Prosthetic Rehabilitation with Implant-Supported Mandibular Overdenture after Partial Glossectomy and Radiation Therapy: A Case Report.

Implant-supported overdenture is a well-established treatment option for many patients who have functional problems with conventional dentures. It may be primary choice for patients with altered jaw anatomy, neuromuscular disorders, pronounced gag reflex, severe residual ridge resorption and oral tissue defects. In this article we describe a case report, where tongue cancer patients occlusion was rehabilitated with an implantretained overdenture. In 2001 patient was operated for squamous cell carcinoma on the left side of the tongue. Before preoperative radiation therapy, small residual mandibular dentition was removed because of its poor prognosis. Radiation dose on mandible was 57-66 Gy. After tumor surgery patient received conventional complete dentures. Ten years later, the patient was referred again to the Turku University Central Hospital due to constant ulceration under the mandibular denture. The residual ridge of the mandible was severely resorbed. Patient's existing lower complete denture was replaced with a milled bar-retained overdenture on four implants. Treatment turned out to be challenging due to severely restricted tongue movement and tissue defects.

Magnetic resonance imaging of the brain used to detect early post-partum activation of multiple sclerosis.

Post-partum relapses are a frequent phenomenon in multiple sclerosis (MS). The purpose of this study was to evaluate the timing and extent of new or growing T2-lesions after delivery in a cohort of Finnish MS patients. In addition to serial magnetic resonance imaging (MRI), the patients were followed up clinically with determination of relapse rate and expanded disability status scale. The annualized relapse rate was decreased during the last trimester of pregnancy [mean 0.14, standard deviation (SD) 0.14] when compared with the time before pregnancy (mean 0.64, SD 0.14; P = 0.04) and to time post-partum (mean 1.50, SD 0.45; P = 0.0002). New or enlarging lesions were detected in the post-partum images in 14 of 28 patients. Gadolinium-enhancing lesions in post-partum MRI were present in eight of 13 patients. There was a significant increase in the number of T2-lesions (P = 0.0009), in the total volume of MS-lesions measured from fluid-attenuated inversion recovery images (P = 0.0126) and in the number of diffusion weighted imaging hyperintense lesions (P = 0.0098) in the post-partum images. The clinical results support the earlier findings of decreased disease activity in late pregnancy. The clinical and MRI findings indicate that post-partum activation is an early and common phenomenon amongst mothers with MS.

Reproducibility of Tract-based and Region-of-Interest DTI Analysis of Long Association Tracts.

PURPOSE: Reproducibility of two different methods for quantifying fiber tracts by using a diffusion tensor imaging (DTI) sequence suitable for clinical magnetic resonance imaging (MRI) protocols was evaluated. METHODS: DTI of 15 subjects was used to analyze intra-rater and inter-rater reproducibility. Another 10 subjects underwent MRI twice for assessment of between-scan reliability. Ten long association tracts were defined by fiber tracking using inclusion and exclusion regions of interest (ROIs). Whole-tract analysis and tractography-based core analysis were performed, and the effect of fractional anisotropy (FA 0.15/0.30) and turning angle threshold (27°/60°) on reproducibility was evaluated. Additionally, ROI measurements were performed in the core of the tracts. RESULTS: For the tract-based methods, intra-rater and inter-rater reliabilities of FA and mean diffusivity (MD) measurements were excellent. Between-scan reproducibility was good or excellent in 127 of 130 of the measurements. There was no systematic difference in the reproducibility of the FA, MD, and volume measurements depending on the FA or turning angle threshold. For the cross-sectional ROI measurements, reliability showed large variation from poor to excellent depending on the tract. CONCLUSIONS: Compared with the commonly used cross-sectional core ROI method, the tract-based analyses seem to be a more robust way to identify and measure white matter tracts of interest, and provide a novel reproducible tool to perform core analysis.

Phenotype of a homozygous CADASIL patient in comparison to 9 age-matched heterozygous patients with the same R133C Notch3 mutation.

BACKGROUND AND PURPOSE: CADASIL is an autosomal dominant arteriopathy, characterized by multiple brain infarcts, cognitive decline, and finally dementia, which is caused by mutations in Notch3 gene encoding a Notch3 receptor protein. We describe the clinical, neuropsychological, imaging, genetic, and skin biopsy findings in a CADASIL patient homozygous for the C475T mutation resulting in R133C amino acid substitution, in comparison to 9 age-matched heterozygous patients with the same mutation. METHODS: The patients were examined clinically and neuropsychologically and with MRI and positron emission tomography for assessment of cerebral blood flow. The gene defect was analyzed by sequencing the products of polymerase chain reaction of exons 3 and 4 of the Notch3 gene. Dermal arteries were analyzed electron microscopically. RESULTS: The homozygous patient had his first-ever stroke at age 28 years. This is markedly earlier than the average, but the patient's heterozygous son had his first transient ischemic attack-like episode at the same age and another heterozygous patient had his first-ever stroke when only 2 years older. He was neuropsychologically more severely deteriorated than all but 1 of the heterozygous patients. These 2 patients had the most severe (confluent grade D) white matter MRI changes. Positron emission tomography showed markedly reduced cerebral blood flow. Skin biopsy revealed profuse deposits of granular osmiophilic material. The progression of disease in the homozygous case was, however, slower than in the most severely affected heterozygous patient. CONCLUSIONS: Our homozygous patient's phenotype is within the clinical spectrum of CADASIL, although at its severe end. Thus, CADASIL may follow the classic definition of a dominant disease, according to which the heterozygous and homozygous patients are clinically indistinguishable.

Experience in qualitative and quantitative FDG PET in follow-up of patients with suspected recurrence from head and neck cancer.

We evaluated positron emission tomography (PET) with 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG) in the detection of recurrent head and neck cancer, and compared visual and quantitative interpretation of PET images for their accuracy in the identification of tumour recurrence. Sixty-two FDG PET studies were performed in 56 patients having a total of 81 lesions, which were clinically suspected for recurrent carcinoma of the head and neck. The PET images were interpreted visually, and tracer uptake was quantitated as the standardised uptake value adjusted to body weight (SUV). Sensitivity of visual interpretation of the PET images for the presence of malignancy ranged from 84 to 95%, and specificity from 84 to 93%, respectively, depending on the selected scheme for grading of the lesions. Malignant lesions accumulated significantly more FDG than the benign ones (the median SUVs were 6.8 and 3.3, respectively, P<0.001). However, there was a wide overlap of the FDG uptake values between these two groups. Hence, the highest accuracy of quantitative analysis in correct identification of tumour recurrence (75% at Receiver Operating Curve analysis) was inferior to that of visual analysis (89%). FDG PET is feasible for the detection of recurrent head and neck cancer. Although quantitation of FDG uptake using SUV shows significantly higher tracer concentrations for malignant than benign lesions, the wide overlap of individual SUVs between these two groups is a serious concern in diagnostic evaluation. Therefore, in clinical practice it may be preferable to identify the presence of tumour recurrence within this patient group by qualitative interpretation of the PET images.

Single lung allotransplantation in pigs. A morphologic study of tissue preservation with modified Euro-Collins and fluorocarbon solutions.

In the present study the functional and morphologic effects of two pulmoplegic solutions are evaluated. Single left-lung allotransplantation with ligation of the right pulmonary artery was performed in 15 piglets (13-20 kg). The lungs were preserved after donor prostaglandin E-1 treatment with single pulmonary artery flush with either modified Euro-Collins solution (mECS) (9 pigs) or oxygenated fluorocarbon emulsion (FC-43) (6 pigs) and transplanted after 6-hr storage in cold Physiosol solution. Tidal volumes of 15 ml/kg x fr (18) with 40% inspired oxygen were used for ventilation during reperfusion. Function of the transplanted lung was monitored for 4 hr postoperatively by determining pa CO2 and pa O2 levels from arterial samples and by noninvasive monitoring of end-tidal CO2 values and arterial oxygen saturations. Sequential morphologic changes in pulmonary artery flow surface and lung tissue were studied after 6-hr storage and 4-hr reperfusion, using light, scanning, and transmission electron microscopy (LM, SEM, TEM). There was no mortality. After transplantation the mECS group experienced significant hypoxia and hypercarbia and had low end-tidal CO2 values as signs of defective oxygenation and gas exchange, whereas the FC-43 group was normoxic and normoventilated without disturbed elimination of carbon dioxide. After storage and reperfusion, LM showed signs of increased vascular permeability and reperfusion damage--more evident in the mECS group compared with the FC-43 group--while the lymphoid cell population was more intensely activated in the latter group. Electron microscopy after storage showed good overall preservation of structures in both groups. After reperfusion preservation of pulmonary artery flow surface and lung tissue was estimated to be moderate in the mECS group, whereas it was good-to-moderate in the FC-43 group by SEM (NS). TEM of lung tissue, however, showed significantly better-preserved alveolar epithelial lining in the FC-43 group compared with the mECS group. In conclusion, oxygenated fluorocarbon (FC-43) pulmoplegia gave better functional and morphologic preservation of lung grafts compared with modified Euro-Collins solution.

Serious adverse events after measles-mumps-rubella vaccination during a fourteen-year prospective follow-up.

BACKGROUND: Several disorders have been attributed to measles-mumps-rubella (MMR) vaccination during the past decade. The aim of this prospective follow-up study was to identify serious adverse events causally related to MMR vaccination. METHODS: When the MMR vaccination program was launched in Finland in 1982, a countrywide surveillance system was set up to detect serious adverse events associated with MMR. To obtain detailed case histories vaccinees' clinical charts were reviewed. Serum samples were analyzed to trace concurrent infections. SETTING: All hospitals and health centers in Finland from 1982 through 1996. RESULTS: Immunization of 1.8 million individuals and consumption of almost 3 million vaccine doses by the end of 1996 gave rise to 173 potentially serious reactions claimed to have been caused by MMR vaccination. In all, 77 neurologic, 73 allergic and 22 miscellaneous reactions and 1 death were reported, febrile seizure being the most common event. However, 45% of these events proved to be probably caused or contributed by some other factor, giving an incidence of serious adverse events with possible or indeterminate causal relation with MMR vaccination of 5.3 per 100,000 vaccinees or 3.2 per 100,000 vaccine doses. CONCLUSIONS: Causality between immunization and a subsequent untoward event cannot be estimated solely on the basis of a temporal relation. Comprehensive analysis of the reported adverse reactions established that serious events causally related to MMR vaccine are rare and greatly outweighed by the risks of natural MMR diseases.

T1 in subacute and chronic brain infarctions. Time-dependent development.

RATIONALE AND OBJECTIVES: Time-dependent behavior of T1 in brain infarcts and in brain tissue of the contralateral hemisphere was studied in the subacute and early chronic stages of stroke. METHODS: T1 was measured from magnetic resonance images (MRIs) of 29 patients as a function of infarct location and age. Another group of 11 patients was studied with consecutive MRI studies during the first 5 weeks after the onset of infarct, and the distribution of T1 in the infarctions was analyzed from T1 maps using a histographic method. RESULTS: During the first 2 months after a stroke, T1 was longer in the infarcted gray matter than in the infarcted white matter (P = .002), and prolonged linearly in both. The histographic analysis showed a component arising from tissue breakdown products that could be identified for up to 5 weeks. A transient lengthening in T1 of the contralateral hemisphere, reaching a maximum at 3 weeks, also was observed. CONCLUSIONS: These characteristics of recent infarctions differentiate them from older, gliotic lesions. The lengthening of T1 in the contralateral hemisphere may reflect remote flow and metabolic effects of brain infarctions.

A nationwide analysis of laparoscopic complications.

OBJECTIVE: To evaluate the nationwide incidence of laparoscopic complications, as the number of demanding gynecologic laparoscopic procedures increases worldwide. METHODS: The National Patient Insurance Association was founded in 1987 in Finland. All major complications are reported to the Association because it handles financial compensation for patients' injuries without proof of malpractice. We analyzed 256 complications following laparoscopic procedures occurring in 1990-1994. There were 160 minor complications, which were defined as mild infections, mild hemorrhages, and failed sterilization. In all, 96 major complications occurred, including intestinal, urinary tract, and vascular injuries. The number of gynecologic laparoscopies (70,607 procedures) was obtained from the Finnish Hospital Discharge Register. RESULTS: The total complication rate was 3.6/1000 procedures, and the rate of major complications was 1.4/1000 procedures. In diagnostic laparoscopies, the annual major complication rate was constantly below 0.6/1000, and in sterilization, it was below 0.8/1000. In operative laparoscopies, major complications increased from 0/1000 in 1990 to 10.5/1000 in 1993 and leveled to 10.1/1000 in 1994. In all, intestinal injuries occurred in 0.6/1000, ureteral injuries in 0.3/1000, bladder injuries in 0.3/1000, and vascular injuries in 0.1/1000 laparoscopic procedures. CONCLUSIONS: Diagnostic and sterilization laparoscopies appear to be safe, but more complex laparoscopies are associated with an unacceptably high number of serious complications requiring continuous follow-up and expertise.

A randomized double-dummy comparison between indomethacin and nylidrin in threatened preterm labor.

We compared the tocolytic effect of indomethacin and nylidrin in a prospective double-blind trial in which the appearance of the tocolytic treatment (always intravenous infusion and rectal suppositories/oral capsules) was identical to the subjects. Sixty healthy women in imminent preterm labor between 25-34 weeks of singleton gestation were included. Thirty of these women received indomethacin (concomitantly with placebo infusion), with doses as follows: day 1, 100-mg rectal suppository followed by two oral capsules (50 mg) at 8-hour intervals; days 2 and 3, three 50-mg oral capsules each day. Thirty women received intravenous nylidrin (concomitantly with rectal/oral placebo), initiated with the dose of 50 micrograms/minute and continued at the dose of 100-150 micrograms/minute for a maximum of 3 days. Preterm labor was arrested for 24, 48, and 72 hours in 100, 96, and 90%, respectively, of subjects in the indomethacin group, compared with 100, 76, and 73% of women in the nylidrin group; the difference was significant (P less than .05) at 48 hours. Women progressed beyond 37 gestational weeks more commonly (P less than .05) with indomethacin (21 of 30, 70%) than with nylidrin (13 of 30, 43%). Indomethacin treatment was accompanied by maternal side effects 20% of the time, significantly less commonly (P less than .001) than with nylidrin (83%). The neonatal outcome was similar in the two study groups. We conclude from this double-dummy technique trial that indomethacin is more effective and better tolerated than nylidrin in arresting imminent preterm labor.

Major complications of laparoscopy: a follow-up Finnish study.

OBJECTIVE: To examine recent figures on major laparoscopic complications in Finland. METHODS: This was a nationwide record-linkage study from January 1995 through December 1996 including all Finnish hospitals performing gynecologic laparoscopies. Data files of the National Patient Insurance Association and the Finnish Hospital Discharge Register were used. Data were compared with previous results from 1990 to 1994. RESULTS: Among 32,205 gynecologic laparoscopies, 130 major complications were noted. The total complication rate was 4.0 per 1000 procedures: 0.6 per 1000 in diagnostic laparoscopies, 0.5 per 1000 in sterilization, and 12.6 per 1000 in operative laparoscopies. Intestinal injuries were reported in 0.7 per 1000, incisional hernias in 0.3 per 1000, urinary tract injuries in 2.5 per 1000, major vascular injuries in 0.1 per 1000, and other injuries in 0.5 per 1000 gynecologic laparoscopic procedures. Seventy-five percent (88 of 118) of the major complications in operative laparoscopies occurred during hysterectomies. The total major complication rate decreased from 4.9% in 1993 to 2.3% in 1996 (chi2 = 8.55, P = .003), but the incidence of ureteral injuries remained stable, at about 1% of laparoscopic hysterectomies. Ureteral injuries were most common in local hospitals (2.6%), followed by central (1.1%) and university hospitals (0.9%). From 1990 through 1996, the relative risk for ureteral injury in laparoscopic hysterectomies, compared with other operative laparoscopies was 29.0 (95% confidence interval [CI] 13.3, 63.0), for bladder injury 13.0 (95% CI 6.0, 28.2), for intestinal injury 1.3 (95% CI 0.6, 2.5), and for major vascular injury 0.4 (95% CI 0.1, 3.6). Compared with the figures for 1990-1994, all major complications in operative laparoscopies increased, from 0 per 1000 in 1990 to 14.0 per 1000 in 1996 (chi2 = 20.28, P<.001), but part of this increase was due to the increased proportion of laparoscopic hysterectomies. CONCLUSION: Laparoscopic hysterectomies are still associated with a stable 1% risk of ureteral injury, whereas other major complications were decreasing until 1996. Complications in other laparoscopic procedures generally are rare.

Bacterial vaginosis in early pregnancy and pregnancy outcome.

OBJECTIVE: We assessed the association between bacterial vaginosis in early pregnancy and adverse pregnancy outcome. METHODS: Vaginal swabs for bacterial culture, Gram stain, and Papanicolaou stain were taken at the first prenatal visit between 8-17 weeks' gestation in 790 healthy nulliparous women. RESULTS: Culture-proven bacterial vaginosis was detected in 169 of 790 women (21.4%), 167 (98.8%) of whom could also be identified by Gram stain. Papanicolaou smears were available from 299 women, among whom 101 had bacterial vaginosis on culture; of these 101, 78 (77.2%) could be detected by Papanicolaou stain. Of the 751 women whose clinical follow-up was completed, 42 had been treated for preterm uterine contractions (preterm labor), but only 17 delivered between 20-36 weeks' gestation (preterm birth). Premature rupture of membranes (PROM) occurred more than 6 hours before delivery in 80 cases (nine preterm and 71 term). Bacterial vaginosis in early pregnancy predicted preterm labor, preterm birth, or preterm PROM with a sensitivity of 41-67%, specificity of 79%, and negative predictive value of 96-99%, but the positive predictive value was low at 4-11%. However, bacterial vaginosis was associated with a 2.6-fold risk (95% confidence interval [CI] 1.3-4.9) for preterm labor, a 6.9-fold risk (95% CI 2.5-18.8) for preterm birth, and a 7.3-fold risk (95% CI 1.8-29.4) for preterm PROM. CONCLUSIONS: Bacterial vaginosis in early pregnancy can be detected reliably by Gram stain and, in most cases, by Papanicolaou smear. Although bacterial vaginosis is associated with preterm labor, preterm birth, and preterm PROM, the clinical usefulness of its assessment is limited because of the high rate of false-positive findings.

Depression and anxiety in early pregnancy and risk for preeclampsia.

OBJECTIVE: To examine whether depression and anxiety in early pregnancy are associated with preeclampsia in an unselected nulliparous population. METHODS: In this prospective population-based study during pregnancy at outpatient maternity clinics in the Helsinki metropolitan area, depression was assessed by a Finnish modification of the short form of the Beck Depression Inventory and anxiety by one established question. Preeclampsia was defined as elevated blood pressure (BP) (more than 140/100 mmHg) and proteinuria (0.3 g during 24 hours or more). Age, smoking, alcohol consumption, marital status, socioeconomic status, and bacterial vaginosis were analyzed as potentially confounding factors in a multiple logistic regression analysis. RESULTS: Six hundred twenty-three consecutive nulliparous women with singleton pregnancies were studied at ten to 17 (median 12) weeks' gestation and at delivery. Of them, 28 (4.5%) women developed preeclampsia. Depression (mean Beck score 4.5, range 3-17) was observed in 185 (30%), women and anxiety was observed in 99 (16%) in early pregnancy. In multivariate analysis, after adjustment for potentially confounding factors, depression was associated with increased risk (odds ratio [OR] 2.5; 95% confidence interval [CI] 1.1, 5.4) for preeclampsia, as was anxiety (OR 3.2; 95% CI 1.4, 7.4). Either depression or anxiety, or both, were associated with increased risk (OR 3.1; 95% CI 1.4, 6.9) for preeclampsia. Bacterial vaginosis together with depression was associated with increased risk (OR 5.3; 95% CI 1.8, 15.0) for preeclampsia. CONCLUSION: Depression and anxiety in early pregnancy are associated with risk for subsequent preeclampsia, a risk further increased by bacterial vaginosis.

Vaginal clindamycin in preventing preterm birth and peripartal infections in asymptomatic women with bacterial vaginosis: a randomized, controlled trial.

OBJECTIVE: To determine whether treatment of bacterial vaginosis (BV) in early pregnancy decreases the risk of preterm delivery and peripartum infectious morbidity. METHODS: In this multicenter, randomized, double-masked, placebo-controlled intervention trial, screening for BV was performed by vaginal Gram stain obtained from 5432 healthy women with singleton pregnancies during the first antenatal clinic visit at 10--17 weeks' gestation. Bacterial vaginosis-positive women with no past history of preterm delivery were randomized to a single course of treatment with either 2% vaginal clindamycin cream or identical placebo cream for 7 days. Repeat Gram stains were taken 1 week after treatment and at 30--36 weeks' gestation. Preterm delivery was defined as spontaneous delivery before 37 gestational weeks. Peripartum infectious morbidity was defined as postpartum endometritis, postpartum sepsis, postcesarean wound infection, or episiotomy wound infection, necessitating antimicrobial therapy. According to the power analysis, 180 patients were needed for both treatment arms to show a three-fold difference in the rates of preterm births. RESULTS: The overall prevalence of BV was 10.4%. Of all BV-positive women, 375 (66%) were randomized to the treatment arms. The primary cure rate was 66% in the clindamycin group; in the placebo group, 34% spontaneously cleared BV (odds ratio [OR] 1.9, 95% confidence interval [CI] 1.3, 2.8). The rate of preterm deliveries was 5% in the clindamycin group and 4% in the placebo group (OR 1.3, 95% CI 0.5, 3.5). The rate of peripartum infectious morbidity was 11% in the clindamycin group and 18% in the placebo group (OR 1.6, 95% CI 0.9, 2.8). Bacterial vaginosis recurred in 7% of women. The rate of preterm deliveries was 15% in this subgroup compared with 2% among women who remained BV negative (OR 9.3, 95% CI 1.6, 53.5). CONCLUSION: Vaginal clindamycin did not decrease the rate of preterm deliveries or peripartum infections, but recurrent or persistent BV increased the risk for these complications.

Preoperative prediction of postoperative morbidity in coronary artery bypass grafting.

BACKGROUND: The risk factors of patients selected for coronary artery bypass grafting have increased in recent years because of the aging population. Prediction of postoperative complications is essential for optimal use of the available resources. The aim of this study was to develop a scoring method for prediction of postoperative morbidity of individual patients undergoing bypass grafting. METHODS: Data from 386 consecutive patients who underwent coronary artery bypass grafting in a single center were retrospectively collected. The relationship between the preoperative risk factors and the postoperative morbidity was analyzed by the Bayesian approach. Three risk indices (15-factor and seven-factor computed and seven-factor manual models) were developed for the prediction of morbidity. The criterion for morbidity was a prolonged hospital stay postoperatively (> 12 days) because of adverse events. RESULTS: The best predictive preoperative factors for increased morbidity were emergency operation, diabetes, rhythm other than sinus rhythm on the electrocardiogram or recent myocardial infarction, low ejection fraction (< 0.49), age greater than 70 years, decreased renal function, chronic pulmonary disease, cerebrovascular disease, and obesity. The sensitivity of the scoring methods ranged from 51% to 72% and the specificity, from 77% to 86%. CONCLUSIONS: The results show that individual patients can be stratified according to postoperative risk for complications on the basis of preoperative information that is available for most patients.

MR of intracranial tumors: combined use of gadolinium and magnetization transfer.

PURPOSE: To study the potential combined application of gadolinium and magnetization transfer in the MR imaging of intracranial tumors. METHODS: Twenty-two patients were imaged at low field strength (0.1 T). Corresponding gradient-echo partial saturation images without and with magnetization transfer pulse were produced. Images with intermediate repetition times were obtained in 18 cases; five different sequences were produced in 4 cases. Gadopentetate dimeglumine was used at a dose of 0.1 mmol/kg. RESULTS: Magnetization transfer effect increased the contrast between enhancing lesion and normal brain and the contrast between edema and normal brain; the contrast between enhancing lesion and edema was not significantly changed. On intermediate-repetition-time magnetization transfer images the contrast between enhancing tumor and normal brain and the contrast between edema and normal brain were superior to short-repetition-time magnetization transfer images, but the differentiation between enhancing tumor and edema was poorer. CONCLUSION: Magnetization transfer can be used to improve contrast in Gd-enhanced MR imaging. Combining magnetization transfer with an intermediate-repetition-time image provides the possibility for displaying both enhancing and nonenhancing lesions on a single MR image.

Spin-lattice relaxation and magnetization transfer in intracranial tumors in vivo: effects of Gd-DTPA on relaxation parameters.

Spin-lattice relaxation time T1 and relaxation parameters in magnetization transfer (MT) imaging were measured in 11 intracranial tumors before and after injection of Gd-DTPA at 0.1 T by using the inversion recovery method and the saturation transfer technique, respectively. Preinjection T1 relaxation times of the tumors were longer than those of white matter, but after Gd-enhancement the relaxation times of most tumors were in the same range as those of white matter. Gd-DTPA shortened the apparent relaxation time in the presence of off-resonance saturation pulse (T1a) due to marked shortening of the relaxation time of mobile water (T1w). Gd-DTPA decreased the magnetization transfer contrast (MTC) but did not influence on the magnetization transfer rate (Rwm). The parameters MTC and Rwm differed clearly between Gd-enhanced tumors and normal brain, whereas the relaxation time T1a was in many Gd-enhanced tumors in the same range as in normal brain.

MR classification of brain gliomas: value of magnetization transfer and conventional imaging.

We compared quantitative analysis of conventional MR and magnetization transfer (MT) images with visual morphologic assessment of standard images in the classification of gliomas. Thirty-two patients with gliomas were imaged preoperatively. Relative signal intensities on T2- and T1-weighted images, Gd-enhancement, signal heterogeneity on T2-weighted and Gd-enhanced T1-weighted images and MT ratios were measured. In 16 astrocytomas, the MT ratios were correlated with the volume fraction of tumor cell nuclei in histological sections. Among the conventional sequences T2-weighted images were most accurate for quantitative classification; signal heterogeneity was more accurate than relative signal intensity. MT ratios were superior to quantitative analysis of conventional images and equal to visual morphologic evaluation in discriminating between low-grade and high-grade gliomas and correlated with the volume fraction of nuclei in the tumor tissue (r = 0.71, p < .01). The results indicate that quantitative analysis is generally of minor value in the grading of gliomas. In spite of sensitivity to tissue changes associated with malignancy MT imaging cannot significantly improve MR classification of gliomas.

Evaluation of the relationship between preoperative risk scores, postoperative and total length of stays and hospital costs in coronary bypass surgery.

OBJECTIVES: Several risk indices have been developed for the prediction of postoperative mortality and morbidity in coronary artery bypass operations, in which the risk scores are currently recorded as routine praxis. The aim of the present study was to determine whether the risk scores can be used to predict the hospital (LOS) and postoperative (POS) lengths of stay and total costs among coronary artery bypass graft (CABG) patients. METHODS: All first-time CABG patients (n=2104) treated at Helsinki University Central Hospital during 1997-1998 were preoperatively scored using the Cleveland Clinic preoperative model. A multivariate analysis was used to evaluate the effects of the risk scores on the LOS and POS and total costs. RESULTS: The mean preoperative risk score for the patients was 1.69. The increase in preoperative risk score was associated with an increase in the LOS (0.8 days by point), and POS (with 0.55 days by point). An age over 74 years increased the LOS by an extra day. The mean total cost for the CABG procedure was 8750 euros (SD 4430 euros). The costs increased as the risk score increased. Compared with the zero risk score, a score value of 2 was associated with a 1300 euros increase in total cost and a score value of over 6 was associated with an over 7000 euros cost increase. On average, the costs increased by 6980 euros (80%) for one major complication and by 935 euros (10%) in the elderly (>74 years of age). CONCLUSIONS: The results show that increasing risk scores were associated with longer postoperative hospital lengths of stay (POS and LOS) and with increased total costs. An age over 74 years appears to be an independent risk factor in increased POS, LOS and total cost. These results may help to estimate the impact of the preoperative risk profile on the resource requirement in CABG surgery.

Low-dose and conventional-dose high resolution CT of pulmonary changes in breast cancer patients treated by tangential field radiotherapy.

Twenty-seven consecutive breast cancer patients receiving tangential field radiation therapy were followed by high resolution CT (HRCT) in order to compare the accuracy of reduced-dose HRCT and conventional-dose HRCT in the evaluation of subtle pulmonary changes. Thin section 1-mm HRCT images were obtained at identical levels at 120 kVp, with 320 mAs, 200 mAs, 160 mAs, 120 mAs and 60 mAs settings. HRCT was performed during the planning of radiotherapy and 4, 8 and 24 weeks after the completion of radiotherapy. Radiation was administered according to an individual CT-based plan by tangential fields with 4 or 6 MV photons to the whole breast given with 5 fractions of 1.9 Gy weekly to a total dose of 50 Gy. The tumor bed was boosted by electrons to 60 Gy. Pathological changes were detected in 21 examinations of 10 patients: 9 patients out of 27 (33%) showed radiation induced changes; 1 patient developed metastases within the irradiated volume. Septal thickening appeared in 5 patients at 4 weeks and in another 5 patients at 8 weeks. Parenchymal consolidation was detected in 1 patient at 4 weeks and in 5 patients at 8 weeks. HRCT using 160 mAs yield good quality images of subtle radiation induced injuries. The diagnostic validity of HRCT using lower than 160 mAs depends on the detail analyzed.