On-site CT-derived cFFR in patients with suspected coronary artery disease: Feasibility on a 128-row CT scanner in everyday clinical practice

PURPOSE

 Technical feasibility of CT-based calculation of fractional flow reserve (cFFR) using a 128-row computed tomography scanner in an everyday routine setting. Post-processing and everyday practicability should be analyzed on the scanner on-site in connection with clinical parameters.

MATERIALS AND METHODS

 This single-center retrospective analysis included 230 patients (74 female; mean age 63.8 years) with CCTA within 21 months between 01/2018 and 09/2019 without non-pathological examinations. cFFR values were obtained using a deep learning-based non-commercial research prototype (cFFR Version3.5.0; Siemens Healthineers GmbH, Erlangen). cFFR values were evaluated at two points: at the maximum point of the stenosis and 1.0 cm distal to the stenosis. Comparison with invasive coronary angiography in 57/230 patients (24.7 %) was performed. CT parameters and quality were evaluated. Further subgroup classification concerning criteria of technical postprocessing was performed: no changes necessary, minor corrections necessary, major corrections necessary, and no evaluation was possible. The required time from starting the software to the final result was evaluated.

RESULTS

 A total of 116/448 (25.9 %) mild, 223/448 (49.8 %) moderate, and 109/448 (24.3 %) obstructive stenoses was found. The mean cFFR at the maximum point of the stenosis was 0.92 ± 0.09 and significantly higher than the cFRR value of 0.89 ± 0.13 distal to the stenosis (p < 0.001*). The mean degree of stenosis was 44.02 ± 26.99 % (range: 1-99 %) with an area of 5.39 ± 3.30 mm2. In a total of 45 patients (19.1 %), a relevant reduction in cFFR below 0.80 was determined. Overall, in 57/230 patients (24.8 %), catheter angiography was performed. No significant difference in the degree of maximal stenosis (CAD-RADS 0-2/3/4) was detected between the classification of CCTA and ICA (p = 0.171). The mean post-processing time varied significantly with 8.34 ± 4.66 min. in single-vessel CAD vs. 12.91 ± 3.92 min. in two-vessel CAD vs. 21.80 ± 5.94 min. in three-vessel CAD (each p < 0.001).

CONCLUSION

 Noninvasive onsite quantification of cFFR is feasible with minimal observer interaction in a routine real-world setting on a 128-row scanner. Deep learning-based algorithms allow a robust and semi-automatic on-site determination of cFFR based on data from standard CT scanners.

KEY POINTS

· Non-invasive on-site quantification of cFFR is feasible with minimal observer interaction.. · Deep-learning based algorithms allow robust and semi-automatic on-site determination of cFFR.. · The mean follow-up time varied significantly with the extent of vascular CAD..

Discharge of iodine-containing contrast media into the environment - problem analysis and implementation of measures to reduce discharge by means of separation toilets - experience from a pilot project

PURPOSE

Environmental aspects and sustainability are becoming increasingly important. In addition to energy consumption, the consumption and environmental discharge of contrast agents pose a particular challenge. Because of their desired stability, X-ray contrast agents (XCAs) are deposited in surface water at a rate of up to 400 tons per year.

MATERIALS AND METHODS

In a pilot project, a set of measures (installation of specific separation toilets, the establishment of feedback systems, interviews, questionnaires, and observation) was implemented to sensitize patients and staff to the problem of XCAs during outpatient CT examinations and a retention and recovery system for XCAs was evaluated.

RESULTS

In the initial baseline phase, a separation toilet with an additional collection system and a feedback/button system was installed. The built-in feedback system indicated that the separation toilets were used by approx. 16 % of patients without measures. In two subsequent intervention phases, accompanying measures significantly (p < 0.01) increased the use of these separation toilets to 21 % and 25 %, respectively. The measures to reduce the discharge of XCAs were positively assessed by both staff and patients.

CONCLUSION

Measures to reduce the discharge of XCAs into the environment have a high acceptance among staff and patients. The subsequent installation of separation toilets is one possibility to achieve on-site retention of XCAs. However, this measure is likely to be of high value only if patients stay on site for a correspondingly long time, as is the case in cardiology, for example.

KEY POINTS

· The input of X-ray contrast agents into the environment is relevant in light of the quantity. · Measures to reduce the discharge of X-ray contrast agents into the environment have been investigated in pilot projects. · The (subsequent) installation of separation toilets is possible and allows retention of X-ray contrast agents. · This measure is considered useful by patients and staff. · The financing of these measures needs to be clarified.

CITATION FORMAT

· Beer M, Schuler J, Kraus E et al. Discharge of iodine-containing contrast media into the environment - problem analysis and implementation of measures to reduce discharge by means of separation toilets - experience from a pilot project. Fortschr Röntgenstr 2023; 195: 1122 - 1127.

[Resilience against IT attacks in hospitals : Results from an exercise in a German university hospital]

BACKGROUND

According to the legal definition healthcare systems and their components (e.g., hospitals) are part of the critical infrastructure of modern industrial nations. During the last few years hospitals increasingly became targets of cyber attacks causing severe impairment of their operability for weeks or even months. According to the German federal strategy for protection of critical infrastructures (KRITIS strategy), hospitals are obligated to take precautions against potential cyber attacks or other IT incidents.

OBJECTIVE

This article describes the process of planning, execution and results of an advanced table-top exercise which took place in a university hospital in Germany and simulated the first 3 days after a cyber attack causing a total failure of highly critical IT systems.

MATERIAL AND METHODS

During a first stage lasting about 8 months IT-dependent processes within the clinical routine were identified and analyzed. Then paper-based and off-line back-up processes and workarounds were developed and department-specific emergency plans were defined. Finally, selected central facilities such as pharmacy, laboratory, radiology, IT and the hospitals crisis management team took part in the actual disaster exercise. Afterwards the participants were asked to evaluate the exercise and the hospitals cyber security using a questionnaire. On this basis the authors visualized the hospital's resilience against cyber incidents and defined short-term, medium-term and long-term needs for action.

RESULTS

Of the participants 85% assessed the exercise as beneficial, 97% indicated that they received adequate support during the preparations and 75% had received sufficient information; however, only 34% had the opinion that the hospital's and their own preparedness against critical IT failures were sufficient. Before the exercise took place, IT-specific emergency plans were present only in 1.7% of the hospital facilities but after the exercise in 86.7% of the clinical and technical departments. The highest resilience against cyber attacks was not surprisingly reported by facilities that still work routinely with paper-based or off-line processes, the IT department showed the lowest resilience as it would come to a complete shutdown in cases of a total IT failure.

CONCLUSION

The authors concluded that the planning phase is the most important stage of developing the whole exercise, giving the best opportunity for working out fallback levels and workarounds and through this strengthen the hospitals resilience against cyber attacks and comparable incidents. A meticulous preparedness can minimize the severe effects a total IT failure can cause on patient care, staff and the hospital as a whole.

Noninvasive liver iron quantification by MRI using refocused gradient-echo (bSSFP): preliminary results

PURPOSE

To evaluate the feasibility of using a balanced steady-state free precession sequence (bSSFP) to determine liver iron content (LIC).

METHOD

Thirty-five consecutive patients with liver iron overload were examined with bSSFP. Signal intensity ratios of liver parenchyma to paraspinal muscles were retrospectively correlated with LIC values obtained by FerriScan, which was used as the reference method. Combinations of bSSFP protocols were also evaluated. The best combination was utilized to calculate LIC from bSSFP data. The sensitivity and specificity for the therapeutically relevant LIC threshold of 80 µmol/g (4.5 mg/g) were determined.

RESULTS

LIC values ranged from 24 to 756 µmol/g. The best SIR-to-LIC correlation of a single protocol was obtained with a 3.5-ms repetition time (TR) and 17° excitation flip angle (FA). A combination of protocols with TRs of 3.5, 5, and 6.5 ms, each at 17° FA, yielded a superior correlation. LIC values calculated using this combination resulted in a sensitivity/specificity of 0.91/0.85.

CONCLUSION

bSSFP is basically suitable to determine LIC. Its advantages are high SNR efficiency and the ability to acquire the entire liver in a breath hold without acceleration techniques.

KEY POINTS

· The bSSFP sequence is suited to quantify liver iron overload.. · bSSFP has a high scanning efficiency and potential for LIC screening.. · Despite susceptibility artifacts, the LIC determined from bSSFP data showed high accuracy..

CITATION FORMAT

· Wunderlich AP, Cario H, Götz M et al. Noninvasive liver iron quantification by MRI using refocused gradient-echo (bSSFP): preliminary results. Fortschr Röntgenstr 2023; 195: 804 - 808.

[Update: Small bowel diseases in computed tomography and magnetic resonance imaging]

CLINICAL/METHODICAL ISSUE

Radiological procedures play a crucial role in the diagnosis of small bowel disease. Due to a broad and quite nonspecific spectrum of symptoms, clinical evaluation is often difficult, and endoscopic procedures require significant manpower, are time-consuming and expensive. In contrast, radiologic imaging can provide important information about morphologic and functional variations of the small bowel and help to identify various disease entities, such as inflammation, tumors, vascular problems, and obstruction.

STANDARD RADIOLOGICAL METHODS

The most common radiological modalities in small bowel diagnostics include ultrasound (US), computed tomography (CT), magnetic resonance imaging (MRI), and fluoroscopy. Each of these modalities has its own advantages and limitations, and the choice of imaging modality depends on clinical symptoms and suspected diagnosis in addition to availability.

METHODOLOGICAL INNOVATIONS

In recent years, significant progress has been made, especially in cross-sectional imaging modalities, as a result of new and further technical developments.

PERFORMANCE

These range from increasing detail resolution to functional and molecular imaging techniques that go far beyond simple morphology. In addition, information technology (IT) applications, which include artificial intelligence and radiomics, are assuming an increasing role.

ACHIEVEMENTS

Many of the methods mentioned are still in early stages and need to be further developed for daily practice, but some have already found their way into clinical routine.

PRACTICAL RECOMMENDATIONS

The aim of this work is to provide a review of the most important disease entities of the small intestine, including new and innovative diagnostic approaches.

Volumetric Evaluation of 3D Multi-Gradient-Echo MRI Data to Assess Whole Liver Iron Distribution by Segmental R2* Analysis: First Experience

PURPOSE

MR transverse relaxation rate R₂* has been shown to be useful for monitoring liver iron overload. A sequence enabling acquisition of the whole liver in a single breath hold is now available, thus allowing volumetric hepatic R₂* distribution studies. We evaluated the feasibility of computer-assisted whole liver segmentation of 3 D multi-gradient-echo MRI data, and compared whole liver R₂* determination to analyzing only a single slice. Also, segmental R₂* differences were studied.

MATERIALS AND METHODS

The liver of 44 patients, investigated by multi-gradient echo MRI at 1.5 T, was segmented and divided into nine segments. Segmental R₂* values were examined for all patients together and with respect to two criteria: average R₂* values, and reason for iron overload. Correlation of single-slice and volumetric data was tested with Spearman's rank test, segmental and group differences were evaluated by analysis of variance.

RESULTS

Whole-liver R₂* values correlated excellent to single slice data (p < 0.001). The lowest R₂* occurred in segment 1 (S1), differences of S1 with regard to other segments were significant in five cases and highly significant in two cases. Patients with high average R₂* showed significant differences between S1 and segments 2, 6, and 7. Disease-related differences with respect to S1 were significant in segments 3 to 5 and 7.

CONCLUSION

Our results suggest inhomogeneous hepatic iron distribution. Low R₂* in S1 may be explained by its special vascularization.

KEY POINTS

· Hepatic R2* distribution is not as homogeneous as previously thought.. · Liver segments might have a functional relevance.. · Segmental and total liver R2* values coincide best in segment 8..

CITATION FORMAT

· Wunderlich AP, Cario H, Kannengießer S et al. Volumetric Evaluation of 3D Multi-Gradient-Echo MRI Data to Assess Whole Liver Iron Distribution by Segmental R2* Analysis: First Experience. Fortschr Röntgenstr 2023; 195: 224 - 233.

Acinar cystic transformation of the pancreas-a rare case in a young patient

Acinar cystic transformation (ACT) is a very rare transformation of the pancreas and has been described in less than 100 cases since its first report in 2002. The aim of this case report is to get a better understanding of this pancreatic transformation, which to date appears to be non-malignant. However, radical surgery was performed in most cases due to misinterpreting the initial diagnosis. ACT may be misdiagnosed for intraductal papillary mucinous neoplasms and is currently not included as a potential differential diagnosis for cystic lesions of the pancreas. ACT belongs to the benign cystic alterations of the pancreas. Despite its rarity, it should be considered as a potential differential diagnosis with regard to cystic lesions in the pancreas, especially in order to avoid unnecessary surgery.

Sarcopenia - Definition, Radiological Diagnosis, Clinical Significance

BACKGROUND

 Sarcopenia is an age-related syndrome characterized by a loss of muscle mass and strength. As a result, the independence of the elderly is reduced and the hospitalization rate and mortality increase. The onset of sarcopenia often begins in middle age due to an unbalanced diet or malnutrition in association with a lack of physical activity. This effect is intensified by concomitant diseases such as obesity or metabolic diseases including diabetes mellitus.

METHOD

 With effective preventative diagnostic procedures and specific therapeutic treatment of sarcopenia, the negative effects on the individual can be reduced and the negative impact on health as well as socioeconomic effects can be prevented. Various diagnostic options are available for this purpose. In addition to basic clinical methods such as measuring muscle strength, sarcopenia can also be detected using imaging techniques like dual X-ray absorptiometry (DXA), computed tomography (CT), magnetic resonance imaging (MRI), and sonography. DXA, as a simple and cost-effective method, offers a low-dose option for assessing body composition. With cross-sectional imaging techniques such as CT and MRI, further diagnostic possibilities are available, including MR spectroscopy (MRS) for noninvasive molecular analysis of muscle tissue. CT can also be used in the context of examinations performed for other indications to acquire additional parameters of the skeletal muscles (opportunistic secondary use of CT data), such as abdominal muscle mass (total abdominal muscle area - TAMA) or the psoas as well as the pectoralis muscle index. The importance of sarcopenia is already well studied for patients with various tumor entities and also infections such as SARS-COV2.

RESULTS AND CONCLUSION

 Sarcopenia will become increasingly important, not least due to demographic changes in the population. In this review, the possibilities for the diagnosis of sarcopenia, the clinical significance, and therapeutic options are described. In particular, CT examinations, which are repeatedly performed on tumor patients, can be used for diagnostics. This opportunistic use can be supported by the use of artificial intelligence.

KEY POINTS

· Sarcopenia is an age-related syndrome with loss of muscle mass and strength.. · Early detection and therapy can prevent negative effects of sarcopenia.. · In addition to DEXA, cross-sectional imaging techniques (CT, MRI) are available for diagnostic purposes.. · The use of artificial intelligence (AI) offers further possibilities in sarcopenia diagnostics..

CITATION FORMAT

· Vogele D, Otto S, Sollmann N et al. Sarcopenia - Definition, Radiological Diagnosis, Clinical Significance. Fortschr Röntgenstr 2023; DOI: 10.1055/a-1990-0201.

Evaluation of an elective ultrasound course for medical students

To evaluate the educational benefits of teaching ultrasound in an elective radiological course for medical students. We conducted a single-center retrospective analysis of a one-week elective ultrasound course in which 39 medical students (25 female; median age 25.8 ± 2.8 years, range 21-35, 4th and 5th years of undergraduate medical education) participated as part of their radiological training. The students completed a pre- and post-course questionnaire using a five-point Likert scale for self-assessment of technical knowledge, confidence in the procedure regarding different organs, motivation for performing ultrasound, and the importance of ultrasound in medical education. The students also assessed the value of ultrasound teaching in the context of their general medical degree. Pre-test and post-test scores showed significantly improved radiology knowledge (p ≤ 0.001) concerning all abdominal organs (liver, spleen, gallbladder, kidney, urinary bladder, aorta and retroperitoneum). A significant improvement was registered in performing ultrasound of peripheral arteries and venous structures (each p = 0.001), and also of the thyroid gland (p = 0.006). General surveys at the end of the elective were overwhelmingly positive, with constructive criticism and complimentary comments. Systematic training in ultrasound markedly improved the students' skills. This was especially pronounced for solid organ structures, while students requested more education regarding the retroperitoneum and vascular structures. Teaching ultrasound in an elective hands-on training course improves anatomical understanding and practical skills associated with increased motivation. The results affirm the necessity and clinical relevance of the course during the radiological training of medical students.

Longitudinal CT Imaging to Explore the Predictive Power of 3D Radiomic Tumour Heterogeneity in Precise Imaging of Mantle Cell Lymphoma (MCL)

The study's primary aim is to evaluate the predictive performance of CT-derived 3D radiomics for MCL risk stratification. The secondary objective is to search for radiomic features associated with sustained remission. Included were 70 patients: 31 MCL patients and 39 control subjects with normal axillary lymph nodes followed over five years. Radiomic analysis of all targets (n = 745) was performed and features selected using the Mann Whitney U test; the discriminative power of identifying "high-risk MCL" was evaluated by receiver operating characteristics (ROC). The four radiomic features, "Uniformity", "Entropy", "Skewness" and "Difference Entropy" showed predictive significance for relapse (p < 0.05)-in contrast to the routine size measurements, which showed no relevant difference. The best prognostication for relapse achieved the feature "Uniformity" (AUC-ROC-curve 0.87; optimal cut-off ≤0.0159 to predict relapse with 87% sensitivity, 65% specificity, 69% accuracy). Several radiomic features, including the parameter "Short Axis," were associated with sustained remission. CT-derived 3D radiomics improves the predictive estimation of MCL patients; in combination with the ability to identify potential radiomic features that are characteristic for sustained remission, it may assist physicians in the clinical management of MCL.

[Hepatolienal candidosis as a rare differential diagnosis of disseminated small parenchym lesions]

HISTORY

We report about a 17-year-old patient with the secondary malignancy of acute myeloid leukemia (AML). He developed fever of unclear origin during the hematopoietic stem cell transplantation.History We report about a 17-year-old patient with the secondary malignancy of acute myeloid leukemia (AML). He developed fever of unclear origin during the hematopoietic stem cell transplantation.

EXAMINATIONS

In the focus search, the routine sonography of the abdomen showed disseminated hypoechoic small- parenchymal lesions of the liver. In the complementary MRI, disseminated small lesions of the liver parenchyma and the spleen were demarked after contrast agent administration.

DIAGNOSIS

Imaging revealed suspicion of hepatolienal candiasis.Diagnosis Imaging revealed suspicion of hepatolienal candiasis.

THERAPY

Empirical therapy with amphotericin B was used. A sonographic punch biopsy of the liver was performed. The pathological examination showed oval particles in the PAS staining in the sense of an opportunistic mycosis of the Candida infection type.

CONCLUSION

The case shows that in immunosuppressed patients, candidiasis must always be considered as a differential diagnosis with simultaneous parenchymal changes in the liver and/or spleen. In addition, in the screening situation, a suitable linear transducer should be used when asking about fungal lesions in the liver and spleen. Alternatively, if suspected hepato-lienal candidiasis could be diagnosed by a contrast-enhanced MRI of the upper abdomen/abdomen.

Computed Tomography-Based Tumor Heterogeneity Analysis Reveals Differences in a Cohort with Advanced Pancreatic Carcinoma under Palliative Chemotherapy

Purpose

Imaging in pancreatic cancer is a challenge, especially regarding therapy response evaluation. Tumor size, attenuation, and perfusion are widely used as parameters for computed tomography (CT) examinations, but are often limited due to blurry tumor borders and missing qualitative parameters. To improve monitoring of therapy response, we tested a new CT-based approach of tumor heterogeneity feature analysis.

Methods

A total of 13 patients with pancreatic adenocarcinoma undergoing abdominal CT according to standard as baseline imaging with clinical follow-up and imaging (median time span 64 days) under systematic therapy (FOLFIRINOX/gemcitabine) were retrospectively analyzed. Progression was defined as new lesions and local tumor spread. Tumor heterogeneity analysis was performed using mintLesion®. Seven different image features referring to image heterogeneity were analyzed. Statistical analysis was performed with Spearman's rank correlation and Mann-Whitney U test.

Results

During follow-up, tumor volume did not significantly change between our groups with overall progression (local and systemic) and progression-free patients (p = 0.661). Mean positivity of pixel values were significantly higher in patients without progression compared to patients with progression (p = 0.030). There was a significant negative correlation between changes in kurtosis and time to local tumor spread (p = 0.008) or systemic progression (p = 0.017).

Conclusions

Results suggest that analysis of tumor heterogeneity might provide valuable information from routine-acquired images regarding therapy response evaluation. This might help adjusting therapy regimes and could be easily integrated in clinical workflows. Furthermore, this procedure might possibly predict therapy response and, hence could lead the way to find a potential marker for progression-free survival.

Pathognomonic imaging signs in abdominal radiology

The imaging evaluation of the abdomen is of crucial importance for every radiologist. In addition to ultrasound, conventional radiographs and contrast-enhanced computed tomography (CT) are the most common imaging procedures in the abdominal region. Numerous pathognomonic signs should be known in this context by every radiologist. Radiographs of the abdomen are an often used first step in radiologic imaging, while CT examinations are carried out for further differentiation, in oncological settings and in time-critical emergency situations. A fast and clear assignment of these signs to a specific disease is the basis for a correct diagnosis. This pictorial review describes the most common pathognomonic signs in abdominal imaging. The knowledge of these pictograms is therefore essential for radiologists interested in abdominal medicine and should also be addressed in training and further education.

Clinical and imaging features of myeloid sarcoma: a German multicenter study

Background

Myeloid sarcoma (MS), also known as chloroma, is an extramedullary manifestation of malignant primitive myeloid cells. Previously, only small studies investigated clinical and imaging features of MS. The purpose of this study was to elucidate clinical and imaging features of MS based upon a multicenter patient sample.

Methods

Patient records of radiological databases of 4 German university hospitals were retrospectively screened for MS in the time period 01/2001 and 06/2019. Overall, 151 cases/76 females (50.3%) with a mean age of 55.5 ± 15.1 years and 183 histopathological confirmation or clinically suspicious lesions of MS were included into this study. The underlying hematological disease, localizations, and clinical symptoms as well as imaging features on CT and MRI were investigated.

Results

In 15 patients (9.9% of all 151 cases) the manifestation of MS preceded the systemic hematological disease. In 43 cases (28.4%), first presentation of MS occurred simultaneously with the initial diagnosis of leukemia, and 92 (60.9%) patients presented MS after the initial diagnosis. In 37 patients (24.5%), the diagnosis was made incidentally by imaging. Clinically, cutaneous lesions were detected in 35 of 151 cases (23.2%). Other leading symptoms were pain (n = 28/151, 18.5%), neurological deficit (n = 27/151, 17.9%), swelling (n = 14/151, 9.3%) and dysfunction of the affected organ (n = 10/151, 6.0%). Most commonly, skin was affected (n = 30/151, 16.6%), followed by bone (n = 29/151, 16.0%) and lymphatic tissue (n = 21/151, 11.4%). Other localizations were rare. On CT, most lesions were homogenous. On T2-weighted imaging, most of the lesions were hyperintense. On T1-weighted images, MS was hypointense in n = 22/54 (40.7%) and isointense in n = 30/54 (55.6%). A diffusion restriction was identified in most cases with a mean ADC value of 0.76 ± 0.19 × 10^− 3 mm²/s.

Conclusions

The present study shows clinical and imaging features of MS based upon a large patient sample in a multicenter design. MS occurs in most cases meta-chronous to the hematological disease and most commonly affects the cutis. One fourth of cases were identified incidentally on imaging, which needs awareness of the radiologists for possible diagnosis of MS.

Genotyping of circulating tumor DNA in cholangiocarcinoma reveals diagnostic and prognostic information

Diagnosis of Cholangiocarcinoma (CCA) is difficult, thus a noninvasive approach towards (i) assessing and (ii) monitoring the tumor-specific mutational profile is desirable to improve diagnosis and tailor treatment. Tumor tissue and corresponding ctDNA samples were collected from patients with CCA prior to and during chemotherapy and were subjected to deep sequencing of 15 genes frequently mutated in CCA. A set of ctDNA samples was also submitted for 710 gene oncopanel sequencing to identify progression signatures. The blood/tissue concordance was 74% overall and 92% for intrahepatic tumors only. Variant allele frequency (VAF) in ctDNA correlated with tumor load and in the group of intrahepatic CCA with PFS. 63% of therapy naive patients had their mutational profile changed during chemotherapy. A set of 76 potential progression driver genes was identified among 710 candidates. The molecular landscape of CCA is accessible via ctDNA. This could be helpful to facilitate diagnosis and personalize and adapt therapeutic strategies.

Diagnostic accuracy of MRI with MRCP and B-Mode-sonography with elastography of the pancreas in patients with cystic fibrosis: a point-to-point comparison

Objective

For patients with cystic fibrosis, the imaging of the pancreas is of crucial importance for the early detection of pancreatic carcinoma. Comparative studies between Magnetic Resonance Imaging (MRI) and sonographic pancreas sonography are not yet available. The aim of the study was to compare MRI, sonography and point-shearwave elastography (pSWE). A total of 19 patients were included (10 male, 9 female; age 29.7 ± 14.3 years) in the study. Ultrasonography with pSWE and contrast enhanced MRI with MRCP were performed.

Results

Significant differences between measurements of pancreatic body were registered in MRI with 1.4 ± 0.6 cm vs 1.0 ± 0.4 cm in ultrasound (p = 0.049), however not for pancreatic head and tail. In 10/19 patients (52.6%) pancreatic parenchyma did not show in MRI because of complete lipomatous transformation, but could be detected in ultrasound. pSWE-values showed no significant differences between the full and partial fatty transformation in pancreatic head (p = 0.968), body (p = 0.657) and tail (p = 0.840). pSWE-values did not correlate with measured signal intensity in T1w flash (p = 0.930, r = 0.025) and T2w HASTE sequences (p = 0.152, r = − 0.375). In patients with CF ultrasound is superior to MRI for displaying full fibro-fatty parenchymal transformation, pancreatic duct. Ultrasound elastography did not provide additional clinical relevant information.

Electronic supplementary material

The online version of this article (10.1186/s13104-019-4193-4) contains supplementary material, which is available to authorized users.

Ultrasound point shear wave elastography of the pancreas: comparison of patients with type 1 diabetes and healthy volunteers - results from a pilot study

Background

The aims of this study were to establish shear wave elastography of the pancreas by comparing measurements in patients with type 1 diabetes (T1D) and healthy volunteers and to consider whether this method could contribute to the screening or prevention of T1D.

Methods

This pilot study included 15 patients with T1D (10 men, 5 women) and 15 healthy volunteers (10 men, 5 women) as controls. Measurements were performed with a Siemens Acuson S3000 (Siemens Healthcare, Erlangen, Germany) using a 6C1 convex transducer and the Virtual Touch™ tissue quantification (VTQ) method.

Results

The mean shear wave velocity of the head of the pancreas was 1.0 ± 0.2 m/s (median: 1.1 m/s) for the study group and likewise 1.0 ± 0.2 m/s (median: 0.9 m/s) for the control group. Velocities of 1.2 ± 0.2 m/s (median: 1.2 m/s) were measured in the body of the pancreas in both groups. There was a significant difference between the values obtained in the tail of the pancreas: patients 1.1 ± 0.1 m/s (median: 1.0 m/s) versus controls 0.9 ± 0.1 m/s (median: 0.8 m/s) (p = 0.0474). The mean value in the whole pancreas of the study group was not significantly above that of the control group: 1.1 ± 0.1 m/s (median: 1.0 m/s) versus 1.0 ± 0.1 m/s (median: 1.0 m/s) (p = 0.2453).

Conclusions

Sonoelastography of the pancreas revealed no overall difference between patients with T1D and healthy volunteers. Patients with T1D showed higher values only in the tail segment. Future studies need to determine whether specific regional differences can be found in a larger study population.

Point shear wave elastography of the pancreas in patients with cystic fibrosis: a comparison with healthy controls

PURPOSE

Manifestations of cystic fibrosis in the pancreas are gaining in clinical importance as patients live longer. Conventional ultrasonography and point shear wave elastography (pSWE) imaging are non-invasive and readily available diagnostic methods that are easy to perform. The aim of this study was to perform conventional ultrasonography and obtain pSWE values in the pancreases of patients with cystic fibrosis and to compare the findings with those of healthy controls.

METHODS

27 patients with cystic fibrosis (13 women/14 men; mean age 27.7 ± 13.7 years; range 9-58 years) and 60 healthy control subjects (30 women/30 men; mean age 30.3 ± 10.0 years; range 22-55 years) underwent examinations of the pancreas with conventional ultrasound and pSWE imaging.

RESULTS

Patients with cystic fibrosis have an echogenic pancreatic parenchyma. We found cystic lesions of the pancreas in six patients. pSWE imaging of the pancreatic parenchyma gave significantly lower shear wave velocities in patients with cystic fibrosis than in the control group (1.01 m/s vs 1.30 m/s; p < 0.001).

CONCLUSIONS

Using pSWE imaging in vivo, we have shown that the pancreas is considerably softer in patients with cystic fibrosis than in a healthy control population.

Overstaging: A Challenge in Rectal Cancer Treatment

Background

Preoperative staging, including computed tomography (CT), magnetic resonance imaging (MRI), and endoscopic ultrasound (EUS), is decisive to envisage the therapeutic concept for rectal cancer (RC). Overstaging may subject the patient to neoadjuvant therapy that does not improve survival but may lead to therapy-associated morbidity.

Methods

This study retrospectively compares and values EUS, CT, and MRI in Union Internationale Contre le Cancer (UICC) stage I-III RC with a focus on overstaging. RC patients receiving primary operation only at the University Clinic Ulm were analyzed. The therapeutic relevance of preoperative staging was determined by comparison with postoperative pathological workup.

Results

244 examinations in 184 RC patients (EUS: n = 63, CT: n = 143, MRI: n = 38) revealed therapy-relevant overstaging into the T3/4 category in 10 (16%) EUS, 18 (13%) CT, and 10 (26%) MRI cases. Patients were upgraded to the N+ category in 13 (21%) EUS, 29 (20%) CT, and 11 (29%) MRI cases. As a result, UICC stages II and III turned out to be overstaged in 13 (21%) EUS, 18 (13%) CT, and 10 (26%) MRI cases.

Conclusion

More than 10% therapy-relevant overstaging by any method represents a major challenge for modern RC therapy. Physicians should scrupulously consider this fact in their treatment considerations to avoid overtreatment.

Caliber of the common bile duct: effect of cholecystectomy and other factors in a ultrasonographic study of 8534 patients

OBJECTIVE

The objective of the present study was to analyze the effects of different factors impacting the caliber of the common bile duct (CBD) and a comparison of maximum extrahepatic bile duct caliber in patients with and without a history of cholecystectomy.

MATERIAL AND METHODS

A retrospective data analysis was undertaken of 8534 patients (4480 females; 4054 males; average age: 59.2±18.0 years) with sonographic documentation of bile duct caliber. Maximum intra- and extrahepatic bile duct diameters were studied. The normal maximum diameter of the extrahepatic bile duct was defined as 7 mm. In patients who had undergone prior cholecystectomy, a maximum bile duct diameter<10 mm was considered normal.

RESULTS

The average maximum diameter of the CBD amounted to 5.3±3.0 mm for the overall collective. In patients who had undergone prior cholecystectomy, maximum CBD diameters in the normal range (<7 mm) were documented in 55%, while larger diameters (>7 mm) were observed in 45%. In the collective of patients without prior cholecystectomy, CBD diameters in the normal range (<7 mm) were found in 81%, with larger diameters observed in only 18.4% of patients. In both subgroups, there was a significant association between age and bile duct diameter (for those with prior cholecystectomy, p=0.0003; without prior cholecystectomy, p<0.0001). No statistically significant influence on CBD diameter was observed for either prior cholecystectomy (p=0.2116) or time interval since cholecystectomy (p=0.3537). Females, both with and without a history of prior cholecystectomy, showed a 1.4-1.5-fold higher risk of exhibiting a CBD diameter>7 mm (for those with prior cholecystectomy, p=0.0485; without prior cholecystectomy, p<0.001).

CONCLUSIONS

Our data show a positive correlation between age and CBD diameter. There was no statistically significant relationship between CBD diameter and prior cholecystectomy, postoperative interval and BMI.

Frequence, spectrum and prognostic impact of additional malignancies in patients with gastrointestinal stromal tumors

Currently available data on prognostic implication of additional neoplasms in GIST miss comprehensive information on patient outcome with regard to overall or disease specific and disease free survival. Registry data of GIST patients with and without additional neoplasm were compared in retrospective case series. We investigated a total of 836 patients from the multi-center Ulmer GIST registry. Additionally, a second cohort encompassing 143 consecutively recruited patients of a single oncology center were analyzed. The frequency of additional malignant neoplasms in GIST patients was 31.9% and 42.0% in both cohorts with a mean follow-up time of 54 and 65 months (median 48 and 60 months), respectively. The spectrum of additional neoplasms in both cohorts encompasses gastrointestinal tumors (43.5%), uro-genital and breast cancers (34.1%), hematological malignancies (7.3%), skin cancer (7.3%) and others. Additional neoplasms have had a significant impact on patient outcome. The five year overall survival in GIST with additional malignant neoplasms (n = 267) was 62.8% compared to 83.4% in patients without other tumors (n = 569) (P < .001, HR=0.397, 95% CI: 0.298-0.530). Five-year disease specific survival was not different between both groups (90.8% versus 90.9%). 34.2% of all deaths (n = 66 of n = 193) were GIST-related. The presented data suggest a close association between the duration of follow-up and the rate of additional malignancies in GIST patients. Moreover the data indicate a strong impact of additional malignant neoplasms in GIST on patient outcome. A comprehensive follow-up strategy of GIST patients appears to be warranted.

3D detection of colonic polyps by CT colonography: accuracy, pitfalls, and solutions by adjunct 2D workup

Computed tomography colonography (CTC) enables evaluation of the colon with minimal invasiveness. In spite of advances in multidetector CT (MDCT) technology and advanced software features, including electronic bowel cleansing (digital removal and tagging of fluid and debris), a number of potential pitfalls in the evaluation of the 3D volumetric dataset persist. The purpose of this article is to illustrate the strengths and potential pitfalls in the detection of colorectal polyps using CTC via a primary three-dimensional (3D) approach for evaluation.

Influence of plasma cortisol and other laboratory parameters on nonalcoholic Fatty liver disease

The objective of the present study was to analyse the association between the plasma cortisol concentration and nonalcoholic fatty liver disease (NAFLD). A total of 1 326 subjects (age 18-65 years) were examined in the context of an epidemiological study of a population-based random sample. Medical history and anthropometric data of 662 women and 664 men were documented. In addition, laboratory examinations were performed and the fat concentration of the liver was estimated by ultrasound examination. Mean cortisol concentration in plasma was 260.4±156.8 nmol/l for women and 295.8±161.2 nmol/l for men. NAFLD was identified in 17.7% in women and 35.1% in men. Plasma cortisol concentration showed no association with the existence of NAFLD. NAFLD correlated positive with age, body-mass index (BMI), waist-to-hip-ratio (WHR), alanine aminotransferase (ALT), and triglycerides. The present study failed to establish any association of plasma cortisol concentrations and NAFLD.

[Perfusion computed tomography for diffuse liver diseases]

CLINICAL/METHODICAL ISSUE

Perfusion computed tomography (CT) has its main application in the clinical routine diagnosis of neuroradiological problems.

STANDARD RADIOLOGICAL METHODS

Polyphase multi-detector spiral computed tomography is primarily used in liver diagnostics.

METHODICAL INNOVATIONS

The use of perfusion CT is also possible for the diagnostics and differentiation of diffuse hepatic diseases.

PERFORMANCE

The differentiation between cirrhosis and cirrhosis-like parenchymal changes is possible. It also helps to detect early stages of malignant tumors.

ACHIEVEMENTS

However, there are some negative aspects, particularly that of radiation exposure.

PRACTICAL RECOMMENDATIONS

This paper summarizes the technical basics and possible applications of perfusion CT in cases of diffuse liver disease and weighs up the advantages and disadvantages of the examinations.

Effect of oxygen and lipid supplementation on the volatile composition of chemically defined medium and Chardonnay wine fermented with Saccharomyces cerevisiae

Oxygen or lipids are required to complete stressful alcoholic fermentation. Lack of these nutrients can inhibit sugar uptake and growth, which leads to incomplete or 'stuck' fermentation. Oxygen or lipids supplementation not only restores yeast fermentative activity and also affects formation of yeast volatile metabolites. To clarify the effect of oxygen and lipid supplementation on the formation of flavour active metabolites during wine fermentation, we evaluated the addition of these two nutrients to chemically defined grape juice and filter clarified Chardonnay must. Lipid addition increased the concentration of esters, higher alcohols and volatile acids, whereas oxygen increased the concentration of higher alcohols and altered the proportion of acetate to ethyl esters and the proportion of branch-chain acids to medium-chain fatty acids. Combined addition of lipids and oxygen showed an additive effect on concentration of higher alcohols whereas oxygen suppressed the enhancing effect of lipids on formation of esters and volatile acids. Our results demonstrate the potential of lipid and oxygen supplementation for the manipulation of wine aroma in white wine fermentation.

[Quantifying the inflammatory activity in Crohn's disease using CE dynamic MRI]

PURPOSE

Evaluation of dynamic contrast enhanced MRI in patients with Crohn's disease to assess local inflammatory activity.

MATERIAL AND METHODS

Prospective study of 13 patients with histologically proven Crohn's disease. Axial and coronal slices were acquired by a 1.5 T MR (Magnetom Vision, Siemens, Germany): T1 flash 2 D (TR 72.5 ms, TE 4.1 ms), T2 (TR 2730 ms, TE 138 ms), turbo-flash sequences T1 (TR 94.2 ms, TE 4.1 ms) post contrast media fat saturated (Magnevist, 0.2 ml/kg, flow 4 ml/s). In area of maximal thickening of terminal ileal wall, axial dynamic T1 sequences (TR 11 ms, TE 4.2 ms) were acquired every 1.5 s post contrast media application for a total duration of 1 min. Contrast uptake was subjectively measured by semiquantitative score and computed assisted ROI evaluation. MR parameters were correlated with CDAI (Crohn's disease activity index) and SAI (severe activity index).

RESULTS

Contrast uptake in the intestinal wall occurred after 18.5 s (range: 3.0 - 28.0), contrast upslope until plateau phase lasted for 16.1 s (range: 8.0 - 50.0). Maximum contrast enhancement into the bowel wall was 266 % (105 - 450 %) of baseline. After maximum contrast uptake, we observed a plateau phase in all cases for the total duration of measurement. A significant correlation existed for maximum contrast uptake to CDAI (r = 0.591; p = 0.033), for beginning of contrast upslope to the time until plateau phase (r = 0.822; p = 0.001), and for the time until plateau phase to CDAI (r = 0.562; p = 0.046). CDAI was on average 108, median 106; SAI was on average 114, median 115. SAI correlated significantly to CDAI (r = 0.874). Maximum contrast uptake, beginning of contrast upslope, and time until plateau phase were independent to creeping fat, local lymphadenitis, laboratory parameters, temperature, body mass index, heart frequency and systolic blood pressure.

CONCLUSION

Dynamic MRI enables to quantify local inflammatory activity of bowel wall in patients with Crohn's disease. Larger studies are necessary to establish this method in clinical routine.

Structure-function analysis of BfpB, a secretin-like protein encoded by the bundle-forming-pilus operon of enteropathogenic Escherichia coli

Production of type IV bundle-forming pili by enteropathogenic Escherichia coli (EPEC) requires BfpB, an outer-membrane lipoprotein and member of the secretin protein superfamily. BfpB was found to compose a ring-shaped, high-molecular-weight outer-membrane complex that is stable in 4% sodium dodecyl sulfate at temperatures of < or = 65 degrees C. Chemical cross-linking and immunoprecipitation experiments disclosed that the BfpB multimeric complex interacts with BfpG, and mutational studies showed that BfpG is required for the formation and/or stability of the multimer but not for the outer-membrane localization of BfpB. Formation of the BfpB multimer also does not require BfpA, the repeating subunit of the pilus filament. Functional studies of the BfpB-BfpG complex revealed that its presence confers vancomycin sensitivity, indicating that it may form an incompletely gated channel through the outer membrane. BfpB expression is also associated with accumulation of EPEC proteins in growth medium, suggesting that it may support both pilus biogenesis and protein secretion.

Clinical magnetic resonance imaging and arthroscopic findings in knees: a comparative prospective study of meniscus anterior cruciate ligament and cartilage lesions

We compared the diagnostic and predictive value of magnetic resonance imaging (MRI) and clinical findings with arthroscopy in 61 knees in a prospective study. In meniscal tears, the accuracy and positive predictive value of MRI was found to be nearly twice that of clinical examination. The sensitivity, specificity, and negative predictive value of MRI were comparable to the figures found in other studies. We recommend MRI as a clarifying diagnostic tool when a clinical examination indicates a lesion of the meniscus. In our study, the clinical relevance of MRI in anterior cruciate ligament lesions and especially in cartilage lesions was more doubtful. The combination of clinical and MRI findings would reduce the number of blank arthroscopies to 5%. MRI is a valuable diagnostic tool in planning the type of anesthesia and treatment, and could significantly reduce the need for a second arthroscopy.