Neovascularization, vascular mimicry and molecular exchange: The imaging of tumorous tissue aggressiveness based on tissue perfusion.

Angiogenesis in healthy tissue and within malignant tumors differs on many levels, which may partly be explained by vascular mimicry formation resulting in altered contrast material or different radiopharmaceuticals distributions. Failed remodulation results in changes in the molecular exchange through the capillary wall and those consequences affect the behavior of contrast agents and radiopharmaceuticals. One of the most indicative signs of malignant tissue is the increased permeability and the faster molecular exchange that occurs between the extracellular and intravascular spaces. Dynamic imaging can help to assess the changed microenvironment. The fast-distribution of molecules reflects newly developed conditions in blood-flow redistribution inside a tumor and within the affected organ during the early stages of tumor formation. Tumor development, as well as aggressiveness, can be assessed based on the change to the vascular bed development, the level of molecular exchange within the tissue, and/or indicative distribution within the organ. The study of the vascular network organization and its impact on the distribution of molecules is important to our understanding of the image pattern in several imaging methods, which in turn influences our interpretation of the findings. A hybrid imaging approach (including PET/MRI) allows the quantification of vascularization and/or its pathophysiological impressions in structural and metabolic images. It might optimize the evaluation of the pretreatment imaging, as well as help assess the effect of therapy targeting neovascularization; antiVEGF drugs and embolization-based therapies, for example.

Assessment of Prostate Carcinoma Aggressiveness: Relation to 68Ga-PSMA-11-PET/MRI and Gleason Score.

BACKGROUND/AIM: To test the correlation of 68Ga-PSMA-11 uptake and the expression of PSMA (prostatic specific membrane antigen) with the Gleason score, apparent diffusion coefficient (ADC) and pharmacokinetic parameters obtained from dynamic contrast agent-enhanced MRI/PET. PATIENTS AND METHODS: Forty newly diagnosed, therapy naïve patients with prostatic carcinoma (PC) (mean age of 56.7, range=34-79), who were referred for 68Ga-PSMA-11-PET/MRI for primary staging and had undergone radical prostatectomy (RAPE) were included in this prospective study. Their blood samples were tested for serum levels of prostate-specific antigen (PSA) and proPSA. The patients' prostates were evaluated using whole-mount sections, which helped determine the extent and grade of the tumor; tests were performed to determine immunohistochemical PSMA expression. RESULTS: A correlation between PSMA expression and the accumulation of 68Ga-PSMA-11 was found using the Spearman correlation coefficient (p=0.0011). A stronger correlation was found between Gleason patterns 3 or 4 and PSMA expression (p=0.06). Furthermore, the correlation of Gleason score with the overall 68Ga-PSMA-11 accumulation within the tumor or non-tumor tissue was found to be significant (p=0.0157). A significant relation was found only with the Kep elimination rate constant, which was stronger in Gleason pattern 4 than in Gleason pattern 3. A weaker correlation was found between the accumulation of 68Ga-PSMA-11 and Ktrans in Gleason pattern 4: the most significant relation being between ADCmin and Gleason pattern 3 and 4 (p=0.0074). The total size of the tumor correlated with levels of proPSA (p<0.0001), and its extra prostatic extension correlated with levels of proPSA (p<0.0001). CONCLUSION: 68Ga-PSMA-11 correlates well with the expression of PSMA. Gleason pattern 3 and 4 had a higher correlation with 68Ga-PSMA-11 levels than did Gleason pattern 5. Either no correlation, or a weak correlation, was established with pharmacokinetics.

The imaging of the hypoxic microenvironment in tumorous tissue using PET/CT and PET/MRI.

Tissue hypoxia becomes the driver of the micro-environmental transformation of the malignant tumorous tissue in majority of solid tumors. Even more, during the development of solid tumors, a large amount of nutrients is consumed due to rapid proliferation of tumor cells. The way of use of nutrients could be assessed using the probes during positron emission tomography (PET), the most frequent is the use of 18F-fluorodeoxyglucose (18F-FDG) demonstrating the turn-over of glucose exploitation in a manner of Warburg phenomenon. Even tumor cells can undergo metabolic reprogramming by changing the expression of glycolysis-related proteins, development of hypoxic condition increases glucose uptake to promote their growth. The hypoxic conditions are stimulation also the development of drug and/or radiation resistance, thus, the identification of the hypoxic tissue could play an important role in therapy planning. The process that enables use of hypoxia specific PET radiopharmaceutical starts when it enters cell by passive diffusion. Intracellularly, a model substance - 18F-fluoromisonidazol (18F-FMISO) is reduced by nitroreductase enzymes to become trapped in cells within reduced tissue oxygen partial pressure. The identification of the hypoxic tissue aids to plan the target to radiotherapy in squamous cell carcinomas of head and neck or cervical carcinoma, when 18F-FMISO-PET/CT is used as a planning procedure for a target volume, while 18F-FDG-PET/MRI is being the local and whole body staging procedure. Hypoxia imaging helps to identify the high-grade component of an astrocytic tumor before stereotactic biopsy.

Acute Mediastinitis - Outcomes and Prognostic Factors of Surgical Therapy (A Single-Center Experience).

PURPOSE: The aims of this work were the retrospective analysis of a cohort of patients with acute mediastinitis treated at the authors' worksite over a 15-year period and the identification of factors that significantly affect the outcomes of the therapy. METHODS: During the period 2006-2020, 80 patients with acute mediastinitis were treated. Within the cohort, the following were observed: the causes and the type of acute mediastinitis, length of anamnesis, comorbidities, diagnostic methods, time from the diagnosis to surgery, types and number of surgical procedures, results of microbiological tests, complications, and outcomes of the treatment. RESULTS: The most common type of acute mediastinitis was descending mediastinitis (48.75%). A total of 116 surgical procedures were performed. Ten patients in the cohort died (12.5%). Patients older than 60 years were at a 6.8 times higher risk of death. Patients with more than two comorbidities were at a 14.3 times higher risk of death. The presence of yeasts in the culture material increased the risk of death by 4.4 times. CONCLUSION: Early diagnosis, removal of the cause of mediastinitis, sufficient mediastinal debridement, and multiple drainage thereof with the possibility of continual postoperative lavage are essential for the successful treatment of acute mediastinitis.

Is ultra low-dose CT with tin filtration useful for examination of SI joints? Can it replace X-ray in diagnostics of sacroiliitis?

OBJECTIVES: The first objective of our study was to determine the radiation exposure received by patients during tin-filtrated ultra-low-dose computed tomography (TFULDCT) of sacroiliac joints and to compare those to conventional X-ray doses. For comparison, we added a cohort examined by low-dose CT (LDCT) without tin filtration. The second objective was to compare the results of TFULDCT and X-ray in the detection of sacroiliitis. METHODS: Our retrospective study covered 45 patients, who were examined for suspected axial spondyloarthritis (AxSpA). The first group underwent TFULDCT as well as conventional radiography (CR); the second group underwent LDCT only without tin filtration. Effective doses of TFULDCT, LDCT and CR were calculated by an experienced medical physicist. TFULDCT and CR were independently evaluated by three investigators, who decided on the presence or absence of rheumatoid inflammatory bone changes. The results were statistically evaluated. RESULTS: In our cohort, the median effective dose for TFULDCT was 0.11 mSv, range (0.06-0.40 mSv), for LDCT 0.5 mSv (0.29-0.89 mSv), and for CR 0.25 mSv (0.06-1.87 mSv). We proved that TFULDCT produces a significantly lower percentage of uncertain results (23.3%; 95% CI: 11.3-41.6%) than CR (66.7%; 95% CI: 48.3-81.1%). CONCLUSIONS: Tin filtration helps to reduce CT radiation exposure to values lower than those resulting from CR. TFULDCT offers better overall diagnostic performance than CR. Our results prove that TFULDCT can replace CR in the diagnosis of sacroiliitis in the radiographical stage of AxSpA.

Why Use Position Features in Liver Segmentation Performed by Convolutional Neural Network.

Liver volumetry is an important tool in clinical practice. The calculation of liver volume is primarily based on Computed Tomography. Unfortunately, automatic segmentation algorithms based on handcrafted features tend to leak segmented objects into surrounding tissues like the heart or the spleen. Currently, convolutional neural networks are widely used in various applications of computer vision including image segmentation, while providing very promising results. In our work, we utilize robustly segmentable structures like the spine, body surface, and sagittal plane. They are used as key points for position estimation inside the body. The signed distance fields derived from these structures are calculated and used as an additional channel on the input of our convolutional neural network, to be more specific U-Net, which is widely used in medical image segmentation tasks. Our work shows that this additional position information improves the results of the segmentation. We test our approach in two experiments on two public datasets of Computed Tomography images. To evaluate the results, we use the Accuracy, the Hausdorff distance, and the Dice coefficient. Code is publicly available at: https://gitlab.com/hachaf/liver-segmentation.git.

The Use of CT Pattern in Differentiating Non-invasive, Minimally Invasive and Invasive Variants of Lung Adenocarcinoma.

BACKGROUND/AIM: This study determined whether computed tomography (CT) is an appropriate means by which to differentiate non-invasive and minimally invasive forms of pulmonary adenocarcinoma from the invasive variant. PATIENTS AND METHODS: A total of 64 patients (38 men and 26 women, aged 42-76, mean age 64), who underwent surgery for pulmonary adenocarcinoma and a chest CT no less than 1 month before surgery, were included in the study. Lesions exhibiting ground glass opacity or ground glass opacity with a solid component of 5 mm or smaller, were defined as minimally invasive or non-invasive adenocarcinomas. CT findings were correlated with histopathological examination. RESULTS: Distinguishing minimally invasive and non-invasive adenocarcinoma from invasive adenocarcinoma using CT was achieved with a sensitivity of 77.7%, a specificity of 97.8%, a positive predictive value of 93.3%, and a negative predictive value of 91.8%. CONCLUSION: CT can be useful in assessing the degree of invasiveness of pulmonary adenocarcinoma and is a potential tool for the individualization of treatment.

Mesenchymal Stromal Cell Therapy in Novel Porcine Model of Diffuse Liver Damage Induced by Repeated Biliary Obstruction.

In liver surgery, biliary obstruction can lead to secondary biliary cirrhosis, a life-threatening disease with liver transplantation as the only curative treatment option. Mesenchymal stromal cells (MSC) have been shown to improve liver function in both acute and chronic liver disease models. This study evaluated the effect of allogenic MSC transplantation in a large animal model of repeated biliary obstruction followed by partial hepatectomy. MSC transplantation supported the growth of regenerated liver tissue after 14 days (MSC group, n = 10: from 1087 ± 108 (0 h) to 1243 ± 92 mL (14 days); control group, n = 11: from 1080 ± 95 (0 h) to 1100 ± 105 mL (14 days), p = 0.016), with a lower volume fraction of hepatocytes in regenerated liver tissue compared to resected liver tissue (59.5 ± 10.2% vs. 70.2 ± 5.6%, p < 0.05). Volume fraction of connective tissue, blood vessels and bile vessels in regenerated liver tissue, serum levels of liver enzymes (AST, ALT, ALP and GGT) and liver metabolites (albumin, bilirubin, urea and creatinine), as well as plasma levels of IL-6, IL-8, TNF-α and TGF-ß, were not affected by MSC transplantation. In our novel, large animal (pig) model of repeated biliary obstruction followed by partial hepatectomy, MSC transplantation promoted growth of liver tissue without any effect on liver function. This study underscores the importance of translating results between small and large animal models as well as the careful translation of results from animal model into human medicine.

Computed tomography with a full FOV photon-counting detector in a clinical setting, the first experience.

OBJECTIVES: to assess the feasibility of CT with an integrated photon-counting-detector system (PC-CT) in the body imaging of clinical patients. METHODS: 120 examinations using photon counting detector CT were evaluated in six groups: 1/ a standard-dose lung, 2/ low-dose lung, 3/ ultra-high resolution (UHR) lung, 4/ standard-dose abdominal, 5/ lower-dose abdominal, 6/ UHR abdominal CTA. All CT examinations were performed on a single-source prototype device equipped with a photon counting detector covering a 50 cm scan field of view. Standard dose examinations were performed with the use of detector element size of 0.4 mm, ultra-high-resolution examinations with the detector element size of 0.2 mm, respectively. The stability of the system during imaging was tested. The diagnostic quality of the acquired images was assessed based on the imaging of key structures and the noise level in five-point scale, the effective dose equivalent, dose length product and noise level, and also relation to body mass index and body surface area were compared with three similar groups of CT images made with energy integrating high end scanner. The parameters were evaluated using Wilcoxon test for independent samples, the independence was tested using Kruskal-Wallis test. RESULTS: When PC-CT images radiation dose is compared with the similar imaging using energy integrating CT, the PC-CT shows lower dose in ultra-high resolution mode, the dose is significantly lower (p < 0.0001), the standard dose examinations were performed with the comparable radiation doses. PC-CT exhibited the significantly higher ratio between parenchyma signal and background noise both in lung and in abdominal imaging (p < 0.0001). CONCLUSIONS: PC-CT showed imaging stability and excellent diagnostic quality at dose values that are comparable or better to the quality of energy integrating CT, the better signal and improved resolution is most important advantage of photon counting detector CT over energy integrating detector CT.

Influence of Mesenchymal Stem Cell Administration on The Outcome of Partial Liver Resection in a Porcine Model of Sinusoidal Obstruction Syndrome.

BACKGROUND: In patients with colorectal liver metastases, the possibility for radical liver resection can be limited by oxaliplatin-induced sinusoidal obstruction syndrome (SOS). This study investigates the potential of mesenchymal stem cells (MSC) to improve the outcome of liver resections in pigs with SOS. MATERIALS AND METHODS: SOS was induced in all animals (n=20) on day 0. Animals in the experimental group (n=8) received allogeneic MSC on day 7. Liver resection was performed in all animals on day 14 and the animals were observed until day 28. Ultrasound volumetry, biochemical analysis and histological examination of liver parenchyma was performed during the follow-up period. RESULTS: Six animals from the control group died prematurely, while all animals survived in the experimental group. According to histology, biochemical analysis and ultrasound volumetry, there were no significant differences between the groups documenting the effect of MSC. CONCLUSION: Single dose allogeneic MSC administration improved survival of animals with SOS undergoing partial liver resection. Further experiments with different timing of liver resection and MSC administration should be performed to investigate the effect of MSC in more detail.

A Comparison of 18F-FDG-PET/MRI and 18F-FDG-PET/CT in the Cancer Staging of Locoregional Lymph Nodes.

AIM: The aim of the study was to evaluate the yields of 2-deoxy-2-[18F]-fluoro-D-glucose positron-emission tomography/magnetic resonance imaging (18F-FDG-PET/MRI) and 18F-FDG-PET/computed tomography (CT) for the detection of metastatic involvement of locoregional neck nodes in patients with head and neck malignancy. PATIENTS AND METHODS: A total of 90 patients (66 men and 24 women) met the inclusion criteria. Preoperative staging was performed: 53 examinations using PET/CT and 37 using PET/MRI. RESULTS: For PET/MRI, the study demonstrated a sensitivity of 89%, specificity of 64%, positive predictive value of 85%, and negative predictive value of 70%; PET/CT had a sensitivity of 95%, specificity 47%, positive predictive value of 82%, and negative predictive value of 78%. CONCLUSION: Both methods have a high yield in N-clinical staging with statistically insignificant differences. We assume PET/MRI to be the first-choice method in organ-targeted examinations, for pediatric patients and repeat examinations. In cases of MRI contraindication, PET/CT can be used with no impact on the quality of care.

Submucosal mucoid as a late complication after appendectomy-A case report.

INTRODUCTION: Shortly after an operation infection, intraabdominal abscess, seroma, haemorrhage or development of paralytic ileus may occur. Postoperative adhesions, nonspecific abdominal pain without signs of obstruction, incisional hernia and appendicitis or mucocele in appendiceal stump present common late complications. We present a unique case of a late complication after appendectomy. PRESENTATION OF CASE: The case report describes a unique expansion in the ascending colon of a young athlete with long-lasting abdominal pain in the lower right quadrant. Colonoscopy showed a lesion in a wall of the ascending colon. Computed tomography (CT) confirmed a cystoid formation of high content density in a wall of the caecum. A right hemicolectomy was performed. Histology showed a lesion located in the submucosa with intestinal lining and stroma rich in lymphoid cells. These are the typical attributes of the wall of the appendix. Other parts of the wall were not demonstrated, and there was no communication with the lumen of the native bowel. CONCLUSION: A submucosal cavity filled with acellular matter, which were probably disintegrated epithelioid structures, and calcifications were found in the ascending colon, while no intestinal cell atypia or dysplasia was found. The case cannot be classified under any previously presented diagnosis.

Cystic Appearance on Imaging Methods (Bosniak III-IV) in Histologically Confirmed Papillary Renal Cell Carcinoma is Mainly Characteristic of Papillary Renal Cell Carcinoma Type 1 and Might Predict a Relatively Indolent Behavior of Papillary Renal Cell Carcinoma.

AIM: The aim of this study was to determine the proportion of cystic tumors according to preoperative CT (Bosniak III, IV) among surgically treated patients with histologically confirmed papillary renal cell carcinoma (pRCC) and to assess progression rates among patients with and without cystic appearance on imaging. METHODS: A total of 138 patients with pRCC histology surgically treated in the period of January 2007-March 2017 were included. Clinical and radiological characteristics, type of surgery, histopathology results, and follow-up data were recorded and statistically evaluated. RESULTS: Forty-one cases (29.7%) of cystic lesions (10× BIIF, 14× BIII, 17× BIV) were detected by CT. Patients with pRCC1 significantly more frequently presented with cystic appearance on CT (33/78; 42.3%) in comparison to other papillary types (8/60; 13.3%; p = 0.0002). During a median follow-up time of 49.4 months, only 2 patients with cystic lesions progressed after surgery. CONCLUSIONS: Cystic appearance on imaging methods is mainly a characteristic of pRCC1 (42.3%). Cystic morphology on imaging might predict a relatively indolent behavior of all pRCC types. Preoperative scoring systems including tumor growth patterns (cystic vs. solid) are needed for further classification.

Contribution of Computed Tomographic Angiography to Pretreatment Planning of Radio-embolization of Liver Tumors.

Transarterial radio-embolization (TARE) using yttrium-90 microspheres is a promising method based on the brachytherapeutic effect of radionuclide with beta-minus decay dissolved in solid microparticles applied directly to tumor-supplying arteries. This treatment is complex, as well as logistically and technically extremely demanding and must be planned in detail. The visualization of the vascular supply of the liver and the possible parasitic supply of the tumor is essential not only for indication of the procedure and correct identification of the arteries to which the microspheres will be applied, but also for prevention of non-target deposition of radioactive material. This review addresses the use of computed tomographic angiography in the preparatory phase of TARE.

Tumor-related Perfusion Changes in White Matter Adjacent to Brain Tumors: Pharmacodynamic Analysis of Dynamic 3T Magnetic Resonance Imaging.

BACKGROUND/AIM: To verify perfusion differences in white matter adjacent to glioblastomas and metastatic tumors in dynamic contrast-enhanced (DCE) 3T-magnetic resonance imaging (MRI) using gradient echo (GRE) T1 techniques. MATERIALS AND METHODS: A retrospective comparative study was carried out on adults with glioblastoma (n=67) and brain metastases (n=31). In each patient, conventional 3T-MRI and DCE-MRI with 25 acquisitions of GRE-T1 were performed. The initial area under the contrast-uptake curve (iAUC) and transfer constant (Ktrans) in peritumoral regions of the white matter were evaluated using T1 pharmacodynamic modeling software. RESULTS: Statistically significantly higher relative iAUC (p<0.001) and Ktrans (p<0.01) values were recorded for peritumoral white matter near glioblastomas compared to that near metastases: 2.29 (SD=1.11) and 2.12 (SD=1.05) vs. 0.96 (SD=0.31) and 1.18 (SD=0.35), respectively. CONCLUSION: In comparison to Ktrans, the iAUC obtained by DCE-MRI is more suitable for assessing glioblastomas because it better reflects pharmacokinetic peritumoral changes. Increased iAUC in white matter near to tumor generally indicates glioblastoma, however, a low level does not exclude it.

Monitoring after radiofrequency ablation of liver tumors: contrast-enhanced ultrasound (CEUS) vs. contrast-enhanced computer tomography (CECT), two days after procedure.

AIM: Our research evaluated the ability of contrast-enhanced ultrasound (CEUS) and contrast enhanced computer tomography (CECT), performed 48 h after radiofrequency ablation (RFA), to detect residual tumor tissue. As recently published studies have evaluated periprocedural CEUS performed within 24 h after procedure and their results were not satisfactory, it seems that postponing the control test by one day could increase the sensitivity of both methods. PATIENTS AND METHODS: We evaluated 33 patients with 37 lesions, who met the criteria for our study. The criteria were 1) the treated lesion is sonographically viewable and 2) the patient underwent both CEUS and CECT control 48 h after treatment and additional follow-up 3 months later by CECT. Presence of residual tumor tissue and the size of necrosis were recorded and compared to the results of 3-months CECT. RESULTS: Nine residues were present in our group. CEUS and CECT showed similar sensitivity (66.7% and 77.8%, respectively) and identical specificity (both 96.4%) for detection of residual tumor tissue. CEUS significantly underestimated the size of necrosis in comparison to CECT (on average by 2.4 mm, P=0.0005). Over the 3-months follow-up period the size of necrosis decreased in all patients (on average by 7.2 mm, P<0.0001). CONCLUSION: The quality of tumor residue detection in 48-h CEUS was comparable to that of 48-h CECT. This finding suggests the CEUS being a feasible substitute for CECT. Both methods show reasonable sensitivity; therefore this timing seems to be appropriate for the first post-treatment control while also allowing for early retreatment if residual tumor tissue is found.

Iodine Content Analysis Using Dual-Energy Computed Tomography as a Biomarker of Transitional Cell Carcinoma, an Experience with Separation of the Clotted Blood and Tumorous Tissue.

BACKGROUND/AIM: The aim of this study was to evaluate the possibility to discriminate the blood clot from tumorous tissue in the assessment of transitional cell carcinoma (TCC), when CT data are used only from single-phase dual-energy CT (DECT). MATERIALS AND METHODS: A total of 18 patients were included into the retrospective analysis of the prospectively collected data (the average age was 67.3 years, range=62-79 years, 12 males, 6 females). DECT was performed in all patients after intravenous administration of the iodinated contrast material. DECT analysis using three-material decomposition algorithm was used to discriminate blood and enhancing tumorous tissue. In all patients, TCC was detected and subsequently kidney surgery or endoscopy was performed within the next two weeks. The findings were compared with DECT results. RESULTS: In our cohort of patients we found 9 TCC of the renal pelvis or ureter and 7 TCC of the urinary bladder. The accuracy of the TCC detection was 94% (17/18). The presence of coagulated blood within the urinary collecting system together with a tumor was detected in 7 CT examinations. The blood coagulum without a confirmed malignant tumor was found in one case with false positive DECT finding. In other 6 cases bleeding was confirmed during surgery or endoscopy (accuracy 87%). CONCLUSION: The dual-energy data analysis enables discrimination of a blood clot from tumorous tissue. It helps in detection of UCC in cases when the excretion potential of the kidneys is decreased due to fulfillment of the collecting system with blood clots.

Pre-surgical Multiparametric Assessment of Breast Lesions Using 3-Tesla Magnetic Resonance.

BACKGROUND/AIM: The aim of this study was to evaluate experience with multiparametric breast imaging on 3-Tesla magnetic resonance (3T-MRI) scanner using a dedicated 18-channel coil compared to histological findings in women after surgery. MATERIALS AND METHODS: The study included 100 women with 105 Breast Imaging Reporting and Data System (BI-RADS) 4 to 6 lesions by mammography who were examined using 3T-MRI and subsequently underwent surgery. MRI included non-contrast T1, T2 and T2 short tau inversion recovery (STIR) sequences, diffusion-weighted imaging with apparent diffusion coeficient maps, postcontrast dynamic study and single-voxel MRI spectroscopy. The results were compared to those of histopathological examination. RESULTS: A sensitivity of 98.68% was found for the whole population, with a specificity of 86.20%. The most valuable findings were diffusion restriction with sensitivity of 90.79% and specificity of 89.66%, and increased choline in the spectrum with sensitivity of 68.42% and specificity of 93.10%. Evaluation of the enhancement curve had sensitivity of 45.05% and specificity of 72.41%. In examination of lymph nodes, 3T-MRI had sensitivity of 92.59% and specificity of 93.87%. CONCLUSION: Multiparametric 3T-MRI breast imaging shows excellent results in evaluation of breast cancer compared to histological findings, both for primary tumor and nodal metastases. The greatest contribution to improving diagnostic performance is the evaluation of diffusion.

The use of porcine corrosion casts for teaching human anatomy.

In teaching and learning human anatomy, anatomical autopsy and prosected specimens have always been indispensable. However, alternative methods must often be used to demonstrate particularly delicate structures. Corrosion casting of porcine organs with Biodur E20® Plus is valuable for teaching and learning both gross anatomy and, uniquely, the micromorphology of cardiovascular, respiratory, digestive, and urogenital systems. Assessments of casts with a stereomicroscope and/or scanning electron microscope as well as highlighting cast structures using color coding help students to better understand how the structures that they have observed as two-dimensional images actually exist in three dimensions, and students found using the casts to be highly effective in their learning. Reconstructions of cast hollow structures from (micro-)computed tomography scans and videos facilitate detailed analyses of branching patterns and spatial arrangements in cast structures, aid in the understanding of clinically relevant structures and provide innovative visual aids. The casting protocol and teaching manual we offer can be adjusted to different technical capabilities and might also be found useful for veterinary or other biological science classes.

Assessment of myocardial enhancement during coronary CT angiography in critically ill patients.

There are still challenges and unmet needs for the imaging techniques, such as conditions of uncertain origin in patients with clinically serious, life-threatening conditions with unknown cause that are not associated with dominant chest pain, ECG changes or other symptoms indicating a possible primarily cardiac or coronary cause. The contribution of the myocardial enhancement evaluation of urgent cardiac CTA scans significantly improves to determining the diagnosis of acute myocardial injury and choosing appropriate treatment. When incorporating the myocardial enhancement assessment into the imaging algorithm of an emergency department, emphasis is placed on a uniform imaging procedure and a uniform evaluation approach. The color coded images of the myocardial enhancement in emergency situations helps identify the most serious pathologies and shorten the time to adequate targeted therapy in patients.