Comparison of two immobilization techniques using portal film and digitally reconstructed radiographs for pediatric patients with brain tumors.

PURPOSE: To compare the accuracy of two immobilization techniques for pediatric brain tumor patients. METHODS AND MATERIALS: We analyzed data from 128 treatments involving 22 patients. Patients were immobilized with either a relocatable head frame (12 patients) or a vacuum bag (10 patients). Orthogonal portal films were used as verification images. Errors in patient positioning were measured by comparing verification images with digitally reconstructed radiographs generated by a three-dimensional treatment-planning system. RESULTS: With the head frame, systematic errors ranged from 1.4 mm to 2.1 mm; random errors, from 1.7 mm to 2.1 mm. With the vacuum bag, systematic errors ranged from 2.1 mm to 2.5 mm; random errors, from 2.0 mm to 2.6 mm. For the head frame, the mean length of the radial displacement was 4.4 mm; 90% of the total three-dimensional deviation was less than 6.8 mm. The corresponding values for the vacuum bag were 5.0 and 6.6 mm, respectively. CONCLUSIONS: The head frame and vacuum bag techniques limit the random and systematic errors in each of the three directions to within +/- 5 mm. We have used these results to determine the margin used to create the planning target volume for conformal radiation therapy.

Temporal patterns of veterans' psychiatric service utilization, disability payments, and cocaine use.

This study examined temporal patterns of service utilization, disability benefits, and substance use. Specifically, it investigated whether the first day of the first week of each month (when disability payments are disbursed) was associated with increased emergency room (ER) use and more frequent cocaine use among psychiatric patients. All 1993 psychiatric ER presentations (n=1,448) at a Veterans Administration hospital were reviewed in order by the week of each month in which they occurred. A random subsample of only those admitted to an inpatient psychiatric service (n=143) was further assessed for amount of disability payments received and recent cocaine use. This study found that for the total population of patients utilizing the ER, most ER visits occurred during the first week, followed by weeks two, three, and four respectively. The highest percentage (49%) of patients who used cocaine were those admitted during the first week of the month, followed by week two (39%), week four (28%) and week three (25%). For the subsample of patients admitted to inpatient services, patients hospitalized during the fourth week of the month were those receiving the highest disability payments. This study found that cocaine users have the most ER visits during the first week of the month following receipt of benefits. Current data, if confirmed, would suggest public policy changes, such as payment of entitlement money to cocaine users through a third-party payee and stipulated treatment for psychiatric patients with substance use disorders as a condition of payment. Ethical and political issues, including confidentiality and patient autonomy, would need to be considered in any such policy changes.

Underdiagnosis of PTSD and substance use disorders in hospitalized female veterans.

Discharge diagnoses of 31 female veterans and 31 male veterans hospitalized at a large urban VA medical center were examined to elucidate possible biases in clinicians' diagnostic practices. Only one woman in the sample was diagnosed as having posttraumatic stress disorder, compared with seven men. All men given this diagnosis were combat veterans. Although about half of each group had a drug-positive urine screen on admission, only 11 women received a diagnosis of a substance use disorder, compared with 24 men. VA clinicians may need further training and experience assessing the presentation of PTSD and substance use disorders in women.

Use of psychiatric services by homeless veterans.

Patients treated in a Department of Veterans Affairs (VA) emergency room were evaluated to delineate the differences in use of services between homeless and domiciled veterans who have mental disorders. Data were obtained and compared on DSM-III-R diagnoses, number of hospitalizations, lengths of stay, and outpatient visits in the preceding year. Homeless veterans with mental disorders were significantly more likely to have emergency visits and psychiatric admissions in the preceding 12 months than were the domiciled veterans. However, the average length of stay was shorter for the homeless group. These differences must be accounted for in the design of programs targeting homeless veterans with mental illness.

Identifying homeless mentally ill veterans in jail: a preliminary report.

Increasing evidence exists that suggests associations between mental illness, homelessness, and criminal activity and arrest. This article describes a program for identifying and providing treatment and housing for homeless mentally ill veterans detained at the Cook County Jail in Chicago. Preliminary data are provided describing characteristics of the veterans assessed in the jail, as well as those veterans who follow up with services upon release. The usefulness of an urban jail as a site for outreach efforts targeting homeless mentally ill veterans is discussed.

Ruptured pancreaticoduodenal arterial aneurysms: diagnosis and treatment by angiographic intervention.

This article describes a 54-year-old patient who presented with a long history of epigastric pain. Laboratory values revealed a decreased red blood cell count, decreased hemoglobin level, and positive stool hemoccult test. A computed tomography scan of the abdomen revealed intra-abdominal and retroperitoneal hematomas. Emergency laparotomy was performed, but a bleeding source was not evident. Superselective angiography demonstrated bleeding aneurysms of the pancreaticoduodenal artery. Coil embolization with angiography guidance was successful in arresting the bleeding sites.

Homeless women, disaffiliation and social agencies.

Homeless individuals have limited social support systems. Not clearly defined, however, is the relationship between homelessness, gender, and social agencies. In our study 102 homeless individuals were interviewed in shelters. This included administration of the SADS and the subject's rating their perceived level of support from friends, family and social agencies. Significant findings in the analysis showed a higher level of perceived support by males than by females (p < 0.05). More precisely, this was true in the area of support from social agencies, where females rated support from these organizations as significantly lower than did males (p < 0.05). The findings were unchanged when age, presence of psychiatric illness or length of time homeless were factored in. Important implications for public policy are clear since existing social service agencies working with the homeless are less likely to be perceived as supportive by females than by males.

Serial nonenhancing magnetic resonance imaging scans of high grade glioblastoma multiforme.

Magnetic resonance imaging (MRI) from clinical experience has proven to be superior to all other diagnostic imaging modalities, including computed tomography (CT) in the detection of intracranial neoplasms. Although glioblastoma multiforme presents a challenge for all diagnostic imaging modalities including MRI, MRI is paramount to CT in detecting subtle abnormal water accumulation in brain tissue caused by tumor even before there is disruption of the blood brain barrier. Currently, clinical research and investigational trials on nonionic gadolinium contrast agents have proven that nonionic gadolinium HP-DO3A (ProHance) contrast agents have lower osmolality and greater stability, which make them superior compounds to gadolinium diethylenetriamine-pentacetic acid (Gd-DTPA). Therefore, the nonionic gadolinium contrasts have been safely administered more rapidly, in higher or multiple doses for contrast enhanced MRI without adverse side effects or changes in serum iron or total bilirubin, and the intensity of the area of enhancement and number of lesions detected were superior to that of Gd-DTPA (Magnevist) at the standard dose (0.1 mmol/Kg). Perhaps if the nonionic gadolinium contrast agent, ProHance, had been approved by the Food and Drug Administration (FDA) when this MRI was performed in 1990 it would have aided in providing contrast enhancement and visualization of the tumor lesion to assist in patient diagnosis and management. Magnetic resonance imaging also provides unique multiplanar capabilities that allow for optimal visualization of the temporal and occipital lobes of the brain without bone interference.(ABSTRACT TRUNCATED AT 250 WORDS)

Increased exercise capacity in hypoxemic patients after long-term oxygen therapy.

Low-flow continuous oxygen can lead to significant improvement in exercise capacity in selected patients with stable hypoxemic pulmonary disease. Although the mechanisms of improvement are incompletely understood, two tenable hypotheses are (1) the relief of hypoxic pulmonary vasoconstriction and (2) improved peripheral oxygen delivery. This prospective study was performed to examine these two hypotheses. Stable patients with hypoxemic lung disease performed symptom-limited ergometry with hemodynamic monitoring before and after greater than one month of long-term home oxygen therapy. There were 22 patients who increased exercise capacity by greater than 100 KPM/min and greater than 4 min duration and 11 patients who did not increase their exercise capacity greater than 2 min or in KPM/min. Neither the responders nor the nonresponders had significant changes in pulmonary pressures or resistances or effective arterial volume elastances at exercise after long-term O2 therapy. The responders had significant increases in oxygen delivery during exercise (148 +/- 33 ml/min vs 184 +/- 51 ml/min, p = 0.004), cardiac output (7.7 +/- 1.6 L/min vs 8.7 +/- 2.1 L/min, p = 0.003), and arterial oxygen content (18.6 +/- 2.6 ml/dl vs 20.2 +/- 2.8 ml/dl, p = 0.02). The nonresponders had no significant changes in these parameters during exercise. Increased exercise capacity in response to long-term O2 therapy is associated with increased O2 delivery not relief of hypoxic vasoconstriction (in terms of pressure or resistance or arterial elastance). Increased O2 delivery can accrue from both increased cardiac output and increased arterial O2 content. Increase in arterial O2 content is unique to O2 relative to all vasodilator drugs.

Left and right ventricular systolic function and exercise capacity with coronary artery disease.

This prospective study of symptom-limited supine ergometry was conducted to determine the contributions of right ventricular (RV) and left ventricular (LV) systolic function to the exercise capacity of a cohort of patients with coronary artery disease (CAD). Patients with unstable angina, angiographically proven CAD (n = 53) and stable symptoms after medical therapy or angioplasty were included. Documented myocardial infarction (greater than or equal to 2 weeks before exercise) was present in 43 of 53 patients. Angina was the limiting symptom in 11 of 53; the other 42 stopped exercise with dyspnea or fatigue, or both. Oxygen consumption was measured on-line during exercise with a metabolic cart. RV ejection fraction and LV ejection fraction were measured by validated methods from gated blood pool radionuclide ventriculography. There were weak but statistically significant correlations between exercise oxygen consumption and exercise RV ejection fraction (r = 0.30, p less than 0.05) and between exercise oxygen consumption and exercise LV ejection fraction (r = 0.38, p less than 0.01). Multivariate regression analysis, including exercise RV ejection fraction, exercise LV ejection fraction and exercise heart rate versus exercise oxygen consumption revealed a better relation (r = 0.48, p less than 0.005) than any variable in univariate regression. The values of RV and LV ejection fraction at rest did not correlate significantly (r = 0.2, difference not significant), but the exercise values did correlate weakly (r = 0.41, p less than 0.01). The reserve of LV ejection fraction, defined as exercise minus rest value, correlated weakly with exercise oxygen consumption (r = 0.32, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Reduced exercise capacity of chronic obstructive pulmonary disease patients exercising with noseclip/mouthpiece.

A noseclip and low resistance mouthpiece are often used to monitor exhaled gases during exercise. Because otolaryngologic studies suggest that 50% of airway resistance is in the nose and mouth, it was hypothesized that patients with advanced chronic obstructive pulmonary disease might be artifactually limited by exercise testing with a noseclip and mouthpiece. Accordingly, 12 patients with stable chronic obstructive pulmonary disease performed identical symptom-limited supine bicycle exercise tests with and without noseclip and mouthpiece. Right-sided cardiac hemodynamic measurements, radionuclide ventriculography and arterial and mixed venous gas sampling were performed during each exercise test. Exhaled gases were analyzed during the noseclip/mouthpiece exercise. The order of exercise tests was alternated. Comparing exercises with and without a noseclip, there were significant reductions in exercise duration (397 +/- 270 vs 300 +/- 230 seconds, p less than 0.01), exercise oxygen consumption (780 +/- 279 vs 638 +/- 200 ml/min, p less than 0.01) and exercise cardiac output (8.4 +/- 2.7 vs 7.3 +/- 2.0 liters/min, p less than 0.05), an increase in right ventricular ejection fraction (0.39 +/- 0.08 vs 0.43 +/- 0.08, p less than 0.01) and no change in exercise heart rate (106 +/- 14 vs 106 +/- 14), right-sided cardiac pressures or arterial and mixed venous blood gases. These data suggest that a noseclip/mouthpiece can limit exercise tolerance in advanced chronic obstructive pulmonary disease patients. This limitation may result from decreased right-sided cardiac preload (venous return).

Magnetic resonance imaging of an adult with the Dandy-Walker syndrome.

A 30-year-old retired veteran was asymptomatic for two decades; he had carried out normal everyday living activities and was self-supporting. It was not until he was struck by an automobile, which resulted in head trauma, that the Dandy-Walker syndrome was incidentally discovered by computed tomography. Most patients with the Dandy-Walker syndrome or malformation are infants and seldom live into adulthood. Therefore, this patient is one of the very few patients with this malformation who remained in a state of cerebrospinal fluid compensation and lived to adulthood.The head trauma he received in the accident is believed to have activated neurological deficits, visual impairment, and diplopia. Although magnetic resonance imaging revealed severe hydrocephalus and lobar holoprosencephaly, the patient had no symptoms of increased intracranial pressure and no craniofacial deformities except for macrocephaly, and was capable of performing everyday living activities adequately.

AIDS: the role of imaging modalities and infection control policies.

The availability of imaging modalities, such as the chest radiograph, gallium scan, double-contrast barium enema, computed tomography, and nuclear magnetic resonance, are very helpful in the diagnosis, treatment, and follow-up evaluation of patients with acquired immunodeficiency syndrome (AIDS). Because this syndrome causes irreversible destruction of the immune system, patients are susceptible to a multitude of opportunistic infections and malignancies. Health care professionals and the general public would be less fearful and apprehensive of AIDS victims if properly informed about the communicability of this syndrome.

Microcystic adenoma: the specificity of computerized tomography in making the distinction.

Microcystic adenoma can be diagnosed by computerized tomography (CT) alone. With highly specific CT, the central, stellate ("starlight") calcifications that are pathognomonic of microcystic adenoma can be distinguished. Microcystic adenoma, a glycogen-rich, cystic neoplasm of the pancreas, is usually composed of groups of cysts smaller than 2 cm. The lesion is possibly premalignant.

Computed tomography: detecting intra-abdominal abscesses.

Detection of intra-abdominal abscesses by computed tomography (CT) has an estimated accuracy rate of greater than 90 percent. Features helpful in detecting these abscesses include extraluminal gas, the "rind" sign, airfluid interface, and low and high density areas. The author presents three cases to illustrate the usefulness of this modality.

Pneumatosis coli: a case presentation and review of the literature.

The case of pneumatosis coli presented here was felt to have occurred concomitantly with chronic obstructive pulmonary disease in combination with prolonged intestinal distention. This condition usually requires no treatment because it is often self-limiting. In this case, because of radiographic and clinical findings suggestive of intestinal obstruction, the patient underwent an exploratory laparotomy and tube cecostomy for decompression and drainage of the markedly distended cecum and transverse colon.