ERS statement on chest imaging in acute respiratory failure

Chest imaging in patients with acute respiratory failure plays an important role in diagnosing, monitoring and assessing the underlying disease. The available modalities range from plain chest X-ray to computed tomography, lung ultrasound, electrical impedance tomography and positron emission tomography. Surprisingly, there are presently no clear-cut recommendations for critical care physicians regarding indications for and limitations of these different techniques.The purpose of the present European Respiratory Society (ERS) statement is to provide physicians with a comprehensive clinical review of chest imaging techniques for the assessment of patients with acute respiratory failure, based on the scientific evidence as identified by systematic searches. For each of these imaging techniques, the panel evaluated the following items: possible indications, technical aspects, qualitative and quantitative analysis of lung morphology and the potential interplay with mechanical ventilation. A systematic search of the literature was performed from inception to September 2018. A first search provided 1833 references. After evaluating the full text and discussion among the committee, 135 references were used to prepare the current statement.These chest imaging techniques allow a better assessment and understanding of the pathogenesis and pathophysiology of patients with acute respiratory failure, but have different indications and can provide additional information to each other.

European Respiratory Society International Congress, Paris, 2018: highlights from the Clinical Assembly

This article contains highlights and a selection of the scientific advances from the European Respiratory Society's Clinical Assembly (Assembly 1 and its five respective groups) that were presented at the 2018 European Respiratory Society International Congress in Paris, France. The most relevant topics from each of the groups will be discussed, covering a wide range of areas including clinical problems, rehabilitation and chronic care, thoracic imaging, interventional pulmonology, and general practice and primary care. The newest research, actual data and highlight sessions will be discussed.

Chronic thromboembolic pulmonary hypertension (CTEPH): Updated Recommendations from the Cologne Consensus Conference 2018

Chronic thromboembolic pulmonary hypertension (CTEPH) is a subgroup of pulmonary hypertension that differs from all other forms of PH in terms of its pathophysiology, patient characteristics and treatment. For implementation of the European Guidelines on Diagnosis and Treatment of Pulmonary Hypertension in Germany, the Cologne Consensus Conference 2016 was held and last updated in spring of 2018. One of the working groups was dedicated to CTEPH, practical and controversial issues were commented and updated. In every patient with suspected PH, CTEPH or chronic thromboembolic disease (CTED, i.e. symptomatic residual vasculopathy without pulmonary hypertension) should be excluded. Primary treatment is surgical pulmonary endarterectomy (PEA) in a multidisciplinary CTEPH centre. Inoperable patients or patients with persistent or recurrent CTEPH after PEA are candidates for targeted drug therapy. There is increasing experience with balloon pulmonary angioplasty (BPA) for inoperable patients; this option, like PEA, is reserved for specialised centres with expertise in this treatment method.

European Respiratory Society International Congress 2017: highlights from the Clinical Assembly

This article contains highlights and a selection of the scientific advances from the European Respiratory Society's Clinical Assembly (Assembly 1 and its six respective groups) that were presented at the 2017 European Respiratory Society International Congress in Milan, Italy. The most relevant topics from each of the groups will be discussed, covering a wide range of areas including clinical problems, rehabilitation and chronic care, thoracic imaging, interventional pulmonology, diffuse and parenchymal lung diseases, and general practice and primary care. In this comprehensive review, the newest research and actual data as well as award-winning abstracts and highlight sessions will be discussed.

Nuklearmedizin in Deutschland

Aim: To explain the spectrum and number of in-vivo nuclear medicine examinations and therapies based on official statistics about out-patient and in-patient care. Trends in time of the frequency and spectrum of procedures as well as data on the health care structure for nuclear medicine in Germany should be collected. Methods: Data from the Gesundheitsberichterstattung des Bundes, from the frequency statistics of the statutory health insurance for out-patients and from the Bundes - ärztekammer were used. Customized queries were performed to analyse temporal changes. Results: Nuclear medicine physicians are more frequently consulted by out-patients over the last years (2008: 2 024 498; 2009: 2 164 664) and the number of colleagues in private practice increased. For in-patients, the frequency of conventional nuclear medicine procedures (mainly for brain, lymphatic system, lung and heart) increased since 2008 after a decline in previous years (2009: 323 515; +4.6%) and the number of PET(/CT) examinations continued to rise (2009: 25 123; +18%), even if changes in OPS keys may hamper comparisons. Nearly 600 gamma cameras and 76 PET(/CT) scanners were installed in hospitals in 2008. Nuclear medicine procedures are increasingly performed as cross sectional imaging like SPECT(/CT) and PET(/CT). With the supply shortfall with 99Mo, the frequency of thyroid scans with 123I iodine increased as well as the use of 18F PET as a substitute for conventional bone scans. The number of radionuclide therapies, in particular non-thyroid treatments, increased since the mid-nineties and stabilized at nearly 50 000 cases per year with shorter lengths of stay. Conclusion: The details of the present analysis may help to understand the positive evolution of key numbers for nuclear medicine.

Clinical highlights from the 2016 European Respiratory Society International Congress

This article contains highlights and a selection of the scientific advances from the European Respiratory Society (ERS) Clinical Assembly (Assembly 1) and its six respective groups (Groups 1.1-1.6) that were presented at the 2016 ERS International Congress in London, UK. The most relevant topics for clinicians will be discussed, covering a wide range of areas including clinical problems, rehabilitation and chronic care, thoracic imaging, interventional pulmonology, diffuse and parenchymal lung diseases, and general practice and primary care. In this comprehensive review, the newest research and actual data will be discussed and put into perspective.

[Chronic thromboembolic pulmonary hypertension: Recommendations of the Cologne Consensus Conference 2016]

The 2015 European Guidelines on Pulmonary Hypertension did not cover only pulmonary arterial hypertension (PAH), but also other significant subgroups of pulmonary hypertension (PH). In June 2016, a Consensus Conference organized by the PH working groups of the German Society of Cardiology (DGK), the German Society of Respiratory Medicine (DGP) and the German Society of Pediatric Cardiology (DGPK) was held in Cologne, Germany to discuss open and controversial issues surrounding the practical implementation of the European Guidelines. Several working groups were initiated, one of which was dedicated to the diagnosis and treatment of chronic thromboembolic pulmonary hypertension (CTEPH). In every patient with PH of unknown cause CTEPH should be excluded. The primary treatment option is surgical pulmonary endarterectomy (PEA) in a specialized multidisciplinary CTEPH center. Inoperable patients or patients with persistent or recurrent CTEPH after PEA are candidates for targeted drug therapy. For balloon pulmonary angioplasty (BPA), there is currently only limited experience. This option - as PEA - is reserved to specialized centers with expertise for this treatment method. In addition, a brief overview is given on pulmonary artery sarcoma, since its surgical treatment is often analogous to PEA. The recommendations of this working group are summarized in the present paper.

In Silico Oncology: Quantification of the In Vivo Antitumor Efficacy of Cisplatin-Based Doublet Therapy in Non-Small Cell Lung Cancer (NSCLC) through a Multiscale Mechanistic Model

The 5-year survival of non-small cell lung cancer patients can be as low as 1% in advanced stages. For patients with resectable disease, the successful choice of preoperative chemotherapy is critical to eliminate micrometastasis and improve operability. In silico experimentations can suggest the optimal treatment protocol for each patient based on their own multiscale data. A determinant for reliable predictions is the a priori estimation of the drugs’ cytotoxic efficacy on cancer cells for a given treatment. In the present work a mechanistic model of cancer response to treatment is applied for the estimation of a plausible value range of the cell killing efficacy of various cisplatin-based doublet regimens. Among others, the model incorporates the cancer related mechanism of uncontrolled proliferation, population heterogeneity, hypoxia and treatment resistance. The methodology is based on the provision of tumor volumetric data at two time points, before and after or during treatment. It takes into account the effect of tumor microenvironment and cell repopulation on treatment outcome. A thorough sensitivity analysis based on one-factor-at-a-time and latin hypercube sampling/partial rank correlation coefficient approaches has established the volume growth rate and the growth fraction at diagnosis as key features for more accurate estimates. The methodology is applied on the retrospective data of thirteen patients with non-small cell lung cancer who received cisplatin in combination with gemcitabine, vinorelbine or docetaxel in the neoadjuvant context. The selection of model input values has been guided by a comprehensive literature survey on cancer-specific proliferation kinetics. The latin hypercube sampling has been recruited to compensate for patient-specific uncertainties. Concluding, the present work provides a quantitative framework for the estimation of the in-vivo cell-killing ability of various chemotherapies. Correlation studies of such estimates with the molecular profile of patients could serve as a basis for reliable personalized predictions.

Less than 14% of medically treated patients with locally advanced and metastatic non-small cell lung cancer are expected to be alive 5 years after diagnosis. Standard therapeutic strategies include the administration of two drugs in combination, aiming at shrinking the tumor before surgery and improving overall survival. Knowing the sensitivity profile of each patient to different treatment strategies at diagnosis may help choose the most appropriate ones. We develop a methodology for the quantitative estimation of the cytotoxic efficacy of cisplatin-based doublets on cancer cells by applying a simulation model of cancer progression and response. The model incorporates the proliferation cycle, quiescence, differentiation and loss of tumor cells. We evaluate the effect of in vivo microenvironment of real tumors, as expressed by measurable tumor proliferation kinetics, such as how fast the tumor grows, the percentage of cells that are actively dividing, the resistance of stem cells, etc. on treatment outcome so as to derive more accurate estimates. A literature survey guides the selection of values. The methodology is applied to a real clinical dataset of patients. Correlation studies between the derived cytotoxicities and the patients’ molecular profile could lead to predictions of treatment response at the time of diagnosis.

Functional Characterization of Patients with Chronic Thromboembolic Disease

BACKGROUND

Patients with chronic thromboembolic pulmonary disease (CTED) have persistent pulmonary vascular obstruction and exercise intolerance without pulmonary hypertension at rest and may benefit from pulmonary endarterectomy. However, up to now, CTED has been poorly characterized.

OBJECTIVES

This study aimed to analyze the exercise capacity and limiting factors in CTED.

METHODS

We compared right heart catheterization and cardiopulmonary exercise test results of patients with CTED [mean pulmonary artery pressure (mPAP) at rest <25 mm Hg, n = 10], chronic thromboembolic pulmonary hypertension (CTEPH, n = 31) and a control group (n = 41) presenting with dyspnea but normal pulmonary vascular imaging and excluded pulmonary hypertension.

RESULTS

Subjects with CTED show a reduced oxygen uptake [median 76/interquartile range (IQR) 22% pred.] and work rate (median 76/IQR 21 W). The work rate was significantly lower compared to control subjects (p = 0.04) but not significantly different from CTEPH patients (p = 0.66). Oxygen pulse and breathing reserve were normal. CTED subjects showed decreased end-tidal CO2 at anaerobic threshold (28.4/4.3 mm Hg), an elevated VE/VCO2 slope (42.5/23.5), breathing equivalents (EQO2 32.0/8.7, EQCO2 39.5/8.8), alveolar-capillary oxygen gradient (34.7/15.5 mm Hg) and capillary end-tidal carbon dioxide gradient (8.8/5.7 mm Hg) compared to control subjects (p < 0.001). The degree of limitation was similar to that in CTEPH.

CONCLUSIONS

Despite an mPAP of <25 mm Hg, subjects with CTED show objective functional impairment and similar limitations to patients with CTEPH. Functional limitation is characterized by gas exchange disturbance and ineffective ventilation.

Assessment of operability by means of CTPA and perfusion SPECT in patients with chronic thromboembolic pulmonary hypertension

BACKGROUND

Chronic thromboembolic pulmonary hypertension (CTEPH) can potentially be cured by pulmonary thrombendarterectomy (PEA), the criteria for differentiation between operable and non-operable patients are not standardized.

PURPOSE

To retrospectively evaluate the value of rigidly registered computed tomography pulmonary angiography (CTPA) and single photon emission CT (SPECT) in differentiating for PEA.

MATERIAL AND METHODS

Forty-nine patients with CTEPH (21 men; age, 58 ± 13 years) were evaluated by an interdisciplinary expert board using all available diagnostic information and their consensus statement as gold standard. For SPECT a lobe based perfusion score was visually assessed using the score of 0 (lack of perfusion) to 1 (normal perfusion) calculating percentage of vascular obstruction (PVO). By CTPA, vascular obstruction index (OI) of central, peripheral, and global PA-bed were determined. The accuracy of the alignment between CTPA and SPECT was determined by fusion score (FS) ranging from 1 (no alignment) to 5 (exact alignment). Angiography provided PA pressure (PAP), pulmonary vascular resistance (PVR), and PA wedge pressure (PAWP). Receiver operating characteristics (ROC) analysis was performed.

RESULTS

Twenty-nine patients were considered surgically amenable, and 20 patients were inoperable. Mean PAP, PVR, and PAWP were 48 ± 11 mmHg, 868 ± 461 dynes*sec*cm(-5), and 11 ± 5 mmHg, without differences between surgical and non-surgical patients (P > 0.5). In all patients accurate registration was reached (FS = 4.1 ± 0.7; range, 2-5). PVO and central OI separated PEA-amenable patients (P ≤ 0.001) resulting in the area under the curve of 0.828 (cutoff for PVO: 37.8% with a sensitivity of 82% and specificity of 79%) and 0.755 (cutoff for central OI: 29% with a sensitivity and specificity of 86.2% and 79%) for operability.

CONCLUSION

An accurate interpretation of rigidly registered CTPA and perfusion SPECT may contribute to stratification of operability in patients with CTEPH.

PET-based delineation of tumour volumes in lung cancer: comparison with pathological findings

PURPOSE

The objective of the study was to validate an adaptive, contrast-oriented thresholding algorithm (COA) for tumour delineation in (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) for non-small cell lung cancer (NSCLC) in comparison with pathological findings. The impact of tumour localization, tumour size and uptake heterogeneity on PET delineation results was also investigated.

METHODS

PET tumour delineation by COA was compared with both CT delineation and pathological findings in 15 patients to investigate its validity. Correlations between anatomical volume, metabolic volume and the pathology reference as well as between the corresponding maximal diameters were determined. Differences between PET delineations and pathological results were investigated with respect to tumour localization and uptake heterogeneity.

RESULTS

The delineated volumes and maximal diameters measured on PET and CT images significantly correlated with the pathology reference (both r > 0.95, p < 0.0001). Both PET and CT contours resulted in overestimation of the pathological volume (PET 32.5 ± 26.5%, CT 46.6 ± 27.4%). CT volumes were larger than those delineated on PET images (CT 60.6 ± 86.3 ml, PET 48.3 ± 61.7 ml). Maximal tumour diameters were similar for PET and CT (51.4 ± 19.8 mm for CT versus 53.4 ± 19.1 mm for PET), slightly overestimating the pathological reference (mean difference CT 4.3 ± 3.2 mm, PET 6.2 ± 5.1 mm). PET volumes of lung tumours located in the lower lobe were significantly different from those determined from pathology (p = 0.037), whereas no significant differences were observed for tumours located in the upper lobe (p = 0.066). Only minor correlation was found between pathological tumour size and PET heterogeneity (r = -0.24).

CONCLUSION

PET tumour delineation by COA showed a good correlation with pathological findings. Tumour localization had an influence on PET delineation results. The impact of tracer uptake heterogeneity on PET delineation should be considered carefully and individually in each patient. Altogether, PET tumour delineation by COA for NSCLC patients is feasible and reliable with the potential for routine clinical application.

Integration of FDG-PET/CT into external beam radiation therapy planning: technical aspects and recommendations on methodological approaches

This work addresses the clinical adoption of FDG-PET/CT for image-guided radiation therapy planning (RTP). As such, important technical and methodological aspects of PET/CT-based RTP are reviewed and practical recommendations are given for routine patient management and clinical studies. First, recent developments in PET/CT hardware that are relevant to RTP are reviewed in the context of quality control and system calibration procedures that are mandatory for a reproducible adoption of PET/CT in RTP. Second, recommendations are provided on image acquisition and reconstruction to support the standardization of imaging protocols. A major prerequisite for routine RTP is a complete and secure data transfer to the actual planning system. Third, state-of-the-art tools for image fusion and co-registration are discussed briefly in the context of PET/CT imaging pre- and post-RTP. This includes a brief review of state-of-the-art image contouring algorithms relevant to PET/CT-guided RTP. Finally, practical aspects of clinical workflow and patient management, such as patient setup and requirements for staff training are emphasized. PET/CT-guided RTP mandates attention to logistical aspects, patient set-up and acquisition parameters as well as an in-depth appreciation of quality control and protocol standardization.

CONCLUSION

Upon fulfilling the requirements to perform PET/CT for RTP, a new dimension of molecular imaging can be added to traditional morphological imaging. As a consequence, PET/CT imaging will support improved RTP and better patient care. This document serves as a guidance on practical and clinically validated instructions that are deemed useful to the staff involved in PET/CT-guided RTP.

Multi-centre calibration of an adaptive thresholding method for PET-based delineation of tumour volumes in radiotherapy planning of lung cancer

PURPOSE

To evaluate the calibration of an adaptive thresholding algorithm (contrast-oriented algorithm) for FDG PET-based delineation of tumour volumes in eleven centres with respect to scanner types and image data processing by phantom measurements.

METHODS

A cylindrical phantom with spheres of different diameters was filled with FDG realizing different signal-to-background ratios and scanned using 5 Siemens Biograph PET/CT scanners, 5 Philips Gemini PET/CT scanners, and one Siemens ECAT-ART PET scanner. All scans were analysed by the contrast-oriented algorithm implemented in two different software packages. For each site, the threshold SUVs of all spheres best matching the known sphere volumes were determined. Calibration parameters a and b were calculated for each combination of scanner and image-analysis software package. In addition, "scanner-type-specific" calibration curves were determined from all values obtained for each combination of scanner type and software package. Both kinds of calibration curves were used for volume delineation of the spheres.

RESULTS

Only minor differences in calibration parameters were observed for scanners of the same type (Δa ≤4%, Δb ≤14%) provided that identical imaging protocols were used whereas significant differences were found comparing calibration parameters of the ART scanner with those of scanners of different type (Δa ≤60%, Δb ≤54%). After calibration, for all scanners investigated the calculated SUV thresholds for auto-contouring did not differ significantly (all p>0.58). The resulting sphere volumes deviated by less than -7% to +8% from the true values.

CONCLUSION

After multi-centre calibration the use of the contrast-oriented algorithm for FDG PET-based delineation of tumour volumes in the different centres using different scanner types and specific imaging protocols is feasible.

F-18-FDG-PET confined radiotherapy of locally advanced NSCLC with concomitant chemotherapy: results of the PET-PLAN pilot trial

PURPOSE

The integration of fluoro-deoxy-D-glucose positron emission tomography (FDG-PET) in the process of radiotherapy (RT) planning of locally advanced non-small-cell lung cancer (NSCLC) may improve diagnostic accuracy and minimize interobserver variability compared with target volume definition solely based on computed tomography. Furthermore, irradiating only FDG-PET-positive findings and omitting elective nodal regions may allow dose escalation by treating smaller volumes. The aim of this prospective pilot trial was to evaluate the therapeutic safety of FDG-PET-based RT treatment planning with an autocontour-derived delineation of the primary tumor.

METHODS AND MATERIALS

Eligible patients had Stages II-III inoperable NSCLC, and simultaneous, platinum-based radiochemotherapy was indicated. FDG-PET and computed tomography acquisitions in RT treatment planning position were coregistered. The clinical target volume (CTV) included the FDG-PET-defined primary tumor, which was autodelineated with a source-to-background algorithm, plus FDG-PET-positive lymph node stations. Limited by dose restrictions for normal tissues, prescribed total doses were in the range of 66.6 to 73.8 Gy. The primary endpoint was the rate of out-of-field isolated nodal recurrences (INR).

RESULTS

As per intent to treat, 32 patients received radiochemotherapy. In 15 of these patients, dose escalation above 66.6 Gy was achieved. No Grade 4 toxicities occurred. After a median follow-up time of 27.2 months, the estimated median survival time was 19.3 months. During the observation period, one INR was observed in 23 evaluable patients.

CONCLUSIONS

FDG-PET-confined target volume definition in radiochemotherapy of NSCLC, based on a contrast-oriented source-to-background algorithm, was associated with a low risk of INR. It might provide improved tumor control because of dose escalation.

Retrospective web-based multicenter evaluation of ¹⁸F-FDG-PET and CT derived predictive factors. Radioimmunotherapy with yttrium-90-ibritumomab tiuxetan in follicular non Hodgkin's lymphoma

AIM

Although predictive factors (PF) for conventional lymphoma therapy are established and frequently used in clinical practice and medical research, the PF for radioimmunotherapy (RIT) have not been fully defined until now. The aim of this multicenter evaluation is to prove the feasibility of the multicenter web-based data collection and to preliminary explore imaging findings and prediction of therapy response in patients with follicular lymphoma (FL) following radioimmunotherapy (RIT) with 90Y-ibritumomab tiuxetan.

PATIENTS, METHODS

We retrospectively analyzed and correlated clinical and imaging data (CT and FDG-PET) before and after RIT as documented by the RIT-Network. Evaluation of treatment response was done on both patient and lesion basis. Every measurable lesion was analyzed in terms of standardized uptake value (SUV), volume (CT and PET) and response. PF were identified using a uni- and multivariate model. A web-based system was used for the documentation and evaluation of clinical and imaging data.

RESULTS

16 patients with at least one PET before and after RIT were eligible for analysis. Concerning response three months postRIT, 5 patients achieved a CR, 6 patients a PR and 4 patients remained with NC. A total of 159 lesions were measured (mean 10±8). In the multivariate model the log lesion volume (p < 0.0001), the total (p = 0.03) and maximum lesion volume (p = 0.05) were predictors for response (CR + PR). Concerning the lesional CR initial small lesion volume (p = 0.009) and its high metabolic activity (p = 0.01) were identified as predictors. The web-based system showed no major disturbances allowing secure data transfer and central image interpretation in a reasonable time.

CONCLUSION

The use of a web-based multicenter archiving system for clinical and imaging data is technically feasible in a multicenter setting and allows a central analysis. This preliminary analysis suggests that FDG-PET may predict the likelihood of response to RIT.

Prospective study of p-[123I]iodo-L-phenylalanine and SPECT for the evaluation of newly diagnosed cerebral lesions: specific confirmation of glioma

PURPOSE

The differentiation between gliomas, metastases and gliotic or inflammatory lesions by imaging techniques remains a challenge. Gliomas frequently exhibit increased uptake of radiolabelled amino acids and are thus amenable to PET or SPECT imaging. Recently, p-[123I]iodo-L-phenylalanine (IPA) was validated for the visualization of glioma by SPECT and received orphan drug status. Here we investigated its diagnostic performance for differentiating indeterminate brain lesions.

METHODS

This prospective open study included 67 patients with newly diagnosed brain lesions suspicious for glioma (34 without and 33 with contrast enhancement in the MRI scan). Patients received 250 MBq IPA intravenously after overnight fasting. SPECT images at 30 min and 3 h post-injection were iteratively reconstructed and visually interpreted after image fusion with an MRI brain scan (fluid-attenuated inversion recovery sequence or T1-weighted contrast-enhanced image). Findings were correlated with results of stereotactic or open biopsies or serial imaging.

RESULTS

Twenty-seven low-grade (2 WHO I, 25 WHO II) and 24 high-grade gliomas (1 WHO III, 23 WHO IV), 3 metastases originating from lung cancer as well as 13 non-neoplastic lesions were proven. All non-neoplastic lesions and all metastases were negative with IPA SPECT. Forty gliomas were true-positive (TP) and 11 false-negative (FN) findings (8 WHO II, 1 WHO III, 2 WHO IV) occurred. There were no false-positive (FP) findings. For the differentiation of primary brain tumours and non-neoplastic lesions, sensitivity and specificity were 78 and 100%. In 34 lesions without contrast enhancement in MRI, IPA SPECT resulted in 17 TP, 8 true-negative, 9 FN and no FP findings (sensitivity 65%, specificity 100%).

CONCLUSION

In patients with suspected glioma, IPA SPECT shows a high specificity, but especially in low-grade gliomas FN findings may occur. Due to the high positive predictive value a positive finding allows a suspected glioma to be confirmed.

Extraosseous manifestation of multiple myeloma with unusual appearance in computed tomography--case report

Extramedullary Localizations at diagnosis or during the course of multiple myeloma are rare. We report on a 70 year old patient, presenting multiple hypoechoic liver lesions during an ultrasound examination. The following contrast-enhanced computed tomography demonstrated hypodense liver Lesions with slight contrast enhancement and hyperdense polypoid masses in the wall of the gall bladder as well as a small pericostal tumor. A punch biopsy of the liver and immunohistochemical studies confirmed the diagnosis of extramedullary multiple myeloma. In a follow-up CT five weeks later the liver lesions and the pericostal tumor clearly showed progress, the masses in the gall bladder had developed into a concentric wall-thickening. Additionally, polypoid contrast-enhancing masses in the gastric wall became apparent as well as a hypodense lesion in the spleen. Radiologists should be aware that multiple myeloma can on rare occasions present as hypodense nodules in the liver or new masses in other organs in CT. Because of the morphologic similarity to metastatic disease, a biopsy may be necessary for definitive diagnosis.

Progression of fibrosis in usual interstitial pneumonia: serial evaluation of the native lung after single lung transplantation

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a progressive disease with a poor prognosis. Usual interstitial pneumonia (UIP) is the histopathological pattern identifying patients with the clinical entity of IPF. Despite aggressive immunosuppressive therapy the clinical course is usually dismal. For selected patients only lung transplantation improves prognosis and quality of life. After lung transplantation patients often receive a potent cyclosporine-based immunosuppressive therapy. Some reports suggest that cyclosporine has the potential to prevent progression of fibrosis.

OBJECTIVE

In patients with single lung transplantation (sLTx) for UIP we evaluated the effect of cyclosporine-based immunosuppressive therapy on progression of fibrosis using a high-resolution computed tomography (HRCT) scoring system.

METHODS

This retrospective observational study included 13 patients (24-64 years old) with histologically confirmed UIP who had HRCT scans preceding and following sLTx and who survived at least 6 months after sLTx. All patients were initially treated with cyclosporin A, prednisone and azathioprine. Three radiologists analyzed HRCT scans by setting a score regarding fibrosis [fibrosis score (FS); range 0-5 for each lobe] and ground-glass opacity [ground-glass score (GGS); range 0-5 for each lobe]. A comparison of serial changes (interval: 12-96 months posttransplant, 2-4 HRCT examinations/patient) was performed with the sign test.

RESULTS

Mean pretransplant FS and GGS of the nontransplanted lung were 1.80 and 1.61, respectively. Comparing pre- and posttransplant HRCT scans, mean lung FS significantly increased (0.35 +/- 0.15/year; p = 0.00024), while GGS tended to decrease (0.06 +/- 0.26/year; p = 0.5).

CONCLUSION

A cyclosporin A based triple immunosuppressive regimen following sLTx does not seem to prevent progression of the fibrotic changes of the native lung in patients with IPF.

Cytotoxicity of iodinated and gadolinium-based contrast agents in renal tubular cells at angiographic concentrations: in vitro study

PURPOSE

To test in vitro whether gadolinium-based contrast agents induce fewer toxic effects on renal tubular cells than does an iodinated contrast medium at concentrations used for angiography.

MATERIALS AND METHODS

LLC-PK1 cells were incubated with iomeprol, gadopentetate dimeglumine, gadobenate dimeglumine, gadoterate meglumine, gadodiamide, and corresponding mannitol solutions for 24 hours at 37 degrees C in two experimental settings: measurements with equally attenuating solutions and measurements with equimolar solutions. Cytotoxicity was assessed with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, trypan blue testing, and an assay to detect apoptosis and necrosis. Data were analyzed with analyses of variance and post hoc tests.

RESULTS

Yielding the same x-ray attenuation, iomeprol-300 and iomeprol-150 at concentrations of 2.34-18.75 mg of iodine per milliliter induced significantly (P < .001) lower inhibition of MTT conversion (74%-102% of undamaged control cells) compared with 15.63-125.00 mmol/L concentrations of the gadolinium-based agents (mean percentages of undamaged control cells: 48%-80%, 50%-87%, 60%-95%, and 56%-92% with gadopentetate dimeglumine, gadobenate dimeglumine, gadoterate meglumine, and gadodiamide, respectively). At equimolar concentrations (62.5 mmol/L), iomeprol-190 induced a mean extent of inhibition of MTT conversion (69% of undamaged control cells) similar to that induced by gadoterate meglumine (71%) and gadodiamide (70%), whereas gadopentetate dimeglumine and gadobenate dimeglumine induced stronger effects (63% and 64%, respectively; P < .001). At trypan blue testing, there were more dead cells after incubation with 125 mmol/L gadopentetate dimeglumine than after incubation with iomeprol-190 (57% vs 19%, P < .001). The 125 mmol/L gadopentetate and gadobenate formulations induced more necrosis and apoptosis than did gadoterate meglumine, gadodiamide, and iomeprol (mean percentage difference between treated and untreated control cells: for necrosis, +124%, +95%, +17%, -6%, and +3%, respectively; for apoptosis, +34%, +35%, +13%, +4%, and +5%, respectively; P < .001).

CONCLUSION

At angiographic concentrations, gadolinium-based contrast agents do not induce fewer cytotoxic effects on cultured renal tubular cells than does iomeprol.

Dünndarmobstruktion durch Retention einer Videoendoskopie-Kapsel bei einem Patienten mit Rektumkarzinomrezidiv

Wireless capsule endoscopy has become the most sensitive and most specific diagnostic modality for evaluation of the mucosa of the small bowel and is increasingly used by gastroenterologists. The most important complication is retention of the video capsule in patients with pre-existing strictures of the small bowel. We report on a case of a 73-year-old man who underwent capsule endoscopy because of obscure gastrointestinal bleeding. The capsule was retained in the ileum leading to small bowel obstruction during the following days. Surgery demonstrated that the capsule had been retained in a segment of the ileum which was infiltrated by a recurrence of rectum carcinoma. Radiologists should know this complication of capsule endoscopy as well as the relative importance of the radiographic techniques for evaluating the small bowel, which possibly could predict a free passage of the video capsule.

[Imaging diagnostics of the pharynx and larynx]

The pharynx and larynx represent very sophisticated regions and may be involved in a diverse range of pathologic conditions. Evaluation of the head and neck has developed significantly with the establishment of CT and MRI as they provide true insights into the endoscopically blind areas as well as depth of tumor infiltration, its submucosal growth and contralateral involvement, cartilage invasion, bone marrow invasion, and nonpalpable adenopathy. Inflammations in the head and neck region are only exceptionally imaged with CT or MRI; indications are the diagnosis of retrotonsillar and parapharyngeal abscesses and ensuing complications. The different imaging modalities of malignant pharyngeal and laryngeal tumors and their differential diagnosis are presented in this paper.

[Nevoid basal cell carcinoma syndrome]

Nevoid Basal Cell Carcinoma Syndrome (NBCCS) is an autosomal-dominant disorder characterized by multiple basal cell carcinomas, jaw cysts, palmar/plantar pits, calcification of the falx cerebri, and spine and rib anomalies. The combination of clinical, imaging, and histological findings is helpful in identifying NBCCS patients. Imaging plays a crucial role in evaluation of these patients. We present a wide variety of clinical and radiological findings characteristic of this disease.

Successful treatment of disseminated aspergillosis with the combination of voriconazole, caspofungin, granulocyte transfusions, and surgery followed by allogeneic blood stem cell transplantation in a patient with primary failure of an autologous stem cell graft

The treatment of disseminated aspergillus infections in neutropenic patients remains a major challenge in spite of several new antifungal drugs. We report the case of a patient with multiple myeloma in prolonged neutropenia after primary failure of an autologous stem cell graft who developed invasive aspergillosis despite voriconazole monotherapy. He responded to a combination of voriconazole and caspofungin, supported by granulocyte transfusions and surgery. A subsequent allogeneic peripheral blood stem cell transplantation did not lead to recurring aspergillus infection. The patient is well and free of clinical disease with respect to the fungal infection and myeloma more than 18 months after the allogeneic transplantation.

CT Scan Findings in Chronic Thromboembolic Pulmonary Hypertension

STUDY OBJECTIVES

The aim was to correlate CT scan findings with hemodynamic measurements in patients who had undergone pulmonary thromboendarterectomy (PTE) and to evaluate whether CT scan findings can help to predict surgical outcome.

PATIENTS AND METHOD

Sixty patients who underwent PTE and preoperative helical CT scanning were included. Preoperative and postoperative hemodynamics were correlated with preoperative CT imaging features.

RESULTS

The diameter of the main pulmonary artery (PA) and the ratio of the PA and the diameter of the ascending aorta correlated with preoperative mean pulmonary artery pressure (PAP) [r = 0.42; p < 0.001; and r = 0.48; p < 0.0001, respectively]. There was a significant correlation of subpleural densities with preoperative pulmonary vascular resistance (PVR) [r = 0.44; p < 0.001] and of the number of abnormal perfused lobes with preoperative PAP (r = 0.66; p < 0.0001) and PVR (r = 0.76; p < 0.0001). Postoperative PVR correlated negatively with the presence and extent of central thrombi (r = -0.36; p = 0.007) and dilated bronchial arteries (p = 0.03) seen on preoperative CT scans. Sixty percent of patients (3 of 5 patients) without visible central thromboembolic material on CT scans had an inadequate hemodynamic improvement in contrast to 4% of patients (2 of 51 patients) with central thrombi (p = 0.003). Preoperative PVR (r = 0.31; p = 0.018) and the extent of abnormal lung perfusion (r = 0.37; p = 0.007) and of subpleural densities (r = 0.32; p = 0.017) were positively correlated with postoperative PVR.

CONCLUSIONS

In patients with thromboembolic pulmonary hypertension, CT scan findings can help to predict hemodynamic improvement after PTE. The absence of central thrombi is a significant risk factor for inadequate hemodynamic improvement.

Cytotoxic effects of ionic high-osmolar, nonionic monomeric, and nonionic iso-osmolar dimeric iodinated contrast media on renal tubular cells in vitro

PURPOSE

To compare the cytotoxic effects of dimeric and monomeric iodinated contrast media on renal tubular cells in vitro with regard to osmolality.

MATERIALS AND METHODS

LLC-PK1 cells were incubated with ioxithalamate, ioversol, iomeprol-300, iomeprol-150, iodixanol, iotrolan, and hyperosmolar mannitol solutions for 1-24 hours at concentrations from 18.75 to 150 mg of iodine per milliliter. Cytotoxic effects were assessed with 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. Data were analyzed with one-way analysis of variance; post hoc tests were performed.

RESULTS

At equal iodine concentrations, ioxithalamate showed stronger cytotoxic effects than did other contrast media (MTT conversion for ioxithalamate was 4% vs that for ioversol of 32%, that for iomeprol-300 of 34%, that for iodixanol of 40%, and that for iotrolan of 41% of undamaged control cells at 75 mg of iodine per milliliter, n = 61-90, P < .001); there was no significant difference between low-osmolar monomeric and iso-osmolar dimeric contrast media (P > .05). At equal molarity, dimeric contrast media induced significantly stronger cytotoxic effects than did low-osmolar monomeric contrast media (40% for iodixanol and 41% for iotrolan vs 64% for ioversol and 59% for iomeprol-300 at 98.5 mmol/L, n = 61-75, P < .001). At equimolar concentrations, both dimeric contrast media showed stronger cytotoxic effects than did iso-osmolar formulation of iomeprol-150 (51% for iodixanol and 50% for iotrolan vs 77% for iomeprol-150 at 98.5 mmol/L, n = 35-40, P < .001). Mannitol solutions induced weaker cytotoxic effects than did corresponding contrast media compounds (74% for mannitol-520 vs 34% for iomeprol-300 and 41% for mannitol-1860 vs 4% for ioxithalamate, P < .001).

CONCLUSION

Besides hyperosmolality, direct cytotoxic effects of contrast media molecules contribute to their cytotoxic effects. Results of this study indicate that dimeric contrast media molecules have a greater potential for cytotoxic effects on proximal renal tubular cells in vitro than do monomeric contrast media molecules.

[CT findings in patients with chronic thrombembolic pulmonary hypertension]

Chronic thromboembolic pulmonary hypertension (CTEPH) is thought to be a rare complication of pulmonary embolism. However, it was recently demonstrated that CTEPH is more common than previously thought after pulmonary embolism. Without treatment, CTEPH is associated with a very high mortality rate. Making the correct diagnosis early is essential, because there is a potential curative treatment in the form of pulmonary thromboendarterectomy (PTE). Because of the unspecific clinical symptoms of CTEPH, the different imaging modalities play a crucial role in diagnosis making. Since the introduction of the multidetector CT technology, CT has become an important part in the diagnostic work up of pulmonary embolism and CTEPH and is often used as a first-line diagnostic tool. CT is not only a reliable tool for the diagnosis of CTEPH, but also is helpful in estimating the operability of these patients. PTE is still associated with a mortality rate of about 10%. Particularly an insufficient decrease of the pulmonary vascular resistance after PTE leads to a very high mortality rate. Therefore, it is crucial to correlate the degree of the surgical accessible obstruction of the pulmonary vasculature with the degree of pulmonary hypertension in deciding for or against PTE. The aim of this review is to describe the CT findings in patients with CTEPH and their use in differentiating CTEPH from other diseases like acute pulmonary embolism and primary pulmonary hypertension. Moreover, the correlation of different CT imaging features with surgical success after PTE will be discussed.

Effects of Dimeric Radiographic Contrast Medium Iotrolan on Swine Renal Arteries

RATIONALE AND OBJECTIVES

To investigate whether the lower incidence of vasodilatation upon vascular injection of iotrolan, as compared with monomeric contrast media, is solely the result of its isotonicity.

MATERIALS AND METHODS

In an organ bath, isolated segments of swine renal arteries, uncontracted or precontracted by 10 microm phenylephrine, were incubated with increasing concentrations of iotrolan-300, iohexol-300, iomeprol-300, iomeprol-150, and mannitol solutions with the same molarity as the contrast media.

RESULTS

At equal iodine and equimolar concentrations, iotrolan-300 relaxed precontracted arteries less than iohexol-300, iomeprol-300, and iomeprol-150, which was, like iotrolan-300, iso-osmolar to blood (P < 0.05). There was no significant difference between iohexol-300 and iomeprol-300 (P > 0.05). Iotrolan had no significant effect on the basal tonus of the vessels whereas iohexol and iomeprol induced a slight relaxation.

CONCLUSIONS

Iotrolan, even at equimolar concentrations, resulted in less vasorelaxation than iohexol and iomeprol. Both osmolarity and chemotoxicity contribute to the greater vasorelaxant effect on swine renal artery of monomeric contrast media when compared to that of the nonionic dimeric contrast medium, iotrolan.

[High-resolution CT in the differential diagnosis of consolidative processes (I. Acute processes)]

Consolidations are usually result of the replacement of the alveolar air by fluid, cells or tissue but these can also be seen with extensive interstitial processes. These diseases cannot be clearly categorized into the classic classification scheme of airspace and interstitial disease since there are features of both categories seen in the imaging and histologic findings. Because this definition includes wide variety of diseases with overlapping HRCT-findings it is difficult to distinguish among these entities with imaging criteria alone. However, integration of HRCT-findings and clinical findings may enable a narrower differential diagnosis. This review describes the most common types of lung diseases associated with acute appearance of consolidation and discuss the differential diagnosis.

[High-resolution CT in the differential diagnosis of consolidative lung processes. (Part 2, Chronic processes)]

Consolidations are characterized on CT by the presence of one or more airspace opacities with little or no volume loss. Because HRCT findings overlap among various entities, it may be sometimes to be impossible to make a definite diagnosis with imaging criteria alone. If the symptoms are chronic (weeks to months) the differential diagnosis may include alveolar proteinosis, bronchioloalveolar carcinoma, lymphoma as well as inflammatory diseases. This review describes the most common types of lung diseases associated with chronic appearance of consolidation and discuss the differential diagnosis.

[Computed tomography of cystic lung diseases]

A cystic lesion in the lung is defined as a well-demarcated epithel-lined cavity, that can be mostly filled with air, water, as well as solid material content. This definition includes a wide variety of diseases such as bronchogenic cyst, abscess formation, lymphangioleiomyomatosis, Langerhans cell histiocytosis, emphysema, bronchiectasis, and pneumatoceles. Despite the difficulties in differential diagnosis, there are some diagnostic criteria for CT-scanning helping the radiologist to differentiate between these cystic entities. Moreover, clinical informations are extremely important. The most important clinical parameters include age, sex, clinical history and symptoms. Thus, a better understanding of classic CT appearance of cystic lung disease will allow more definitive diagnosis and could, in some cases, avoid biopsy.

Regional services for children and youth with diabetes

A regional diabetes program for children and youth comprising outreach clinics, frequent routine and emergency telephone contact, and a camping program was developed within the State Children's Medical Services (Crippled Children's) Program. The pediatric nurse specialist in diabetes served as the pivotal professional in the education and supervision of patients. Cost benefit was calculated from estimated hospital days prevented based on average length of admissions at diagnosis (14 days) and hospital days in the year prior to referral of those with established diabetes. During the first year 369 hospital days were prevented, for an estimated savings of $65,000; the second year 547 hospital days were avoided, a value of $96,000. Total annual program costs to the state and private patients (including camp fees) were $36,000. Although hospital costs are an apparent and useful reference to justify funding, the main value of the program must be in the prevention of secondary physical and emotional disability. This requires continuous commitment and availability of persons who know the patient and family, who can interpret information related to metabolic control of diabetes, and who are able to influence the family and community to respond appropriately to the youngster's needs.

The role of urine sugar in diabetic management

The concentration of reducing sugar in the urine is commonly used in the management of diabetes in children. Supplemental doses of regular insulin are administered in response to the concentration of urine sugar according to a protocol termed the "sliding scale." This practice assumes that the concentration of sugar in urine is a good indicator of the plasma glucose concentration. This assumption was tested by comparing urine sugar concentrations in first and second voided urines with the plasma glucose concentrations in 220 children with diabetes. The correlation was good (r = .92) for both the first and second voided urine specimens. Thus, urine sugar concentrations in general define the level of plasma glucose. The large standard deviation of the plasma glucose at each concentration of urine sugar, however, limits the usefulness of urine sugar as an accurate reflection of the coincident plasma glucose concentration. The urine sugar concentration, although useful for the general management of diabetes, provides significant risk when used to guide frequent adjustments in insulin administration. Therefore, the "sliding scale" should not be used in the treatment of children with diabetes.

Good diabetic control - a study in mass delusion

The terms "diabetic control" and "diabetic management" are not synonymous. Diabetic control implies normal glucose metabolism, typically monitored by periodic determinations of plasma glucose and urine reducing sugar concentrations. A group of 220 diabetic children attending a camp complied 74% of the time with the request to collect and test their urine for URS. Fifty percent of random URS values determined by the children varied from those obtained on the same specimens of urine by laboratory technicians. Good diabetic control defined URS less than 25gm/24 hours was found in 18 of 54 children.