Integrated 3D Anatomical Model for Automatic Myocardial Segmentation in Cardiac CT Imagery.

Segmentation of epicardial and endocardial boundaries is a critical step in diagnosing cardiovascular function in heart patients. The manual tracing of organ contours in Computed Tomography Angiography (CTA) slices is subjective, time-consuming and impractical in clinical setting. We propose a novel multi-dimensional automatic edge detection algorithm based on shape priors and principal component analysis (PCA). We have developed a highly customized parametric model for implicit representations of segmenting curves (3D) for Left Ventricle (LV), Right Ventricle (RV), and Epicardium (Epi) used simultaneously to achieve myocardial segmentation. We have combined these representations in a region-based image modeling framework with high level constraints enabling the modeling of complex cardiac anatomical structures to automatically guide the segmentation of endo/epicardial boundaries. Test results on 30 short-axis CTA datasets show robust segmentation with error (mean ± std mm) of (1.46 ± 0.41), (2.06 ± 0.65), (2.88 ± 0.59) for LV, RV and Epi respectively.

Factors affecting formation and rupture of intracranial saccular aneurysms.

Unruptured intracranial aneurysms represent a decisional challenge. Treatment risks have to be balanced against an unknown probability of rupture. A better understanding of the physiopathology is the basis for a better prediction of the natural history of an individual patient. Knowledge about the possible determining factors arises from a careful comparison between ruptured versus unruptured aneurysms and from the prospective observation and analysis of unbiased series with untreated, unruptured aneurysms. The key point is the correct identification of the determining variables for the fate of a specific aneurysm in a given individual. Thus, the increased knowledge of mechanisms of formation and eventual rupture of aneurysms should provide significant clues to the identification of rupture-prone aneurysms. Factors like structural vessel wall defects, local hemodynamic stress determined also by peculiar geometric configurations, and inflammation as trigger of a wall remodeling are crucial. In this sense the study of genetic modifiers of inflammatory responses together with the computational study of the vessel tree might contribute to identify aneurysms prone to rupture. The aim of this article is to underline the value of a unifying hypothesis that merges the role of geometry, with that of hemodynamics and of genetics as concerns vessel wall structure and inflammatory pathways.

Numerical treatment of boundary conditions to replace lateral branches in hemodynamics.

In this paper, we discuss a technique for weakly enforcing flow rate conditions in computational hemodynamics. In particular, we study the effectiveness of cutting lateral branches from the computational domain and replacing them with non-perturbing boundary conditions to simplify the geometrical reconstruction and the numerical simulation. All these features are investigated both in the case of rigid and compliant walls. Several numerical results are presented to discuss the reliability of the proposed method.

An objective approach to digital removal of saccular aneurysms: technique and applications.

Human studies of haemodynamic factors in the pathogenesis of cerebral aneurysms require knowledge of the pre-aneurysmal vasculature. This paper presents an objective and automated technique to digitally remove an aneurysm and reconstruct the parent artery, based on lumen geometries segmented from angiographic images. Relying on robust computational geometry concepts, notably Voronoi diagrams of the digitised lumen surface, the aneurysm attachment region is first defined objectively using lumen centrelines. Centrelines within this region are replaced by smooth interpolations, which then guide the interpolation of Voronoi points within the attachment region. Combined with Voronoi points from outside the attachment region, the parent artery lumen, without the aneurysm, can be reconstructed. Plausible reconstructions were obtained, automatically, for a set of 10 side-wall or terminal aneurysms, of various sizes and shapes, from the ANEURISK project data set. Application of image-based computational fluid dynamics analysis to a five side-wall aneurysm cases data set revealed an association between the recently proposed gradient oscillatory number (GON) and the site of aneurysm formation in four of five cases; however, elevated GON was also evident at non-aneurysmal sites. A potential application to the automated delineation of aneurysms for morphological characterisations is also suggested. The proposed approach may serve as a broad platform for investigating haemodynamic and morphological factors in aneurysm initiation, rupture and therapy in a way amenable to large-scale clinical studies or routine clinical use. Nevertheless, while the parent artery reconstructions are plausible, it remains to be proven that they are faithful representations of the pre-aneurysmal artery.

ACE inhibition reduces glomerulosclerosis and regenerates glomerular tissue in a model of progressive renal disease.

Today angiotensin II inhibition is primarily used to slow the rate of progression of kidney diseases. There is evidence that these therapies can induce a partial regression of glomerular lesions. However, we do not know yet the extent of sclerotic lesion regression and whether new glomerular tissue is formed to help support the renal function. We used male Munich Wistar Fromter (MWF) rats, an experimental model for progressive kidney disease, to quantify kidney structural lesions upon angiotensin-converting enzyme (ACE) inhibition therapy. Animals were studied at 50 weeks of age, when renal function and structure are severely altered, and after a 10-week observation period, without or with treatment with lisinopril (80 mg/l in drinking water). A group of untreated Wistar rats was used as controls. With age, proteinuria, and serum creatinine worsen, but lisinopril almost normalized proteinuria and stabilized serum creatinine. Serial section analysis of whole glomerular tufts showed that at baseline, glomerulosclerosis affected the entire glomerular population, and that these changes further increased with age. Lisinopril significantly reduced incidence and extent of glomerulosclerosis, with the presence of glomerular tufts not affected by sclerosis (23% of glomeruli). Glomerular volume was not significantly affected by treatment, and glomerular mass spared from sclerosis increased from 46.9 to 65.5% upon treatment, indicating consistent regeneration of glomerular tissue. Lisinopril normalized baseline glomerular transforming growth factor-beta and alpha-smooth muscle actin overexpression, and prevented worsening of interstitial changes. Hence, ACE inhibition, which is widely used in human kidney disease, may not only halt the progression of renal failure, but also actually induce the regeneration of new renal tissue.

Mortality in psychiatric patients 5 to 21 years after hospital admission in Italy.

BACKGROUND: Mental disorders have an increased mortality risk. However, most data have been provided by few countries, some mental disorders have received little attention, long-term studies of large samples are scarce, and insufficient control for confounding variables has lead to artefactual inconsistencies across studies. The aims of this study were: to quantify the mortality risk in psychiatric patients 5 to 21 years after hospital admission and to investigate temporal trends in mortality risk and predictive factors associated with mortality. METHOD: All patients admitted to an in-patient psychiatric unit in Italy between 1978 and 1994 were included and vital status and death causes were determined up to 21 years after admission. The observed number of deaths in the sample was compared with the expected number of deaths in the general population. Cox proportional hazard models were fitted to identify predictors of mortality. RESULTS: Mortality from natural and unnatural causes was higher than expected across all mental disorders. Standardized mortality risk was higher in males (SMR = 4.55; 95% CI 4.17-4.97) than in females (SMR = 3.43; 95% CI 3.07-3.83). Individuals aged less than 40 years were at higher risk in both sexes. The first several years following admission were characterized by a faster decline in survival. Several demographic and clinical factors were predictors of mortality. CONCLUSIONS: Mortality is high in individuals with mental disorders. Prevention of unnatural death causes is an important goal though insufficient to abate excess mortality, since natural death causes account for it to a larger extent.

Gender differences in depression. Critical review.

BACKGROUND: With few exceptions, the prevalence, incidence and morbidity risk of depressive disorders are higher in females than in males, beginning at mid-puberty and persisting through adult life. AIMS: To review putative risk factors leading to gender differences in depressive disorders. METHOD: A critical review of the literature, dealing separately with artefactual and genuine determinants of gender differences in depressive disorders. RESULTS: Although artefactual determinants may enhance a female preponderance to some extent, gender differences in depressive disorders are genuine. At present, adverse experiences in childhood, depression and anxiety disorders in childhood and adolescence, sociocultural roles with related adverse experiences, and psychological attributes related to vulnerability to life events and coping skills are likely to be involved. Genetic and biological factors and poor social support, however, have few or no effects in the emergence of gender differences. CONCLUSIONS: Determinants of gender differences in depressive disorders are far from being established and their combination into integrated aetiological models continues to be lacking.

The Personal Health Questionnaire: a new screening instrument for detection of ICD-10 depressive disorders in primary care.

BACKGROUND: The next generation of studies on antidepressant drug prescriptions in general practice needs to assess both the patterns of prescription and its appropriateness. This study aimed to assess the performance of the Personal Health Questionnaire (PHQ), a new questionnaire for detecting individuals with ICD- 10 depressive disorders, to be used in association with companion instruments for assessing the 'quality' of antidepressant prescriptions in primary care settings. METHODS: The PHQ was completed by 1,413 primary care attenders (100 were re-tested after 7-14 days) and 139 were selected and interviewed using the SCAN-2 and the 17-item HDRS. All data were analysed using appropriately weighted procedures to control for two-phase sampling design and non-response bias. Individual weights were estimated by logistic regression analysis and trimming strategy. RESULTS: PHQ internal consistency and test-retest on both Likert score and number of symptoms were high. The PHQ discriminated well between individuals with and without depressive disorders. A Likert score > or = 9 provided a good trade-off between sensitivity (0.78) and specificity (0.83). The screening accuracy of the PHQ in detecting subjects likely to benefit from antidepressant drug treatment (SCAN cases with a HDRS total score of 13 or higher) was satisfactory (ROC area 0.87: sensitivity 0.84; specificity 0.78). CONCLUSIONS: The PHQ can be strongly suggested as an accurate and economic screener to identify primary care attenders at high risk of being clinically depressed. However, in order to identify patients requiring antidepressant drug treatment, a second-phase assessment of PHQ high scorers (total score of > or = 10), using the HDRS, is needed.

An international study of the relation between somatic symptoms and depression.

BACKGROUND AND METHODS: Patients with depression, particularly those seen by primary care physicians, may report somatic symptoms, such as headache, constipation, weakness, or back pain. Some previous studies have suggested that patients in non-Western countries are more likely to report somatic symptoms than are patients in Western countries. We used data from the World Health Organization's study of psychological problems in general health care to examine the relation between somatic symptoms and depression. The study, conducted in 1991 and 1992, screened 25,916 patients at 15 primary care centers in 14 countries on 5 continents. Of the patients in the original sample, 5447 underwent a structured assessment of depressive and somatoform disorders. RESULTS: A total of 1146 patients (weighted prevalence, 10.1 percent) met the criteria for major depression. The range of patients with depression who reported only somatic symptoms was 45 to 95 percent (overall prevalence, 69 percent; P=0.002 for the comparison among centers). A somatic presentation was more common at centers where patients lacked an ongoing relationship with a primary care physician than at centers where most patients had a personal physician (odds ratio, 1.8; 95 percent confidence interval, 1.2 to 2.7). Half the depressed patients reported multiple unexplained somatic symptoms, and 11 percent denied psychological symptoms of depression on direct questioning. Neither of these proportions varied significantly among the centers. Although the overall prevalence of depressive symptoms varied markedly among the centers, the frequencies of psychological and physical symptoms were similar. CONCLUSIONS: Somatic symptoms of depression are common in many countries, but their frequency varies depending on how somatization is defined. There is substantial variation in how frequently patients with depression present with strictly somatic symptoms. In part, this variation may reflect characteristics of physicians and health care systems, as well as cultural differences among patients.

Evaluating psychiatric morbidity in a general hospital: a two-phase epidemiological survey.

BACKGROUND: This study aimed to assess psychiatric morbidity and to collect information on disability, life events and family support in a representative sample of patients admitted to a general hospital. METHODS: On the basis of information collected in a pilot study a systematic sample of patients consecutively admitted to seven general medical and seven surgical wards of the Academic General Hospital of Verona was selected and interviewed using a two-phase screening procedure and standardized instruments (GHQ-12, HADS, BDQ and CIDI-PHC). All data were analysed using appropriately weighted logistic regression procedures. RESULTS: A total of 1039 patients completed the GHQ-12 and 298 (28.7%) were high-scorers: 363 patients were interviewed with CIDI-PHC. The prevalence of ICD-10 cases was 26.1%. The most common psychiatric diagnoses were current depression (12.8%) and generalized anxiety disorder (10.8%), followed by alcohol related disorders (5 %). A higher prevalence of ICD-10 cases was found in medical wards, among females, patients older than 24 years, unemployed and separated/divorced people. Life events were associated with psychopathology, and so was the number of disability days. Although 49.8% of ICD-10 cases were identified by the hospital doctors as having a psychological disorder, 23.1% of ICD-10 cases were referred to the liaison psychiatric service. CONCLUSION: The results of the present study stress the need to collect epidemiologically-based data on psychological disorders and their recognition not only in general practice, but also in general hospital settings, in order to have a more complete picture of the pathways to specialist care.

Anxiety and depression disorders 5 years after severe injuries: a prospective follow-up study.

Individuals with severe injuries were investigated 5 years after the traumatic events, and predictors of anxiety and depression disorders were identified. Trauma victims were selected who had an Injury Severity Score of > or = 16 and were brought to all hospitals in the Mersey region and North Wales over 1 year. The 212 patients aged > or = 15 years who left the hospital alive and lived within an accessible distance of the study hospital in Warrington were contacted 5 years later and 158 (74.5%) received follow-up assessment. Thirty-eight subjects (36.9%) reported "definite" anxiety and/or depression disorders and, of these, only 21.1% reported taking psychotropic medications. Factors associated with anxiety and/or depression disorders at follow-up were: sequelae of head injury (i.e., cognitive problems, posttraumatic seizures, facial pain): writing impairment: disability due to thorax problems; and a new trauma during follow-up. Initial severity or types of injuries and overall residual disability rated by the investigator were not strong predictors of anxiety and/or depression disorders at follow-up.

Typologies of anxiety, depression and somatization symptoms among primary care attenders with no formal mental disorder.

BACKGROUND: Typologies of anxiety, depression and somatization symptoms were investigated in individuals with no formal mental disorders, making no a priori assumptions about symptom distribution and inter-relationship. METHOD: The subjects were 1617 adult primary care attenders from the WHO Collaborative Project on Psychological Problems in General Health Care, with at least three symptoms of anxiety, depression and/or somatization, but with no formal ICD-10 disorders. Analyses were based on the grade of membership model, a multivariate statistical procedure exploring indistinct boundaries between disease categories and preserving the heterogeneity of clinical picture within each category. RESULTS: Six prototype categories (or pure types) best described the structure of symptoms included in analyses. Pure type I included the full set of somatization symptoms. Pure type II was characterized by most anxiety and depression symptoms. Pure type III resembled generalized anxiety disorder. Pure type IV consisted of individuals reporting sporadic symptoms of anxiety, depression or somatization. Pure type V defined individuals with sleep problems. Finally, pure type VI was characterized by anxiety symptoms, including panic-like symptoms. CONCLUSIONS: These findings provide support to the existence of a mixed anxiety-depression category crossing the diagnostic boundaries of current anxiety and depression disorders. Moreover, criteria of anxiety and somatization disorders may be re-examined to assess whether lower diagnostic thresholds can be identified that both preserve the symptom profile and clinical features of current diagnostic categories and allow for a better characterization of individuals with substantial psychopathology though not meeting the high symptom thresholds required for a diagnosis of formal mental disorders.

Frequency of contact with community-based psychiatric services and the lunar cycle: a 10-year case-register study.

The relationship between the lunar cycle and the frequency of contact with community-based psychiatric services was assessed using the South Verona Psychiatric Case Register data. For each day of the study period (January 1982-December 1991) we recorded the number of contacts made by South Verona residents with psychiatric services and the corresponding day of the lunar cycle. First, the synodic month was divided into four interval phases (usually called new moon, first quarter, full moon and third quarter), and interphase differences in the mean number of contacts were tested using one-way analysis of variance. Second. the null hypothesis of no relationship between the lunar cycle and the frequency of contact with psychiatric services was tested against the alternative hypothesis of a sinusoidal distribution according to the lunar phase. The average number of contacts with psychiatric services on each day of the lunar cycle over the 10-year period was obtained and a sine-wave curve was fitted to the data. Both for total and drop-in contacts, no significant differences in mean number of contacts were found between the four interval phases of the synodic month (new moon, first quarter, full moon and third quarter). Similarly, no significant results were found by setting the expected surge in consultations at 1-3 days after the full moon and the period of the sine-wave curve equal to 30 days. When the period of the sine-wave curve was allowed to vary in order to fit the data best, none of the statistical tests reached the level of significance required to dismiss the possibility of false-positive results. These findings did not support the theory that a relationship exists between the lunar cycle and the frequency of contact with community-based psychiatric services.

Lunar cycle and consultations for anxiety and depression in general practice.

The influence of the moon on patient consultations for anxiety or depression in general practice was assessed through a retrospective survey based on general practice medical records and on lunar records detailing the dates and times of different phases of the moon. Seven-hundred-eighty-two patients continuously registered in a general practice in Beckenham, South London, between 1971 and 1988 were included in analyses. No statistically significant lunar effect was found by setting the expected surge in consultations one to three days after the full moon and the period of the sine-wave curve to 30 days. Similarly, no statistically significant lunar effect was found, when the period of the sine-wave curve was allowed to vary in order to best fit the data. The moon had little influence on when individuals consulted their general practitioner with anxiety or depression.

Gender and cross-cultural differences in somatic symptoms associated with emotional distress. An international study in primary care.

BACKGROUND: Gender and cross-cultural differences in the association between somatic symptoms and emotional distress were investigated, using data from the World Health Organization Collaborative Project on Psychological Problems in General Health Care. METHODS: Data were collected at 15 centres in 14 countries around the world. At each centre, a stratified random sample of primary care attenders aged 15-65 years was assessed using, among other instruments, the 28-item General Health Questionnaire and the Composite International Diagnostic Interview-Primary Health Care Version. RESULTS: Females reported higher levels of somatic symptoms and emotional distress than males. A strong correlation between somatic symptoms and emotional distress was found in both sexes, with females reporting more somatic symptoms at each level of emotional distress. However, linear regression analysis showed that gender had no significant effect on level of somatic symptoms, when the effects of centre and emotional distress were controlled for. In both sexes, no specific pattern of association emerged between somatic symptom clusters and either anxiety or depression. Primary care attenders from less developed centres reported more somatic symptoms and showed greater gender differences than individuals from more developed centres, but inter-centre differences were small. Finally, gender was not a significant predictor of reason for consultation (somatic versus mental/behavioural symptoms), after controlling for levels of somatic symptoms and emotional distress as well as for centre effect. CONCLUSIONS: These data do not support the common belief that females somatize more than males or the traditional view that somatization is a basic orientation prevailing in developing countries. Instead, somatic symptoms and emotional distress are strongly associated in primary care attenders, with few differences between the two sexes and across cultures.

Test-retest reliability of the Social Problem Questionnaire in primary care in Italy.

The 1-week test-retest reliability of the Social Problem Questionnaire (SPQ) was investigated in a sample of 100 primary care attenders in Italy. The questionnaire was found to be simple and readily acceptable to primary care attenders. Reliability coefficients were high for housing, financial and work problems (Pearson's r and the intraclass correlation coefficient > or = 0.75) and relatively low for problems with spouse or partner (Pearson's r and the intraclass correlation coefficient = 0.30). Pearson's r and the intraclass correlation coefficient were 0.77 and 0.76, respectively, for the overall severity score reported on the SPQ; the two coefficients were 0.63 and 0.62, respectively, for the overall number of problems reported on the SPQ. When the proportion of specific agreement was computed, agreement on absence of social problems was higher compared to agreement on presence. Reliability coefficients tended to be higher in males compared to females. Systematic differences between scores on the first and second tests were found for problems in housing conditions and social relationships excluding relatives (lower scores on the second test), as well as for the residual category "other social problems" (higher scores on the second test).

Efficacy of the alcohol use disorders identification test as a screening tool for hazardous alcohol intake and related disorders in primary care: a validity study.

OBJECTIVE: To determine the properties of the alcohol use disorders identification test in screening primary care attenders for alcohol problems. DESIGN: A validity study among consecutive primary care attenders aged 18-65 years. Every third subject completed the alcohol use disorders identification test (a 10 item self report questionnaire on alcohol intake and related problems) and was interviewed by an investigator with the composite international diagnostic interview alcohol use module (a standardised interview for the independent assessment of alcohol intake and related disorders). SETTING: 10 primary care clinics in Verona, north eastern Italy. PATIENTS: 500 subjects were approached and 482 (96.4%) completed evaluation. RESULTS: When the alcohol use disorders identification test was used to detect subjects with alcohol problems the area under the receiver operating characteristic curve was 0.95. The cut off score of 5 was associated with a sensitivity of 0.84, a specificity of 0.90, and a positive predictive value of 0.60. The screening ability of the total score derived from summing the responses to the five items minimising the probability of misclassification between subjects with and without alcohol problems provided an area under the receiver operating characteristic curve of 0.93. A score of 5 or more on the five items was associated with a sensitivity of 0.79, a specificity of 0.95, and a positive predictive value of 0.73. CONCLUSIONS: The alcohol use disorders identification test performs well in detecting subjects with formal alcohol disorders and those with hazardous alcohol intake. Using five of the 10 items on the questionnaire gives reasonable accuracy, and these are recommended as questions of choice to screen patients for alcohol problems.

The validity of two versions of the GHQ in the WHO study of mental illness in general health care.

BACKGROUND: In recent years the 12-item General Health Questionnaire (GHQ-12) has been extensively used as a short screening instrument, producing results that are comparable to longer versions of the GHQ. METHODS: The validity of the GHQ-12 was compared with the GHQ-28 in a World Health organization study of psychological disorders in general health care. Results are presented for 5438 patients interviewed in 15 centres using the primary care version of the Composite International Diagnostic Instrument, or CIDI-PC. RESULTS: Results were uniformly good, with the average area under the ROC curve 88, range from 83 to 95. Minor variations in the criteria used for defining a case made little difference to the validity of the GHQ, and complex scoring methods offered no advantages over simpler ones. The GHQ was translated into 10 other languages for the purposes of this study, and validity coefficients were almost as high as in the original language. There was no tendency for the GHQ to work less efficiently in developing countries. Finally gender, age and educational level are shown to have no significant effect on the validity of the GHQ. CONCLUSIONS: If investigators wish to use a screening instrument as a case detector, the shorter GHQ is remarkably robust and works as well as the longer instrument. The latter should only be preferred if there is an interest in the scaled scores provided in addition to the total score.

Identification of psychiatric distress by primary care physicians.

The aims of the present study were to evaluate the extent to which primary care physicians' (PCPs) identification of psychiatric distress is related to a number of nonpsychopathological factors, such as patient sociodemographic and health-related characteristics, and to assess the impact of depression on PCP identification of psychiatric distress, controlling for patient sociodemographic and health-related characteristics. Two patient samples were chosen to explore these issues: 1) patients not fulfilling any ICD-10-defined or subthreshold psychiatric diagnosis and, 2) patients with an ICD-10 diagnosis of current depression. Patients attending 46 primary care clinics during an index period were screened by the General Health Questionnaire (GHQ)-12 and selected for a second stage interview according to GHQ score. Among the 559 interviewed patients, 123 had no mental disorder and 66 had an ICD-10 current depressive disorder. Identification of psychiatric distress by the PCP was associated with retirement among subjects without mental disorders but not among depressed patients. Patient's negative overall health self-perception and severity of physical illness were significantly related to identification of psychiatric distress in the two groups, whereas neither disability nor reason for medical consultation had a significant effect. Patients with current depression, compared with those without, were 4.3 times more likely to be identified by PCPs as having psychiatric distress when adjusting for all the above nonpsychopathological variables. Patients with depression and comorbid anxiety disorders were more likely to be recognized by the PCP as compared with those with pure depression. Finally, among depressive symptoms, diurnal variation and symptoms related to suicidal tendencies were predictive of identification of psychiatric distress, whereas increase of appetite was negatively associated with PCP recognition.