Eckhart Fröhlich

Dynamic contrast-enhanced ultrasound for quantification of tissue perfusion.

Dynamic contrast‐enhanced ultrasound (US) imaging, a technique that uses microbubble contrast agents with diagnostic US, has recently been technically summarized and reviewed by a European Federation of Societies for Ultrasound in Medicine and Biology position paper. However, the practical applications of this imaging technique were not included. This article reviews and discusses the published literature on the clinical use of dynamic contrast‐enhanced US. This review finds that dynamic contrast‐enhanced US imaging is the most sensitive cross‐sectional real‐time method for measuring the perfusion of parenchymatous organs noninvasively. It can measure parenchymal perfusion and therefore can differentiate between benign and malignant tumors. The most important routine clinical role of dynamic contrast‐enhanced US is the prediction of tumor responses to chemotherapy within a very short time, shorter than using Response Evaluation Criteria in Solid Tumors criteria. Other applications found include quantifying the hepatic transit time, diabetic kidneys, transplant grafts, and Crohn disease. In addition, the problems involved in using dynamic contrast‐enhanced US are discussed.

Liver perfusion with dynamic multidetector-row computed tomography as an objective method to evaluate the efficacy of chemotherapy in patients with colorectal cancer.

A total of 24 liver metastases of colorectal cancer were evaluated by dynamic multiphasic CT. Under chemotherapy, follow-up examinations were performed every 3 months. The tumor marker CEA before vs. after chemotherapy correlated with the mean contrast enhancement within the margin of metastases. The total size of metastases correlated with the size of central necrosis as well as with the size of marginal contrast enhancement. CT is able to quantify perfusion and local activity of liver metastases to determine the efficacy of chemotherapy.

Kontrastmittelsonografie zur Charakterisierung von Lebertumoren: Praktische Aspekte

This review article reports on evidence-based and clinical aspects of contrast-enhanced ultrasound of liver masses. The advanced possibilities of contrast-enhanced ultrasound to detect and characterise liver tumors are described as well as limitations and pitfalls of the method. The choice of the ultrasound device and contrast agents as well as the qualifications of the examiners according to guidelines are discussed.

[Suspected acute coronary syndrome in patients without ST-elevation. Exclusion of infarction, early clinical estimation and non-coronary diagnoses].

Background and objective: Patients admitted to the hospital with suspected acute coronary syndrome (ACS) represent a collective at high risk. The NOWIS substudy aimed at evaluating 3 points: (1) Safe exclusion of myocardial infarction by history, symptoms, biochemical markers and the ECG, (2) value of the first diagnosis by the physician in the emergency room, and (3) prevalence and distribution of non-coronary leading diagnoses. Patients and methods: In 164 patients admitted with suspected ACS without ST-segment elevation (73 % men, median age 66 years) the cardiac markers myoglobin, troponin T and CK/CK-MB were assessed on admission and 4 h later. In 2 of the NOWIS centers, the diagnosis on admission, derived from the ECG, history and clinical symptoms, was compared with the leading diagnosis at discharge, based on coronary angiography and, if negative, on additional esophago-gastroscopy. Results: (1) Myoglobin was the biochemical marker with the highest sensitivity 4 h after admission for acute myocardial infarction (»classic« definition by CK-MB elevation) with 90.4 %, followed by troponin T with 84.6 %. Four h after admission, in 15.4 % of the infarction patients (prevalence 31.7 %) troponin T was normal. (2) The admission diagnosis instable angina pectoris was confirmed in 46.7 % (57 of 122), suspected acute infarction in 76.2 % (32 of 42). On the other hand, 90.4 % (57 of 63) of the patients with instable angina as leading diagnosis at discharge were correctly diagnosed on admission, but only 61.5 % (32 of 42) of the patients with infarction. (3) At discharge, 29.9 % (49 of 164) of the patients had a non-coronary leading diagnosis. Here, the most common were gastro-intestinal (55.1 %), costo-vertebral (18.4 %) and broncho-pulmonary (16.3 %). Conclusions: (1) Troponin and myoglobin are helpful in patients without ST-segment elevation; yet, 4 h after admission, a safe exclusion of myocardial infarction is not possible. (2) The clinical diagnosis on admission is important. However, it corresponds with the leading diagnosis at discharge, based on coronary angiography, in only 50 to 75 %. Patients admitted with suspected ACS should be monitored for 24 h in the hospital (chest pain units or coronary care units). (3) Nearly one third of the patients initially admitted with suspected ACS show a non-coronary leading diagnosis, thus underlining the value of further investigations and of an interdisciplinary approach.

How to Improve Reprocessing of Flexible Endoscopes Nationwide? Data from the German Colorectal Cancer Screening Program

Background and Aims. International studies revealed prevalences of around 50% of microbiological contaminations in reprocessed flexible endoscopes. In Germany a system was installed where the qualification for refund for colonoscopies was made conditional on successfully passing twice annually a microbiological surveillance test of reprocessed endoscopes. This study is an implementation and outcome evaluation as well as a general discussion of the quality assessment assurance in colonoscopy in Germany. Methods. German data from 2003–2008 were analysed: number of endoscopic units performing therapeutic and/or screening colonoscopies; results of all microbiological surveillance tests of reprocessing quality; number of failed surveillance tests and retests; number of qualifications for refund from the public health system cancelled due to repeated failure of microbiological surveillance tests. Results. After the introduction of the quality assessment assurance, the percentage of failed microbiological surveillance tests dropped significantly and steadily from close to 17% to below 5%. Conclusions. This study evidences (1st) the successful implementation of the quality assessment assurance in Germany and (2nd) a substantial improvement in the quality of reprocessing flexible endoscopes achieved by these measures.

Effect of quality assessment assurance in 2002 (before starting the German colorectal cancer screening programme by colonoscopy) on the quality of reprocessing of flexible endoscopes - a nationwide analysis.

BACKGROUND International studies in the 1990 s and the HYGEA study from Germany in 2002 revealed prevalences of around 50 % of microbiological contaminations in reprocessed flexible endoscopes. Before introducing the colorectal cancer screening programme by colonoscopy in Germany in 2002, the Kassenärztliche Bundesvereinigung (KBV) and the key stakeholders of the public health insurance system agreed on a quality assessment assurance for reprocessing endoscopes where the qualification for refund for colonoscopies from the public health system was made conditional on adequate qualifications of the gastroenterologist; on a minimum number of performed procedures per year; and on adequate endoscope reprocessing documented by negative surveillance cultures two times per year. This study is an implementation and outcome evaluation of the quality assessment assurance in colonoscopy in Germany. METHODS The following data - per year and per Kassenärztliche Vereinigung (KV) - were obtained from the KBV: the number of endoscopic units performing therapeutic and/or screening colonoscopies within each KV; the results of all microbiological surveillance tests of reprocessing quality (two per year per unit); the number of failed surveillance tests and re-tests; and the number of qualifications for refund from the public health system cancelled due to repeated failure of microbiological surveillance tests. RESULTS The percentages of actually performed hygiene control tests (out of those prescribed by the assurance system) reached 95 % already in 2004 and remained above or close to this level thereafter. After the introduction of the quality assessment assurance, the percentage of failed microbiological surveillance tests dropped significantly and steadily from close to 17 % in 2003 to below 4 % in 2007. CONCLUSIONS This study evidences 1. the successful implementation of the quality assessment assurance in Germany and 2. a substantial improvement in the quality of reprocessing flexible endoscopes achieved by these measures with a drop from 50 % of failed tests observed before the introduction in 2000 - 2001 to below 4 % in 2007.

Use of Ultrasound in the Diagnostic Work-Up of Adult Intussusception – A Multicenter Retrospective Analysis

PURPOSE  To evaluate the use of ultrasound (US) in the diagnostic work-up of adult intussusception (AI). METHODS  This multicenter study includes 26 consecutive patients diagnosed with AI between January 2010 and November 2017. A retrospective chart analysis was conducted with a focus on abdominal US findings and diagnostic accuracy of different imaging modalities (ultrasound, computed tomography (CT), magnetic resonance imaging). If available, surgical and pathological findings served as the gold standard (76.9 %). US examiners certified according to DEGUM grade 2 or 3 were classified as experts. Otherwise, they were regarded to have basic skills. RESULTS  During diagnostic work-up, 92.3 % underwent abdominal US. US was the first-line imaging modality in 88.5 % of cases. The accuracy regarding the detection of AI (85 %), correct localization (95 %) and detection of complications (100 %) was excellent and comparable with CT (81 %, 90.5 %, and 91.7 %) when performed by experts. 72.7 % of tumorous lead points were detected by experienced examiners. In contrast, AI was detected in only 45.5 % of cases by examiners with basic skills. AI was diagnosed prior to surgery in all patients. CONCLUSION  US is reliable in the diagnostic work-up of AI when performed by experienced examiners with high-quality equipment. US, CT and MRI should be used in a complementary fashion since combination provides excellent sensitivity regarding the detection and correct localization of AI as well as the detection of complications. The impact of real-time imaging is illustrated by supplementary videos.

Piktocam statt Piktogramm – Validierungsstudie zur Qualitätsverbesserung der Bilddokumentation beim abdominellen Ultraschall

AIM To replace pictograms with pictocam pictures: A prospective blinded quality improvement study in documenting image orientation and localisation in abdominal ultrasound imaging. MATERIALS AND METHODS A minicam was mounted on the ultrasound scanhead to record pictocam pictures. The primary examiner produced an ultrasound image together with the routinely embedded pictogram. Subsequently the pictogram was covered by the synchronically taken pictocam picture. Subsequently, the primary examiner assessed the pictograms and the second examiner the pictocam pictures (blinded to the pictogram findings of the primary examiner). RESULTS A total of 679 paired pictogram and pictocam pictures were available from 114 patients. The localisation of the utrasound head showed an absolute or close agreement of 99.7% (677/679) with a 95% confidence interval of [98.94%-99.96%]. The angle of the ultrasound head showed an absolute or close agreement of 99.0% (672/679) with a 95% confidence interval of [97.98% - 99.58%]. CONCLUSION This study shows that the pictogram can validely be replaced by a pictocam picture. The routine addition of a minicam to the ultrasound scanhead would thus not only improve the quality of the documentation, but would also result in time savings during examinations.

Piktocam statt Piktogramm: validierungsstudie zur qualitätsverbesserung der bilddokumentation beim abdominellen ultraschall / Pictocam instead of Pictogram: a quality improvement study in abdominal ultrasound imaging

AIM To replace pictograms with pictocam pictures: A prospective blinded quality improvement study in documenting image orientation and localisation in abdominal ultrasound imaging. MATERIALS AND METHODS A minicam was mounted on the ultrasound scanhead to record pictocam pictures. The primary examiner produced an ultrasound image together with the routinely embedded pictogram. Subsequently the pictogram was covered by the synchronically taken pictocam picture. Subsequently, the primary examiner assessed the pictograms and the second examiner the pictocam pictures (blinded to the pictogram findings of the primary examiner). RESULTS A total of 679 paired pictogram and pictocam pictures were available from 114 patients. The localisation of the utrasound head showed an absolute or close agreement of 99.7% (677/679) with a 95% confidence interval of [98.94%-99.96%]. The angle of the ultrasound head showed an absolute or close agreement of 99.0% (672/679) with a 95% confidence interval of [97.98% - 99.58%]. CONCLUSION This study shows that the pictogram can validely be replaced by a pictocam picture. The routine addition of a minicam to the ultrasound scanhead would thus not only improve the quality of the documentation, but would also result in time savings during examinations.

Verdachtsdiagnose akutes Koronarsyndrom bei Patienten ohne ST-Hebung

Background and objective: Patients admitted to the hospital with suspected acute coronary syndrome (ACS) represent a collective at high risk. The NOWIS substudy aimed at evaluating 3 points: (1) Safe exclusion of myocardial infarction by history, symptoms, biochemical markers and the ECG, (2) value of the first diagnosis by the physician in the emergency room, and (3) prevalence and distribution of non-coronary leading diagnoses. Patients and methods: In 164 patients admitted with suspected ACS without ST-segment elevation (73 % men, median age 66 years) the cardiac markers myoglobin, troponin T and CK/CK-MB were assessed on admission and 4 h later. In 2 of the NOWIS centers, the diagnosis on admission, derived from the ECG, history and clinical symptoms, was compared with the leading diagnosis at discharge, based on coronary angiography and, if negative, on additional esophago-gastroscopy. Results: (1) Myoglobin was the biochemical marker with the highest sensitivity 4 h after admission for acute myocardial infarction (»classic« definition by CK-MB elevation) with 90.4 %, followed by troponin T with 84.6 %. Four h after admission, in 15.4 % of the infarction patients (prevalence 31.7 %) troponin T was normal. (2) The admission diagnosis instable angina pectoris was confirmed in 46.7 % (57 of 122), suspected acute infarction in 76.2 % (32 of 42). On the other hand, 90.4 % (57 of 63) of the patients with instable angina as leading diagnosis at discharge were correctly diagnosed on admission, but only 61.5 % (32 of 42) of the patients with infarction. (3) At discharge, 29.9 % (49 of 164) of the patients had a non-coronary leading diagnosis. Here, the most common were gastro-intestinal (55.1 %), costo-vertebral (18.4 %) and broncho-pulmonary (16.3 %). Conclusions: (1) Troponin and myoglobin are helpful in patients without ST-segment elevation; yet, 4 h after admission, a safe exclusion of myocardial infarction is not possible. (2) The clinical diagnosis on admission is important. However, it corresponds with the leading diagnosis at discharge, based on coronary angiography, in only 50 to 75 %. Patients admitted with suspected ACS should be monitored for 24 h in the hospital (chest pain units or coronary care units). (3) Nearly one third of the patients initially admitted with suspected ACS show a non-coronary leading diagnosis, thus underlining the value of further investigations and of an interdisciplinary approach.