[Clinically relevant incidental cardiovascular findings in CT examinations]. / Klinisch relevante kardiovaskuläre Zufallsbefunde bei CT­Untersuchungen.

BACKGROUND AND METHOD: Incidental cardiovascular findings are a frequent phenomenon in computed tomography (CT) examinations. As the result of a dedicated PubMed search this article gives a systemic overview of the current literature on the most important incidental cardiovascular findings, their prevalence and clinical relevance. RESULTS: The majority of incidental cardiovascular findings are of only low clinical relevance; however, highly relevant incidental findings, such as aortic aneurysms, thromboses and thromboembolic events can also occasionally be found, especially in oncology patients. CONCLUSION: The scans from every CT examination should also be investigated for incidental findings as they can be of decisive importance for the further clinical management of patients, depending on their clinical relevance.

Sequential therapy with cyclophosphamide and mycophenolic acid in patients with progressive immunoglobulin A nephropathy: a long-term follow-up.

In progressive immunoglobulin (Ig)A nephropathy (IgAN), cyclophosphamide pulse therapy (CyP), high-dose intravenous immunoglobulins (IVIg) and mycophenolic acid (MPA) have been used to stop progressive loss of renal function, but disease progression may occur after the end of the initial treatment. Here, we report the long-term follow-up of patients with progressive IgAN with MPA as maintenance therapy after CyP (CyP-MPA). In a median observation time of 6·2 years, we analysed the slopes of the loss of renal function of 47 patients with biopsy-proven IgAN and treated with CyP. Thirty-one patients with further progression were treated with MPA maintenance for a median time of 5·2 years. Follow-up was compared with symptomatic therapy and IVIg as historically matched control groups. Median loss of renal function was reduced significantly from 0·9 ml/min to 0·1 ml/min per month with CyP (P < 0·05), and with MPA in patients with a relapse from -0·4 ml/min to -0·1 ml/min per month (P < 0·05) until the end of the study. Proteinuria decreased significantly from 1·6 g/l to 1·0 g/l after CyP, and during MPA treatment to 0·6 g/l (P = 0·001 Friedman test). Median renal survival time was in patients with CyP 10·5 years (range = 3·2-17·8), with CyP-MPA 10·7 years (range = 8·3-13·1), with IVIg 4·7 years (range = 2·6-6·6), and in untreated patients 1·2 years (range = 0·8-1·6; log-rank test P < 0·01). In patients with progressive IgAN, our long-term follow-up observation indicates that sequential CyP-MPA therapy maintains renal survival significantly.

[Molecular imaging of head and neck cancers : Perspectives of PET/MRI]. / Molekulare Bildgebung bei Kopf-Hals-Tumoren : Perspektive der PET-MRT.

BACKGROUND: The (18)F-fluorodeoxyglucose positron emission tomography-computed tomography ((18)F-FDG-PET/CT) procedure is a cornerstone in the diagnostics of head and neck cancers. Several years ago PET-magnetic resonance imaging (PET/MRI) also became available as an alternative hybrid multimodal imaging method. OBJECTIVE: Does PET/MRI have advantages over PET/CT in the diagnostics of head and neck cancers? MATERIAL AND METHODS: The diagnostic accuracy of the standard imaging methods CT, MRI and PET/CT is depicted according to currently available meta-analyses and studies concerning the use of PET/MRI for these indications are summarized. RESULTS: In all studies published up to now PET/MRI did not show superiority regarding the diagnostic accuracy in head and neck cancers; however, there is some evidence that in the future PET/MRI can contribute to tumor characterization and possibly be used to predict tumor response to therapy with the use of multiparametric imaging. CONCLUSION: Currently, (18)F-FDG-PET/CT is not outperformed by PET/MRI in the diagnostics of head and neck cancers. The additive value of PET/MRI due to the use of multiparametric imaging needs to be investigated in future research.

Initial clinical results of simultaneous 18F-FDG PET/MRI in comparison to 18F-FDG PET/CT in patients with head and neck cancer.

PURPOSE: The aim of this study was to evaluate the diagnostic capability of simultaneous (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/MRI compared to (18)F-FDG PET/CT as well as their single components in head and neck cancer patients. METHODS: In a prospective study 17 patients underwent (18)F-FDG PET/CT for staging or follow-up and an additional (18)F-FDG PET/MRI scan with whole-body imaging and dedicated examination of the neck. MRI, CT and PET images as well as PET/MRI and PET/CT examinations were evaluated independently and in a blinded fashion by two reader groups. Results were compared with the reference standard (final diagnosis determined in consensus using all available data including histology and follow-up). Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated. RESULTS: A total of 23 malignant tumours were found with the reference standard. PET/CT showed a sensitivity of 82.7%, a specificity of 87.3%, a PPV of 73.2% and a NPV of 92.4%. Corresponding values for PET/MRI were 80.5, 88.2, 75.6 and 92.5%. No statistically significant difference in diagnostic capability could be found between PET/CT and PET/MRI. Evaluation of the PET part from PET/CT revealed highest sensitivity of 95.7%, and MRI showed best specificity of 96.4%. There was a high inter-rater agreement in all modalities (Cohen's kappa 0.61-0.82). CONCLUSION: PET/MRI of patients with head and neck cancer yielded good diagnostic capability, similar to PET/CT. Further studies on larger cohorts to prove these first results seem justified.

[Spondylosclerosis hemispherica: a rare radiological syndrome of the spine]. / Spondylosclerosis hemispherica: Ein seltenes bildmorphologisches Syndrom der Wirbelsäule.

BACKGROUND: Spondylosclerosis hemispherica is a rare syndrome of the spine and was described first by Dihlmann. The typical radiographic appearance is a hemispherical sclerosis of the vertebral body, which is accompanied by pain in the affected region. Usually it appears at the lower lumbar spine. The etiology varies and includes degenerative disk diseases, scoliosis, bacterial infections, ankylosing spondylitis, osteoid osteoma, and malignant diseases.The radiological findings of 2 patients with spondylosclerosis hemispherica are presented and the current literature discussed. MATERIAL AND METHODS: Two women (33 and 60 years old) with spondylosclerosis hemispherica of the lower spine suffered from low back pain and fulfilled all criteria of Dihlmann's description. Malignant disease was excluded in both cases with a broad diagnostic workup (lab values, x-ray, CT scan, MRI) and in one case a biopsy from the affected vertebra was taken. RESULTS: In both cases all radiological findings demonstrated the typical changes of spondylosclerosis hemispherica with sclerosis of the vertebra body and erosions at the upper and inferior end plates. Malignant disease was excluded in one case with a biopsy and in the other case with noninvasive diagnostic procedures. Both patients were treated nonsurgically. During clinical follow-up, the patients were in a good condition with decreasing regional low back pain and no ongoing radiological changes in the affected vertebral bodies. CONCLUSION: Spondylosclerosis hemispherica is a syndrome with a typical radiographic appearance. The etiology of spondylosclerosis hemispherica is manifold; however, malignancy must be excluded. In most cases, noninvasive diagnostics are sufficient to rule out malignant growth even in cases with concomitant degenerative changes of the affected segment. Thus, there is no need for a biopsy except in cases with ambiguous results. Subsequently, close clinical and radiological follow-up of the patients with spondylosclerosis hemispherica is necessary.

Imaging of the sinuses for functional sinus surgery using navigational guidance.

Advances in the understanding of mucociliary activity and pathophysiology of the nasal cavity and paranasal sinuses have revolutionized the surgical management of chronic and recurrent sinusitis. The development of functional endoscopic sinus surgery (FESS) can also be seen as the pioneer task in endoscopic surgery. Today, in more than 50% of all sinus surgeries FESS is being used. Inflammatory causes are the most common indication for surgery, which can be evaluated best preoperatively using (multi-detector) computed tomography. Even today there are further relevant developments of FESS that result in alleviation of the surgeon due to different degrees of automation. Using a preoperatively acquired navigational dataset helps choosing the optimal surgical strategy. Intraoperatively the navigational dataset is at present mainly used for localization of surgical tools. These newer operation methods demand for high-quality radiological imaging and evaluation, consisting of delineation of the local (inflammatory) process, detection of disease related complications and description of anatomical variations that may be important to the surgeon. Since patients with chronic recurrent sinusitis are relatively young on average and recurrent disease or further CT examinations are not uncommon, there should always be a focus on reduction of radiation exposure as much as possible. Technical advances like cone-beam tomography seem promising to further improve dose reduction as well as spatial resolution.

Hypernatremia without water depletion.

Hypernatremia is generally thought to be a condition in which water depletion raises the serum sodium concentration despite some salt loss. However, many patients with hypernatremia have been shown to have normal or increased total body water, indicating that these patients are salt- and frequently water-overloaded. Possible pathophysiological reasons for these abnormalities are discussed. Recognition of this clinical condition is important because therapy should avoid further worsening the salt and water overload.

[Polycomb and trithorax control genome expression by determining the alternative epigenetic states of chromatin for key developmental regulators].

The Polycomb (PcG) and Trithorax (TrxG) group proteins are essential for development in all multicellular organisms. Mutations of the PcG and TrxG genes act as early embryonic lethals, while their overexpression correlates with malignancies. Comparative genome analysis showed that PcG and TrxG form a binary regulatory system that functions as an epigenetic rheostat to determine the threshold levels of extracellular signals affecting the expression levels of key developmental genes.

Clinical management of COVID-19: Experiences of the COVID-19 epidemic from Groote Schuur Hospital, Cape Town, South Africa.

The SARS-CoV-2 pandemic has presented clinicians with an enormous challenge in managing a respiratory virus that is not only capable of causing severe pneumonia and acute respiratory distress syndrome, but also multisystem disease. The extraordinary pace of clinical research, and particularly the surge in adaptive trials of new and repurposed treatments, have provided rapid answers to questions of whether such treatments work, and has resulted in corticosteroids taking centre stage in the management of hospitalised patients requiring oxygen support. Some treatment modalities, such as the role of anticoagulation to prevent and treat potential thromboembolic complications, remain controversial, as does the use of high-level oxygen support, outside of an intensive care unit setting. In this paper, we describe the clinical management of COVID-19 patients admitted to Groote Schuur Hospital, a major tertiary level hospital at the epicentre of South Africa's SARS-CoV-2 epidemic during its first 4 months.

[Impulse oscillometry in the diagnosis of the severity of obstructive pulmonary disease]. / Die Impulsoszillometrie in der Schweregraddiagnostik obstruktiver Lungenerkrankungen.

Impulse oscillometry (IOS) is a computer-supported method for the measurement of complex mechanical airway characteristics. The aim of this study was to evaluate the applicability of IOS in the diagnosis of obstructive airway diseases in comparison to the standard methods of spirometry, pneumotachymetry, and bodyplethysmography. 244 patients (age 61.5 +/- 13.6 years; 61 % men) with bronchial asthma (n = 65) and chronic obstructive pulmonary disease (COPD) (n = 179) were retrospectively analysed. By means of body plethysmography (Srtot < 120%pred) an obstruction was diagnosed in 94%, by pneumotachymetry (FEV1 < 80%pred) in 78 %, and by IOS depending on the parameter chosen in 87-94% of patients. Mild and medium obstructions could be identified by means of all IOS parameters except for R20: severe obstructions, however, were better detected by means of the frequency-dependent resistance FDR and reactance at 5 Hz, X5. The parameters R5, X5, and Zrs, however, showed a tendency to underestimate the degree of obstruction. Bronchial obstruction can reliably be diagnosed by IOS when, in cases of severe obstruction, more complex parameters like FDR and X5 are included. The parameters of the standard methods (body plethysmography and pneumotachymetry) show relatively low correlations due to the different measurement methods not only in comparison to IOS but also to one another. In summary, IOS is a convenient method for patients with a low dependency on cooperation for the evaluation of obstructive airway diseases complementary to the established standard methods and, in addition, is useful as a sensitive screening tool for the early detection of bronchial obstruction.

[Analysis of the quality of life of patients with osteoid osteoma before and after radiofrequency ablation treatment]. / Analyse der Lebensqualität von Patienten mit Osteoidosteom vor und nach Behandlung mittels Radiofrequenzablation.

BACKGROUND: The aim of this study was to investigate the effectiveness of the treatment of osteoid osteomas (OO) by radiofrequency ablation (RFA). In particular, the recurrence rate and the improvement in the quality of life as assessed by the reduction of pain intensity were evaluated. METHODS: Retrospective analysis of 26 patients after RFA of an OO and prospective analysis of 14 patients using a self-developed quality of life questionnaire. The questionnaire, the electronic patient file and the histopathological findings were processed. RESULTS: An average of 22 months passed between the first onset of complaints and the causative treatment by RFA. After RFA, there was a significant reduction in pain symptoms and thus an increase in the quality of life. These results confirm that RFA from OO is a safe and efficient treatment procedure. DISCUSSION: In order to avoid long-term conservative treatment attempts and to reduce effects on the musculoskeletal system, a timely RFA of OO should be performed after diagnosis.

Glucocorticoid-induced alterations in the sodium potassium pump of the human erythrocyte.

To evaluate the effects of glucocorticoids on the Na-K pump in human subjects, were evaluated the intracellular sodium and potassium, 42K influx across and the [3H]ouabain binding to cell membranes of intact human erythrocytes from a group of subjects taking glucocorticoids and a group of normal subjects. Intracellular sodium concentration was lower (7.2 +/- 0.4 vs. 10.9 +/- 0.2 mmol/liter cell water) and intracellular potassium concentration higher (149.8 +/- 1.5 vs. 137.2 +/- 1.2 mmol/liter cell water) in erythrocytes from steroid-treated patients. In spite of a significantly decrease intracellular sodium which normally diminishes ouabain-sensitive 42K influx, the ouabain-sensitive K influx was unchanged in erythrocytes from the steroid-treated group. Maximum [3H]ouabain binding was markedly higher in the steroid-treated group (835 +/- 44 vs. 449 +/- 11 sites/cell). There was close linear correlation between [3H]ouabain binding and inhibition of K pump, suggesting the specificity of ouabain binding to Na-K pump sites on the cell membrane. Association kinetics for ouabain were similar in the two groups despite the marked difference in the amount of [3H]ouabain binding. External potassium concentration required for half-maximum ouabain-sensitive K influx was identical in the two groups. Thus, the additional Na-K pump sites in the steroid-treated group were qualitatively similar to those in normals. These results suggest that administration of glucocorticoids leads to an increase in the number of Na-K pump sites. The increase in the number of Na-K pump sites may explain the low levels of intracellular sodium and higher cell potassium observed in steroid-treated subjects.

Mechanism of alteration of sodium potassium pump of erythrocytes from patients with chronic renal failure.

We examined intracellular electrolytes, K influx, and [3H]ouabain-binding capacity of erythrocytes from 32 normal subjects and 45 patients with end-stage renal failure on dialysis, including 16 with high intracellular Na (mean 17.3 +/- 3.9 mmol/liter cell water). The [3H]ouabain-binding capacity of erythrocytes with high cell Na was markedly reduced as compared with that of erythrocytes from normal subjects (274 +/- 52 vs. 455 +/- 59 sites/cell, P less than 0.001). The mean serum creatinine was higher in the uremic group with high cell Na. There was a significant linear correlation between intracellular Na and [3H]ouabain-binding in both normal and uremic subjects. Cross-incubation of normal cells with uremic plasma for 24 h failed to reduce [3H]ouabain-binding capacity of normal cells. In spite of a substantial increase in cell Na, K pump influx was not higher in uremic erythrocytes with high cell Na. When intracellular Na was altered with nystatin (cell Na equal to 120 mmol/liter cell water in both groups), K pump influx was proportional to the number of Na-K pump sites so that the ion turnover rate per pump site was similar in the two groups. Uremic plasma failed to depress K pump influx of normal erythrocytes. The passive net influx of Na in uremic cells with high intracellular Na was not different from that observed in erythrocytes from normal subjects. When erythrocytes were separated by age on Percoll density gradients, the number of Na-K pump sites of the youngest uremic cells was significantly lower than that of the youngest normal cells, suggesting that decreased synthesis of Na-K pump sites, rather than accelerated loss of Na-K pump sites during aging, was responsible for the decrease in [3H]ouabain-binding capacity of erythrocytes from uremic subjects. Taken together, these findings suggest that a decrease in the number of Na-K pump sites plays a major role in the abnormality of Na-K pump of erythrocytes from patients with chronic renal failure.

Effects of hypotonic saline loading in hydrated dog: evidence for a saline-induced limit on distal tubular sodium transport.

We performed studies on dogs under hydrated conditions, utilizing the rate of free water formation (C(H2O)) as an index of the rate of distal tubular sodium transport. Since C(H2O) could be progressively increased with no evidence of a maximal rate during loading with hypotonic (2.5%) mannitol, it was concluded that there is no limit on distal tubular sodium transport during mannitol loading. In contrast, during hypotonic (0.45%) saline loading C(H2O) rose initially, but as urine flow (V) exceeded 25% of the filtered load C(H2O) attained maximal levels (up to 20% of the filtered load) and remained stable as V increased to 50% of the filtered load. It was concluded that saline loading progressively inhibits proximal sodium reabsorption. Initially, the distal tubule absorbes a large fraction of the proximal rejectate and sodium excretion rises slightly. Eventually, an alteration in distal sodium transport appears which culminates in a maximal rate or transport limit. This distal transport limit provoked by saline loading could not be characterized by a classical Tm as seen with glucose and does not seem to be consequent to high rates of flow through the distal tubule. Regardless of the precise nature of this limit, the major increment in sodium excretion develops during saline loading only after saline alters the capacity of the distal tubule to transport sodium.

Attachment of HeT-A sequences to chromosomal termini in Drosophila melanogaster may occur by different mechanisms.

Drosophila telomeres contain arrays of the retrotransposonlike elements HeT-A and TART. Their transposition to broken chromosomal termini has been implicated in chromosome healing and telomere elongation. The HeT-A element is attached by its 3' end, which contains the promoter. To monitor the behavior of HeT-A elements, we used the yellow gene with terminal deficiencies consisting of breaks in the yellow promoter region that result in the y-null phenotype. Attachment of the HeT-A element provides the promoterless yellow gene with a promoter that activates yellow expression in bristles. The frequency of HeT-A transpositions to the yellow terminal deficiency depends on the genotype of the line and varies from 2 x 10(-3) to less than 2 x 10(-5). Loss of the attached HeT-A due to incomplete replication at the telomere leads to inactivation of yellow expression, which is restored by attachment of a new HeT-A element upstream of yellow. New HeT-A additions occur at a frequency of about 1.2 x 10(-3). Short DNA attachments are generated by gene conversion using the homologous telomeric sequences as templates. Longer DNA attachments are generated either by conventional transposition of an HeT-A element to the chromosomal terminus or by recombination between the 3' terminus of telomeric HeT-A elements and the receding end of HeT-A attached to the yellow gene.

Treatment of invasive pulmonary aspergillosis in neutropenic patients by additional bronchoscopic amphotericin B instillation.

BACKGROUND: Invasive pulmonary aspergillosis (IPA) remains a life-threatening condition despite systemic antifungal therapy. OBJECTIVES: This retrospective analysis investigated whether additional bronchoscopic instillation of amphotericin B (amB) would improve efficacy of antifungal treatment in patients with haematological malignancies suffering from IPA. METHODS: Twenty patients (40.6 +/- 14.2 years, 14 male) with preceding chemotherapy, bone marrow or stem cell transplantation complicated by severe IPA who did not respond sufficiently to systemic antifungal therapy were additionally treated by repeated bronchoscopic instillations of amB solution (91 instillations, on average 4.6 +/- 2.2 instillations per patient over a period of 24.1 +/- 21.0 days). Therapeutic response to this combined treatment regimen was monitored by chest X-ray and CT scan. RESULTS: The mean infiltration sizes during systemic antifungal therapy alone (mean duration 11.9 +/- 9.9 days) did not change significantly. However, after additional bronchoscopic instillation of amB solution infiltration sizes were reduced significantly (p < 0.05). A total resolution of infiltrates was seen in 3 and a partial reduction in 13 of 20 patients. Mean duration of total antifungal treatment was 50.1 +/- 24.0 days. The mean follow-up period was 34.1 +/- 31.2 months. The IPA-related mortality rate was 18.8% (3 of 16 patients). CONCLUSIONS: Additional bronchoscopic instillation of amB may improve the efficacy of systemic antifungal therapy in patients with haematological malignancies complicated by severe IPA. Bronchoscopic instillation of amB should be considered as an additional treatment option in cases with IPA unresponsive to systemic therapy.

[Conversion coefficients for estimation of effective dose to patients from dose area product during fluoroscopy x-ray examinations]. / Konversionsfaktoren zur Ermittlung der effektiven Dosis für Patienten aus dem Dosisflächenprodukt bei Röntgendurchleuchtungsuntersuchungen.

PURPOSE: The effective dose, which is related to the stochastic radiation risk, cannot be measured directly. Therefore, conversion coefficients for estimating the effective dose for patients were calculated for fluoroscopy X-ray examinations from the dose area product which can be easily measured. MATERIALS AND METHODS: Conversion coefficients were calculated using the PC-based Monte Carlo program PCXMC in software version 1.5.1. Conversion coefficients were determined for tube voltages between 60 kV and 110 kV, for additional cupper filtration up to 0.9 mm, for different projections (a. p., p. a. and lateral) and X-ray field size (between 20 cm x 20 cm and 40 cm x 40 cm in image plane) and field position (from head to leg). RESULTS: Tube voltage, filtration and field position have a significant effect on conversion coefficients. Conversion coefficients increase as the tube voltage and filtration increase. Depending on the radiation spectrum used, the conversion coefficients may differ up to a factor of 4 for the same X-ray examination. The highest conversion coefficients were found for irradiation of the body region followed by the head and leg region. The effect of the field size and projection is moderate. Conversion coefficients for a. p. projection are higher than those for p. a. and lateral projections. CONCLUSION: Effective dose can be easily estimated by multiplying relevant conversion coefficients by the dose area product. Using conversion coefficients from the literature that do not take additional cupper filtration into consideration can underestimate the effective dose by a factor or up to 2 or more depending on the filtration used.

Influence of grid control and object detection on radiation exposure and image quality using mobile C-arms - first results.

PURPOSE: The objective of this study was to examine the extent to which the image quality on mobile C-arms can be improved by an innovative exposure rate control system (grid control). In addition, the possible dose reduction in the pulsed fluoroscopy mode using 25 pulses/sec produced by automatic adjustment of the pulse rate through motion detection was to be determined. MATERIALS AND METHODS: As opposed to conventional exposure rate control systems, which use a measuring circle in the center of the field of view, grid control is based on a fine mesh of square cells which are overlaid on the entire fluoroscopic image. The system uses only those cells for exposure control that are covered by the object to be visualized. This is intended to ensure optimally exposed images, regardless of the size, shape and position of the object to be visualized. The system also automatically detects any motion of the object. If a pulse rate of 25 pulses/sec is selected and no changes in the image are observed, the pulse rate used for pulsed fluoroscopy is gradually reduced. This may decrease the radiation exposure. The influence of grid control on image quality was examined using an anthropomorphic phantom. The dose reduction achieved with the help of object detection was determined by evaluating the examination data of 146 patients from 5 different countries. RESULTS: The image of the static phantom made with grid control was always optimally exposed, regardless of the position of the object to be visualized. The average dose reduction when using 25 pulses/sec resulting from object detection and automatic down-pulsing was 21 %, and the maximum dose reduction was 60 %. CONCLUSION: Grid control facilitates C-arm operation, since optimum image exposure can be obtained independently of object positioning. Object detection may lead to a reduction in radiation exposure for the patient and operating staff.