Spindle cell oncocytoma of the neurohypophysis with metastasis to the sphenoparietal sinus and immunohistochemical negativity for S100 and epithelial membrane antigen (EMA).

We report the case of a 61-year-old male with spindle cell oncocytoma of the hypophysis. On presentation to the Department of Neurosurgery at the German Armed Forces Hospital of Ulm, the patient reported a history of several years of left sixth nerve palsy, right ptosis, increased sensitivity to light, and a bilateral retrobulbar pressure sensation. Pituitary function was normal. A chromophobe non-functioning pituitary adenoma was initially suspected. The diagnosis was established on the basis of examination at a histopathology reference laboratory using immunohistochemistry to identify cell surface markers. During two years of follow-up, there were two clinical recurrences requiring surgery. To our knowledge, this is the 35th documented case of spindle cell oncocytoma of the pituitary gland and the first that was immunohistochemically negative for epithelial membrane antigen (EMA) and S100; and the first that displayed haematogenous metastasis to the right sphenoparietal sinus. The three surgical procedures were associated with massive intraoperative bleeding and thus resulted in subtotal tumor resection. Following surgery for the recurrences, the patient underwent radiotherapy.

Multifocal and hormone-dependent epithelioid hemangioendothelioma with osteolysis of the second cervical vertebral body: report of an unprecedented surgical approach by using autologous bone graft.

We report the case of a 28-year-old female patient who complained of extreme neck pain when giving birth to a child. Magnetic resonance imaging (MRI) of the cervical spine demonstrated an osteolytic lesion at the second cervical vertebral body (C2). In this presentation, we highlight a transoral surgical approach in order to prevent instability of this osteolytic lesion. To the best of our knowledge, this is the first time that such a route of access has been described for this tumor entity. A histopathologic examination led to the diagnosis of epithelioid hemangioendothelioma. During a follow-up period of 33 months, the patient had no complaints.

Dual-energy CT in sacral fragility fractures: defining a cut-off Hounsfield unit value for the presence of traumatic bone marrow edema in patients with osteoporosis.

BACKGROUND: Demographic change entails an increasing incidence of fragility fractures. Dual-energy CT (DECT) with virtual non-calcium (VNCa) reconstructions has been introduced as a promising diagnostic method for evaluating bone microarchitecture and marrow simultaneously. This study aims to define the most accurate cut-off value in Hounsfield units (HU) for discriminating the presence and absence of bone marrow edema (BME) in sacral fragility fractures. METHODS: Forty-six patients (40 women, 6 men; 79.7 ± 9.2 years) with suspected fragility fractures of the sacrum underwent both DECT (90 kVp / 150 kVp with tin prefiltration) and MRI. Nine regions-of-interest were placed in each sacrum on DECT-VNCa images. The resulting 414 HU measurements were stratified into "edema" (n = 80) and "no edema" groups (n = 334) based on reference BME detection in T2-weighted MRI sequences. Area under the receiver operating characteristic curve was calculated to determine the desired cut-off value and an associated conspicuity range for edema detection. RESULTS: The mean density within the "edema" group of measurements (+ 3.1 ± 8.3 HU) was substantially higher compared to the "no edema" group (-51.7 ± 21.8 HU; p < 0.010). Analysis in DECT-VNCa images suggested a cut-off value of -12.9 HU that enabled sensitivity and specificity of 100% for BME detection compared to MRI. A range of HU values between -14.0 and + 20.0 is considered indicative of BME in the sacrum. CONCLUSIONS: Quantitative analysis of DECT-VNCa with a cut-off of -12.9 HU allows for excellent diagnostic accuracy in the assessment of sacral fragility fractures with associated BME. A diagnostic "one-stop-shop" approach without additional MRI is feasible.

Low-Dose CT in Pelvic Imaging: Comparing Dose and Image Quality in Relation to Clinical Value in a Phantom Study.

OBJECTIVE. The aim of this phantom study was to determine whether low-dose CT of the pelvis can be performed using a dose similar to that used in a standard radio-graphic examination and to ascertain whether CT, with its better delineation of complex structures, has greater clinical value than radiography and therefore will result in improved patient care. Special consideration was given to CT performed using the tin filtration technique. MATERIALS AND METHODS. For dose comparison, an anthropomorphic phantom with 20 thermoluminescent dosimeters, two different CT scanners, and three conventional radiography devices were used. Seven CT protocols (including tin filtration) and four different radiographic examinations were performed. Dose calculations, objective and subjective evaluations of image quality, and figure-of-merit calculations were compared among the techniques. Furthermore, the images obtained were evaluated in a clinical context. Intraclass correlation was determined for the subjective results. RESULTS. The dose values of the tested low-dose CT protocols, in particular those using the tin filtration technique, corresponded to or were only slightly higher than the dose values of conventional pelvic radiographic images obtained in three views. Low-dose CT examinations were rated sufficient for consolidation control and had an informative value that was significantly higher than that of conventional radiography. Tin filtering showed the best results for low-dose CT in terms of combining dose and clinically relevant image quality. CONCLUSION. In this phantom study, low-dose CT was superior to radiography for visualizing and evaluating the dorsal pelvic ring, with only marginally higher radiation exposure occurring when the latest-generation CT systems were used. Tin filtration can improve image quality, create further dose reductions, or provide both benefits.

Dose Reduction in Dental CT: A Phantom Study With Special Focus on Tin Filter Technique.

OBJECTIVE. The purpose of this study was to determine in a phantom the dose exposure of different dental 3D sectional imaging methods (CT and cone-beam CT [CBCT]) and different CT protocols. The aim was to establish optimal protocols with the lowest possible dose and diagnostically high image quality with special consideration given to tin prefiltration. MATERIALS AND METHODS. Dose was determined with thermoluminescence detectors at 20 different measuring points on an anthropomorphic phantom. Eight different CT protocols with and without tin filtering were compared with iterative reconstruction methods and a standard CBCT protocol. Objective and subjective image evaluations and a figure-of-merit analysis of the image data were performed by radiologists and maxillofacial surgeons. RESULTS. The determined dose-length products of the nine examinations were 5.0-111.9 mGy · cm with a calculated effective whole body dose of 20.7-505.9 µSv. Cone-beam CT was in the upper midfield with an effective dose of 229.3 µSv. On the basis of dose, objective image quality, and clinical evaluation results, tin filter protocols performed best. Protocols with higher doses were significantly less useful in the figure of merit comparison but because of their detailed bony representation are particularly necessary to answer certain questions about trauma and tumors. CONCLUSION. The use of tin filtering can reduce dose in dental CT examinations, compared with standard low-dose examinations, while maintaining good image quality. The dose performance is significantly inferior even to that of a cone-beam CT examination. High-dose protocols are necessary only for certain questions.

Nucleus replacement could get a new chance with annulus closure.

PURPOSE: Disc herniations are usually treated by decompression of the spinal nerves via a partial nucleotomy. As a consequence of reduced disc height (DH), reduced intradiscal pressure (IDP) and increased range of motion (ROM), accelerated degeneration may occur. Nucleus replacement implants are intended to restore those values, but are associated with the risk of extrusion. METHODS: In six fresh frozen lumbar spinal segments (L2-3/L3-4/L4-5/L5-S1, age median 64.5 years (57-72), Pfirrmann grade 2-3), a prolapse was provoked through a box defect (6 × 10 mm) in the annulus. The herniated nucleus material was removed and replaced by a novel collagen-based nucleus implant. An annulus closure device sealed the defect. ROM, neutral zone (NZ) and IDP were measured in the (1) intact and (2) defect state, (3) postoperatively and (4) after cyclic loading (n = 100,000 cycles) applying pure moments (± 7.5 Nm) in flexion-extension, lateral bending and axial rotation. Additionally, the change in DH was determined. Extrusion of implants or nucleus material was evaluated macroscopically. RESULTS: In all specimens, a prolapse could be provoked which decreased DH. Subsequent nucleotomy changed ROM/NZ and IDP considerably. Initial values could be restored by the implantation. Macroscopically, none of the implants nor nucleus material did migrate after cyclic loading. CONCLUSIONS: In this study, a prolapse followed by a nucleotomy resulted in a biomechanical destabilisation. Implantation of the nucleus replacement combined with an annulus closure restored the intact condition without showing signs of extrusion nor migration after cyclic loading. Hence, nucleus replacements could have a new chance in combination with annulus closure devices.

Correction to: Nucleus replacement could get a new chance with annulus closure.

Unfortunately, Fig. 7 and last paragraph of the result section have been incorrectly published. The complete corrected Fig. 7 and last paragraph of the results part (IDP measurements) have been as follows.

Dual-energy CT as an innovative method for diagnosing fragility fractures of the pelvic ring: a retrospective comparison with MRI as the gold standard.

INTRODUCTION: As the average age of society increases, so does the number of cases of fragility fractures of the pelvis (FFP). Magnetic resonance imaging (MRI) can visualise associated oedema and is thus the gold standard for diagnosing such fractures. MRI, however, is costly, not always available, and involves certain exclusion criteria. Dual-energy computed tomography (DECT) appears to be a promising alternative. It is unclear, however, whether it could be used for diagnosing FFP with similar sensitivity/specificity. The aim of our study was thus to compare conventional CT and DECT with MRI in cases of suspected FFP. MATERIALS AND METHODS: A total of 46 patients with suspected FFP underwent MRI, CT and DECT scans. There were three comparison groups for each of these patients: conventional CT image analysis without dual-energy modification (Arm 1), DECT analysis (Arm 2) and MRI as the gold standard (Arm 3). Diagnosis and FFP classification were performed by a radiologist in random order and without clinical information. The sensitivity and specificity of conventional CT and DECT were calculated in comparison with MRI as the reference standard. RESULTS: With 100% sensitivity and specificity, DECT is on par with MRI when it comes to diagnosing fragility fractures of the pelvis and is superior to conventional CT (90.3% sensitivity, 100% specificity). In terms of classification as well, there were no differences between DECT and MRI. On conventional CT, on the other hand, 16 patients were classified differently than they were on MRI. CONCLUSIONS: Our study shows DECT to be reliable and superior to conventional CT in terms of oedema detection and specific fracture classification in FFP. DECT thus combines the advantages of conventional CT (good visualisation of bone matter) and MRI (medullary cavity and visualisation of occult fractures).

A pedicle screw system and a lamina hook system provide similar primary and long-term stability: a biomechanical in vitro study with quasi-static and dynamic loading conditions.

PURPOSE: For the stabilization of the thoracolumbar spine area, various stabilization techniques have been developed in recent decades. The aim of these techniques is to immobilize the treated segment to repositioning or correct the spine and guaranty long-term stability to achieve a reliable fusion. The aim of this study was to simulate in an in vitro experiment the postoperative long-term situation in elderly osteoporotic patients to compare two different stabilization principles; a pedicle screw system and a lamina hook system. METHODS: Two comparable groups with respect to age and bone mineral density with each n = 6 fresh-frozen human, bi-segmental thoracolumbar spine specimens (T11-L1) were used. Antero-posterior and lateral radiographs were taken before the test, to assess the spinal status. Then the intact specimens were biomechanically characterized with pure moments in the three anatomical planes in different states in terms of range of motion and neutral zone. After implantation of either, a pedicle screw system or a lamina hook system, the primary stability was determined under the same conditions. Subsequently the specimens were cyclically loaded under complex loading, using a custom-made set-up in a dynamic materials testing machine with increasing moments from 3 to 66 Nm until 100,000 cycles or until one of the three defined "failure" criteria was reached. (1) A failure of a bony structure. (2) Exceeding of the threefold ROM of the primary stability after implantation in flexion plus extension. (3) Reaching of the ROM based on the intact state before implantation both in flexion plus extension. RESULTS: The results showed that the ROM was strongly reduced after instrumentation similar for both implant systems in all motion planes. The highest stabilization was found in flexion/extension. During cyclic loading with increasing moments, the ROM increased continuously for both systems. The number of load cycles until one of the failure criteria was reached varied only slightly between the two groups. In the pedicle screw group 30,000 (median) loading cycles (range 5000-80,000) with a corresponding moment of 24 Nm (range 9-54) could be reached. In the lamina hook group 32,500 load cycles (range 20,000-45,000) could be achieved with a corresponding moment of 25.5 Nm (range 18-33). There was a slight trend that the pedicle screw system is influenced more by bone mineral density. CONCLUSION: Both implant systems provide similar primary stability and similar long-term stability. In the pedicle screw group, there was a stronger correlation between bone mineral density and the reached number of load cycles.

[Radiological diagnostics of patellofemoral instability and patellar dislocation]. / Radiologische Diagnostik der patellofemoralen Instabilität und Patellaluxation.

Patellofemoral instability (PFI) describes a (sub)luxation of the patella in the patellofemoral joint. Pathophysiologically, PFI is usually due to a nonphysiological movement of the patella, so-called maltracking, either due to acute trauma with injury to the supporting ligamentous apparatus or due to the presence of anatomical risk factors. Radiologically assessable risk factors for maltracking include trochlear dysplasia, patella alta, patellar tilt, lateralization of the tibial tuberosity, torsional deformity and genu valgum. This article presents the most commonly used and best validated measurement techniques. In addition, the characteristic injury pattern after lateral patellar dislocation is shown.

Influence of cervical total disc replacement on motion in the target and adjacent segments.

BACKGROUND CONTEXT: The motion limitation after cervical discectomy and fusion alters the spine´s kinematics. Unphysiological strains may be the result and possible explanation for adjacent segment degeneration. Alterations to cervical kinematics due to cervical total disc replacement (TDR), especially two-level, are still under investigated. PURPOSE: To investigate cervical motion including coupled motions after one-level and two-level TDR in the treated and also the adjacent segments. STUDY DESIGN: An in-vitro study using pure moment loading of human donor spines. METHODS: Seven fresh frozen human cervical spine specimens (C4-T1, median age 46 with range 19-60 years, four female) were included in this study. Specimens were tested in the intact condition first, followed by one-level TDR at C5-6 which was subsequently extended one level further caudal (C5-7). Each specimen was quasistatically loaded with pure moments up to 1.5 Nm in flexion/extension (FE), lateral bending (LB), and axial rotation (AR) in a universal spine tester for 3.5 cycles at 1 °/s. During the tests three dimensional motion tracking was performed for each vertebral body individually. From that, the primary and coupled ROM of each spinal level during the third full cycle of motion were evaluated. Nonparametric statistical analysis was performed using a Friedman-test and post hoc correction with Dunn-Bonferroni-tests (p<.05). Ethics approval was obtained in advance. RESULTS: In FE, one-level TDR (C5-6) moderately increased primary FE in all four segments, but only significantly at the cranial adjacent level C4-5. Additional TDR at C6-7 further increased the ROM at the target segment without much influence on the other levels. Increasing implant height at C6-7 partially counteracted the increased FE. Coupled motions were minimal in all test conditions at all levels. In LB, coupled AR was observed in all test conditions at all levels. One-level TDR decreased primary LB at the target segment C5-6 significantly, without much influence on the other levels. Extending TDR to C6-7 decreased ROM in the target segment but without gaining statistical significance. Increasing implant height at C6-7 further decreased primary LB at the target segment, still without significance. Notably, coupled AR was significantly decreased at the cranial adjacent segment C4-5 compared to the intact condition. In AR, coupled LB was observed in all test conditions at the levels C4-5, C5-6, and C6-7, while the transition level to the thoracic spine C7-T1 showed only little coupled LB. Both one-level and two-level TDR showed little influence on primary AR or coupled motions at any level. Only after increasing implant height at C6-7 was the motion of the caudally adjacent level C7-T1 significantly altered. CONCLUSION: Evaluating primary FE, LB, and AR together with the associated coupled motions revealed widespread influence of cervical TDR not only on the motion of the treated level but also at the adjacent segments. The influence of two-level TDR is more widespread and involves more levels than one-level TDR. CLINICAL SIGNIFICANCE: The prevention of unphysiological strains due to altered kinematics after cervical fusion, which could possibly explain adjacent segment degeneration, were a driving factor in the development of TDR. These experimental findings suggest cervical TDR influences the whole cervical spine, not only the treated segment. The effect becomes more extensive, involving more levels and motion directions, after two-level than after one-level TDR.

The Influence of Computed Tomography Contrast Agent on Radiation-Induced Gene Expression and Double-Strand Breaks.

After nuclear scenarios, combined injuries of acute radiation syndrome (ARS) with, e.g., abdominal trauma, will occur and may require contrast-enhanced computed tomography (CT) scans for diagnostic purposes. Here, we investigated the effect of iodinated contrast agents on radiation-induced gene expression (GE) changes used for biodosimetry (AEN, BAX, CDKN1A, EDA2R, APOBEC3H) and for hematologic ARS severity prediction (FDXR, DDB2, WNT3, POU2AF1), and on the induction of double-strand breaks (DSBs) used for biodosimetry. Whole blood samples from 10 healthy donors (5 males, 5 females, mean age: 28 ± 2 years) were irradiated with X rays (0, 1 and 4 Gy) with and without the addition of iodinated contrast agent (0.016 ml contrast agent/ml blood) to the blood prior to the exposure. The amount of contrast agent was set to be equivalent to the blood concentration of an average patient (80 kg) during a contrast-enhanced CT scan. After irradiation, blood samples were incubated at 37°C for 20 min (DSB) and 8 h (GE, DSB). GE was measured employing quantitative real-time polymerase chain reaction. DSB foci were revealed by γH2AX + 53BP1 immunostaining and quantified automatically in >927 cells/sample. Radiation-induced differential gene expression (DGE) and DSB foci were calculated using the respective unexposed sample without supplementation of contrast agent as the reference. Neither the GE nor the number of DSB foci was significantly (P = 0.07-0.94) altered by the contrast agent application. However, for some GE and DSB comparisons with/without contrast agent, there were weakly significant differences (P = 0.03-0.04) without an inherent logic and thus are likely due to inter-individual variation. In nuclear events, the diagnostics of combined injuries can require the use of an iodinated contrast agent, which, according to our results, does not alter or influence radiation-induced GE changes and the quantity of DSB foci. Therefore, the gene expression and γH2AX focus assay can still be applied for biodosimetry and/or hematologic ARS severity prediction in such scenarios.

[Stress reactions and stress fractures]. / Stressreaktionen und Stressfrakturen.

Bone stress injuries is an umbrella term that encompasses repetitive microtraumatic events that accumulate to surpass the threshold of bone failure, which can range from bone marrow edema to frank stress fracture as the end point. Due to nonspecific clinical complaints and physical findings, imaging plays a central role in the diagnostic workup of these entities. Magnetic resonance imaging (MRI) is the most important imaging modality with a high sensitivity and specificity and allows for differential diagnosis of other diseases. Edema-sensitive with fat suppression and T1-weighted sequences are the core sequence types, and contrast-enhanced imaging-albeit displaying subtle fractures much more easily-is rarely necessary. Furthermore, MRI enables differentiation of injury severity, which has an impact on length of rehabilitation, therapeutic regimen, and the time to return to sports in athletes.

[Stress fractures in the military context]. / Stressfrakturen im militärischen Kontext.

BACKGROUND: Soldiers, especially as recruits, are exposed to significantly elevated stress patterns of the foot due to occupation-related marching and excessive running. This can lead to military-specific stress fractures of the metatarsals, i.e., marching fractures. The treatment and prevention of stress fractures are of particular importance in the military context due to the impact on operational capability and treatment costs. A uniform classification of these fractures does not yet exist. OBJECTIVE: Review of stress fractures in the military setting with presentation of the incidence, risk factors, classification, treatment and prevention possibilities. MATERIAL AND METHODS: A PubMed®-based review of the current literature on stress fractures in the military context was conducted and the results were discussed with a focus on specific military medical treatment options. RESULTS: There are several possibilities to classify stress fractures, the most well-known being a 4-level magnetic resonance imaging (MRI)-based classification. Prevention and treatment possibilities are multifaceted but so far insufficiently validated. CONCLUSION: Military-specific stress fractures should be grouped according to a 4-level and MRI-based classification. The treatment options include both conservative and surgical measures and should be implemented taking the patient's individual requirements into account. Preventive measures play a key role in the military context. They include the adaptation of screening tools, training and equipment and require continuous evaluation and development.

Thermoluminescence Dosimetry in Abdominal CT for Urinary Stone Detection: Effective Radiation Dose Reduction With Tin Prefiltration at 100 kVp.

OBJECTIVES: Spectral shaping via tin prefiltration has gained recognition for dose saving in high-contrast imaging tasks. The aim of this phantom dosimetry study was to investigate whether the use of tin filters can also reduce the effective radiation dose in 100 kVp abdominal computed tomography (CT) compared with standard low-dose scans for suspected urolithiasis. METHODS: Using a third-generation dual-source CT scanner, 4 scan protocols each were used on a standard (P1-P4) and a modified obese Alderson-Rando phantom (P5-P8), in which 11 urinary stones of different compositions were placed. Hereby 1 scan protocol represented standard low-dose settings (P1/P5: 110 kVp/120 kVp), whereas 3 experimental protocols used low-kilovoltage spectral shaping (P2/P3/P4 and P6/P7/P8: 100 kVp with tin prefiltration). Radiation dose was recorded by thermoluminescent dosimeters at 24 measurement sites. For objective assessment of image quality, dose-weighted contrast-to-noise ratios were calculated and compared between scan protocols. Additional subjective image quality analysis was performed by 2 radiologists using equidistant 5-point scales for estimation image noise, artifacts, kidney stone detectability, and delineation of bone and soft tissue. RESULTS: Both conventional low-dose protocols without tin prefiltration were associated with the highest individual equivalent doses and the highest effective radiation dose in the experimental setup (P1: 0.29-6.43 mGy, 1.45-1.83 mSv; P5: 0.50-9.35 mGy, 2.33-2.79 mSv). With no false-positive diagnoses, both readers correctly detected each of the 11 urinary calculi irrespective of scan protocol and phantom configuration. Protocols using spectral shaping via tin prefiltration allowed for effective radiation dose reduction of up to 38% on the standard phantom and 18% on the modified obese phantom, while maintaining overall diagnostic image quality. Effective dose was approximately 10% lower in a male versus female anatomy and could be reduced by another 10% if gonadal protection was used ( P < 0.001). CONCLUSIONS: Spectral shaping via tin prefiltration at 100 kVp is a suitable means to reduce the effective radiation dose in abdominal CT imaging of patients with suspected urolithiasis. The dose reduction potential is slightly less pronounced in a modified phantom emulating an obese body composition compared with a standard phantom.

Myocardial deformation parameters assessed by CMR feature tracking in chronic heart failure: the influence of an optimal medical therapy on myocardial remodelling.

BACKGROUND: Myocardial deformation parameters have been shown to yield early detection of pathological changes in chronic heart failure (CHF). Aim of our study was to evaluate myocardial deformation changes under optimal medical therapy (OMT) in CHF patients. METHODS: CHF patients were examined longitudinally with two cardiac magnetic resonance imaging (CMR) examinations at a median time interval of 140 days. Left and right ventricular volumes were quantified, and deformation analysis was performed using feature tracking, respectively. RESULTS: 57 patients were included into the study. There was a high rate of OMT with a prescription of beta blockers in 98.2% and ACE-inhibitors/Angiotensin receptor blockers in 93.0%. In the total cohort, there were indications of positive remodelling with a significant improvement in left ventricular (LV) ejection fraction (38.9% ± 11.6 vs. 43.0% ± 12.7, p = 0.009), LV enddiastolic volume indexed (92.1 ml/m2 ± 23.5 vs. 87.2 ml/m2 ± 21.2, p = 0.007), LV mass (140.3 g ± 35.7 vs. 128.0 g ± 34.4, p = 0.001) and right ventricular global longitudinal strain (RV GLS) (-18.1% ± 5.1 vs. -20.3% ± 4.5, p < 0.001) during follow-up. DISCUSSION: Patients with CHF and OMT show positive reverse remodelling with improvement of LV volumes and function and RV GLS. This has a potential impact on the surveillance of this patient group, which should be further investigated in larger prospective studies.

Baseline angina burden predicts quality of life and functional improvement in patients with viable myocardium treated for chronic total occlusion.

Chronic total occlusion (CTO) is a common finding in patients with known or suspected coronary artery disease and has a distinctive role in these patients' quality of life. However, there is still a lack of evidence of correct patient selection for percutaneous coronary intervention (PCI). From July 2017 to August 2020, 68 patients with successful PCI of a CTO and previous evidence of viability for PCI by cardiovascular magnetic resonance imaging (CMR) were prospectively included in this single-centre observational study. Of these patients, 62 underwent follow-up CMR, and 56 underwent surveys using the Seattle Angina Questionnaire before PCI and 3, 12 and 24 months after PCI. The CMR results were assessed for volumetric, functional and deformation parameters. From the baseline to the follow-up, there was a significant reduction in the left ventricular volumes (all p < 0.001) and an increase in the left ventricular ejection fraction (57.6 ± 11.6% vs. 60.3 ± 9.4%, p = 0.006). Among the deformation parameters, only the left ventricular radial strain showed significant improvement. The SAQ showed an early improvement that emphasised angina stability and frequency as well as a summary score, which persisted after 24 months. A low SAQ summary score before PCI was the best predictive factor of good clinical improvement thereafter. Improvements in myocardial function and quality of life can be achieved with PCI of a CTO. Patient selection for PCI should be performed primarily among relevantly symptomatic patients when evidence of viability for PCI is present. The SAQ can help guide such patient selection.Trial registration ISRCTN, identifier: ISRCTN33203221. Retrospectively registered on 01.04.2020. https://www.isrctn.com/ISRCTN33203221.

Tin filter compared to low kV protocols - optimizing sinonasal imaging in computed tomography.

OBJECTIVES: Paranasal sinus imaging due to chronic inflammatory disease is one of the most common examinations in head and neck radiology with CT imaging considered the current gold standard. In this phantom study we analyzed different low dose CT protocols in terms of image quality, radiation exposure and subjective evaluation in order to establish an optimized scanning protocol. METHODS: In a phantom study, an Alderson phantom was scanned using 12 protocols between 70-120 kV and 25-200 mAs with and without tin filtration. For all datasets, iterative reconstruction was used. Data were objectively evaluated (image noise, (dose-weighted) contrast-to-noise ratio) and for subjective evaluation an online survey using a Likert scale was performed to reach a large group of clinically experienced reader (n = 62). The protocol was considered diagnostically insufficient if the median score was 4 and above and if more than 10% of raters scored 4 and above on the Likert scale. For an interreader agreement an ICC was calculated. To compare clinical value in relation to the applied dose and the objective image parameters, we calculated a figure of merit (FOM) and ranked the protocols accordingly. RESULTS: There was an overall moderate agreement between the 62 readers for the 12 examined CT protocols. In this phantom study, protocols with 100 kV with spectral shaping and 50-100 mAs obtained the best results for its combination of dose, image quality and clinical information value for diagnosing sinusitis (FOM 1st- 2nd place) with the 70 kV and 50 mAs as a good alternative as well (Sinusitis: FOM shared 2nd). For preoperative planning, where a higher dose is necessary, 100 kV with spectral shaping and 100 mAs achieved the overall best results (FOM 1st place) with 70 kV and 50 mAs ranking 4th. CONCLUSION: 100-kV protocols with spectral shaping or low kV protocols (70 kV) with a similarly low dose showed the best figure of merit for imaging sinonasal disease and preoperative planning. With modern scanner technology available, spectral shaping or low KV protocols should be used for sinusitis imaging.