Iterative Denoising Accelerated 3D FLAIR Sequence for Hydrops MR Imaging at 3T.

BACKGROUND AND PURPOSE: 3D FLAIR sequences have become the criterion standard for identifying endolymphatic hydrops, but scan time remains an important limitation to their widespread use. Our purpose was to evaluate the diagnostic performance and image quality of an accelerated 3D FLAIR sequence combined with an iterative denoising algorithm. MATERIALS AND METHODS: This was a retrospective study performed on 30 patients with clinical suspicion of endolymphatic hydrops who underwent 3T MR imaging 4 hours after gadolinium injection using two 3D FLAIR sequences. The first (conventional FLAIR) was accelerated with a conventional turbo factor of 187. The second was accelerated with an increased turbo factor of 263, resulting in a 33% scan time reduction (5 minutes 36 seconds versus 8 minutes 15 seconds, respectively). A sequence was reconstructed in-line immediately after the accelerated 3D FLAIR acquisition from the same raw data with iterative denoising (accelerated-FLAIR iterative denoising). The signal intensity ratio image quality score and endolymphatic hydrops diagnosis were evaluated. RESULTS: The mean signal intensity ratio for symptomatic and asymptomatic ears of accelerated-FLAIR iterative denoising was significantly higher than the mean SNR of conventional FLAIR (29.5 versus 19 and 25.9 versus 16.3, P < .001). Compared with the conventional FLAIR sequence, the image-quality score was higher with accelerated-FLAIR iterative denoising (mean image-quality score, 3.8 [SD, 0.4] versus 3.3 [SD, 0.6] for accelerated-FLAIR iterative denoising and conventional FLAIR, respectively, P = .003). There was no significant difference in the diagnosis of endolymphatic hydrops between the 2 sequences. Interreader agreement was good-to-excellent. CONCLUSIONS: The iterative denoising algorithm applied to an accelerated 3D FLAIR sequence for exploration of endolymphatic hydrops enabled significantly reducing the scan time without compromising image quality and diagnostic performance.

Adrenaline: communication by electron emission. Effect of concentration and temperature. Product analysis.

BACKGROUND: Based on the recent findings about the ability of sexual hormones to emit electrons (e(aq) (-)) and to act as electron mediator, it was of interest to investigate adrenaline as an important neurotransmitter. MATERIALS AND METHODS: Highest purity adrenaline (ADR) and chemicals were used for preparation of aqueous solutions (pH ~7.4). The excitation of ADR in singlet state was achieved by irradiation of airfree aqueous solution with monochromatic UV light at λ = 254 nm. The emitted "solvated electrons" (e(aq) (-)) were scavenged by chloroethanol, where the quantum yield of Cl(-) ions, Q(Cl(-))=Q(e(aq) (-)). ADR degradation and formation of photolytic products were followed by HPLC analysis. RESULTS AND CONCLUSION: It was found that Q(e(aq) (-)) values decrease with increasing ADR concentration: for 2.5×10(-5) mol/L ADR was determined as Q(e(aq) (-))=6×10(-3), whereas for 1×10(-3) mol/L ADR was found to be 0.9×10(-3). This is explained by formation of associates in ground state, which consume a part of emitted e(aq) (-). As a main photolytic product aminochrome was determined.

Radiation sensitivity of N. pharaonis in comparison with E. coli K12 strains.

To investigate the radiation sensitivity of the natronobacterium Natronomonas pharaonis in comparison with Escherichia coli strains (N. pharaonis DSM 2160T, E. coli strains AB1157 and K12 lambda s) were exposed to gamma-radiation (60Co-gamma-source, 100 Gy min-1) in the presence of oxygen (air) and under strongly reduced oxygen conditions (argon-saturated medium). After irradiation, the colony-forming ability (dose-survival curves) and the D37 dose were determined. The oxygen content of the solutions containing high NaCl concentrations was measured with an oxygen electrode (Clark electrode). It was found that N. pharaonis can tolerate a remarkably higher irradiation dose than the two E. coli strains (approx. 1.5-fold of K12 lambda s and approx. 4-fold of AB1157). The oxygen enhancement ratio (OER) is 2.8 for N. pharaonis and 2.6 for both E. coli strains. Therefore the higher radiation resistance of the N. pharaonis is not due to the low oxygen content of the cell solution (high salt concentration) but is probably related to the higher DNA repair ability of this archaebacteria strain.

Electrovaporization of prostate at power settings below 100 W.

BACKGROUND AND PURPOSE: Prostate electrovaporization has usually been performed at high power settings in the pure cut mode, using traditional electrosurgical generators. However, this practice is empirically based on the fact that a vaporization electrode is larger than a cutting wire loop. The role of the electrosurgical unit (ESU) in prostate electrovaporization has not been studied in detail. METHODS: In this Phase II cohort comparison study, we evaluated two different ESUs, coupled to the most clinically efficient vaporization roller electrode available in our opinion, to determine the lowest panel power settings that permit consistent tissue removal despite the desiccation normally produced during electrovaporization. RESULTS: One of these ESUs, the Excalibur Plus, permitted prostate electrovaporization at panel settings below 100 W for the first time, without compromising satisfactory early clinical outcomes. In a small number of cases, the spiked VaporTrode-Force 2 combination permitted effective electrovaporization at a lower power setting (180 W) than has previously been described when this ESU was coupled with the grooved VaporTrode, regardless of prostate size. During bench tests, a comparison of the actual power output curves in the clinically effective panel power setting range for each ESU revealed that the Force 2 overestimated the actual power output as impedance increased, while the Excalibur Plus underestimated it. This difference may explain why tissue could be vaporized at such low panel settings without the use of computer-controlled technology. CONCLUSION: These findings indicate a potential for improving the safety and efficiency of tissue clearance during prostate electrovaporization through future modifications in monopolar electrode design coupled with use of a generator that can either maintain or slowly increase actual power output as impedance increases at low panel settings. A Phase III clinical study would be justified on the basis of our preliminary results.

American Academy of Pediatrics. Committee on Children with Disabilities. The treatment of neurologically impaired children using patterning.

This statement reviews patterning as a treatment for children with neurologic impairments. This treatment is based on an outmoded and oversimplified theory of brain development. Current information does not support the claims of proponents that this treatment is efficacious, and its use continues to be unwarranted.

American Academy of Pediatrics. Committee on Children With Disabilities. Care coordination: integrating health and related systems of care for children with special health care needs.

Care coordination is a process that links children with special health care needs and their families to services and resources in a coordinated effort to maximize the potential of the children and provide them with optimal health care. Care coordination often is complicated because there is no single entry point to multiple systems of care, and complex criteria determine the availability of funding and services among public and private payers. Economic and sociocultural barriers to coordination of care exist and affect families and health care professionals. In their important role of providing a medical home for all children, primary care pediatricians have a vital role in the process of care coordination, in concert with the family.

Applications of electrical energy to the prostate: an evolutionary perspective.

PURPOSE: We review modern electrosurgical treatments for removing benign prostatic tissue based on an historical perspective of medical applications of electrical energy. MATERIALS AND METHODS: We reviewed historical reports and landmark observations concerning the evolution of medical applications of electrical energy in the literature, with a special focus on the development of principles pertinent to the transurethral electrosurgical removal of prostate tissue. RESULTS: Modern transurethral electrosurgery of the prostate in a fluid medium has been well founded on key electrosurgical principles. Traditionally, the best clinical results and the least complications have been obtained through an understanding of the important precepts of this form of energy. These precepts have included distinctions between the reliability of effect and safety with direct and alternating current, and how different tissue effects can be achieved, either with selective current modes (cutting and coagulating waveforms) or by varying the size and configuration of the active electrode and its application time. CONCLUSIONS: This review chronicles the prominent role of electrosurgery in our efforts to debulk an enlarged prostate in patients with symptomatic voiding dysfunction. History reminds us that many of today's "new ideas" are merely updated variations on a theme, have often been tried before in a fashion by our predecessors and have for one reason or another fallen by the wayside. The conundrum of the perfect combination of electrosurgical variables that can fulfill our goal of making this an efficient and complication-free treatment continues to stimulate and challenge us as we move towards the next millennium.

Advanced carcinoma of the larynx: results of surgery and radiotherapy without induction chemotherapy (1980-1985): a multivariate analysis.

PURPOSE: Induction chemotherapy has been proposed in the case of advanced laryngeal cancer in order to preserve laryngeal function in those patients who are complete responders. To clarify the treatment policies, a retrospective multicentric analysis of 116 patients with advanced carcinoma of the larynx treated by radical surgery and postoperative radiotherapy was carried out in order to evaluate prognostic factors for local control and survival. METHODS AND MATERIALS: Between 1980 and 1985, 116 patients with Stage III squamous cell carcinoma of the larynx underwent radical surgery and postoperative radiotherapy with a curative intent. Treatments were very homogenous, and doses delivered were in the range of 50-65 Gy according to nodal involvement and surgical margins status. RESULTS: The local recurrence rate and the local disease-free survival rate at 5 years were 22.5% and 76.3%, respectively. Actuarial survival at 5 years was 68.3% with 44 patients still alive with no evidence of disease (NED) with more than 5 years follow-up. For both overall survival and relapse-free survival, cervical node involvement with capsular rupture was found to be the only significant adverse pronostic factor in univariate and multivariate analysis. No other parameter was predictive either for local recurrence or for survival. CONCLUSIONS: Local prognosis and survival depend largely on nodal involvement and capsular rupture while increasing doses of radiation strategy is likely to reduce the risk of local and nodal recurrence. Preservation of functional larynx is certainly an important goal to achieve when treating advanced carcinoma of the larynx, provided that local failure rate and survival be similar. In the unique randomized study previously published in the literature comparing radical surgery and postoperative radiotherapy to induction chemotherapy and radiotherapy, the local-regional failure rate was drastically increased in the chemotherapy arm. Other results from well-designed controlled studies are awaited before recommending systematic induction chemotherapy and larynx preservation in complete responders. On the other hand, testing synchronous or alternated chemotherapy vs. induction chemotherapy may address the pending questions about the optimal treatment of advanced laryngeal carcinoma.

[Results of postoperative cervical node irradiation in carcinoma of the pharyngo-larynx. A study of the cooperative group of radiotherapists]. / Résultats de l'irradiation ganglionnaire cervicale postopératoire dans les carcinomes du pharyngolarynx. Etude du groupe coopérateur des radiothérapeutes de centre.

From 1981 to 1985, 428 patients presenting with an epidermoid carcinoma of the hypopharynx and/or larynx were treated with a curative intent by surgical resection and postoperative irradiation. Two-thirds of the tumours were T3 and 60% of patients presented with a clinical node involvement. The rates of local failure were 8%, 18% and 13%, respectively, for cancers of the larynx, of the piriform sinus and of the posterior wall; the rates of regional failure were 8%, 23% and 13%, respectively. There is no head and neck site with either a high or low risk of recurrence after resection, but the capsular rupture remains a factor of poor prognosis. The survival rate at 5 years of the whole series is 38%, for laryngeal localisation it reaches 62%. The risk of metastases is related to the node involvement and the interval between surgery and irradiation.

[Postoperative radiotherapy in carcinoma of the pyriform sinus. Work of the "Groupe radiothérapie de la Féderation national des centres de lutte le cancer"]. / Radiothérapie postopératoire dans les cancers du sinus piriforme. Travail du groupe radiothérapie de la Fédération nationale des centres de lutte contre le cancer.

Between January 1980 to December 1985, 248 patients with advanced squamous cell carcinoma of the pyriform sinus were retrospectively analysed. Criteria for inclusion in the study were the following: no previous treatment and treatment combining total pharyngolaryngectomy and postoperative radiotherapy. Mean follow up was 5 years with a minimum of 3 years. Seventy-one patients had a local regional recurrence (27.4%). Clinical staging at presentation and residual tumor at the primary site after surgery were factors significantly associated with higher local failure rates. The 5 year survival rate was 33% and the median survival time was 32 months (plateau was reached after the 6th year). The most frequent severe complication observed was pharyngeal stenosis occurring in 6% of the cases. This study confirms the poor prognosis of squamous cell carcinoma of the pyriform sinus, in spite of the combination of radical surgery and high dose postoperative radiotherapy.

Overlooking: a sign of bilateral central scotomata in children.

Four children are reported who always looked above objects of visual interest (overlooking). All had bilateral central scotomata (loss of central visual field). Three had optic nerve disease selectively affecting the papillomacular fibers; the fourth had ocular colobomata affecting the maculae. Overlooking is an important sign of bilateral central scotomata in children: it is an adaptation to loss of central vision.

Differentiation of reperfused-viable (stunned) from reperfused-infarcted myocardium at 1 to 3 days postreperfusion by in vivo phosphorus-31 nuclear magnetic resonance spectroscopy.

Thrombolytic therapy has increased the need for a technique to assess the viability of recently reperfused myocardium. This study examined the ability of in vivo phosphorus-31 (P-31) nuclear magnetic resonance (NMR) spectroscopy to distinguish reperfused-viable (stunned) from reperfused-infarcted myocardium at 6, 30, and 54 hours following coronary artery occlusion in a canine model. A 15-minute occlusion produced reperfused-viable myocardium in five animals and a 360-minute occlusion produced reperfused-infarcted myocardium in six animals. Postreperfusion risk zone myocardial phosphocreatine (PCr) concentration measured by P-31 NMR spectroscopy was significantly depressed throughout the 3-day study period in infarcted but not in viable myocardium (p less than 0.01 between groups, all time points). The postreperfusion ratio of inorganic phosphate (Pi) to PCr concentration, as determined by NMR spectroscopy, was elevated throughout the study period in infarcted but not in viable reperfused myocardium (p less than 0.01 between groups, all time points). Postreperfusion Pi concentration was elevated at 6 hours but not subsequently in reperfused-infarcted myocardium, and was not elevated in reperfused-viable myocardium. Logistic regression models selected PCr concentration and the Pi/PCr ratio as providing the best discrimination between reperfused-viable and reperfused-infarcted myocardium. The accuracy of P-31 NMR variables selected by logistic regression analysis for determining myocardial viability ranged from 97% to 100%.

Effect of variation in heart size on quantitative thallium SPECT.

Quantitative single-photon emission tomographic (SPECT) thallium 201 (201Tl) cardiac studies are frequently used to improve test accuracy. One common technique uses polar mapping of relative tracer distribution to compare patient data to emplates from "normal" patient data. Commercial software does not correct for cardiac size variations. This study's purpose was to determine the effect of uncorrected variations in heart size on the variance of the normal population, which is the basis of template significance levels. Twenty-one male volunteers with low probability (less than 5%) for coronary disease underwent SPECT-Tl stress test. Data analysis with and without size correction was performed. Data were corrected for size by use of a three-dimensional compression/expansion algorithm. Quantitative data were generated by radial search to maximum activity in short-axis reconstructions. The mean activity and its variance was calculated from 288 points encompassing the myocardium. Mean and variance differences were analyzed by paired t test. There was no difference in activity means (pT greater than .9), indicating that size correction does not distort the data. The corrected data had, however, significantly lower variance (pT less than .0001). This shows that ventricular size variation contributes significantly to "normal" template variance and may adversely affect diagnostic accuracy in the absence of volume correction.

Home care for ventilator-dependent children. Psychosocial impact on the family.

The impact of providing home care for ventilator-dependent children was studied in a cross-sectional survey of 18 northern California families. Through the use of a confidential structured interview and the impact on Family Scale, we obtained information on family demographics; the childrens' medical conditions; financial, social, and personal impact on the family; and parental coping-mastery of the care of a ventilator-dependent child at home. Analysis of scores from the impact on Family Scale showed no differences in the perceived family impact between primary caretakers and their spouses. Primary caretakers in the sample, however, showed significantly reduced Coping subscale scores with a longer duration of home ventilatory care. This finding, if confirmed in future studies, has policy implications for physicians and other health professionals working with ventilator-dependent children and their families, especially those who care for children over long periods.

Preparation and evaluation of a 99mTc-SnF2 colloid kit for leukocyte labeling.

Stannous fluoride colloid (SFC) kits for instant radiolabeling with 99mTc were prepared and evaluated for suitability as a leukocyte radiolabeling agent. Technetium-99m labeling for kits stored at -15 degrees C for up to 3 mo was greater than 95% as determined by instant thin layer chromatography while colloid particles of 1-3 microns were measured by electron microscope for these preparations. Canine leukocyte preparations labeled with [99mTc]SFC and characterized by triple density gradients of metrizamide in plasma demonstrated an 83% leukocyte association. Analysis of labeled cell preparation for up to 3 hr demonstrated label stability. Labeled leukocytes, when readministered in normal dogs, demonstrated bi-exponential blood clearance with uptake and subsequent clearance from lung. There was increasing uptake of labeled leukocytes by the liver until steady state was achieved. Furthermore, when whole blood samples were analyzed by the triple density gradient method, an increasing monocyte-to-granulocyte ratio was observed to occur with time. By 3 hr 95% of the whole blood activity was associated with the leukocyte fraction. Dogs in which a 24-hr sterile abscess was created demonstrated elevated blood-pool activity as compared to control with localization of the labeled cells at inflammatory sites within 3 hr following cell readministration.

Reperfused-viable and reperfused-infarcted myocardium: differentiation with in vivo P-31 MR spectroscopy.

The ability of in vivo phosphorus-31 magnetic resonance (MR) spectroscopy to permit accurate distinction between reperfused-viable and reperfused-infarcted myocardium was examined in a canine model of acute coronary occlusion. In vivo myocardial pH and phosphocreatine, adenosine triphosphate, and inorganic phosphate levels were measured at baseline and for the first 90 minutes after reperfusion of a total coronary artery occlusion producing either predominantly viable (nine animals) or infarcted (nine animals) myocardium in the region of metabolic study. Myocardial viability was assessed in each animal by means of postmortem triphenyltetrazolium chloride staining. Tissue was characterized from the in vivo P-31 MR data by means of logistic regression analysis. The accuracy of using the P-31 MR data for distinguishing reperfused-viable from reperfused-infarcted myocardium was 100% (69 of 69 data points, 18 of 18 animals). Results of the logistic regression procedure indicated that phosphocreatine was the metabolic variable enabling most effective separation of reperfused-viable and reperfused-infarcted myocardium. Thus, metabolic data obtained with P-31 MR spectroscopy permit effective separation of reperfused-viable from reperfused-infarcted myocardium.

Radionuclide detection of abnormal ventricular filling patterns in rejecting human allografts.

Parameters of systolic and diastolic function obtained from radionuclide ventriculography (RNV) were evaluated in nine cardiac allograft recipients. In 25 examinations, left end-diastolic volume (LEDV), cardiac output (CO), left ejection fraction (LEF), right ejection fraction (REF), heart rate (HR), peak filling rate (PFR), time to peak filling rate (TPFR), peak ejection rate (PER), and average filling rate for the first half of diastole (DFRH) were determined. Endomyocardial biopsy was obtained within 48 hours. Biopsies were divided into three treatment classes (0 = normal; 1 = rejection but not requiring supplemental therapy; and 2 = rejection requiring supplemental immunotherapy). Two independent variables of diastolic function proved to be significant (DFRH P less than 0.00001, and PFR P less than 0.002) predictors of the dependent variable class when regression analysis was applied to the data. Alterations in diastolic function associated with acute rejection are detectable on RNV and simulate changes anticipated in a primary restrictive cardiomyopathy.