Feasibility of renal perfusion quantification by Fourier decomposition MRI.

PURPOSE: To evaluate the feasibility of perfusion measurements in the human kidney by Fourier decomposition MRI (FD-MRI). METHODS: Renal perfusion measurements by FD-MRI and arterial spin labeling (ASL) were performed using a 1.5 T whole-body MR-scanner (Magnetom Avanto, Siemens Healthineers AG, Germany) in 15 healthy volunteers (mean age 33.0 ± 13.6 years). Five healthy volunteers were measured twice to evaluate the reproducibility. Besides, five patients with renal artery stenosis (RAS) (mean age 58.4 ± 16.2 years) were included in the study to evaluate potential clinical use of the FD-MRI for evaluating renal perfusion. For renal FD-MRI, coronal 2D-TrueFisp sequence (1 section; section thickness: 10 mm; FOV: 400 × 400 mm 2; TR/TE: 2.06/0.89 ms; 250 images; 0,36 s/image), for renal ASL, coronal FAIR-TrueFisp sequence (1 section; section thickness: 10 mm; FOV: 400 × 400 mm2; TR/TE 4.0/2.0 ms, TI 1200 ms, 30 averages; 8,32 s/average) were acquired without any triggering. Perfusion parameter maps of the kidneys were calculated for both methods. After manual segmentation, ROI-based analysis (whole kidney, cortex and medulla, respectively) was performed and the results were subsequently compared using the Student t-test. RESULTS: The acquisition times were 1.30 min and 4.16 min, for renal FD-MRI and ASL, respectively. No significant difference in global renal perfusion (RBF) between both methods was detected (mean RBF in the right kidney: 308.4 ± 31.5 mL/100 mL/min for FD-MRI; 315.2 ± 41.1 for ASL; in the left kidney: 315.6 ± 32.8 mL/100 mL/min for FD-MRI; 310.2 ± 39.1 mL/100 mL/min for ASL, respectively). The results indicated good reproducibility of both considered methods. However, cortico-medullar differentiation was not possible by FD-MRI, probably due to lower SNR compared to ASL. Significant difference in the side-separated RBF were measured by FD-MRI as well as by ASL (p < 0.05) in patients with RAS. CONCLUSIONS: FD-MRI is a novel, rapid approach for contrast-free perfusion quantification in the human kidney. Main advantage of this new method compared to ASL perfusion is the significant shorter acquisition time and lower dependency on patient's compliance. However, lower SNR of FD-MRI needs further improvement to make FD-MRI a competitive alternative to ASL.

CFA-15 - a perfluorinated metal-organic framework with linear 1-D CuII-chains containing accessible unsaturated, reactive metal centres.

The synthesis and crystal structure of the perfluorinated metal-organic framework CFA-15 (Coordination Framework Augsburg University-15), CuII3(tfpc)2(OH)2·DMF, as well as the crystal structure of its ligand (H2-tfpc = 3,5-bis(trifluoromethyl)-1H-pyrazole-4-carboxylic acid) are described. The MOF crystallizes in the monoclinic crystal system within the chiral space group C2 (no. 5). It features a 3-D microporous framework with rhombic channels along the c-axis. The MOF is formed by 1-D chains of Cu(ii) ions expanding in the c-direction, bridged by OH- groups, DMF molecules and tfpc2- ligands. Two different Cu(ii) species are located within the structure, bridged in a {Cu1-Cu1-Cu2-Cu1-Cu1-Cu2} mode. By thermal treatment, it was possible to remove coordinated solvent molecules and generate free accessible, unsaturated and reactive metal centres. The structure of activated CFA-15 was refined via Rietveld method. DRIFT measurements, which were used to study adsorption of CO2 and NO in the MOF, showed a formation of a stable NO-CFA-15 complex. CFA-15 was further characterized by thermogravimetric analysis, variable temperature powder X-ray diffraction measurements, IR spectroscopy, as well as photoluminescence and gas sorption measurements. The isosteric heats of adsorption for CO, CO2, H2 and O2 were determined, and compared to DFT calculated sorption energies as well as to data reported in literature for similar materials.

A gesture-controlled projection display for CT-guided interventions.

PURPOSE: The interaction with interventional imaging systems within a sterile environment is a challenging task for physicians. Direct physician-machine interaction during an intervention is rather limited because of sterility and workspace restrictions. METHODS: We present a gesture-controlled projection display that enables a direct and natural physician-machine interaction during computed tomography (CT)-based interventions. Therefore, a graphical user interface is projected on a radiation shield located in front of the physician. Hand gestures in front of this display are captured and classified using a leap motion controller. We propose a gesture set to control basic functions of intervention software such as gestures for 2D image exploration, 3D object manipulation and selection. Our methods were evaluated in a clinically oriented user study with 12 participants. RESULTS: The results of the performed user study confirm that the display and the underlying interaction concept are accepted by clinical users. The recognition of the gestures is robust, although there is potential for improvements. The gesture training times are less than 10 min, but vary heavily between the participants of the study. The developed gestures are connected logically to the intervention software and intuitive to use. CONCLUSIONS: The proposed gesture-controlled projection display counters current thinking, namely it gives the radiologist complete control of the intervention software. It opens new possibilities for direct physician-machine interaction during CT-based interventions and is well suited to become an integral part of future interventional suites.

Alteration of monocyte function following major injury.

The macrophage exerts its stimulatory and regulatory functions within the specific immune response via the interleukin 1 (IL-1) and prostaglandin E2 (PGE2), respectively. In a screening study of macrophage-related variables following injury, a total of 58 patients (mean age, 32 years; mean injury Severity Score, 38), macrophagic phenotyping with the monoclonal antibody Leu M3 and serial measuring of the antagonistic monokines IL-1 and PGE2 and of the macrophage-activating lymphokine interferon gamma were carried out on posttrauma days 0, 1, 3, 5, 7, 10, 14, and 21. The posttraumatic course was characterized by significant monocytosis, showing a peak value of 32% of Leu M3-positive cells compared with 15% of these cells in normal control subjects. During the posttrauma course, the macrophagic PGE2 output was significantly elevated up to eightfold on days 5 and 7 compared with that of control subjects (0.441 +/- 0.14 ng/mL vs 0.052 +/- 0.01 ng/mL). Conversely, macrophagic IL-1 synthesis was significantly suppressed until day 10. Levels of interferon gamma were suppressed to a significant degree during the two-day observation period, with a trend to slow recovery at the end of week 3. These data suggest that a negative regulatory macrophagic function may be the event initiating posttraumatic immunosuppression. To restore impaired macrophagic T-helper cell interaction, cyclo-oxygenase inhibition and substitution of interferon gamma may be useful to potentiate facilitatory macrophagic function and to block inhibitory macrophagic activity.

Improved watershed transform for medical image segmentation using prior information.

The watershed transform has interesting properties that make it useful for many different image segmentation applications: it is simple and intuitive, can be parallelized, and always produces a complete division of the image. However, when applied to medical image analysis, it has important drawbacks (oversegmentation, sensitivity to noise, poor detection of thin or low signal to noise ratio structures). We present an improvement to the watershed transform that enables the introduction of prior information in its calculation. We propose to introduce this information via the use of a previous probability calculation. Furthermore, we introduce a method to combine the watershed transform and atlas registration, through the use of markers. We have applied our new algorithm to two challenging applications: knee cartilage and gray matter/white matter segmentation in MR images. Numerical validation of the results is provided, demonstrating the strength of the algorithm for medical image segmentation.

Un análisis del problema ético y legal del tratamiento del cáncer cervicouterino en mujeres embarazadas: [revisión] / Ethical and legal problem in the treatment of cervical cancer in pregnant women: [review]

Se analiza el problema ético y jurídico del tratamiento del cáncer cervicouterino en mujeres embarazadas. Se realizó una revisión del tema, de las leyes chilenas y de algunas normativas europeas para después analizar la aplicación de los principios de No Maleficencia, Beneficencia, Autonomía y del Doble Efecto. El tema genera una difícil discusión e interpretación, pues tanto las leyes como los principios son orientadores, pero no explícitos para decidir la conducta más adecuada en cada caso. Lo ideal es preservar la vida materna y fetal, pero hay casos en los que, finalmente, es necesario priorizar una sobre la otra. Corresponde al equipo tratante, la madre, el padre, la familia y la sociedad concordar las conductas más responsables y justas posibles.

Authors analyze the ethical and legal problem about the treatment of cervical cáncer in pregnant women. A review of the Chilean laws and European regulations was made in order to analyze the application of the principies of Non maleficence, Beneficence, Autonomy and the Double Effect. The subject generates a difficult discussion and interpretation since both, law and principies, are guiding but do not give an explicit answer to choose the more appropriate behavior in each case. The goal is to preserve maternal and fetal life, but there are cases in which it is necessary to prioritize one over the other. A consensus between medical staff, the mother, the father, the family and society is necessary for a more responsible and fair decision.

[Treatment guidelines for inflammatory and malignant diseases of the thyroid gland]. / Behandlungsrichtlinien bei entzündlichen und malignen Erkrankungen der Schilddrüse.

Most cases of thyroiditis can be treated with antibiotics, antiphlogistics, and corticosteroids. In case of abscess caused by bacterial infection or compression of the trachea surgical therapy is required for drainage and resection. The prognosis for differentiated malignant tumours of the thyroid gland is good even if metastases have occurred. The recommended therapy includes total resection of the thyroid gland and radioiodine therapy to eliminate any remaining thyroid tissue. For anaplastic thyroid carcinomas surgery should be considered because of the extremely poor prognosis for these types of tumours. Resection should be performed to improve the patient's quality of life by avoiding tracheostoma or to ensure normal nutritional uptake. Medullary thyroid carcinoma is known in sporadic and in hereditary forms. Thyroidectomy is the accepted therapy. In 15% of the patients we observed the syndrome of multiple endocrine neoplasms (MEN), which is a form of thyroid carcinoma complicated by pheochromocytoma and hyperparathyroidism. Diagnosis of thyroid carcinomas includes examination of the patient, scintigraphy and ultrasonography of the thyroid gland, and cytological examination by aspiration biopsy. Post-operative care includes substitution of thyroid hormones, regular measurement of the thyreoglobulin levels in the blood, and examination for metastases in the lungs, the abdomen, and the bones.

[Bronchial stump insufficiency: treatment and results]. / Die Bronchusstumpfinsuffizienz: Behandlung und Ergebnisse.

A bronchopleural fistula following lung resection is a dangerous complication. Records from 25 patients with a bronchopleural fistula were followed up in order to propose a therapeutic concept. An early onset of fistula should be treated as an emergency. Late fistulas can be reoperated electively because they are most often rather small and the patients are in a better condition. The suture of the stump alone was successful in only 3 out of 13 cases. Patients with fistulas following lobectomy were reoperated by pneumonectomy with good results. In fistulas due to pneumonectomy the results of either an isolated muscle-flap or a thoracoplasty were disappointing. Instead, a closure of the stump was accomplished by the combination of thoracoplasty and muscle-flap in 3 out of 4 patients. However, 2 patients with an early fistula after pneumonectomy died from septic complications after the fistulas had already been managed. Endoscopic maneuvers like gluing and insertion of spongiosa did not show any success unless combined with operative measures but rather delayed the onset of re-intervention.

[Extended resections in bronchial cancer: complications and late results]. / Erweiterte Resektionen bei Bronchialkarzinom: Komplikationen und Spätergebnisse.

From 1982 through April 1992, 192 patients underwent extended resection for non-small cell carcinoma of the lung (NSCLC) invading the chest wall (n = 52) or the mediastinum (n = 140). Complete resection of the tumor was possible in 81 (58%) patients with invasion of mediastinum and in 34 (65%) patients with invasion of the chest wall. The operative mortality was 9%, respiratory complications causing most of the postoperative morbidity and mortality. Incomplete resection was associated with poor prognosis. The mean survival of these patients was 10 month. The 5 year actuarial survival rate of patients having curative resection was 20%. In these patients the presence of lymphatic metastases significantly reduced survival, with a 3 year actuarial survival rate of 40% of patients with No disease, and 30% or 5% for those with N1 or N2 disease, respectively. In conclusion, extended resection for advanced NSCLC offers a significant chance for long-term survival in the absence of N2 lymphatic metastases. In the presence of N2 metastases and poor overall prognosis however, reasonable palliation is the primary goal of surgical management.

Prostaglandin E2 (PGE2)-dependent suppression of interleukin alpha (IL-2) production in patients with major trauma.

The depression of interleukin-2 synthesis represents a major dysfunction within the cascade of immunologic defects induced by mechanical and thermal trauma. This study was undertaken to elucidate the negative control mechanisms that were responsible for the deficiency of IL-2 production in polytraumatized patients. Peripheral blood mononuclear cells (PBMC's) from 29 patients (average age, 35.8 years; average ISS, 35) were separated on post-trauma days 1, 3, 5, 7, 10, 14, and 21 and cultured as untreated cells (C), cells treated with indomethacin (C + INDO), and cells depleted of adherent cells (C-AC). Cell cultures were assayed for proliferative responses to PHA, IL-2 synthesis, PGE2 production, gamma-interferon levels, and phenotyping studies. On all days post-trauma there was found a marked reduction of IL-2 production compared to controls with a highly significant nadir from day 5 to day 10 with an almost 80% inhibition of IL-2 (p less than 0.005). C + INDO cells showed increases of IL-2 synthesis over untreated cells ranging from 48% (Day 1) to 220% (Day 7). Removal of adherent cells (C-AC) did not reverse the suppression of IL-2 production. gamma-interferon levels were depressed in parallel with IL-2 levels but did not increase with C + INDO. The phenotyping of the PBMC's showed highly significant suppression of OKT3+, OKT4+, and IL-2R+ lymphocytes as well as a highly significant elevation of the monocyte (p less than 0.005) count. There was a highly significant increase of PGE2 synthesis from monocytes, due to the monocytosis and to a higher capacity of synthesis of the individual cells following trauma. PGE2 levels peaked on Day 5 and 7 post-trauma at 400% of control (p less than 0.005). These data suggest that the suppression of IL-2 synthesis post trauma is caused mainly by two factors: the excessive PGE2 output of inhibitory monocytes and inadequate function in immature and/or blocked lymphocytes. The partial restoration of IL-2 synthesis by indomethacin suggests that blockade of the cyclo-oxygenase pathway as an immunomodulating therapy may reverse some of the immunologic abnormalities in multiple trauma patients.