 36 months after transplant.

Equating quantitative emphysema measurements on different CT image reconstructions

PURPOSE

To mathematically model the relationship between CT measurements of emphysema obtained from images reconstructed using different section thicknesses and kernels and to evaluate the accuracy of the models for converting measurements to those of a reference reconstruction.

METHODS

CT raw data from the lung cancer screening examinations of 138 heavy smokers were reconstructed at 15 different combinations of section thickness and kernel. An emphysema index was quantified as the percentage of the lung with attenuation below -950 HU (EI950). Linear, quadratic, and power functions were used to model the relationship between EI950 values obtained with a reference 1 mm, medium smooth kernel reconstruction and values from each of the other 14 reconstructions. Preferred models were selected using the corrected Akaike information criterion (AICc), coefficients of determination (R2), and residuals (conversion errors), and cross-validated by a jackknife approach using the leave-one-out method.

RESULTS

The preferred models were power functions, with model R2 values ranging from 0.949 to 0.998. The errors in converting EI950 measurements from other reconstructions to the 1 mm, medium smooth kernel reconstruction in leave-one-out testing were less than 3.0 index percentage points for all reconstructions, and less than 1.0 index percentage point for five reconstructions. Conversion errors were related in part to image noise, emphysema distribution, and attenuation histogram parameters. Conversion inaccuracy related to increased kernel sharpness tended to be reduced by increased section thickness.

CONCLUSIONS

Image reconstruction-related differences in quantitative emphysema measurements were successfully modeled using power functions.

Quantitative CT assessment of emphysema and airways in relation to lung cancer risk

PURPOSE

To determine whether quantitative computed tomographic (CT) measurements of emphysema and airway dimensions are associated with lung cancer risk in a screening population.

MATERIALS AND METHODS

Institutional review board approval and informed consent for the use of deidentified images were obtained. In this retrospective study, CT scans were analyzed from 279 participants in the CT screening arm of the National Lung Screening Trial who were diagnosed with lung cancer and 279 participants who were not diagnosed with lung cancer after a median follow-up period of 6.6 years. Quantitative CT measurements of emphysema and right upper lobe apical segmental and subsegmental airway dimensions, and multiple patient history-related variables, were compared between the two groups. Significant variables were tested in multivariate models for association with lung cancer by using multiple logistic regression.

RESULTS

The emphysema index of percentage upper lung volume less than -950 HU had the strongest association with lung cancer (mean, 10.7% [standard deviation, 13.5] in patients vs 7.2% [standard deviation, 10.4] in control subjects; P < .001), but the relationship was weak (R(2) = 0.015, P < .001, c = 0.57). No CT measures of emphysema had an association with lung cancer independent of the patient medical history variables. Airway dimensions were not associated with lung cancer.

CONCLUSION

Quantitative CT measurements of emphysema but not airway dimensions were only weakly associated with lung cancer, demonstrating no potential practical value for clinical risk stratification.

Objective assessment of operator performance during ultrasound-guided procedures

PURPOSE

Simulation permits objective assessment of operator performance in a controlled and safe environment. Image-guided procedures often require accurate needle placement, and we designed a system to monitor how ultrasound guidance is used to monitor needle advancement toward a target. The results were correlated with other estimates of operator skill.

METHODS

The simulator consisted of a tissue phantom, ultrasound unit, and electromagnetic tracking system. Operators were asked to guide a needle toward a visible point target. Performance was video-recorded and synchronized with the electromagnetic tracking data. A series of algorithms based on motor control theory and human information processing were used to convert raw tracking data into different performance indices. Scoring algorithms converted the tracking data into efficiency, quality, task difficulty, and targeting scores that were aggregated to create performance indices. After initial feasibility testing, a standardized assessment was developed. Operators (N = 12) with a broad spectrum of skill and experience were enrolled and tested. Overall scores were based on performance during ten simulated procedures. Prior clinical experience was used to independently estimate operator skill.

RESULTS

When summed, the performance indices correlated well with estimated skill. Operators with minimal or no prior experience scored markedly lower than experienced operators. The overall score tended to increase according to operator's clinical experience. Operator experience was linked to decreased variation in multiple aspects of performance. The aggregated results of multiple trials provided the best correlation between estimated skill and performance. A metric for the operator's ability to maintain the needle aimed at the target discriminated between operators with different levels of experience.

CONCLUSIONS

This study used a highly focused task model, standardized assessment, and objective data analysis to assess performance during simulated ultrasound-guided needle placement. The performance indices were closely related to operator experience.

Comparison of perceptions and treatment practices between neurosurgeons and plastic surgeons for infants with deformational plagiocephaly

OBJECT

Deformational plagiocephaly (DP) is the leading cause of head shape abnormalities in infants. Treatment options include conservative measures and cranial molding. Pediatric neurosurgeons and craniofacial plastic surgeons have yet to agree on an ideal therapy, and no definable standards exist for initiating treatment with helmets. Furthermore, there may be differences between specialties in their perceptions of DP severity and need for helmet therapy.

METHODS

Requests to participate in a web-based questionnaire were sent to diplomates of the American Board of Pediatric Neurological Surgery and US and Canadian members of the Pediatric Joint Section of the American Association of Neurological Surgeons and the Congress of Neurological Surgeons and the American Cleft Palate-Craniofacial Association. Questions focused on educational background; practice setting; volume of DP patients; preferences for evaluation, treatment, follow-up; and incentives or deterrents to treat with helmet therapy. Six examples of varying degrees of DP were presented to delineate treatment preferences.

RESULTS

Requests were sent to 302 neurosurgeons and 470 plastic surgeons, and responses were received from 71 neurosurgeons (24%) and 64 plastic surgeons (14%). The following responses represented the greatest variations between specialties: 1) 8% of neurosurgeons and 26% of plastic surgeons strongly agreed with the statement that helmet therapy is more beneficial than conservative therapy (p < 0.01); and 2) 25% of neurosurgeons and 58% of plastic surgeons would treat moderate to severe DP with helmets (p < 0.01).

CONCLUSIONS

Survey responses suggest that neurosurgeons are less likely to prescribe helmet therapy for DP than plastic surgeons. Parents of children with DP are faced with a costly treatment decision that may be influenced more strongly by referral and physician bias than medical evidence.

Effects of CT section thickness and reconstruction kernel on emphysema quantification relationship to the magnitude of the CT emphysema index

RATIONALE AND OBJECTIVES

Computed tomography (CT) section thickness and reconstruction kernel each influence CT measurements of emphysema. This study was performed to assess whether their effects are related to the magnitude of the measurement.

MATERIALS AND METHODS

Low-radiation-dose multidetector CT was performed in 21 subjects representing a wide range of emphysema severity. Images were reconstructed using 20 different combinations of section thickness and reconstruction kernel. Emphysema index values were determined as the percentage of lung pixels having attenuation lower than multiple thresholds ranging from -960 HU to -890 HU. The index values obtained from the different thickness-kernel combinations were compared by repeated measures analysis of variance and Bland-Altman plots of mean versus difference in all subjects, and correlated with quantitative histology (mean linear intercept, Lm) in a subset of resected lung specimens.

RESULTS

The effects of section thickness and reconstruction kernel on the emphysema index were significant (P < .001) and diminished as the index attenuation threshold was raised. The changes in index values from changing the thickness-kernel combination were largest for subjects with intermediate index values (10%-30%), and became progressively smaller for those with lower and higher index values. This pattern was consistent regardless of the thickness-kernel combinations compared and the HU threshold used. Correlations between the emphysema index values obtained with each thickness-kernel combination and Lm ranged from r = 0.55-0.68 (P = .007-.03).

CONCLUSION

The effects of CT section thickness and kernel on emphysema index values varied systematically with the magnitude of the emphysema index. All reconstruction techniques provided significant correlations with quantitative histology.

Effects of diffusion time on short-range hyperpolarized (3)He diffusivity measurements in emphysema

PURPOSE

To characterize the effect of diffusion time on short-range hyperpolarized (3)He magnetic resonance imaging (MRI) diffusion measurements across a wide range of emphysema severity.

MATERIALS AND METHODS

(3)He diffusion MRI was performed on 19 lungs or lobes resected from 18 subjects with varying degrees of emphysema using three diffusion times (1.6 msec, 5 msec, and 10 msec) at constant b value. Emphysema severity was quantified as the mean apparent diffusion coefficient (ADC) and as the percentage of pixels with ADC higher than multiple thresholds from 0.30-0.55 cm(2)/sec (ADC index). Quantitative histology (mean linear intercept) was obtained in 10 of the lung specimens from 10 of the subjects.

RESULTS

The mean ADCs with diffusion times of 1.6, 5.0, and 10.0 msec were 0.46, 0.40, and 0.37 cm(2)/sec, respectively (P < 0.0001, analysis of variance [ANOVA]). There was no relationship between the ADC magnitude and the effect of diffusion time on ADC values. The mean linear intercept correlated with ADC (r = 0.91-0.94, P < 0.001) and ADC index (r = 0.78-0.92, P < 0.01) at all diffusion times.

CONCLUSION

Decreases in ADC with longer diffusion time were unrelated to emphysema severity. The strong correlations between the ADC at all diffusion times tested and quantitative histology demonstrate that ADC is a robust measure of emphysema.

Temporal association of annular tears and nuclear degeneration: lessons from the pediatric population

BACKGROUND AND PURPOSE

Studies done mainly in adults have shown an association between annular tears and nuclear degeneration. We wanted to study this association in the pediatric population to better understand the natural history of disk degeneration in its early stages. We hypothesized that this association is discernible even at a young age and that annular tears precede nuclear degeneration.

MATERIALS AND METHODS

Twenty-six children with back pain and known disk pathology were identified from our radiology report data base. Two neuroradiologists independently evaluated T12 through S1 intervertebral disks in these images. One reader evaluated the disks for the presence and type of annular tears. The other reader graded the signal intensity of the disks on an ordinal scale and the extent of disk degeneration on the Pfirrmann scale. Mean degeneration and signal-intensity grades were compared for disks with radial tears, disks with nonradial tears, and disks without annular tears.

RESULTS

Fifty-six disks had radial tears. These demonstrated significantly higher nuclear degeneration grades and greater signal-intensity loss than disks with nonradial tears or disks with no annular tears. About one third (30.3%) of the disks with radial tears had a normal nuclear signal intensity. Only 3% of disks with a signal-intensity grade of >/=3 had an intact annulus.

CONCLUSIONS

Nuclear degeneration in children is associated with radial annular tears and rarely occurs in the absence of annular tears.

Imaging of liver disease: comparison between quadruple-phase multidetector computed tomography and magnetic resonance imaging

BACKGROUND AND AIM

To compare quadruple-phase multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI) for the assessment of focal and diffuse liver disease.

METHODS

Quadruple-phase contrast-enhanced MDCT and MRI of 37 consecutive patients were retrospectively reviewed by two readers (R1 and R2). In patients with focal liver lesions, the gold standard was histopathology (n = 17) and/or long-term (>6 months) follow-up imaging (n = 27) or transarterial chemoembolization (n = 1). Diffuse liver disease was confirmed by histopathology in all patients, when present.

RESULTS

Both readers identified 60 focal liver lesions on MDCT and 56 focal liver lesions on MRI. Gold standard diagnoses revealed 48 focal liver lesions in 25 patients. Diagnosis of malignant liver lesions revealed a sensitivity of 88% (R1) and 91% (R2) for MRI; 63% (R1) and 66% (R2) for MDCT; and a specificity of 75% (R1) and 79% (R2) for MRI; 50% (R1) and 64% (R2) for MDCT. MRI was superior to MDCT for the diagnosis of malignant focal liver lesions, when the mean areas under the alternative free-response receiver operating characteristic curves (A(Z)) were compared (MRI = 0.93 vs CT = 0.69), (P < 0.00001). Thirty-three patients had histopathologically confirmed diffuse liver disease. Overall diagnosis of diffuse liver disease revealed a sensitivity of 88% (R1) and 92% (R2) for MRI; 75% (R1) and 74% (R2) for MDCT; and a specificity of 100% for both modalities by both readers.

CONCLUSIONS

MRI is superior for the assessment of malignant focal liver lesions and diffuse liver disease compared to quadruple-phase MDCT, and can be considered as primary diagnostic imaging modality for liver imaging.

Salvage radioembolization of liver-dominant metastases with a resin-based microsphere: initial outcomes

PURPOSE

The use of radioembolization of hepatic metastases with yttrium-90 ((90)Y) microspheres is increasing. The present report describes the outcomes in a cohort of patients with metastatic liver tumors treated with a resin-based microsphere agent.

MATERIALS AND METHODS

Thirty patients with colon (n = 13), breast (n = 7), and other primary cancers (n = 10) were treated after the failure of first- and second-line therapy. Overall survival (OS), time to progression (TTP), and time to treatment failure (TTTF) were calculated from the first treatment. Response was measured according to Response Evaluation Criteria In Solid Tumors at interval follow-up imaging.

RESULTS

Thirty patients underwent 56 infusions of (90)Y, and 18 remained alive at the end of the study. Fourteen patients (47%) had a partial response or stable disease. OS (604 vs 251 days), TTP (223 vs 87 days), and TTTF (363 vs 87 days) were all significantly longer for patients who had a partial response or stable disease (P < .05). Median OS, TTP, and TTTF for patients with colorectal carcinoma were 357, 112, and 107 days, respectively, versus 638, 118, and 363 days in patients with other metastatic sources. Median survival was not reached for patients with breast carcinoma, and the TTP and TTTF were each 282 days. One patient (3%) experienced grade 3 toxicity (gastrointestinal ulceration).

CONCLUSIONS

(90)Y microsphere therapy produced promising survival rates compared with systemic salvage options, with minimal toxicity.

Hyperpolarized 3He MR imaging: physiologic monitoring observations and safety considerations in 100 consecutive subjects

PURPOSE

To evaluate the safety of hyperpolarized helium 3 ((3)He) magnetic resonance (MR) imaging.

MATERIALS AND METHODS

Local institutional review board approval and informed consent were obtained. Physiologic monitoring data were obtained before, during, and after hyperpolarized (3)He MR imaging in 100 consecutive subjects (57 men, 43 women; mean age, 52 years +/- 14 [standard deviation]). The subjects inhaled 1-3 L of a gas mixture containing 300-500 mL (3)He and 0-2700 mL N(2) and held their breath for up to 15 seconds during MR imaging. Heart rate and rhythm and oxygen saturation of hemoglobin as measured by pulse oximetry (Spo(2)) were monitored continuously throughout each study. The effects of (3)He MR imaging on vital signs and Spo(2) and the relationship between pulmonary function, number of doses, and clinical classification (healthy volunteers, patients with asthma, heavy smokers, patients undergoing lung volume reduction surgery for severe emphysema, and patients with lung cancer) and the lowest observed Spo(2) were assessed. Any subjective symptoms were noted.

RESULTS

Except for a small postimaging decrease in mean heart rate (from 78 beats per minute +/- 13 to 73 beats per minute +/- 11, P < .001), there was no effect on vital signs. A mean transient decrease in Spo(2) of 4% +/- 3 was observed during the first minute after gas inhalation (P < .001) in 77 subjects who inhaled a dose of 1 L for 10 seconds or less, reaching a nadir of less than 90% at least once in 20 subjects and of less than 85% in four subjects. There was no correlation between the lowest Spo(2) and pulmonary function parameters other than baseline Spo(2) (r = 0.36, P = .001). The lowest mean Spo(2) varied by 1% between the first and second and second and third doses (P < .001) and was unrelated to clinical classification (P = .40). Minor subjective symptoms were noted by 10 subjects. No serious adverse events occurred.

CONCLUSION

Hyperpolarized (3)He MR imaging can be safely performed in healthy subjects, heavy smokers, and those with severe obstructive airflow limitation, although unpredictable transient desaturation suggests that potential subjects should be carefully screened for comorbidities.

Neurologic findings in infants with deformational plagiocephaly

This study evaluates the neurologic profiles of infants with deformational plagiocephaly. Forty-nine infants with deformational plagiocephaly between the ages of 4 and 13 months (mean age, 8.1 months) are evaluated, along with 50 age-matched control subjects (mean age, 8.1 months). A modified version of the Hammersmith infant neurologic assessment was performed on each infant. A caregiver completed a questionnaire regarding the infant's prematurity, development, and health to date. Results are analyzed using t test. There is a statistically significant difference in overall neurologic assessment scores of infants with deformational plagiocephaly vs their healthy peers (P = .002). This difference is predominately in tone, whereby infants with deformational plagiocephaly have significantly more abnormal tone than nonplagiocephalic infants (P = .003). This abnormality is not one of decreased tone but one of variable tone, deflecting abnormally high and low tone. Infants with deformational plagiocephaly are more likely to have altered tone but not exclusively decreased tone.

Distinct cellular and molecular mechanisms underlie functional remodeling of repolarizing K+ currents with left ventricular hypertrophy

Left ventricular hypertrophy (LVH) is associated with electric remodeling and increased arrhythmia risk, although the underlying mechanisms are poorly understood. In the experiments here, functional voltage-gated (Kv) and inwardly rectifying (Kir) K(+) channel remodeling was examined in a mouse model of pressure overload-induced LVH, produced by transverse aortic constriction (TAC). Action potential durations (APDs) at 90% repolarization in TAC LV myocytes and QT(c) intervals in TAC mice were prolonged. Mean whole-cell membrane capacitance (C(m)) was higher, and I(to,f), I(K,slow), I(ss), and I(K1) densities were lower in TAC, than in sham, LV myocytes. Although the primary determinant of the reduced current densities is the increase in C(m), I(K,slow) amplitudes were decreased and I(ss) amplitudes were increased in TAC LV cells. Further experiments revealed regional differences in the effects of LVH. Cellular hypertrophy and increased I(ss) amplitudes were more pronounced in TAC endocardial LV cells, whereas I(K,slow) amplitudes were selectively reduced in TAC epicardial LV cells. Consistent with the similarities in I(to,f) and I(K1) amplitudes, Kv4.2, Kv4.3, and KChIP2 (I(to,f)), as well as Kir2.1 and Kir2.2 (I(K1)), transcript and protein expression levels were similar in TAC and sham LV. Unexpectedly, expression of I(K,slow) channel subunits Kv1.5 and Kv2.1 was increased in TAC LV. Biochemical experiments also demonstrated that, although total protein was unaltered, cell surface expression of TASK1 was increased in TAC LV. Functional changes in repolarizing K(+) currents with LVH, therefore, result from distinct cellular (cardiomyocyte enlargement) and molecular (alterations in the numbers of functional channels) mechanisms.

Lung cancer: interobserver agreement on interpretation of pulmonary findings at low-dose CT screening

PURPOSE

To evaluate agreement among radiologists on the interpretation of pulmonary findings at low-dose computed tomographic (CT) screening examinations for lung cancer.

MATERIALS AND METHODS

Institutional review board approval and informed consent were obtained. HIPAA guidelines were followed. Sixteen radiologists from the 10 National Lung Screening Trial screening centers of the National Cancer Institute's Lung Screening Study network reviewed image subsets from 135 baseline low-dose screening CT examinations in 135 trial participants (89 men, 46 women; mean age, 62.7 years +/- 5.4 [standard deviation]). Interpretations were classified into one of four of the following categories: noncalcified nodule 4 mm or larger in greatest transverse dimension (positive screening result); noncalcified nodule smaller than 4 mm in greatest transverse dimension (negative screening result); calcified, benign nodule (negative screening result); or no nodule (negative screening result). A recommendation for follow-up evaluation was obtained for each case. Interobserver agreement was evaluated by using the multirater kappa statistic and by using response frequencies and descriptive statistics.

RESULTS

Multirater kappa values ranged from 0.58 (for agreement among all four classifications; 95% confidence interval: 0.55, 0.61) to 0.64 (for agreement on classification as a positive or negative screening result; 95% confidence interval: 0.62, 0.65). The average percentage of reader pairs in agreement on the screening result per case (percentage agreement) was 82%. There was wide variation in the total number of abnormalities detected and classified as pulmonary nodules, with differences of up to more than twofold among radiologists. For cases classified as positive, multirater kappa for follow-up recommendations was 0.35.

CONCLUSION

Interobserver agreement was moderate to substantial; potential for considerable improvement exists. Clinical trial registration no. NCT00047385.

Effect of antiplatelet therapy on thromboembolic complications of elective coil embolization of cerebral aneurysms

BACKGROUND AND PURPOSE

Thromboembolic events are the most common complications of elective coil embolization of cerebral aneurysms. Administration of oral clopidogrel and/or aspirin could lower the thromboembolic complication rate.

MATERIALS AND METHODS

Records over a 10-year period were reviewed in a retrospective cohort study. For 369 consecutive elective coil embolization procedures, 25 patients received no antiplatelet drugs, 86 received antiplatelet drugs only after embolization, and 258 received antiplatelet drugs before and after embolization.

RESULTS

Symptomatic thromboembolic complications (transient ischemic attack or stroke within 60 days) occurred in 4 (16%) of 25 when no antiplatelet drugs were given, in 2 (2.3%) of 86 when antiplatelet drugs were administered only after embolization, and in 5 (1.9%) of 258 when antiplatelet drugs were administered before and after embolization. The lower symptomatic thromboembolic complication rate in the patients who received any antiplatelet therapy was statistically significant (P = .004). Clots were visible intraprocedurally in 5 (4.5%) of 111 when no antiplatelet drugs were administered before procedures and in 4 (1.6%) of 258 when they were (P value not significant). None of the 9 was symptomatic postprocedurally, but 7 were lysed or mechanically disrupted. Extracerebral hemorrhagic complications occurred in 0 (0%) of 25 when no antiplatelet drugs were given and in 11 (3.2%) of 344 when they were (P value not significant).

CONCLUSION

Oral clopidogrel and/or aspirin significantly lowered the symptomatic thromboembolic complication rate of elective coil embolization of unruptured cerebral aneurysms. There were trends toward a lower rate of intraprocedural clot formation in patients given antiplatelet drugs before procedures and a higher hemorrhagic complication rate in patients given antiplatelet drugs. Benefits of antiplatelet therapy appear to outweigh risks.

Single-institution experience with matrix coils in the treatment of intracranial aneurysms: comparison with same-center outcomes with the use of platinum coils

BACKGROUND AND PURPOSE

This study was undertaken to analyze the outcomes and treatment-related complications of the polyglycolic/polylactic acid (PGLA)-coated Matrix platinum coils in the treatment of intracranial aneurysms and compare these results with those derived from the same single-institutional experience with use of uncoated, bare platinum coils.

MATERIALS AND METHODS

In this study, we compared 2 groups of patients in a retrospective fashion. The first group consisted of 70 consecutive patients who underwent 82 aneurysm treatments with Matrix coils during the 14-month period of study, from January 2003 to February 2004. We compared this cohort with 70 consecutive patients who underwent a total of 80 aneurysm treatments with bare platinum coils in the 12 months immediately preceding the use of PGLA-coated coils, from January through December 2002. We then recorded the treatment characteristics, angiographic outcomes, and any complications.

RESULTS

There were similar baseline demographic characteristics between the 2 study groups except in age, anatomic location, and length of follow-up. The overall recurrence rate of aneurysms was 41% among the Matrix-treated group and 32% among the patients treated with bare platinum. Among the 42 patients treated with 100% Matrix, the rate of recurrence was 31%. Of the recurrences, 21% of the Matrix group, 19% of the 100% Matrix group, and 9% of the bare platinum group required retreatment. The overall rate of complications was 10% in the Matrix-treated group and 7% in the bare platinum group. There was not a statistically significant difference in the rate of recurrence of aneurysms or complications between the 2 groups.

CONCLUSIONS

On the basis of our single-center experience, there is insufficient evidence to support the use of Matrix coils over bare platinum coils, given their disadvantages.

Identifying reproducible patterns of calvarial dysmorphology in nonsyndromic sagittal craniosynostosis may affect operative intervention and outcomes assessment

BACKGROUND

The authors tested the premise that there are four distinctive patterns of calvarial dysmorphology in nonsyndromic sagittal craniosynostosis that can be reproducibly recognized.

METHODS

Twenty-nine computed tomographic scan data sets of infants met the following criteria: nonsyndromic sagittal craniosynostosis, age younger than 12 months, and satisfactory computed tomographic data. Osseous reformations were constructed in the anteroposterior, right lateral, and vertex projections for each patient. From these images, four templates--coronal constriction, occipital protuberance, bifrontal bossing, and bitemporal protrusion--were selected as prototypes of the specific dysmorphologies the authors observed in patients with sagittal craniosynostosis. Four residents assigned the 29 calvarial image sets to one of the four templates or, if they were unable to do so, to the group "other." The sortings were then assessed for clustering. The same patient computed tomographic data were reformatted with osseous color images, which were then sorted according to template group by eight senior craniofacial surgeons, who repeated the task approximately 3 months later. The repeatability and assessment of clustering of image sets using the templates was evaluated.

RESULTS

In the residents' pilot study, 41 percent (12 of 29) of patients had 100 percent concordance rates, 31 percent (nine of 29) had 75 percent concordance, 24 percent (seven of 29) had 50 percent, and 3 percent (one of 29) had 25 percent concordance. In summary, greater than 70 percent of the patient image sets could be sorted with at least 75 percent concordance by residents. In the senior surgeons' study, 90 percent of patients could be identified as falling into two of five possible groups. Senior raters demonstrated nearly 70 percent repeatability between sortings.

CONCLUSION

These findings support the hypothesis that there are identifiable and reproducible patterns of varying calvarial dysmorphology in patients with sagittal craniosynostosis.

Long-term outcome after chemoembolization and embolization of hepatic metastatic lesions from neuroendocrine tumors

OBJECTIVE

Hepatic artery chemoembolization and hepatic artery embolization (HAE) are accepted treatments of patients with hepatic metastasis from neuroendocrine tumors. Long-term outcome data are limited. We present our experience in the use of hepatic artery chemoembolization in the treatment of patients with hepatic metastasis from neuroendocrine tumors.

MATERIALS AND METHODS

Forty-six patients with carcinoid (n = 31) or islet cell (n = 15) tumors were treated. Overall and progression-free survival times starting with the first treatment were calculated. Potential factors affecting survival, including presence of extrahepatic disease and resection of the primary lesion, were analyzed. Relief of symptoms was subjectively determined for tumors with hormonal secretion.

RESULTS

The 46 patients underwent 93 hepatic artery chemoembolization or HAE sessions. The mean overall survival time for the entire group was 1,273 +/- 185 days. The mean overall survival times for the carcinoid (1,255 +/- 163 days) and islet cell tumor (1,311 +/- 403 days) subgroups were similar (p = 0.66). The progression-free survival times for the carcinoid (602 +/- 144 days) and islet cell (501 +/- 107 days) tumor subgroups also were similar (p = 0.72). The survival time of patients without known extrahepatic metastasis (n = 18; 1,571 +/- 291 days) trended toward significance compared with that of patients with known extrahepatic disease (n = 26; 770 +/- 112 days; p = 0.08). Resection of the primary tumor in 19 of 46 patients did not affect survival (resection survival, 1,558 +/- 400 days; nonresection survival, 1,000 +/- 179 days; p = 0.44). Twenty of 25 patients with hormonally active tumors had relief of symptoms after one cycle of treatment. The 30-day mortality was 4.3%.

CONCLUSION

The overall survival time after hepatic artery chemoembolization or HAE among patients with neuroendocrine tumors is approximately 3.5 years. The progression-free survival time approaches 1.5 years. The presence of extrahepatic metastasis or an unresected primary tumor should not limit the use of hepatic artery chemoembolization or HAE.

Importance of intravertebral fracture clefts in vertebroplasty outcome

OBJECTIVE

The importance of filling intravertebral fracture clefts with polymethylmethacrylate during percutaneous vertebroplasty to maximize stabilization of fracture fragments has been emphasized in the literature. The purpose of this study was to determine whether patients with a single compression fracture with an intravertebral cleft have better outcome after percutaneous vertebroplasty than do patients with a compression fracture but no cleft.

MATERIALS AND METHODS

A retrospective study was conducted to review 354 consecutive percutaneous vertebroplasty procedures on 694 compression fractures. Patients were excluded from consideration if they were treated for metastatic compression fracture or if they were treated at more than a single vertebral body level. Sixty-five patients met the inclusion criteria. Preprocedure radiographs and MR images were reviewed with specific attention to the presence or absence of intravertebral gas or fluid. Images obtained at the procedure also were reviewed for the presence or absence of an intravertebral cleft. Imaging findings were correlated with subjective pain scores immediately, 2 weeks, 1 month, 3 months, 6 months, 1 year, and 2 years after the procedure.

RESULTS

Thirty-one (48%) of the 65 patients had evidence of a fracture cleft. Twenty-seven patients had opacification of an intravertebral fracture cleft at percutaneous vertebroplasty, and four patients had an intravertebral cleft on preprocedure imaging but did not have cleft opacification. Thirty-four (52%) of the patients had no evidence of a fracture cleft and had only a trabecular pattern of opacification. Although there was a trend toward a greater failure rate in patients with a filled cleft, there was no statistically significant difference in subjective pain scores between the groups.

CONCLUSION

Pain relief with vertebroplasty is similar in patients with and those without intravertebral fracture clefts. Because of the small number of unfilled fracture clefts in our population, the true incidence of post-percutaneous vertebroplasty pain in patients with an un-filled cleft remains uncertain.

Comparison of standard- and low-radiation-dose CT for quantification of emphysema

OBJECTIVE

This study was performed to compare standard- and low-radiation-dose techniques in the CT quantification of emphysema.

MATERIALS AND METHODS

The study population consisted of 36 men and 20 women who were current or former heavy smokers and underwent standard-dose (effective tube current, 100-250 mAs) chest CT at our institution within 6 months of having undergone low-dose (effective tube current, 30-60 mAs) chest CT. All CT scans were reconstructed at 5-mm slice thickness with a smooth filter. CT-measured lung volume, mean and median lung attenuation, and percentage of lung volume with attenuation lower than multiple thresholds (emphysema index values) were compared by Pearson correlation, two-tailed and paired Student's t tests, and regression analysis.

RESULTS

There were no significant differences in mean attenuation (-848 vs -846 H, p > 0.35) for the low dose and the standard dose or in median lung attenuation (-879 vs -878 H, p > 0.66). Low- and standard-dose emphysema indexes were correlated at all attenuation thresholds (r = 0.86-0.97). Mean emphysema indexes were higher on the low-dose scans, but the mean difference at all thresholds was less than 3%. The differences were significant (p < 0.05) only at the lower index thresholds, correlated with differences in lung volume (r < or = 0.86), and increased with greater differences in dose.

CONCLUSION

Low-dose technique has minimal effect on CT quantification of emphysema.

Effect of metatarsal pad placement on plantar pressure in people with diabetes mellitus and peripheral neuropathy

BACKGROUND

Standard prevention and treatment strategies to decrease peak plantar pressure include a total contact insert with a metatarsal pad, but no clear guidelines exist to determine optimal placement of the pad with respect to the metatarsal head. The purpose of this study was to determine the effect of metatarsal pad location on peak plantar pressure in subjects with diabetes mellitus and peripheral neuropathy.

METHODS

Twenty subjects with diabetes mellitus, peripheral neuropathy, and a history of forefoot plantar ulcers were studied (12 men and eight women, mean age=57+/-9 years). CT determined the position of the metatarsal pad relative to metatarsal head and peak plantar pressures were measured on subjects in three footwear conditions: extra-depth shoes and a 1) total contact insert, 2) total contact insert and a proximal metatarsal pad, and 3) total contact insert and a distal metatarsal pad. The change in peak plantar pressure between shoe conditions was plotted and compared to metatarsal pad position relative to the second metatarsal head.

RESULTS

Compared to the total contact insert, all metatarsal pad placements between 6.1 mm to 10.6 mm proximal to the metatarsal head line resulted in a pressure reduction (average reduction=32+/-16%). Metatarsal pad placements between 1.8 mm distal and 6.1 mm proximal and between 10.6 mm proximal and 16.8 mm proximal to the metatarsal head line resulted in variable peak plantar pressure reduction (average reduction=16+/-21%). Peak plantar pressure increased when the metatarsal pad was located more than 1.8 mm distal to the metatarsal head line.

CONCLUSIONS

Consistent peak plantar pressure reduction occurred when the metatarsal pad in this study was located between 6 to 11 mm proximal to the metatarsal head line. Pressure reduction lessened as the metatarsal pad moved outside of this range and actually increased if the pad was located too distal of this range. Computational models are needed to help predict optimal location of metatarsal pad with a variety of sizes, shapes, and material properties.

Response of nonmidline pain to percutaneous vertebroplasty

OBJECTIVE

The purpose of this study was to determine the prevalence of nonmidline symptoms in patients undergoing percutaneous vertebroplasty and the response of these symptoms to vertebroplasty.

MATERIALS AND METHODS

This is a retrospective study performed through examination of patient records, baseline questionnaires, demographic sheets, follow-up questionnaires, reports from telephone follow-up, and pain location diagrams completed before and after percutaneous vertebroplasty. Data were gathered from 350 patient encounters, 686 vertebroplasty procedures, and 288 patients. After determining the prevalence of nonmidline pain, analysis of acquired data was performed to determine the efficacy of vertebroplasty in relieving nonmidline pain.

RESULTS

Nonmidline pain was present in 240 of 350 patient encounters. Major symptom areas were the ribs; hip, groin, and buttocks; and legs and thighs. Lesser areas of nonmidline symptoms were the abdomen, shoulders, and waistline. Overall there was improvement in nonmidline pain in 83% of the procedures.

CONCLUSION

Most patients presenting for percutaneous vertebroplasty have nonmidline pain. Vertebroplasty reduced or eliminated nonmidline pain in 76-92% of the patients in whom it was reported. Procedures involving lumbar vertebrae tended to be successful less often than others, but even in these patients the procedure was successful in approximately 75%.

Effect of intraarterial papaverine and/or angioplasty on the cerebral veins in patients with vasospasm after subarachnoid hemorrhage due to ruptured intracranial aneurysms

Object

The goal in this study was to determine if there was a change in intracranial venous diameters after endo-vascular treatment of carotid distribution vasospasm caused by subarachnoid hemorrhage.

Methods

The venous diameters were measured in all patients who received intraarterial papaverine and/or balloon angioplasty for treatment of vasospasm during the study period of 3 years. To evaluate the veins of Labbé and Trolard, the straight sinus, and the superior sagittal sinus (SSS), measurements were performed in a blinded manner with the aid of a magnification loupe. Predetermined sites were evaluated on angiograms obtained before and after endovascular treatment. Forty-three treatments in 26 patients were included: 18 patients (33 territories) were treated with intraarterial papaverine alone, four (four territories) were treated with balloon angioplasty alone, and four (six territories) were treated with both papaverine infusion and angioplasty.

The mean measured venous diameters increased significantly after addition of papaverine (10.9%), and also after combined papaverine and angioplasty (4.2%). There was no statistically significant increase in the mean venous diameters after angioplasty alone. If the initial intracranial pressure (ICP) was less than 15 mm Hg before treatment, the veins showed a greater tendency to dilate than if the initial ICP measurements were greater than 15 mm Hg. The straight sinus and the SSS increased more in diameter than the veins of Labbé and Trolard. There was no statistically significant correlation between the change in venous diameters with treatment and ICP.

Conclusions

Endovascular treatment produces measurable increases in intracranial venous diameters. However, these changes do not correlate with changes in ICP.

Numerical simulation of the plantar pressure distribution in the diabetic foot during the push-off stance

The primary objective of conservative care for the diabetic foot is to protect the foot from excessive pressures. Pressure reduction and redistribution may be achieved by designing and fabricating orthotic devices based on foot structure, tissue mechanics, and external loads on the diabetic foot. The purpose of this paper is to describe the process used for the development of patient-specific mathematical models of the second and third rays of the foot, their solution by the finite element method, and their sensitivity to model parameters and assumptions. We hypothesized that the least complex model to capture the pressure distribution in the region of the metatarsal heads would include the bony structure segmented as toe, metatarsal and support, with cartilage between the bones, plantar fascia and soft tissue. To check the hypothesis, several models were constructed with different levels of details. The process of numerical simulation is comprised of three constituent parts: model definition, numerical solution and prediction. In this paper the main considerations relating model selection and computation of approximate solutions by the finite element method are considered. The fit of forefoot plantar pressures estimated using the FEA models and those explicitly tested were good as evidenced by high Pearson correlations (r=0.70-0.98) and small bias and dispersion. We concluded that incorporating bone support, metatarsal and toes with linear material properties, tendon and fascia with linear material properties, soft tissue with nonlinear material properties, is sufficient for the determination of the pressure distribution in the metatarsal head region in the push-off position, both barefoot and with shoe and total contact insert. Patient-specific examples are presented.

A Prospective Comparison of the Impact of Uterine Artery Embolization, Myomectomy, and Hysterectomy on Ovarian Function

PURPOSE

To prospectively compare uterine artery embolization (UAE) versus myomectomy and hysterectomy with regard to ovarian function as measured by postprocedure follicle-stimulating hormone (FSH) levels and symptoms.

MATERIALS AND METHODS

Fifty-five patients were prospectively enrolled in the study: 33 patients who underwent UAE, seven who underwent myomectomy, and 15 who underwent hysterectomy. Patients had serum FSH and estradiol levels measured on the third day of the menstrual cycle before their procedure and at regular follow-up visits for as long as 6 months. At these intervals, patients were also surveyed regarding menopausal symptoms.

RESULTS

Although a mild transient increase in mean FSH level after UAE was noted at 3 months, there were no statistically significant differences among the three groups in mean FSH levels at 1 month, 3 months, or 6 months of follow-up. Menopausal symptoms arose in the UAE and hysterectomy groups, but there was no statistically significant difference or permanent effect in either group.

CONCLUSION

There is no significant difference in impact on ovarian function after UAE, hysterectomy, or myomectomy at follow-up for a maximum of 6 months.

Efficacy and mechanism of orthotic devices to unload metatarsal heads in people with diabetes and a history of plantar ulcers

BACKGROUND AND PURPOSE

Total-contact inserts (TCIs) and metatarsal pads (MPs) frequently are prescribed to reduce excessive plantar stresses to help prevent skin breakdown in people with diabetes mellitus (DM) and peripheral neuropathy. The first purpose of this study was to determine the effect of a TCI and an MP on metatarsal head peak plantar pressures (PPP) and pressure-time integrals (PTI). The second purpose of this study was to determine a possible mechanism of pressure reduction by measuring contact area and loaded soft-tissue thickness (STT) under the metatarsal heads and second metatarsal shaft.

SUBJECTS

Twenty subjects (12 men and 8 women; age [mean+/-SD]=57+/-9 years) with DM (duration [mean+/-SD]=16+/-11 years), peripheral neuropathy, and a history of plantar ulcers participated.

METHODS

A repeated-measures research design was used, and outcome measures are reported for 3 footwear conditions: shoe, shoe with TCI, and shoe with TCI and MP. In-shoe plantar pressures were collected during walking and during spiral x-ray computed tomography (SXCT). The STT and identification of the pressure sensor and location of the MP in relationship to the metatarsal heads were determined by use of SXCT.

RESULTS

The PPP and the PTI were 16% to 24% lower at the metatarsal heads in the TCI condition than in the shoe condition. The PPP and the PTI decreased an additional 15% to 28% (for a total reduction of 29% to 47%) with the addition of the MP. The contact area increased 27% with the TCI but not with the MP. The STT did not increase under the metatarsal heads in the TCI condition (compared with the shoe condition) but did increase 8% to 22% at metatarsal heads 2 to 5 with the addition of the MP. The PPP increased substantially (308%) and the STT decreased 14% under the shaft of the second metatarsal with the addition of the MP to the TCI-plus-shoe condition.

DISCUSSION AND CONCLUSION

The TCI and the MP caused substantial and additive reductions of pressures under the metatarsal heads. The TCI reduces excessive pressures at the metatarsal heads by increasing the contact area of weight-bearing forces. Conversely, the MP acts by compressing the soft tissues proximal to the metatarsal heads and relieving compression at the metatarsal heads. These findings can assist in the design of effective orthotic devices to relieve excessive plantar stresses that contribute to skin breakdown and subsequent amputation in people with DM and peripheral neuropathy.

Quantifying effects of plaque structure and material properties on stress distributions in human atherosclerotic plaques using 3D FSI models

BACKGROUND

Atherosclerotic plaques may rupture without warning and cause acute cardiovascular syndromes such as heart attack and stroke. Methods to assess plaque vulnerability noninvasively and predict possible plaque rupture are urgently needed.

METHOD

MRI-based three-dimensional unsteady models for human atherosclerotic plaques with multi-component plaque structure and fluid-structure interactions are introduced to perform mechanical analysis for human atherosclerotic plaques.

RESULTS

Stress variations on critical sites such as a thin cap in the plaque can be 300% higher than that at other normal sites. Large calcification block considerably changes stress/strain distributions. Stiffness variations of plaque components (50% reduction or 100% increase) may affect maximal stress values by 20-50%. Plaque cap erosion causes almost no change on maximal stress level at the cap, but leads to 50% increase in maximal strain value.

CONCLUSIONS

Effects caused by atherosclerotic plaque structure, cap thickness and erosion, material properties, and pulsating pressure conditions on stress/strain distributions in the plaque are quantified by extensive computational case studies and parameter evaluations. Computational mechanical analysis has good potential to improve accuracy of plaque vulnerability assessment.

Angioplasty Balloon Inflation Pressures during Treatment of Hemodialysis Graft–related Stenoses

PURPOSE

This two-part prospective investigation was designed to determine the balloon inflation pressures required to dilate stenoses associated with hemodialysis grafts and evaluate the burst pressures of five different angioplasty balloons.

MATERIALS AND METHODS

Eighty-nine patients with dysfunctional hemodialysis grafts were enrolled and underwent fistulography. The diagnostic studies revealed 104 stenoses, which were treated with balloon angioplasty. The characteristics of these stenoses and the balloon inflation pressures required to dilate the lesions were recorded. In part two of this investigation, the burst pressures of five different angioplasty balloons were evaluated immediately after their use during angioplasty procedures. Twenty-five balloons of each type were inflated until the balloon burst or 30 atm of pressure was achieved. Several different statistical tests were used to analyze the data set.

RESULTS

The mean balloon inflation pressure required to dilate all 104 stenoses was 17.2 atm. Subgroup analysis revealed that the mean balloon inflation pressure required to dilate 75 venous anastomotic stenoses was 17.9 atm and that a mean pressure of 15.6 atm was required to dilate 29 stenoses located within the native outflow veins. The angioplasty balloon burst pressure experiments revealed that the majority of the tested balloons can be inflated to pressures 5-6 atm greater than the manufacturers' rated burst pressures. However, the margin of safety for overinflation was variable among the balloons tested, and angioplasty balloons experience fatigue with repeated inflations.

CONCLUSION

The majority of stenoses associated with hemodialysis grafts can be successfully dilated with use of available high-pressure angioplasty balloons.

Comparison of Adjunctive Use of Rofecoxib versus Ibuprofen in the Management of Postoperative Pain after Uterine Artery Embolization

PURPOSE

The primary purpose of the present study was to compare the antiinflammatory effectiveness of rofecoxib with that of ibuprofen in the first 5 days after uterine artery embolization (UAE). The secondary aim was to compare pain levels and narcotic use among patients treated with different embolic agents.

MATERIALS AND METHODS

From July 2003 to June 2004, 68 UAE procedures were performed by one of the authors (D.M.H.). Of this group, 50 women agreed to participate in this study. Exclusion criteria were limited to contraindication to either drug or current steroid or nonsteroidal antiinflammatory drug use. In a randomized, double-blinded fashion, patients received a numbered pill box that contained one of the two agents and its placebo counterpart. Four times per day for 5 days, patients recorded their level of pain on a visual analog scale and the amount of narcotic analgesic drug needed at that time. Score sheets were returned by mail after completion. During the course of the study, three embolic agents (Gold Embospheres, Contour SE particles, and Embospheres) were used in succession, with similar numbers of patients in each group.

RESULTS

Four patients were excluded from analysis: two who were readmitted to the hospital for treatment of pain (one treated with each antiinflammatory medication) and two who failed to complete their score sheets. Subject demographics were very similar with respect to antiinflammatory drug treatment and embolic agent, except that the average age of patients in the Embosphere group was 6 years older than in the Embosphere Gold and Contour SE groups (P= .02). There was no difference in the pain level and narcotic drug intake between the two drug arms, but among embolic agents, the Embosphere Gold group tended to have a higher overall average pain score (P = .12), and the two patients readmitted were in this group. Patients in the Contour SE group tended to use a lower amount of narcotic drug than those in the other two embolic agent groups (P = .09).

CONCLUSIONS

There was no difference between rofecoxib and ibuprofen with respect to postprocedural pain or narcotic use after UAE. Embolic agent appeared to have a greater impact, with patients in the Embosphere Gold group reporting higher pain scores and those in the Contour SE group requiring a lower amount of narcotic drug than those in the Embosphere Gold or Embosphere groups.

Patient factors affecting thermal lesion size with an impedance-based radiofrequency ablation system

PURPOSE

To evaluate factors that affect the size of the thermal lesion created from radiofrequency ablation (RFA) with an impedance-based system.

MATERIALS AND METHODS

Thirty-two nonresectable liver tumors, including hepatocellular carcinomas (HCC) (N=20; 63%) or metastatic tumors (N=12; 37%) were treated in 29 patients with an impedance based RFA system. Tumor diameter was measured at pre-procedure cross sectional imaging. Follow-up imaging was obtained at 1 month and every 3 months afterward to determine the short axis of the resultant thermal lesion. Success at durable tumor destruction was tracked as well as size of the resulting thermal lesion and the resulting thermal lesion/electrode ratio. Time to impedance roll-off was also correlated with treatment success.

RESULTS

Twenty-eight (88%) of the 32 tumors were durably ablated in a single session. Two patients had residual disease and two had local recurrence. All residual or recurrent lesions were in patients with cirrhosis. Three of these patients were retreated resulting in a durable result in 97% of lesions with a mean/median follow up 443/503 days. Mean tumor diameter and resulting thermal lesion size was similar for HCC and metastatic lesions. A significant difference (P=.02) was observed when comparing the thermal lesion/electrode ratios of HCC (1.01+/-0.36) with metastases (1.26+/-0.22). Nine of 20 HCC ablations (45%) resulted in a ratio>1.0, whereas 11 of 12 metastatic ablations (92%) attained a ratio>1.0 (P=.01). Thermal lesion size did not correlate with time to impedance roll-off for the entire group (r=-0.22; P=.90) or by tumor type (HCC r=0.10; P=.68; metastases r=-0.36; P=.23).

CONCLUSION

Thermal lesion size and the ability to obtain a margin of normal tissue are significantly affected by the presence of cirrhosis when using an impedance-based system. Given this limitation, the majority of small hepatic neoplasms can still be successfully treated with RFA.

Quantitative assessment of coronary artery plaque vulnerability by high-resolution magnetic resonance imaging and computational biomechanics: a pilot study ex vivo

The risk of atherosclerotic plaque disruption is thought to be closely related to plaque composition and rupture triggers such as external mechanical forces. The purpose of this study was to integrate MR imaging and computational techniques for the quantification of plaque vulnerability with morphologic data and biomechanical stress/strain distributions that were all based on high-resolution MR images of coronary artery plaque specimens ex vivo. Twenty-two coronary artery plaque specimens were selectively collected from 10 cadavers. Multislice T(2)-weighted spin echo images were acquired with a resolution of 100 x 100 microm(2). Histopathological images were used as the gold standard for the identification of plaque components and vulnerability. Plaque components were classified on MR images, and the stress/strain components were calculated with a two-dimensional computational model with fluid-structure interactions. As expected, vulnerable plaques appeared to result from a large lipid pool, a thin fibrous cap, and some critical stress/strain conditions. An empiric vulnerability marker was derived and was closely related to the vulnerability score that was determined through pathologic examination. Noninvasive quantification of the MR contrast and mechanical properties of plaque may provide a comprehensive biomarker for the assessment of vulnerability of atherosclerotic plaques.

Speech, cognitive, and behavioral outcomes in nonsyndromic craniosynostosis

BACKGROUND

The neuropsychological morbidity of nonsyndromic craniosynostosis is incompletely understood. The purpose of this study was to establish the prevalence of speech-language, cognitive, and behavioral abnormalities in this population and to stratify the findings on the basis of the affected suture and age of diagnosis with speech-language or psychological abnormalities.

METHODS

Charts of all patients with nonsyndromic craniosynostosis evaluated between 1978 and 2000 were reviewed, noting diagnoses of speech-language, cognitive, or behavioral abnormalities. Findings were statistically analyzed for variance with regard to affected suture and diagnosis of abnormalities.

RESULTS

Two hundred fourteen patients with nonsyndromic craniosynostosis had documented follow-up evaluations with an average age of 6 years 4 months at last visit. Speech, cognitive, and/or behavioral abnormalities were manifest in 49 percent of the patients with specific rates for each suture as follows: right unilateral coronal, 61 percent; bilateral coronal, 55 percent; multiple, 47 percent; metopic, 57 percent; left unilateral coronal, 52 percent; lambdoid, 44 percent; and sagittal, 39 percent. This prevalence of abnormalities was a statistically significant increase from the general population. Logistic regression demonstrated that as patient age increased, the percentage of abnormal diagnoses also increased.

CONCLUSIONS

Nonsyndromic craniosynostosis is often associated with cognitive, speech, and/or behavioral abnormalities. The etiopathology of this association is unknown. Furthermore, the proportion of children diagnosed with cognitive and behavioral dysfunction increases with age. Therefore, longitudinal cognitive, behavioral, and speech assessment and treatment are integral to the care of these patients.

Osteoporotic Compression Fractures: Outcomes after Single- versus Multiple-Level Percutaneous Vertebroplasty

PURPOSE

To compare single- and multiple-level percutaneous vertebroplasty (PV) in terms of pain relief, activity level, and analgesic use in patients with osteoporotic vertebral compression fractures (VCFs).

MATERIALS AND METHODS

Institutional review board approval and informed consent were obtained, and the study was HIPAA compliant. One hundred seventy-three patients (mean age at treatment, 73.8 years +/- 11.9 [standard deviation]) with 422 symptomatic osteoporotic VCFs underwent 204 treatment sessions for over 4 years. Pain immediately before and after PV was measured by using a visual analogue scale (VAS). Pain degree, activity level, and analgesic use were assessed at 2 weeks and 1, 3, 6, 12, and 24 months after PV by using telephone interview questionnaires. Data were analyzed by using a combination of paired t tests, analysis of variance, contingency tables, and chi2 tests.

RESULTS

Findings of 172 PV treatment sessions for 149 patients (mean age at treatment, 73.4 years +/- 12), 110 (74%) of whom were women, were assessed; 32 treatment cases were lost to follow-up or lost owing to death. A single fracture level was treated at 65 sessions; two fracture levels, at 52 sessions; and three or more fracture levels, at 55 sessions. The mean VAS pain score decreased significantly (P < .001), from 76 +/- 21 before to 19 +/- 27 immediately after PV. Of the outcomes reported at 24 months, 82% (64 of 78 treatment sessions) were marked to complete resolution of the initial pain, 51% were complete cessation of analgesic use, and 51% were increased activity levels. These results did not differ greatly over time or when stratified into groups according to the number of fracture levels treated.

CONCLUSION

PV performed at a single fracture level and that performed at multiple fracture levels were equally effective in facilitating long-term pain relief, increased activity level, and decreased analgesic use in patients with osteoporotic VCFs.

Hepatic Arterial Chemoembolization for Hepatocellular Carcinoma: Comparison of Survival Rates with Different Embolic Agents

PURPOSE

The optimal embolic agent for transhepatic arterial chemoembolization (TACE) for hepatocellular carcinoma (HCC) has not been identified. This study reports outcomes of TACE for HCC with Gelfoam powder and polyvinyl alcohol (PVA).

MATERIALS AND METHODS

Eighty-one patients underwent 152 TACE sessions with Gelfoam powder (n = 41) or polyvinyl alcohol (PVA) and Ethiodol (n = 40) as the embolic agent. Chemotherapeutic drugs were the same for all patients (50 mg cisplatin, 20 mg doxorubicin, 10 mg mitomycin-c). The groups were compared based on number of TACE sessions, maximum tumor size, bilirubin level, aspartate and alanine aminotransferase levels, Child-Pugh score, Model for End-stage Liver Disease score, and hepatitis B or C virus positivity. The number of cases of each Child class in each group was also evaluated. Survival starting from the first TACE session was calculated according to Kaplan-Meier analysis. Forty-eight patients died during the study period, 19 received transplants, and 14 were alive at the end of the study period.

RESULTS

The groups were statistically similar in all categories regarding liver function, Child-Pugh score, tumor size, hepatitis status, and percentage of patients with Child class A, B, and C disease. The number of TACE sessions was significantly greater for the Gelfoam powder group (mean, 2.2) versus the PVA group (mean, 1.6; P = .01). Overall survival was similar between groups whether patients who received transplants were included in the analysis (mean, 659 days +/- 83 with Gelfoam powder vs 565 days +/- 71 with PVA; P = .42) or were excluded (mean, 519 days +/- 80 with Gelfoam powder vs 511 days +/- 75 with PVA; P = .93).

CONCLUSION

In similar patient groups, survival after treatment of HCC with TACE with Gelfoam powder or PVA and Ethiodol was similar.

Coronary artery calcification and risk factors for atherosclerosis in patients with venous thromboembolism

BACKGROUND

Venous thromboembolism (VTE) and atherosclerosis may be associated and may share common risk factors. We conducted a retrospective case-control study to investigate the association between VTE and coronary atherosclerotic disease (CAD) by means of measuring coronary artery calcification and evaluating clinical risk factors.

METHODS

From 385 consecutive patients suspected of VTE, we randomly selected 89 cases with idiopathic VTE and 89 controls without VTE, frequency matched on gender and age. Risk factors for atherosclerosis were noted for both groups. Coronary artery calcification was quantified on pulmonary computed tomography (CT) angiographic images. The coronary artery calcification and risk factors were compared between the case and control groups. The associations between VTE and the presence of coronary artery calcium and risk factors were assessed with logistic regression analysis.

RESULTS

A higher prevalence of coronary artery calcium was found in the case group (51.7%) than in the control group (28.1%) (p=0.001). The presence of coronary artery calcium was significantly associated with VTE with an odds ratio of 4.3 (95% confidence interval, 1.9-10.1) in a multivariable model. Diabetes mellitus and hypertension were also significantly associated with VTE.

CONCLUSION

A significant association between VTE and CAD suggests that CAD is an independent risk factor for VTE. Diabetes and hypertension are also independent risk factors for VTE.

Computed tomography to visualize and quantify the plantar aponeurosis and flexor hallucis longus tendon in the diabetic foot

BACKGROUND

The purposes of this report were to describe a three-dimensional computed tomography based method to visualize and quantify the thickness of the plantar aponeurosis and flexor hallucis longus tendon and determine the reliability of thickness measures. Given reliable measures, a secondary purpose was to compare plantar aponeurosis and flexor hallucis longus thickness in subjects with diabetes mellitus and peripheral neuropathy to an age and weight matched group without diabetes.

METHODS

CT data from 16 people with diabetes mellitus and peripheral neuropathy (mean age 55.2 (SD 10.5), 4 female, 12 male, body mass index 31.7 (SD 7.6)) and 10 people without diabetes mellitus (mean age 53.8 (SD 9.1), 2 female, 8 male, body mass index 37.0 (SD 8.6)) were analyzed. Length and thickness of the plantar aponeurosis and flexor hallucis longus tendon were measured twice for five subjects from each group in a blinded single observer reliability study.

FINDINGS

The average mean difference of the linear measurements was 0.12 mm (average SD=1.00 mm). Significant differences for measures of plantar aponeurosis thickness (p=0.044) were found between diabetic, 4.2 mm (SD 0.9), and control groups, 3.6 mm (SD 0.8), and approached significance for tendon thickness measured at the midfoot (diabetic group 4.8 mm (SD 0.8), control group 4.3 mm (SD 0.8), p=0.051).

INTERPRETATION

CT was shown to be a reliable imaging technique for visualizing and quantifying soft tissue structures in diabetic feet. The methods and the quantitative description of the plantar aponeurosis and tendon thickness reported in this paper may be useful to those developing three-dimensional computational models of the foot.

Comparison of MELD and Child-Pugh scores to predict survival after chemoembolization for hepatocellular carcinoma

PURPOSE

To compare the value of the Child-Pugh and Model for End-stage Liver Disease (MELD) scores to predict patient survival rates after transarterial chemoembolization (TACE) for hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

Eighty-seven patients underwent 169 TACE sessions. Child-Pugh and MELD values were calculated before initial treatment. Survival length was tracked from the date of the first TACE procedure. Transplant recipients were censored from the study at the time of surgery. Child-Pugh and MELD scores as well as bilirubin and albumin levels and International Normalized Ratio were placed in high and low categories defined by their respective medians. Patient survival was compared at 3 months, 6 months, 12 months, and 24 months, and patterns were tested with chi2 or Fisher exact tests. Survival over the entire period was examined with Kaplan-Meier analysis and differences were tested with log-rank tests.

RESULTS

Mean and median survival times for all patients were 24 and 17 months, respectively. Sixteen patients were censored for transplantation at a mean of 12.9 months. MELD and Child-Pugh scores correlated well with each other (r = 0.68). Child-Pugh score (r = -0.35, P = .04) correlated more strongly with 12-month survival than did MELD score (r = -0.26, P = .12). After high/low score category division, a significantly greater survival difference was predicted by Child-Pugh score (27.2 months vs 10.3 months; P = .03) versus MELD score (27.5 months vs 15.8 months; P = .19). An albumin level greater than 3.4 g/dL was also associated with significantly improved survival (29.3 months vs 10.1 months; P = .0032). Survival differences between high-risk and low-risk groups at the 3-, 6-, 12-, and 24-month intervals were significant for low Child-Pugh scores and for albumin levels greater than 3.4 g/dL. Statistical significance was not approached at any of the time lengths with MELD scores.

CONCLUSIONS

Child-Pugh score correlates better than MELD score to overall patient survival and is a better predictor than MELD score of survival at specific time points. Of the components of the Child-Pugh and MELD systems, albumin level is the most useful predictor of survival.

Feasibility of combining MR perfusion, angiography, and 3He ventilation imaging for evaluation of lung function in a porcine model

RATIONALE AND OBJECTIVE

To assess the feasibility of combining magnetic resonance (MR) perfusion, angiography, and 3He ventilation imaging for the evaluation of lung function in a porcine model.

MATERIALS AND METHODS

Fourteen consecutive porcine models with externally delivered pulmonary emboli and/or airway occlusions were examined with MR perfusion, angiography, and 3He ventilation imaging. Ultrafast gradient-echo sequences were used for 3D perfusion and angiographic imaging, in conjunction with the use of contrast-agent injections. 2D multiple-section 3He imaging was performed subsequently via the inhalation of hyperpolarized 3He gas. The diagnostic accuracy of MR angiography for detecting pulmonary emboli was determined by two reviewers. The diagnostic confidence for different combinations of MR techniques was rated on the basis of a 5-point grading scale (5 = definite).

RESULTS

The sensitivity, specificity, and accuracy of MR angiography for detecting pulmonary emboli were approximately 85.7%, 90.5%, and 88.1%, respectively. The interobserver agreement was very strong (k = 0.82). There was a clear tendency for confidence to increase when first perfusion and then ventilation imaging were added to the angiographic image (Wilcoxon signed ranks test, P = 0.03).

CONCLUSION

The combination of the three methods of MR perfusion, angiography, and 3H ventilation imaging may provide complementary information on abnormal lung anatomy and function.

Power Injection of Microcatheters: An In Vitro Comparison

PURPOSE

To determine the tolerance of 0.021-inch and 0.027-inch microcatheters to power injection in an in vitro flow model.

MATERIALS AND METHODS

Twenty-four microcatheters (0.021-inch, n = 13; 0.027-inch, n = 11) were injected with iothalamate meglumine through a flow model with use of a power injector and high-pressure tubing. Catheters used included Rebar (0.021-inch, n = 4; 0.027-inch, n = 4), Transit (0.021-inch, n = 3; 0.027-inch, n = 3), Renegade (0.021-inch, n = 4; 0.027-inch, n = 4), and Renegade STC-18 (0.021-inch, n = 2) models. Through the 0.021-inch microcatheters, 5-second injections were performed at an initial rate of 0.7 mL/sec. Injection rates were increased by 0.5 mL/sec and the process was repeated until the pressure approached 1,000 psi or catheter breakage occurred. A similar process was repeated for the 0.027-inch catheters starting at a rate of 3.4 mL/sec.

RESULTS

The 0.021-inch catheters were injected 303 times and the 0.027-inch catheters were injected 210 times. Three catheter failures occurred, with all breaks occurring at pressures greater than manufacturer recommendations. The 0.027-inch catheters as a group tolerated significantly higher injection rates than the 0.021-inch catheters. Of the 0.021-inch catheters, the STC-18 also provided superior maximum flow and volume compared with the Renegade catheter. The Rebar catheter tolerated significantly lower maximum injection rates and volumes than the other 0.027-inch catheters.

CONCLUSIONS

The majority of microcatheters can be power-injected in vitro at pressures far greater than manufacturer recommendations. When fractures occur, they are near the hub of the catheter. Significantly greater rates of injection are possible through 0.027-inch catheters.

Coronary Artery Calcification: Effect of Size of Field of View on Multi–Detector Row CT Measurements

The effect of the size of the field of view (FOV) on coronary artery calcium measurements at multi-detector row computed tomography (CT) was assessed. Coronary multi-detector row CT was performed with an identical protocol in 100 consecutive subjects. CT images were reconstructed at different FOV sizes (210, 260, and 310 mm). Calcified coronary lesions were detected in all three image sets in 52 subjects. The FOV sizes tested for multi-detector row CT coronary screening had a negligible effect on coronary artery calcium measurements (P >/=.06). However, risk stratification decreased by one level in seven of 52 subjects when the FOV increased from 210 or 260 to 310 mm.

Estrogen and/or Calcium Plus Vitamin D Increase Mandibular Bone Mass

BACKGROUND

We have previously reported that estrogen/hormone replacement therapy (E/HRT) has beneficial effects on oral bone density over 3 years and that calcium and vitamin D supplementation has a lesser effect. Here we report on mandibular bone mass for 49 women (of the original cohort of 135) who continued in an additional 2-year, open-label extension.

METHODS

Postmenopausal women were randomly assigned to receive calcium and vitamin D plus E/HRT, or calcium and vitamin D only. Regression analysis of mandibular bone mass over time was performed for each woman.

RESULTS

Twenty-two of 26 women who took calcium and vitamin D plus E/HRT for 5 years had small mandibular bone mass increases (0.35 +/- 0.38%, P<0.001). Seventeen of 19 women who took only calcium and vitamin D for 3 years had increases in mandibular bone mass (0.74 +/- 0.89%, P<0.002). The largest gains in mandibular bone mass occurred during the first 3 years of the study.

CONCLUSIONS

The data of this study indicate that E/HRT and/or calcium and vitamin D may result in increases of mandibular bone mass in postmenopausal women. Because of the long-term risks associated with E/HRT, caution should be exercised in prescribing E/HRT for prevention of chronic menopausal conditions.

Is coronary artery calcium mass related to Agatston score?1

RATIONALE AND OBJECTIVES

The objective of this study was to investigate the relationship between the coronary calcium mass and Agatston score measured on multidetector row computed tomography.

MATERIALS AND METHODS

Eighty-three consecutive subjects (60 men and 23 women) referred for coronary screening were examined prospectively by electrocardiogram-triggered sequential multidetector row computed tomography scan (4 x 2.5-mm collimation). Their coronary calcium was quantitated by means of the Agatston scoring and mass method. The values of score and mass were transformed by taking the natural logarithm (ln(value + 1)) to reduce skewness. The relationship between the mass and score was analyzed with multiple regression analysis.

RESULTS

Fifty-one subjects had a total of 328 calcified lesions detected and measured. The relationship between the calcium mass and score in 51 subjects conformed well to a linear relationship (r2 = 0.96). When analyzed in the total of 328 lesions, the relationship had a good empiric fit with a nonlinear (quadratic) model (r2 = 0.96). The best-fit equation was ln(lesion mass + 1) = -0.87 + 0.67 x ln(lesion score + 1) + 0.10 x (ln(lesion score + 1) - 2.86)2. This relationship was consistent in different coronary vessels and at different heart levels (r2 = 0.96 - 0.99), although there was a higher image noise at lower heart levels (paired t-tests, P < .0001).

CONCLUSION

A nonlinear (quadratic) relationship existed strongly and consistently between coronary calcium mass and score, demonstrating a possible cross-sectional conversion between the two measurements.