[Tonometry and pachymetry to evaluate fluctuations of intraocular pressure in the context of SCUBA diving]. / Tonometrie und Pachymetrie zur Erfassung der Augeninnendruckschwankungen beim Scuba-Tauchen.

BACKGROUND: It is currently still not clarified whether diving using a self-contained breathing apparatus (SCUBA) is associated with intraocular pressure (IOP) fluctuations of clinical relevance and whether intensive diving could exacerbate the damage in glaucoma patients. OBJECTIVE: This study aimed to evaluate the effect of SCUBA diving on IOP in healthy volunteers without prior eye injuries or surgery. HYPOTHESIS: recreational diving does not lead to significant increases or fluctuations of the IOP. MATERIAL AND METHODS: The study included 16 divers (5 female) who performed a total of 96 dives with air or nitrox32 to a depth of 20-30 m for an average of 50 min. The central cornea thickness was measured using ultrasonic pachymetry Pocket IITM (Quantel Medical Pocket II™, Quantel Medical, Clermont-Ferrand, France), and the IOP was measured using an Icare® PRO (Icare® PRO, Icare Finland Oy, Espoo, Finland) directly before the dive and 10 min after surfacing. RESULTS: All data refer to the right eye. Average IOP values ranged from 15.6 to 19.2 mm Hg pre-dive and 16.8 to 18.2 mm Hg post-dive. The range of IOP values was 2.2-11.5 mm Hg pre-dive (∆ = 9.3 mm Hg) and 2.7-14.8 mm Hg post-dive (∆ = 12.1 mm Hg). Of the divers 11.5% vs. 18.8% had increased IOP values > 21 mm Hg (pre-dive vs. post-dive). CONCLUSION: This study found no significant differences in IOP values between pre-dive and post-dive measurements in healthy SCUBA divers. Therefore, recreational SCUBA diving is unlikely to affect the IOP in healthy individuals.

[Predictability of residual astigmatism after implantation of posterior chamber toric lenses]. / Prognostizierbarkeit des Restastigmatismus nach torischer Hinterkammerlinsenimplantation.

BACKGROUND: The objective of the study was to examine the predictability of residual astigmatism after cataract surgery and implantation of the posterior chamber aspheric toric lens TECNIS® ZCT, Abott Medical Optic (Ettlingen, Deutschland). MATERIAL AND METHODS: The retrospective study included a total of 88 patient eyes undergoing a cataract operation with a toric lens implantation between March 2014 and October 2015. The inclusion criteria were a regular astigmatism of at least 0.75 dpt. Posterior chamber toric lenses (model Tecnis ZCT) were exclusively implanted. Post-surgery check-ups were performed after 1 day, 1 month and 2 months. Main study outcome was best-corrected visual acuity (BCVA), spherical and astigmatic aberration and the difference between expected and actual residual astigmatism after cataract surgery. RESULTS: The median reduction of corneal astigmatism was from -2.50 dpt (±1.06 dpt) to -0.75 dpt (±0.51 dpt) (p ≤ 0.05). The median BCVA increased from 0.37 logMAR (±0.25 logMAR) before surgery to 0.09 logMAR (±0.10 logMAR) after surgery. The spherical equivalent was reduced from +3.50 dpt (±1.11 dpt) (presurgery) to -0.56 dpt (±0.51 dpt) (postsurgery) in hyperopic patients and from -2.44 dpt (±3.03 dpt) to -0.69 dpt (±0.81 dpt) in myopic patients. By using the power vector analysis no significant deviation from the expected target values was observed; however, the median discrepancy between the expected and actual residual astigmatism was -0.50 dpt despite a surgical orientation of the intraocular lens (IOL) within 5° of the desired axis. The IOL showed a median rotation of 3.00° (±4.46°). CONCLUSION: Implantation of the aspheric toric intraocular lens Tecnis ZCT is a predictable, effective and reproducible tool in cataract surgery to account for regular corneal astigmatis; however, despite an optimal surgical orientation of the toric IOL, a small and rarely a large discrepancy might occur between expected and actual residual astigmatism.

Accuracy of Coronary Plaque Detection and Assessment of Interobserver Agreement for Plaque Quantification Using Automatic Coronary Plaque Analysis Software on Coronary CT Angiography.

PURPOSE: To evaluate the accuracy of automatic plaque detection and the interobserver agreement of automatic versus manually adjusted quantification of coronary plaques on coronary CT angiography (cCTA) using commercially available software. MATERIALS AND METHODS: 10 cCTA datasets were evaluated using plaque software. First, the automatically detected plaques were verified. Second, two observers independently performed plaque quantification without revising the automatically constructed plaque contours (automatic approach). Then, each observer adjusted the plaque contours according to plaque delineation (adjusted approach). The interobserver agreement of both approaches was analyzed. RESULTS: 32 of 114 automatically identified findings were true-positive plaques, while 82 (72 %) were false-positive. 20 of 52 plaques (38 %) were missed by the software (false-negative). The automatic approach provided good interobserver agreement with relative differences of 0.9 ±â€Š16.0 % for plaque area and -3.3 ±â€Š33.8 % for plaque volume. Both observers independently adjusted all contours because they did not represent the plaque delineation. Interobserver agreement decreased for the adjusted approach with relative differences of 25.0 ±â€Š24.8 % for plaque area and 20.0 ±â€Š40.4 % for plaque volume. CONCLUSION: The automatic plaque analysis software is of limited value due to high numbers of false-positive and false-negative plaque findings. The automatic approach was reproducible but it necessitated adjustment of all constructed plaque contours resulting in deterioration of the interobserver agreement. KEY POINTS: • Automatic plaque detection is limited due to high false-positive and false-negative findings.• Automatic plaque quantification was reproducible in the few accurately detected plaques.• The automatically constructed contours did not represent the plaque delineation.• Both observers independently adjusted the plaque contours.• Manual adjustment of plaque contours reduced the interobserver agreement. Citation Format: • Laqmani A, Klink T, Quitzke M et al. Accuracy of Coronary Plaque Detection and Assessment of Interobserver Agreement for Plaque Quantification Using Automatic Coronary Plaque Analysis Software on Coronary CT Angiography. Fortschr Röntgenstr 2016; 188: 933 - 939.

Diagnostic Accuracy of Full-Body Linear X-Ray Scanning in Multiple Trauma Patients in Comparison to Computed Tomography.

PURPOSE: The purpose of this study was to evaluate the diagnostic accuracy of full-body linear X-ray scanning (LS) in multiple trauma patients in comparison to 128-multislice computed tomography (MSCT). MATERIALS AND METHODS: 106 multiple trauma patients (female: 33; male: 73) were retrospectively included in this study. All patients underwent LS of the whole body, including extremities, and MSCT covering the neck, thorax, abdomen, and pelvis. The diagnostic accuracy of LS for the detection of fractures of the truncal skeleton and pneumothoraces was evaluated in comparison to MSCT by two observers in consensus. Extremity fractures detected by LS were documented. RESULTS: The overall sensitivity of LS was 49.2 %, the specificity was 93.3 %, the positive predictive value was 91 %, and the negative predictive value was 57.5 %. The overall sensitivity for vertebral fractures was 16.7 %, and the specificity was 100 %. The sensitivity was 48.7 % and the specificity 98.2 % for all other fractures. Pneumothoraces were detected in 12 patients by CT, but not by LS. 40 extremity fractures were detected by LS, of which 4 fractures were dislocated, and 2 were fully covered by MSCT. CONCLUSION: The diagnostic accuracy of LS is limited in the evaluation of acute trauma of the truncal skeleton. LS allows fast whole-body X-ray imaging, and may be valuable for detecting extremity fractures in trauma patients in addition to MSCT. KEY POINTS:  The overall sensitivity of LS for truncal skeleton injuries in multiple-trauma patients was < 50 %. The diagnostic reference standard MSCT is the preferred and reliable imaging modality. LS may be valuable for quick detection of extremity fractures.

Impact of Hybrid Iterative Reconstruction on Agatston Coronary Artery Calcium Scores in Comparison to Filtered Back Projection in Native Cardiac CT.

PURPOSE: To investigate whether the effects of hybrid iterative reconstruction (HIR) on coronary artery calcium (CAC) measurements using the Agatston score lead to changes in assignment of patients to cardiovascular risk groups compared to filtered back projection (FBP). MATERIALS AND METHODS: 68 patients (mean age 61.5 years; 48 male; 20 female) underwent prospectively ECG-gated, non-enhanced, cardiac 256-MSCT for coronary calcium scoring. Scanning parameters were as follows: Tube voltage, 120 kV; Mean tube current time-product 63.67 mAs (50 - 150 mAs); collimation, 2 × 128 × 0.625 mm. Images were reconstructed with FBP and with HIR at all levels (L1 to L7). Two independent readers measured Agatston scores of all reconstructions and assigned patients to cardiovascular risk groups. Scores of HIR and FBP reconstructions were correlated (Spearman). Interobserver agreement and variability was assessed with ĸ-statistics and Bland-Altmann-Plots. RESULTS: Agatston scores of HIR reconstructions were closely correlated with FBP reconstructions (L1, R = 0.9996; L2, R = 0.9995; L3, R = 0.9991; L4, R = 0.986; L5, R = 0.9986; L6, R = 0.9987; and L7, R = 0.9986). In comparison to FBP, HIR led to reduced Agatston scores between 97 % (L1) and 87.4 % (L7) of the FBP values. Using HIR iterations L1 - L3, all patients were assigned to identical risk groups as after FPB reconstruction. In 5.4 % of patients the risk group after HIR with the maximum iteration level was different from the group after FBP reconstruction. CONCLUSION: There was an excellent correlation of Agatston scores after HIR and FBP with identical risk group assignment at levels 1 - 3 for all patients. Hence it appears that the application of HIR in routine calcium scoring does not entail any disadvantages. Thus, future studies are needed to demonstrate whether HIR is a reliable method for reducing radiation dose in coronary calcium scoring.

[Trabeculectomy versus canaloplasty]. / Trabekulektomie versus Kanaloplastik.

BACKGROUND: Trabeculectomy provides an excellent reduction of intraocular pressure (IOP) and is the reference technique in the treatment of glaucoma patients. Canaloplasty is a relatively new surgical non-penetrating procedure for restoring the natural outflow pathway of aqueous humour. The aim of canaloplasty is to permanently distend the collapsed Schlemm's canal with the placement of a 360° intracanalicular tension suture. OBJECTIVES: This review article describes the comparison between trabeculectomy and canaloplasty with and without cataract surgery. MATERIAL AND METHODS: Original studies, case reports and reviews are described and the results are discussed. RESULTS: Although canaloplasty may not be as effective in reducing IOP, trabeculectomy can be associated with severe vision-threatening complications however, the combination of canaloplasty with cataract surgery achieves a higher IOP reduction than canaloplasty alone. In contrast, trabeculectomy alone provides better IOP control than phacotrabeculectomy due to a higher risk of early bleb scarring induced by an increased intraocular inflammatory reaction. CONCLUSION: If a higher postoperative IOP is acceptable and additional topical glaucoma medication tolerable, canaloplasty can be considered as an alternative to trabeculectomy as the incidence of complications is low and postoperative care less intensive. Canaloplasty may also be suitable for patients with high risk of bleb failure and early glaucoma with a target IOP not necessarily requiring a filtering procedure. Therefore, canaloplasty offers a treatment option for the management of open-angle glaucoma, especially in combination with cataract surgery.

[Comparison of canaloplasty with trabeculectomy]. / Kanaloplastik und Trabekulektomie im Vergleich.

BACKGROUND: Trabeculectomy (TET) is still the gold standard in incisional glaucoma surgery. It achieves an efficient intraocular pressure (IOP) reduction. Unfortunately postsurgical complications of the procedure are frequent. Canaloplasty is a non-penetrating procedure, which aims at restoration of the natural aqueous outflow pathways, without subconjunctival drainage. AIM: This study has compared both surgical procedures concerning IOP, defined success criteria, postoperative medication, visual acuity and postoperative complications/interventions. PATIENTS AND METHODS: In a retrospective study 22 eyes after trabeculectomy and 22 eyes after canaloplasty were included. IOP, complete and qualified success, postoperative medication, visual acuity and complications/interventions were recorded at 6 month, 12 month and at last follow-up postoperatively. RESULTS: The mean IOP in the trabeculectomy and canaloplasty groups decreased from 23.91 ± 10.68 mmHg to 10.82 ± 3.67 mmHg and from 23.68 ± 7.57 mmHg to 14.50 ± 3.80 mmHg, respectively. The postoperative complications and interventions between the two groups did not reveal a statistically significant difference. Complete success (IOP < 21 mmHg and 20 % IOP reduction from baseline without medication) was achieved in 18 eyes (81.8 %) after trabeculectomy and in 11 eyes (50.0 %) after canaloplasty (p = 0.026). CONCLUSION: Canaloplasty and trabeculectomy are safe and effective procedures in the treatment of open-angle glaucoma. Both surgical methods reduce the IOP and the postoperative medication to a statistically significant extent. Trabeculectomy attains higher long-term complete success rates accompanied by slightly increased early postoperative complication rates (n. s.), compared to canaloplasty.

Liver remnant regeneration in donors after living donor liver transplantation: long-term follow-up using CT and MR imaging.

PURPOSE: To assess liver remnant volume regeneration and maintenance, and complications in the long-time follow-up of donors after living donor liver transplantation using CT and MRI. MATERIALS AND METHODS: 47 donors with a mean age of 33.5 years who donated liver tissue for transplantation and who were available for follow-up imaging were included in this retrospective study. Contrast-enhanced CT and MR studies were acquired for routine follow-up. Two observers evaluated pre- and postoperative images regarding anatomy and pathological findings. Volumes were manually measured on contrast-enhanced images in the portal venous phase, and potential postoperative complications were documented. Pre- and postoperative liver volumes were compared for evaluating liver remnant regeneration. RESULTS: 47 preoperative and 89 follow-up studies covered a period of 22.4 months (range: 1 - 84). After right liver lobe (RLL) donation, the mean liver remnant volume was 522.0 ml (±â€Š144.0; 36.1 %; n = 18), after left lateral section (LLS) donation 1,121.7 ml (±â€Š212.8; 79.9 %; n = 24), and after left liver lobe (LLL) donation 1,181.5 ml (±â€Š279.5; 72.0 %; n = 5). Twelve months after donation, the liver remnant volume were 87.3 % (RLL; ±â€Š11.8; n = 11), 95.0 % (LS; ±â€Š11.6; n = 18), and 80.1 % (LLL; ±â€Š2.0; n = 2 LLL) of the preoperative total liver volume. Rapid initial regeneration and maintenance at 80 % of the preoperative liver volume were observed over the total follow-up period.  Minor postoperative complications were found early in 4 patients. No severe or late complications or mortality occurred. CONCLUSION: Rapid regeneration of liver remnant volumes in all donors and volume maintenance over the long-term follow-up period of up to 84 months without severe or late complications are important observations for assessing the safety of LDLT donors. KEY POINTS: Liver remnant volumes of LDLT donors rapidly regenerated after donation and volumes were maintained over the long-term follow-up period of up to 84 months without severe or late complications.

Impact of a 4th generation iterative reconstruction technique on image quality in low-dose computed tomography of the chest in immunocompromised patients.

PURPOSE: To determine the image quality of an iterative reconstruction (IR) technique in low-dose MDCT (LDCT) of the chest of immunocompromised patients in an intraindividual comparison to filtered back projection (FBP) and to evaluate the dose reduction capability. MATERIALS AND METHODS: 30 chest LDCT scans were performed in immunocompromised patients (Brilliance iCT; 20-40 mAs; mean CTDIvol: 1.7 mGy). The raw data were reconstructed using FBP and the IR technique (iDose4™, Philips, Best, The Netherlands) set to seven iteration levels. 30 routine-dose MDCT (RDCT) reconstructed with FBP served as controls (mean exposure: 116 mAs; mean CDTIvol: 7.6 mGy). Three blinded radiologists scored subjective image quality and lesion conspicuity. Quantitative parameters including CT attenuation and objective image noise (OIN) were determined. RESULTS: In LDCT high iDose4™ levels lead to a significant decrease in OIN (FBP vs. iDose7: subscapular muscle 139.4 vs. 40.6 HU). The high iDose4™ levels provided significant improvements in image quality and artifact and noise reduction compared to LDCT FBP images. The conspicuity of subtle lesions was limited in LDCT FBP images. It significantly improved with high iDose4™ levels (> iDose4). LDCT with iDose4™ level 6 was determined to be of equivalent image quality as RDCT with FBP. CONCLUSION: iDose4™ substantially improves image quality and lesion conspicuity and reduces noise in low-dose chest CT. Compared to RDCT, high iDose4™ levels provide equivalent image quality in LDCT, hence suggesting a potential dose reduction of almost 80%.

[Modern filtration surgery. An update]. / Moderne Filtrationschirurgie. Ein Update.

Preoperative treatment with steroids and nonsteroidal anti-inflammatory drugs increases the success of filtration surgery. Surgery with the patient under subconjunctival anesthesia is safe. Intraoperative application of mitomycin C is state of the art and enhances success rates. Perioperative use of bevacizumab seems to attenuate postoperative fibrosis. Postoperative hypotension is avoided by stable fixation of the scleral flap followed by stepwise controlled suturelysis or release. Transconjunctival flap suturing allows fast and simple treatment of overfiltration. The shorter the time lag between trabeculectomy and subsequent cataract surgery the higher the probability of bleb failure will be. The number of antiglaucomatous drugs and severity of glaucomatous damage before surgery correlate with the probability of failure and blindness.

Improved agreement between experienced and inexperienced observers using a standardized evaluation protocol for cardiac volumetry and infarct size measurement.

PURPOSE: To study the agreement between experienced and inexperienced observers before and after training using a standardized evaluation protocol for cardiac magnetic resonance imaging (CMR) measurements of left ventricular (LV) volumes, mass and infarct size. MATERIALS AND METHODS: First, 10 CMR studies from patients with myocardial infarction were analyzed by 2 experienced and 4 inexperienced observers in respect to end-diastolic volume (EDV), end-systolic volume (ESV), ejection fraction (EF), LV mass and infarct size. Subsequently, the inexperienced observers were trained using a standardized evaluation protocol. Thereafter, all observers analyzed another 10 CMR studies. RESULTS: Before training the relative difference between experienced and inexperienced observers was -4.3±8.2% for EDV, -13.3±14.2% for ESV, 5.9±8.2% for EF, -12.2±10.9% for LV mass and -27.0±29.0% for infarct size in gram. After training, agreement significantly improved to 0.2±8.8% for EDV (p<0.05), -2.1±10.9 for ESV (p<0.01), 1.5±6.9% for EF (p<0.05), and -3.6±17.1% for infarct size (p<0.0001), but no improvement was seen for LV mass (-11.2±7.9, p=0.64). A slice based analysis showed, that the variable inclusion of the most basal and apical slices were mainly responsible for the low agreement of the measurements before training. CONCLUSION: Training using a standardized evaluation protocol significantly improved the agreement between experienced and inexperienced observers for important CMR parameters. The proposed evaluation protocol can be used for training to improve the reproducibility of CMR measurements.

[Non-penetrating glaucoma surgery]. / Nicht penetrierende Glaukomchirurgie.

Patients at high risk of developing complications (e.g. high myopia, aphakia, advanced visual field defects) benefit from non-penetrating glaucoma surgery (NPGS). Neovascular glaucoma, traumatic glaucoma or patients with a narrow angle (a scleral spur must at least be visible) are not suitable for NPGS. The aim of deep sclerectomy (DS) is mainly external subconjunctival drainage. Modified with mitomycin C and intrascleral implants, intraocular pressure (IOP) and success of DS are comparable to trabeculectomy. Viscocanalostomy and the further development to canaloplasty aim for blebless IOP control. Viscocanalostomy has an extremely low complication profile but only a slight reduction in IOP. Canaloplasty creates much more favourable results. Combined with phacoemulsification canaloplasty appears to lower IOP comparable to phacotrabeculectomy and demonstrates a more sustainable success compared to canaloplasty alone.

256-MSCT image acquisition with sequential axial scans: evaluation of image quality and resolution in a phantom study.

PURPOSE: Evaluation of image quality and resolution of varying sequential axial scan protocols utilizing two resolution phantoms with a 256-MSCT scanner. MATERIALS AND METHODS: Sequential axial scans were performed on a z-axis and an axial-plane resolution phantom with varying acquisition and reconstruction parameters. Two independent observers evaluated the image quality and resolution, and analyzed quantitative image quality parameters and radiation doses. RESULTS: The best image quality and resolution were achieved with an activated z-flying focal spot (zFFS) and overlapping reconstruction. With an activated zFFS, image degradation was significantly minimized in marginal or overlapping zones of the beam, but the maximum effective detector width was reduced to 82 % and 75 %, respectively depending on the field of view. With a deactivated zFFS, the effective detector width was not restricted, but the image quality decreased and the artifacts increased as the collimation increased. CONCLUSION: For sequential axial CT data acquisition with multi-planar image reformation, the zFFS technique is crucial to achieve the best image quality and resolution. Major advantages are minimized image degradation and increased spatial resolution along the z-axis, but the zFFS reduces the maximum effective detector width.

[Glaucoma surgery in childhood]. / Glaukomchirurgie im Kindesalter.

Technical characteristics and a long-term therapeutic strategy due to a long life expectancy play a key role in pediatric glaucoma surgery. The well-established angle surgery (goniotomy and trabeculotomy) achieves successful results in primary childhood glaucoma. Trabeculectomy seems to have been displaced as a secondary approach by glaucoma drainage devices (GDD) in primary childhood glaucoma due to inferior results, especially for children under 3 years of age. Even for secondary childhood glaucoma the results of GDD are encouraging, especially for therapy refractory aphakic glaucoma. In the first 2 years after GDD surgery success rates are about 80% for pediatric glaucoma and the results appear to be independent of the type of glaucoma and implant used. The complications of GDD are balanced to the faster intraocular pressure (IOP) control during the phase of visual acuity development. Cyclodestructive procedures may be applied as a secondary adjuvant approach but they increase the risk of conjunctival scarring and hypotony for subsequent procedures.

[Complex ligament instabilities after "open book"-fractures of the pelvic ring - finite element computer simulation and crack simulation]. / Komplexe ligamentäre Instabilitäten nach "open book"-Verletzungen des Beckenrings - Finite-Elemente-Computersimulation und Bruchversuch.

BACKGROUND: Instability of pelvic ring fractures is also caused by ligament disruption. Classifications are based on the major forces leading to fracture. Data from injury mechanisms as well as clinical and radiological criteria are used to determine the degree of instability. The major aim of all kinds of stabilisation is the anatomic reconstruction of the bony pelvic ring. The injured ligamentous apparatus is still ignored. Some clinical trials assume that soft-tissue injuries may be the reason for the poor patient outcome in "open book" pelvic ring fractures. The aim of the study was to develop a realistic finite element (FE) computer model to simulate "open book" fractures and predict injury-associated instabilities for osteosynthesis planning. PATIENTS/MATERIAL: We developed a realistic FE computer model of the pelvic ring based on CT data. With anatomic studies a computer model of the ligamentous apparatus was created and inserted into the pelvic ring to complete the bone-ligament complex. Numerical simulations were performed to identify the influence of single pelvic ligaments on the shifting at the intact anterior and posterior pelvic ring. Additionally, a biomechanical validated virtual crack simulation with anterior-posterior compression forces was undertaken to predict complex instabilities in "open book" pelvic ring fractures. RESULTS: The pelvic ligaments have local and general stabilising functions. The sacrospinous and sacrotuberous ligaments are providing the vertical load transfer, whereas the ligaments of the iliosacral joint and the iliolumbal ligament are necessary for the horizontal load transfer. In "open book" fractures ligaments are ruptured stepwise from anterior to posterior. If the intraosseous and posterior ligaments of the iliosacral joint are intact, only single rotational instability along the ipsilateral iliosacral joint occurs. If the ligaments at the posterior pelvic ring are ruptured too, a second axis across both iliosacral joints was measured. In this particular case additional stabilisation of the posterior pelvic ring should be performed. CONCLUSION: With numerical simulations, prediction of injury-associated instabilities is possible. Because of incomplete radiological data the implementation of patient-specific FE pelvic computer models into the clinical routine is still not realistic.