The tools and devices used for patient treatment during interventional procedures must be accurately and safely localized. Recently, procedure guidance has been performed increasingly with MRI, but tool localization has been performed primarily by analyzing the lack of signal caused by displaced excited tissue and/or susceptibility artifacts. In this investigation, a new technique was developed to actively detect and visualize interventional tools using receive coils mounted on the tip of the interventional devices. Unlike earlier methods, in which images from small device-mounted coils are super-imposed on a previously acquired image data set, our localization method uses similar tip-mounted tools in combination with a radiofrequency (RF) switching circuit, standard imaging coils, and specially modified sequences to toggle between the standard and tip-mounted receive coil within a single fluoroscopic mode sequence. With this technique, the misregistration between the reported anatomic location and true location of interventional devices is minimized.

Animals↗

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Fast "real time" imaging with different k-space update strategies for interventional procedures.

Interventional procedures under MR guidance require the images to be acquired with a fast acquisition strategy, a rapid reconstruction algorithm for "real-time" imaging (ie, high temporal resolution), acquisition of at least three adjacent slices to track a tool reliably, and high tissue contrast to ensure safe positioning of interventional devices. Often times, the field strength for interventional MR-imaging units is limited by the open magnet design. This complicates the trade-off between scan time and image quality, particularly when applied during low field interventional MRI procedures. To minimize the impact of some of these trade-offs, a combination of keyhole techniques or modified k-space trajectories, in conjunction with a fluoroscopic (ie, continuous acquisition) mode and a real time reconstruction, permits rapid imaging in a low field system using standard (speed optimized) reconstruction hardware and standard gradient electronics. The purpose of this study was to design and describe different keyhole strategies that can be used in a real time mode to increase the image frame rate by a factor of up to 16. By updating the entire raw data space with our strategies, even small changes of the object could be recognized. Our results using these new strategies on two commercially available open magnet MR-imaging units (Siemens Magnetom Open 0.2T resistive magnet, Toshiba Access 0.064T permanent magnet) and a 1.5T superconductive solenoidal magnet design imager (Siemens SP) are presented to show the potential of these acquisition strategies in interventional MRI. Furthermore, these strategies may also be helpful for several other medical applications requiring high temporal resolution like contrast-enhanced breast imaging or functional brain imaging.

Algorithms↗

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Combined chemotherapy, radiotherapy, and immunotherapy for pancreatic carcinoma--a case report.

Therapeutic modalities for incompletely resected pancreatic carcinoma are rare. Effective treatment must not only prolong the period of palliation but also limit the adverse sequelae of the Whipple procedure so as not to compromise the quality of the remaining life span. New treatments include the use of gemcitabine and type I interferons. We treated a patient with incomplete resection of a pancreatic tumor with two cycles of gemcitabine (1000 mg/m2) and cisplatinum (50 mg/m2) followed by radiotherapy (45 Gy/5 weeks) combined with interferon-beta (three times a week/5 x 10(6) IU). Two small liver metastases occurred subsequently. In all, four cycles of gemcitabine/cisplatinum were delivered. The patient lived at least 9 months with stable metastatic liver disease and local control. He had no acute toxic reactions except for a decrease in the leukocyte count, no long-term side effects, and a satisfactory quality of life. A regimen of sequential gemcitabine/cisplatinum and radiotherapy in combination with interferon-beta deserves further consideration as therapy for pancreatic carcinoma.

Adenocarcinoma↗

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Reduction of combustion by-products in WTE plants: O2 enrichment of underfire air in the MARTIN SYNCOM process.

The SYNCOM process involves oxygen enrichment of underfire air, recirculation of flue gas and a combustion control system using infrared thermography of the waste layer on the grate. At the demonstration plant in Coburg, operational reliability and plant availability using SYNCOM could be proven under real disposal conditions with a waste throughput of 7 t/h. Oxygen enrichment of the underfire air promotes the destruction of pollutants due to the high oxygen partial pressures and temperatures. This is then reflected in very low residual amounts of organic combustion by-products in the bottom ash and flue gas from the SYNCOM unit. The flue gas concentrations of organic pollutants are reduced, as compared with conventional operation, by over 35% (for CO, total hydrocarbons and PCDD/F) at the boiler outlet. As the flue gas flow is reduced by oxygen enrichment and flue gas recirculation, the resulting reduction in terms of kg of pollutant per Mg of waste is even higher. In the bottom ash, the level of organic residues is reduced, by 45% in the case of loss on ignition and by 55% in the case of TOC and dioxins (I-TE of PCDD/F). This is due to the higher oxygen partial pressures and the fuel bed temperature which is increased by 135 to 1200 degrees C. Other important features of the process include more intense sintering and thus improved immobilization of the bottom ash, as well as reduced flue gas and fly ash flows.

Journal Article↗

PubMedDate not supplied

Identification of HIV-infected transfusion recipients: the utility of crossreferencing previous donor records with AIDS case reports.

An expanded "look-back" program has been developed, in which patients who may have been exposed to HIV through blood transfusion were identified via three triggers: the blood that they received was donated by persons who 1) have subsequently been reported to local health departments as meeting the diagnostic criteria for AIDS, 2) have donated since the introduction of anti-HIV screening and tested positive, or 3) have been found to be infected during investigation of reported transfusion-associated HIV infections. In comparing triggers, cross-referencing the list of patients reported to have AIDS (AIDS case list) proved to be the most efficient approach for identifying HIV-infected donors and transfusion recipients. Of the 7973 AIDS patients reported in eight Northern California counties as of December 1988, 316 (4.0%) were determined to have donated at Irwin Memorial Blood Centers between 1977 and 1985. Despite the logarithmic increase in reported cases of AIDS in the San Francisco Bay area over the last 5 years, the rate of detection of previous donors from AIDS case lists remained between 3.3 and 5.4 percent. These persons accounted for 69 percent of the identified infected donors, and their identification led to notification of 60 percent of potentially exposed recipients and 51 percent of known infected recipients. The crossreferencing of AIDS case listings with blood bank records was equally efficient for regions with low and high AIDS prevalence. National adoption of AIDS case list crossreferencing is recommended as an effective means of identifying previously unidentified infected recipients in an effort to limit the secondary spread of HIV infection.

Acquired Immunodeficiency Syndrome↗

PubMedDate not supplied

Increased detection of hepatitis C virus (HCV)-infected blood donors by a multiple-antigen HCV enzyme immunoassay.

A new, multiple-antigen enzyme immunoassay (EIA-2) for hepatitis C virus (HCV) antibodies was evaluated in parallel with the previously available c100-3 HCV EIA (EIA-1) in 14,068 volunteer blood donors as well as in 25 cases of transfusion-associated hepatitis C for which recipient and donor samples were available. When compared to EIA-1, the EIA-2 was more sensitive in detecting HCV-infected blood donors. The EIA-2 detected an additional 1 in 1000 EIA-1-negative, surrogate marker-negative donors who were infected with HCV as demonstrated by polymerase chain reaction (PCR). The specificity of the EIA-2 was comparable to that of the EIA-1, but the two tests appear to detect different populations of false-positive donors. Recombinant immunoblot assay-indeterminate donors were detected five times more frequently by the EIA-2; PCR demonstrated that 21 percent of these donors were infected with HCV. The greater sensitivity of EIA-2 was also found in 25 transfusion recipients with non-A, non-B hepatitis; however, in 16 percent of these cases of posttransfusion HCV infection, the EIA-2 failed to detect an HCV-seropositive donor. These data indicate that EIA-2 testing will significantly reduce, but probably not eliminate, the risk of transfusion-associated HCV infection; we estimate this residual per-unit risk to be 1 in 2000 to 1 in 6000 units transfused. On a national level, it is projected that the replacement of the anti-HCV EIA-1 with the EIA-2 will initially prevent up to 40 additional cases of transfusion-associated hepatitis C per day.

Blood Donors↗

PubMedDate not supplied

Apoptosis in serum of patients with solid tumours.

Apoptosis, which occurs in highly proliferating tumours spontaneously or during anticancer therapy, many lead to an elevated concentration of circulating nucleosomes in blood. In order to quantify the concentration of nucleosomes, we used the Cell Death Detectionplus-ELISA (CDDE) (Boehringer Mannheim, Germany) based on antibodies against histone and DNA, adapted it to the demands of liquid materials and standardized test performance and handling of serum. Furthermore, we investigated serum samples of 185 patients with solid tumours (additionally 24, treated with radio- or chemotherapy), 30 with acute inflammations and 50 healthy persons. Many patients with tumours (78%) and inflammations (77%) showed higher concentrations of serum-nucleosomes (> 100 AU), whereas 96% of all healthy persons had low values (< 100 AU). Follow up-studies revealed an early peak after initiation of therapy and correlated to the clinical outcome. The concentration of nucleosomes is a sensitive marker of cell death and could be used for monitoring the efficacy of antitumour therapy.

Apoptosis↗

PubMedDate not supplied

Long-term results of radiotherapy alone for carcinoma of the vulva.

From 1953 to 1978, definitive radiotherapy for carcinoma of the vulva without surgery was used as a standard therapy at a university hospital in Germany. We retrospectively reviewed the records of 170 patients treated mainly with electron-beam radiation to the vulva and Co-60 to the inguinal lymph nodes. Total doses to the vulva ranged from 6 to 90 Gy. A 30-year retrospective follow-up was accomplished. Tumor and node classification, tumor location, and parity were significant independent factors affecting survival. Actuarial survival was 52% for women with T1 disease, 25% for T2 disease, 10% for T3 tumors, and 0% for T4 tumors; survival with N0 tumors was 39% versus 13% with N2 lesions. Tumors of the labia minora were associated with a better survival rate (40.8% at 5 years) than were tumors at other locations (15%-21% at 5 years). Patients with zero to three children had significantly better results (32% at 5 years) than patients with four to seven children (11%). A dose of 60 Gy did not produce better long-term survival rates compared with lower doses, perhaps because low electron energy missed microscopic disease in deep vulvar tissues. On the basis of this review, patients with vulvar carcinoma should have at least a complete tumor resection. The therapeutic window between tumor control probability and the normal tissue complication rate in nonresected patients is too narrow: local recurrences are quite frequent with lower dose schedules, and survival rates are very poor, whereas complication rates are high with radical dose schedules that nevertheless provide acceptable cure rates.

Adult↗

PubMedDate not supplied

Results of postoperative radiotherapy of cervix carcinoma after radical versus non radical hysterectomy.

UNLABELLED: We studied the outcome of our 68 cervix carcinoma patients treated either with: 1) radical surgery and postoperative 192Ir high-dose rate afterloading brachytherapy or postoperative radiotherapy to the whole pelvis or with 2) standard hysterectomy and postoperative radiotherapy to the whole pelvis. Forty-eight women were treated by radical hysterectomy from 1988 to 1992 and--due to risk factors--by postoperative radiotherapy (Group 1), 20 other patients (Group 2) pretreated with standard hysterectomy were admitted to the university hospital for postoperative radiotherapy of the whole pelvis. Postoperative radiotherapy consisted of 39.6 Gy total dose using the box technique, plus two afterloading applications with a single dose of 7.5 Gy and 6 Gy external beam therapy to the pelvic lymph nodes sparing the midline. Comparing the Kaplan-Meier plots of both groups, the tumor related survival curve, the locoregional control and the rates of metastatic disease were nearly identical. But in the analysis of special subgroups, patients with positive lymph nodes after standard hysterectomy and postoperative radiotherapy had a worse prognosis (75% three years' survival rate) than patients after radical surgery (86% three years' survival rate). Lymphangiosis was a negative prognostic factor for the patients pretreated with standard hysterectomy (60% versus 80% three years' survival rate), but not for patients after radical surgery (80% three years' survival rate), despite the same radiotherapy in both groups. CONCLUSION: Standard hysterectomy fails to be an adequate treatment for early cervix carcinoma because moderately dosed postoperative radiotherapy cannot achieve complete locoregional control in all cases of positive lymph nodes or invasion of lymph vessels. However, based on the empirical results of many authors and our own results, postoperative radiotherapy is further indicated in high risk cases of cervix carcinoma after radical surgery.

Female↗