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1.
Schmerz ; 2023 Mar 20.
Article in German | MEDLINE | ID: mdl-36941442

ABSTRACT

Digital medicine has increasing influence on the German healthcare system. In times of social distancing during the ongoing coronavirus disease 2019 (COVID-19) pandemic, digital tools enable health professionals to maintain medical care. Furthermore, digital elements have potential to provide effective guideline-oriented treatment to a broad range of patients independently from location and time. This survey was used to assess the attitudes of members of the German Pain Society (health professionals) and of associated self-help groups (patients) towards digital medicine. It was sent out as an online survey to health professionals in September 2020 and to patients in February 2021. The survey referred especially to present usage, attitude and potential concerns regarding particular digital elements. Furthermore, technical affinity was assessed. In total, 250 health professionals and 154 patients participated in the survey. The results show that-although digital elements are already known-a substantial proportion of health professionals still lack broad transfer to regular treatment. The potential of digital tools seems to be recognized by both groups; interestingly, patients consider digital medicine as more useful than health professionals. Nevertheless, concerns about for example data security or digital competence remain in both groups. Taken together, our results indicate that disruptive changes, as the implementation of digital medicine in the healthcare system, have to be guided by intense education and channeled by political policies in order to successfully integrate digital elements into medicine on a long-term basis. This would be in favor for all involved parties and is demanded especially by patients.

2.
Article in German | MEDLINE | ID: mdl-36648499

ABSTRACT

Although Germany continues to struggle with the digital transformation of healthcare, there is reason for optimism. The political will to improve healthcare with digital technologies has been underpinned by numerous legal initiatives since 2018. In addition, there is growing acceptance among healthcare providers and the population. The latter has clearly been driven by the corona pandemic, which underscored the need for more digitized care.Digitalization in healthcare has three key drivers: the rapid technological development in data processing, the ever-improving understanding of the biological basis of human life, and growing patient sovereignty coupled with a growing desire for transparency. Prerequisites for digital medicine are data interoperability and the establishment of a networking (telematics) infrastructure (TI). The status of the most important digital TI applications affecting German healthcare are described: the electronic patient record (ePA) as its core as well as electronic prescriptions, medication plans, and communication tools such as Communication in Medicine (KIM) and TI Messenger (TIM). In addition, various telemedical offerings are discussed as well as the introduction of digital health applications (DiGA) into the statutory healthcare system, which Germany has pioneered. Furthermore, the use of medical data as the basis for artificial intelligence (AI) algorithms is discussed. While helpful and capable of improving diagnostics as well as medical therapy, such AI tools will not replace doctors and nurses.


Subject(s)
Artificial Intelligence , Telemedicine , Humans , Germany , Delivery of Health Care , Health Facilities
3.
Lancet Digit Health ; 4(3): e200-e206, 2022 03.
Article in English | MEDLINE | ID: mdl-35216754

ABSTRACT

In 2019, Germany passed the Digital Healthcare Act, which, among other things, created a "Fast-Track" regulatory and reimbursement pathway for digital health applications in the German market. The pathway explicitly provides for flexibility in how researchers can present evidence for new digital products, including the use of real-world data and real-world evidence. Against this backdrop, the Digital Medicine Society and the Health Innovation Hub of the German Federal Ministry of Health convened a set of roundtable discussions to bring together international experts in evidence generation for digital medicine products. This Viewpoint highlights findings from these discussions with the aims of (1) accelerating and stimulating innovative approaches to digital medical product evaluation, and (2) promoting international harmonisation of best evidentiary practices. Advancing these topics and fostering international agreement on evaluation approaches will be vital to the safe, effective, and evidence-based deployment and acceptance of digital health applications globally.


Subject(s)
Delivery of Health Care , Health Facilities , Germany
4.
Article in German | MEDLINE | ID: mdl-35181795

ABSTRACT

Ensuring the quality of healthcare services is a core concern of the statutory health insurance system. It is therefore not surprising that recent initiatives to (further) digitalize the healthcare system, specifically to introduce the electronic patient record and other applications in the telematics infrastructure, with the Patient Data Protection Act ("Patientendaten-Schutz-Gesetz", PDSG) of digital health applications with the Digital Care Act ("Digitale-Versorgung-Gesetz", DVG), or to strengthen hospital IT with the Hospital Future Act ("Krankenhauszukunftsgesetz", KHZG), are justified by ensuring or even increasing the quality-of-service provision.This article sheds light on the question of how the use of various digital solutions relates to the classic goals of quality assurance in healthcare, in particular, whether digital solutions are suitable for promoting quality assurance.It is shown that digital solutions are fundamentally suitable for ensuring quality. This is due to two characteristics of digital solutions: the possibility of comprehensive data collection and the possibility of making data available independent of time and place. However, it is also apparent that the benefits associated with digital solutions are highly dependent on the specific use cases.


Subject(s)
Delivery of Health Care , Health Facilities , Germany , Humans , National Health Programs , Quality of Health Care
8.
Eur J Nucl Med Mol Imaging ; 36 Suppl 1: S139-43, 2009 Mar.
Article in English | MEDLINE | ID: mdl-19104799

ABSTRACT

INTRODUCTION: Continuous ageing of the population coupled with growing health consciousness and continuous technological advances have fueled the rapid rise in healthcare costs in the United States and Europe for the past several decades. The exact impact of new medical technology on long-term spending growth remains the subject of controversy. By all measures it is apparent that new medical technology is the dominant driver of increases in health-care costs and hence insurance premiums. OBJECTIVE: This paper addresses the impact of medical technology on healthcare delivery systems with regard to medical practice and costs. We first explore factors affecting the growth of medical technology and then attempt to provide a means for assessing the effectiveness of medical technology. DISCUSSION: Avoidable healthcare cost drivers are identified and related policy issues are discussed.


Subject(s)
Health Care Costs/trends , Medical Laboratory Science/economics , Medical Laboratory Science/trends , Cost-Benefit Analysis , Health Care Costs/standards , Health Policy , Humans , Insurance, Health/economics , Medical Laboratory Science/standards , Technology Assessment, Biomedical
9.
Hepatogastroenterology ; 54(76): 1176-80, 2007 Jun.
Article in English | MEDLINE | ID: mdl-17629065

ABSTRACT

BACKGROUND/AIMS: To prospectively evaluate the feasibility of postoperative contrast enhanced Multi-detector-CT cholangiography (ceMDCT-CA) in living liver donors and transplant recipients. METHODOLOGY: Fifteen donors and 11 recipients of a right hepatic lobe underwent ceMDCT-CA. Six donors were admitted to exclude biliary leakage; 9 donors and 11 recipients were examined to exclude postoperative biliary obstruction. The examination protocol included the intravenous short-infusion of 100 mL of a biliary contrast agent. CT cholangiography data was acquired with a slice thickness of 1 mm. This scan was followed by examination of the upper abdomen in a venous phase. Data sets were evaluated quantitatively by measurement of the biliary opacification, and qualitatively on the basis of a scale ranging from 1 (non-diagnostic) to 4 (excellent). Opacification was correlated with postoperative serum bilirubin level. RESULTS: CT data provided diagnostic delineation of the biliary tree in all 15 donors and seven of 11 recipients; in 4 recipients the degree of biliary opacification was non-diagnostic. Biliary opacification was generally higher in the donor collective. Four donors and 3 recipients presented a moderate focal biliary constriction without elevation of laboratory values. Six patients showed postoperative fluid collections suggestive of perihepatic biloma, however no biliary fistula could be visualized. CONCLUSIONS: CeMDCT-CA represents a promising tool to non-invasively assess the postoperative biliary morphology in living liver donors and transplant recipients.


Subject(s)
Biliary Tract/diagnostic imaging , Cholangiography/methods , Contrast Media/administration & dosage , Liver Transplantation , Tomography, X-Ray Computed/methods , Adult , Female , Humans , Living Donors , Male , Middle Aged
10.
Radiology ; 238(3): 900-10, 2006 Mar.
Article in English | MEDLINE | ID: mdl-16439567

ABSTRACT

PURPOSE: To prospectively assess parenchymal, vascular, and biliary anatomy of potential living liver donors with an all-inclusive multi-detector row computed tomographic (CT) approach. MATERIALS AND METHODS: A total of 250 potential living liver donors (112 women, 138 men; mean age, 37 years) underwent three-phase, dual-enhancement multi-detector row CT to delineate biliary, vascular, and parenchymal morphology according to an institutional review board-approved protocol. Informed consent was obtained from all subjects. For display of the biliary system, the first CT image set was collected after the infusion of a biliary contrast agent. CT angiography was subsequently performed, after automated injection of a conventional iodinated contrast agent, to display the arterial and portal-hepatic venous systems. All data sets were reconstructed in 1-mm sections. Data analysis was based on source images, multiplanar reconstructions, and three-dimensional postprocessing images; was performed in consensus by two radiologists; and was focused on the detection of biliary and vascular variants, exclusion of focal liver lesions, and determination of hepatic volumes. Preoperative findings were correlated with intraoperative findings (available in 62 subjects). RESULTS: Technical failures were experienced in 10 of 250 examinations. Twenty-seven subjects had moderate adverse reactions related to the biliary contrast agent. Benign hepatic lesions were detected in 61 candidates; one candidate had a renal cell carcinoma. Underlying biliary and vascular anatomy was displayed at least to the second intrahepatic branch in all but seven patients. Detected anatomic variants involved the biliary (38.8%), arterial (40.0%), portal venous (21.4%), and hepatic venous (43.5%) systems. Correlation with intraoperative findings was excellent. Some biliary (n = 4), arterial (n = 5), portal venous (n = 1), and hepatic venous (n = 6) variants were missed or misinterpreted at initial reading of preoperative data; however, variants could be retrospectively depicted in all but one biliary case and one hepatic venous case. CONCLUSION: The outlined three-phase, dual-enhancement multi-detector row CT protocol represents an all-inclusive approach to evaluate potential living liver donors in a single diagnostic step.


Subject(s)
Liver Transplantation , Liver/diagnostic imaging , Living Donors , Tomography, X-Ray Computed/methods , Adolescent , Adult , Contrast Media , Female , Humans , Image Processing, Computer-Assisted , Imaging, Three-Dimensional , Male , Middle Aged , Prospective Studies
11.
Acad Radiol ; 13(2): 262-5, 2006 Feb.
Article in English | MEDLINE | ID: mdl-16428064

ABSTRACT

RATIONALE AND OBJECTIVES: The aim of the study is to evaluate variability in hepatic volumes during the preoperative period in potential liver donors. MATERIALS AND METHODS: Eight potential living liver donors underwent preoperative multirow-detector computed tomographic assessment of hepatic transplant volumes twice. Intraindividual delay between the two examinations range was 3-62 days (mean, 30.1 days). Liver volumes were determined in a blinded fashion by an experienced radiologist and a transplantation surgeon. Results were compared and correlated with time of data acquisition during the day. RESULTS: Interobserver variability for assessments of liver volumes range was 6-32 mL (mean, 16 mL). Intraindividually, the difference between the two volume assessments ranged between -103 and +45 mL (mean, -19 mL), corresponding to percentages of alteration between -7.5% and +3.2%. There was no statistical correlation evident concerning volume alterations and specific time of data acquisition. CONCLUSION: Neither time of data acquisition nor waiting period for the surgical procedure seems to affect the accuracy of liver volume calculation. Apparent volume variations likely are in the range of the method error of the applied technique.


Subject(s)
Liver Transplantation , Liver/anatomy & histology , Liver/diagnostic imaging , Living Donors , Adult , Circadian Rhythm , Donor Selection , Female , Humans , Male , Middle Aged , Observer Variation , Organ Size , Preoperative Care , Retrospective Studies , Tomography, X-Ray Computed
12.
Eur Radiol ; 16(3): 685-91, 2006 Mar.
Article in English | MEDLINE | ID: mdl-16175353

ABSTRACT

High-resolution total-body 3D MR angiography (MRA) has recently become available, revealing additional clinically relevant disease in patients with peripheral arterial occlusive disease (PAOD). However, the actual impact of total-body MRA on patient management in patients with PAOD has not been investigated so far. Two hundred forty-nine consecutive patients with angiographically proven PAOD were prospectively examined by means of contrast-enhanced total-body 3D MRA on a 1.5-T MR scanner. All correlative imaging studies performed within 60 days of total-body MRA were included in the efficacy analysis. Additional clinically relevant disease (luminal narrowing >50%, aneurysmal changes or dissections) was found in 73 segments (52 patients), including the renal arteries (36 segments), carotid arteries (28 segments), subclavian arteries (four segments) and abdominal aortic aneurysms (AAA) (five segments). Of the 73 segments, 36 were deemed necessary for further investigation by means of focused MRA examinations; the diagnosis was confirmed in all cases. Within the 60-day follow-up period, interventional or surgical therapy outside the peripheral arterial tree was performed in nine patients (11 segments), including carotid endatherectomy and renal artery angioplasty. The outlined total-body 3D MRA approach permits a comprehensive evaluation of the arterial system in patients with atherosclerosis and does indeed have an impact on patient management in patients with PAOD.


Subject(s)
Arterial Occlusive Diseases/pathology , Imaging, Three-Dimensional , Magnetic Resonance Angiography/methods , Peripheral Vascular Diseases/pathology , Adult , Aged , Aged, 80 and over , Arterial Occlusive Diseases/therapy , Contrast Media , Female , Humans , Image Processing, Computer-Assisted , Male , Middle Aged , Peripheral Vascular Diseases/therapy , Prospective Studies , Whole Body Imaging
13.
AJR Am J Roentgenol ; 185(4): 979-84, 2005 Oct.
Article in English | MEDLINE | ID: mdl-16177419

ABSTRACT

OBJECTIVE: The objective of our study was to determine the diagnostic performance of MRI based on a HASTE sequence for the detection of pulmonary nodules in comparison with MDCT. MATERIALS AND METHODS: Thirty patients with known pulmonary nodules underwent both MRI and CT. CT of the lung served as the standard of reference and was performed on a 4-MDCT scanner using a routine protocol. MRI was performed with axial and coronal HASTE sequences using a high-performance 1.5-T MR scanner. Image data were analyzed in three steps after completion of all data acquisition. Step 1 was the analysis of all the CT image data. Step 2 was the analysis of all the MR image data while blinded to the results of the CT findings. Step 3 closed with a simultaneous review of all corresponding CT and MRI data, including a one-to-one correlation of the size and location of all the nodules that were detected. RESULTS: Compared with the sensitivity of CT, the sensitivity values for the HASTE MR sequence were as follows: 73% for lesions less than 3 mm, 86.3% for lesions between 3 and 5 mm, 95.7% for lesions between 6 and 10 mm, and 100% for lesions larger than 10 mm. The overall sensitivity of the HASTE sequence for the detection of all pulmonary lesions was 85.4%. CONCLUSION: An MRI examination that consists of a HASTE sequence allows one to detect, exclude, or monitor pulmonary lesions that are 5 mm and bigger. Suspicious lesions smaller than 5 mm still need to be validated using CT.


Subject(s)
Lung Neoplasms/diagnosis , Magnetic Resonance Imaging/methods , Solitary Pulmonary Nodule/diagnosis , Adult , Aged , Aged, 80 and over , Female , Humans , Image Processing, Computer-Assisted , Lung Neoplasms/diagnostic imaging , Male , Middle Aged , ROC Curve , Sensitivity and Specificity , Solitary Pulmonary Nodule/diagnostic imaging , Tomography, X-Ray Computed/methods
14.
World Hosp Health Serv ; 41(2): 32-4, 40, 42, 2005.
Article in English | MEDLINE | ID: mdl-16104457

ABSTRACT

The use of imaging is generally focussed on detecting and characterising suspected or known disease in symptomatic patients. Experience with preventative imaging, aiming at the detection of disease prior to its symptomatic manifestation, is limited. Screening involves the evaluation of asymptomatic individuals at risk for the presence of a particular disease. A screening test is designed to detect a targeted disease at a stage which still permits treatment to succeed in avoiding morbidity and/or mortality. Diseases worthy of screening should be associated with high morbidity and/or mortality if proper treatment is not applied sufficiently early. The screening test itself must not cause harm to the examined subjects. For the test to be cost-effective, the target disease should be highly prevalent in the screened population. Restricting screening to a population known to be at increased risk for the target disease enhances the test's effectiveness.


Subject(s)
Magnetic Resonance Imaging/methods , Mass Screening/methods , Patient Acceptance of Health Care , Primary Prevention/methods , Colonic Diseases/diagnosis , Colonic Diseases/prevention & control , Coronary Angiography/adverse effects , Europe , Humans , Lung Diseases/diagnosis , Lung Diseases/prevention & control , Magnetic Resonance Angiography/methods , Mass Screening/statistics & numerical data , Radiologic Health , Tomography, X-Ray Computed/adverse effects , Treatment Outcome , United States , Vascular Diseases/diagnosis , Vascular Diseases/prevention & control
15.
Eur J Gastroenterol Hepatol ; 17(8): 815-20, 2005 Aug.
Article in English | MEDLINE | ID: mdl-16003129

ABSTRACT

Dark-lumen magnetic resonance colonography has been shown to be an appropriate diagnostic tool for the detection of colorectal pathologies. This review describes the underlying techniques of dark-lumen magnetic resonance colonography concerning data acquisition, image interpretation and diagnostic accuracy for the detection of colorectal pathologies. In addition, techniques to improve patients' acceptance are discussed.


Subject(s)
Colorectal Neoplasms/diagnosis , Magnetic Resonance Imaging/methods , Barium Sulfate , Colonoscopy/methods , Contrast Media , Diagnosis, Differential , Diagnostic Errors , Feces , Female , Humans , Image Interpretation, Computer-Assisted/methods , Male
16.
Liver Transpl ; 11(7): 776-787, 2005 Jul.
Article in English | MEDLINE | ID: mdl-15973711

ABSTRACT

In order to compare the performance of "all-in-one" magnetic resonance imaging (MRI) and "all-in-one" multidetector computed tomography (MDCT) in the preharvest evaluation 25 potential living donors underwent both MRI and MDCT. MRI was performed on a high-performance 1.5-T scanner, computed tomography (CT) on a 4-row multidetector-scanner. Both scan protocols included angiography of the arterial and venous hepatic systems. CT additionally included infusion of a biliary contrast agent. Data analysis was performed by 4 reviewers, based on source images, multiplanar reformats, and three-dimensional (3D) postprocessing. Determination of image quality was based on a 4-point image quality rating (IQR) scale, ranging from 1 = nondiagnostic to 4 = excellent. Preoperative and intraoperative (n = 13) findings were correlated. Magnetic resonance (MR) examinations were generally well tolerated. Within the CT scan, 2 candidates presented moderate adverse reaction to the biliary contrast agent. MRI and CT showed the same benign parenchymal lesions (IQR MR: 3.7; IQR CT: 3.4). Determination of liver volumes was easier based on CT (IQR MR: 3.3; IQR CT: 3.6). Magnetic resonance angiography (MRA) revealed 10 variants of the arterial liver supply (IQR: 3.0) and computed tomographic angiography (CTA) revealed 13 variants (IQR: 3.5). Magnetic resonance cholangiopancreatography (MRCP) identified 4 biliary variants (IQR: 1.3) and CT cholangiography identified 17 (IQR: 3.5). MRI and CT each showed 4 hepatic and portal venous variants (IQR MR: 3.4, CT: 2.8). CT and MR findings correlated well with intraoperative findings. In conclusion, both techniques proved to be efficient to evaluate potential living liver donors' anatomy in a single diagnostic step. The main advantage of CT lies in the ability to accurately assess the biliary anatomy.


Subject(s)
Liver Transplantation , Living Donors , Magnetic Resonance Imaging , Tissue and Organ Harvesting , Tomography, X-Ray Computed/methods , Adult , Biliary Tract/anatomy & histology , Biliary Tract/diagnostic imaging , Female , Hepatic Artery/anatomy & histology , Hepatic Artery/diagnostic imaging , Hepatic Veins/anatomy & histology , Hepatic Veins/diagnostic imaging , Humans , Liver/anatomy & histology , Liver/diagnostic imaging , Magnetic Resonance Imaging/standards , Male , Middle Aged , Portal Vein/anatomy & histology , Portal Vein/diagnostic imaging , Preoperative Care , Prospective Studies , Tomography, X-Ray Computed/standards
17.
J Magn Reson Imaging ; 22(1): 92-100, 2005 Jul.
Article in English | MEDLINE | ID: mdl-15971189

ABSTRACT

PURPOSE: To assess the impact of an additional rectal enema filling in small bowel hydro-MRI in patients with Crohn's disease. MATERIALS AND METHODS: A total of 40 patients with known Crohn's disease were analyzed retrospectively: 20 patients only ingested an oral contrast agent (group A), the other 20 subjects obtained an additional rectal water enema (group B). For small bowel distension, a solution containing 0.2% locust bean gum (LBG) and 2.5% mannitol was used. In all patients, a breathhold contrast-enhanced T1w three-dimensional volumetric interpolated breathhold examination (VIBE) sequence was acquired. Comparative analysis was based on image quality and bowel distension as well as signal-to-noise ratio (SNR) measurements. MR findings were compared with those of conventional colonoscopy, as available (N = 25). RESULTS: The terminal ileum and rectum showed a significantly higher distension following the rectal administration of water. Furthermore, fewer artifacts were seen within group B. This resulted in a higher reader confidence for the diagnosis of bowel disease, not only in the colon, but also in the ileocecal region. Diagnostic accuracy in diagnosing inflammation of the terminal ileum was 100% in group B; in the nonenema group there were three false-negative diagnoses of terminal ileitis. CONCLUSION: Our data show that the additional administration of a rectal enema is useful in small bowel MRI for the visualization of the terminal ileum. The additional time needed for the enema administration was minimal, and small and large bowel pathologies could be diagnosed with high accuracy. Thus, we suggest that a rectal enema in small bowel MR imaging be considered.


Subject(s)
Cecum/pathology , Crohn Disease/diagnosis , Enema , Ileum/pathology , Intestine, Large/pathology , Magnetic Resonance Imaging/methods , Adult , Female , Galactans , Humans , Magnetic Resonance Angiography , Male , Mannans , Mannitol , Middle Aged , Plant Gums , Polysaccharides , Retrospective Studies
18.
Eur Radiol ; 15(8): 1629-33, 2005 Aug.
Article in English | MEDLINE | ID: mdl-15841379

ABSTRACT

The aim of this work was to assess the diagnostic value of fast steady state free precession (SSFP) for the detection, characterization, and delineation of pancreatic lesions. Forty-eight patients referred for magnetic resonance (MR) imaging of the pancreas were included in the study. In addition to the standard protocol, axial pre-contrast SSFP slices of the pancreas were acquired. The standard of reference was defined as based on all imaging data other than SSFP, histopathology, surgery, and/or clinical follow-up. A randomized consensus reading of the SSFP data sets was retrospectively conducted by two board-certified radiologists. The presence of pancreatic lesions, local infiltration, and lymph node metastases was evaluated. Sensitivity and specificity were calculated and a receiver operating characteristic (ROC) analysis was performed. The overall sensitivity and specificity of SSFP were 0.93 and 0.77, respectively. Comparable values were achieved for lymph node detection (0.88/0.91) and assessment of vascular infiltration (0.94/0.91). The mean area under the ROC curve (Az) was 0.91. Owing to its potential to detect vascular infiltration and the rapid acquisition time, SSFP imaging should be supplemented as part of a standard MR protocol of the pancreas.


Subject(s)
Magnetic Resonance Imaging/methods , Pancreas/pathology , Pancreatic Diseases/diagnosis , Contrast Media , Female , Gadolinium , Humans , Image Processing, Computer-Assisted , Male , Meglumine , Middle Aged , Organometallic Compounds , Pancreatic Pseudocyst/diagnosis , ROC Curve , Retrospective Studies , Sensitivity and Specificity
19.
J Magn Reson Imaging ; 21(4): 376-82, 2005 Apr.
Article in English | MEDLINE | ID: mdl-15779026

ABSTRACT

PURPOSE: To evaluate the impact of parallel acquisition techniques (PATs) on image quality and detection of liver metastases using three-dimensional volumetric interpolated breath-hold examination (VIBE) for clinical liver imaging. MATERIALS AND METHODS: Forty-nine patients with various primary malignancies underwent abdominal dynamic contrast-enhanced three-dimensional VIBE magnetic resonance imaging (MRI) (1.5 T) using a standard phased array coil. Recently introduced Generalized Autocalibrating Partially Parallel Acquisition (GRAPPA) and SENSitivity Encoding (mSENSE) PAT reconstruction algorithms were added to reduce scan time twofold. Overall image quality, motion, and aliasing artifacts were classified on a 5-point scale. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) measurements were performed for quantitative comparison. All sequences were evaluated concerning the number of detected lesions. RESULTS: PAT resulted in a reduction of data acquisition time from 23 to 13 seconds. Both GRAPPA and mSENSE data sets yielded 30% less SNR (34.8 +/- 14.1 and 33.1 +/- 13.3, P < 0.001) and 35% less CNR (21.2 +/- 15.0 and 20.9 +/- 12.7, P < 0.05) in comparison to unaccelerated VIBE (SNR = 50.8 +/- 20.3/CNR = 32.5 +/- 19.1). Similarly, PAT revealed lower-image-quality scores than unaccelerated VIBE. GRAPPA resulted in more fold-over artifacts than mSENSE. mSENSE revealed slightly fewer motion artifacts than no PAT. The unaccelerated late-venous-phase VIBE sequence revealed 146 lesions in the same patients. Accelerated images with mSENSE reconstruction detected 138 lesions. GRAPPA revealed 127 lesions, and thus performed inferior to mSENSE. CONCLUSION: At least for arrays with small numbers of elements, such as arrays used in this study, the PAT-induced reduction in scanning times must be weighed against compromises in image quality, which translate into poorer diagnostic performance regarding detection of small hepatic lesions. Thus, the PAT implementations tested in this study should probably be reserved for patients unable to hold their breaths for regular three-dimensional VIBE data sets.


Subject(s)
Abdomen , Magnetic Resonance Imaging/methods , Abdominal Neoplasms/diagnosis , Algorithms , Female , Humans , Imaging, Three-Dimensional , Male , Middle Aged , Respiration
20.
J Nucl Med ; 46(3): 520-5, 2005 Mar.
Article in English | MEDLINE | ID: mdl-15750168

ABSTRACT

UNLABELLED: Our goal was to assess the typical appearance of normal liver tissue immediately after radiofrequency ablation (RF-ablation) when imaged with contrast-enhanced ultrasound, CT, MRI, 18F-FDG PET, and PET/CT. METHODS: Nineteen RF-ablation sessions were performed on nontumorous liver tissue of 10 Göttingen Mini Pigs. CT, ultrasound, MRI, 18F-FDG PET, and PET/CT were performed immediately after the intervention. All imaging procedures were evaluated qualitatively for areas of increased contrast enhancement (morphologic imaging) and regions of elevated tracer uptake (functional imaging). Images were assessed quantitatively by determination of ratios (r(p/p)) comparing contrast enhancement/tracer uptake in the periphery of the necrosis with contrast enhancement/tracer uptake of normal liver parenchyma. RESULTS: On morphologic imaging, an increase in contrast enhancement surrounding the ablative necrosis was detected in all lesions. Quantification of this area of increased contrast enhancement revealed ratios of r(p/p) = 1.57 +/- 0.2 for CT and r(p/p) = 1.57 +/- 0.19 for MRI. On PET and PET/CT, homogeneous tracer utilization was found surrounding all lesions. There were no areas of a focal or rim-like increase in glucose metabolism. The ratio r(p/p) was found to be 1.05 +/- 0.08 for functional data. Histologic examination revealed pooling of blood in the sinusoids of the lesion's periphery that was caused by outflow obstruction due to the central necrosis. CONCLUSION: On morphologic imaging, a rim-like increase of contrast enhancement was found immediately after RF-ablation resembling peripheral hyperperfusion. This area of contrast enhancement may hamper detection of residual tumor. On the basis of homogeneous tracer distribution surrounding the area of necrosis, PET and PET/CT may serve for early assessment of patients after RF-ablation.


Subject(s)
Catheter Ablation/methods , Fluorodeoxyglucose F18 , Liver/diagnostic imaging , Liver/surgery , Positron-Emission Tomography/methods , Surgery, Computer-Assisted/methods , Animals , Diagnostic Imaging/methods , Liver/pathology , Radiography , Radiopharmaceuticals , Swine , Swine, Miniature
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