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A Correction to this paper has been published: https://doi.org/10.1007/s00330-021-07874-1 [ABSTRACT FROM AUTHOR]

A Correction to this paper has been published: https://doi.org/10.1007/s00330-021-07854-5 [ABSTRACT FROM AUTHOR]

A Correction to this paper has been published: https://doi.org/10.1007/s00330-021-07903-z [ABSTRACT FROM AUTHOR]

A Correction to this paper has been published: https://doi.org/10.1007/s00330-021-07829-6 [ABSTRACT FROM AUTHOR]

A Correction to this paper has been published: https://doi.org/10.1007/s00330-021-07795-z [ABSTRACT FROM AUTHOR]

A Correction to this paper has been published: https://doi.org/10.1007/s00330-021-07767-3 [ABSTRACT FROM AUTHOR]

A Correction to this paper has been published: https://doi.org/10.1007/s00330-015-3842-9 [ABSTRACT FROM AUTHOR]

A Correction to this paper has been published: https://doi.org/10.1007/s00330-021-07691-6 [ABSTRACT FROM AUTHOR]

The purpose of this paper is to describe current imaging protocols for MR imaging of the head and neck region and to define results and clinical impact. Depending on the clinical question, different MRI protocols are presented for imaging of the head and neck. The appearance of different pathologic findings on imaging studies and how adapted imaging protocols help to improve differential diagnosis is discussed. In summary, MRI is the method of choice for imaging of the head and neck. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to discuss the capabilities and drawbacks of MR imaging in patients with trauma to the spine and degenerative spinal conditions. In spinal trauma MR imaging is secondary to plain X-ray films and CT because of the greater availability and ease of performance of these techniques and their superior capability for detecting vertebral fractures. Magnetic resonance imaging is useful for detecting ligamentous ruptures and intraspinal mass lesions such as hematoma, and for assessing the state of the spinal cord and prognosis of a cord injury. In degenerative spinal disease the necessity is emphasized of critically evaluating the clinical relevance of any abnormal feature detected, as findings of degenerative pathology are common in individuals without symptoms. Magnetic resonance myelography permits rapid and accurate assessment of the state of the lumbar nerve roots (compressed or not). In the cervical region the quality of the myelographic picture is often degraded in patients with a narrow spinal canal. [ABSTRACT FROM AUTHOR]

This paper is based on 4 years of practical experience with a developmental pre- Digital Imaging and Communications in Medicine (DICOM) picture archiving and communication system (PACS) plus analysis from the respecification study data for a DICOM/HTML PACS replacement. High-performance, but economic, workstations are required within PACS for radiologists to rapidly and accurately report images. For economic reasons such workstations should utilise standard landscape orientation monitors. They must have full Radiology Information System (RIS) integrated reporting functionality to optimise radiologists' work. The workstations must also be capable of displaying request data and both new and associated old images and image reports from multiple modalities. All images should be imported as "folders" according to semi-intelligent "knowledge table" based DICOM 3.0 standard Worklist control exerted by image management servers. This information can be obtained by relevant image lists and decision charts. A description of an optimal standard monitor workstation environment and related issues based on experience and literature review is given. [ABSTRACT FROM AUTHOR]

This paper is a brief introduction to tissue-specific parameters and the utilization of various MR imaging sequences to display these parameters in order to differentiate normal from pathologic tissue and function. The three dominant tissue-specific parameters discussed are proton density, longitudinal relaxation time T1, and transverse relaxation time T2. For the utilization of gradient-echo sequences, transverse relaxation time T2(*) is introduced, more dependent on the environment or tissue interfaces than on the tissue itself. Another tissue-specific parameter is the concentration of macromolecules and their hydration layers as targeted with magnetization transfer imaging. Still another tissue-specific parameter is the chemical environment. Functional parameters that influence the contrast are diffusion, perfusion, flow, or motion. The sequence-related utilization of these tissue-specific parameters start with magnetization preparation as in spectral suppression of fat signal, relaxation-dependent elimination of fat or cerebrospinal fluid (CSF) signal, simple inversion pulse, magnetization transfer saturation, or diffusion weighting. Possible contrast mechanisms for the tissue-specific parameters are discussed for each of the commonly used sequences, whether of spin-echo type or of gradient-echo type, with or without magnetization preparation, conventional single-echo acquisition, or contemporary multiecho acquisition. [ABSTRACT FROM AUTHOR]

There have been remarkable advances in the hardware used for nuclear magnetic resonance imaging scanners. These advances have enabled an extraordinary range of sophisticated magnetic resonance MR sequences to be performed routinely. This paper focuses on the following particular aspects: (a) Magnet system. Advances in magnet technology have allowed superconducting magnets which are low maintenance and have excellent homogeneity and very small stray field footprints. (b) Gradient system. Optimisation of gradient design has allowed gradient coils which provide excellent field for spatial encoding, have reduced diameter and have technology to minimise the effects of eddy currents. These coils can now routinely provide the strength and switching rate required by modern imaging methods. (c) Radio-frequency (RF) system. The advances in digital electronics can now provide RF electronics which have low noise characteristics, high accuracy and improved stability, which are all essential to the formation of excellent images. The use of surface coils has increased with the availability of phased-array systems, which are ideal for spinal work. (d) Computer system. The largest advance in technology has been in the supporting computer hardware which is now affordable, reliable and with performance to match the processing requirements demanded by present imaging sequences. [ABSTRACT FROM AUTHOR]

In this paper two cases of spontaneous pneumomediastinum, occurring in a patient with diabetic ketoacidosis and in a patient with bronchial asthma, are presented. We describe the radiological findings, the differential diagnosis and the important radiographic considerations in establishing the diagnosis. In addition, we discuss the anatomical pathways and review the pathophysiological mechanisms responsible for the development of respiratory spontaneous pneumomediastinum. [ABSTRACT FROM AUTHOR]

X-ray photons which are scattered inside the object slice and reach the detector array increase the detected signal and produce image artifacts as "cupping" effects in large objects and dark bands between regions of high attenuation. The artifact amplitudes increase with scanned volume or slice width. Object scatter can be reduced in third generation computed tomography (CT) geometry by collimating the detector elements. However, a correction can still improve image quality. For fourth generation CT geometry, only poor anti-scatter collimation is possible and a numeric correction is necessary. This paper presents a correction algorithm which can be parameterized for third and fourth generation CT geometry. The method requires low computational effort and allows flexible application to different body regions by simple parameter adjustments. The object scatter intensity which is subtracted from the measured signal is calculated with convolution of the weighted and windowed projection data with a spatially invariant "scatter convolution function". The scatter convolution function is approximated for the desired scanner geometry from pencil beam simulations and measurements using coherent and incoherent differential scatter cross section data. Several examples of phantom and medical objects scanned with third and fourth generation CT systems are discussed. In third generation scanners, scatter artifacts are effectively corrected. For fourth generation geometry with poor anti-scatter collimation, object scatter artifacts are strongly reduced. [ABSTRACT FROM AUTHOR]

Dose values in CT are specified by the manufacturers for all CT systems and operating conditions in phantoms. It is not trivial, however, to derive dose values in patients from this information. Therefore, we have developed a PC-based program which calculates organ dose and effective dose values for arbitrary scan parameters and anatomical ranges. Values for primary radiation are derived from measurements or manufacturer specifications; values for scattered radiation are derived from Monte Carlo calculations tabulated for standard anthropomorphic phantoms. Based on these values, organ doses can be computed by the program for arbitrary scan protocols in conventional and in spiral CT. Effective dose values are also provided, both with ICRP 26 and ICRP 60 tissue-weighting coefficients. Results for several standard CT protocols are presented in tabular form in this paper. In addition, potential for dose reduction is demonstrated, for example, in spiral CT and in quantitative CT. Providing realistic patient dose estimates for arbitrary CT protocols is relevant both for the physician and the patient, and it is particularly useful for educational and training purposes. The program, called WinDose, is now in use at the Erlangen University hospitals (Germany) as an information tool for radiologists and patients. Further extensions are planned. [ABSTRACT FROM AUTHOR]

With the integration of different formerly isolated information systems, such as Hospital Information System (HIS). Radiology Information System (RIS), Picture Archiving and Communication System (PACS) and modalities, we evolve towards an architecture of distributed information processing in radiology, the data being stored in distributed databases. The frontier between the cooperative information systems becomes more subtle than in the past, and it seems more convenient to distinguish the different computer functionalities or services used in radiology than to detail the functions of RIS and PACS. This paper opens with a description of the different computer services used in radiology and how they relate one to another. It also shows how these functionalities could be integrated within a global Radiology Information and Archiving System. Finally, it shows the degree of systems interconnection that can be achieved presently, using the PACS-RIS installation at the University Hospital of Freiburg as an example. [ABSTRACT FROM AUTHOR]

This paper evaluates the management of 31 patients with bile leaks identified over a 7-year period. Leaks complicated cholecystectomy in 19 patients (11 laparoscopic, 8 open), interventional procedures in 10 (including surgery in 1), trauma in one and was spontaneous in one case. Confirmation of the diagnosis typically lagged behind the onset of symptoms (mean for the group 4.2 days), indicating that a high index of suspicion is required in at-risk patients with typical symptoms. These include abdominal pain or distension, fever, bile leaking along a drain, jaundice, abnormal liver function tests and elevated white cell count. Two post-surgical bile leaks required surgical drainage of abdominal cellections. The remainder were successfully managed by non-operative methods including percutaneous drainage, endoscopic retrograde cholangiography with or without sphincterotomy or stent placement and percutaneous stenting. The spontaneous leak and all bile leaks complicating interventional procedures were managed non-operatively, although six patients in this group died due to the underlying malignant pathology. Only the patient with self-inflicted transection of the bile duct died directly from the complications of the bile leak. Although this is a varied, small series, we conclude that the majority of bile leaks can be managed by non-operative techniques. Whilst endoscopy is the primary modality for treatment, percutaneous techniques are crucially important for the management of complex cases and endoscopic failure. [ABSTRACT FROM AUTHOR]

The objective of this paper is to present a new type of volumetric CT which uses the cone-beam technique instead of traditional fan-beam technique. The machine is dedicated to the dento-maxillo-facial imaging, particularly for planning in the field of implantology. The main characteristics of the unit are presented with reference to the technical parameters as well as the software performance. Images obtained are reported as various 2D sections of a volume reconstruction. Also, measurements of the geometric accuracy and the radiation dose absorbed by the patient are obtained using specific phantoms. Absorbed dose is compared with that given off by spiral CT. Geometric accuracy, evaluated with reference to various reconstruction modalities and different spatial orientations, is 0.8-1% for width measurements and 2.2% for height measurements. Radiation dose absorbed during the scan shows different profiles in central and peripheral axes. As regards the maximum value of the central profile, dose from the new unit is approximately one sixth that of traditional spiral CT. The new system appears to be very promising in dentomaxillo-facial imaging and, due to the good ratio between performance and low cost, together with low radiation dose, very interesting in view of large-scale use of the CT technique in such diagnostic applications. [ABSTRACT FROM AUTHOR]

The inguinofemoral region is a crossroads of numerous vascular, nervous and muscular structures. As even the most astute clinician can have difficulty in correctly diagnosing the cause of complaints or a mass in the groin and thigh region, radiological investigation is frequently warranted. For the radiologist involved, knowledge of the anatomy and specific pathology of the groin is essential. This paper deals with the imaging characteristics of the various diseases in the inguinofemoral triangle. Furthermore, this article provides an overview of the role of the various imaging modalities in the evaluation of disease in the groin and upper thigh. A sound working knowledge of groin anatomy and pathology is mandatory. The various imaging modalities used should be considered complementary. [ABSTRACT FROM AUTHOR]

In this paper, the authors present the contribution of CT and MRI to the diagnosis of acute stroke caused by arterial or venous occlusion. The term "early" used in this context means within 6 h of the onset of symptoms. Signs of early ischemic edema are subtle and sometimes difficult to detect by CT or MRI. The purpose of this presentation is to familiarize the clinician and the radiologist with the subtle brain parenchymal changes seen within the first 6 h after onset of symptoms, in order to improve detection of early ischemic infarction and to improve patient care. [ABSTRACT FROM AUTHOR]

Several excellent imaging modalities are available for studying the great vessels of the chest noninvasively. Besides computed tomography (CT), magnetic resonance imaging (MRI) and echocardiography (in particular the transesophageal approach) can accurately depict abnormalities of the thoracic vasculature, and are a valuable substitute for contrast angiography in most circumstances. The aim of this paper is to provide a comprehensive review of the current contribution of CT and MRI to the diagnosis of great vessel pathology of the chest. [ABSTRACT FROM AUTHOR]

There is a large individual variation in human spinal cord and canal size, even in patients of different series studied by the same modality, and no authorized standard method has been established. A comparative study of sagittal diameters of the cervical spinal cord and canal using myelography and MRI is presented. The purposes of this paper are (a) to establish the correction factor (CF) needed for quantitative comparison of the two imaging modalities, and (b) to determine the different factors that may modify the measurement of these diameters. We studied 45 patients with clinical findings compatible with cervical spondilotic myelopathy. In our experience, the CF for accurate correlation of MRI and myelography measurements is 1.32 and depends almost entirely on the radiographic geometry of the myelographic procedure. In addition, there is a variability in the group of MRI results due to imprecision of the pressure-pad measuring/input device of the instrument itself and the sequence performed. [ABSTRACT FROM AUTHOR]

With the advent of ultrasound (US), Doppler and color-flow Doppler imaging, computed tomography (CT), and magnetic resonance angiography (MRA) the ability for non-invasive studies of the abdominal vasculature has been enhanced considerably. In this paper an overview on various abdominal vascular pathologies is presented. Because of the dramatic improvements in image quality, special emphasis is given on the potential role of breathhold contrast-enhanced three-dimensional (3D) MRA which appears to be a versatile non-invasive alternative to conventional angiography. [ABSTRACT FROM AUTHOR]

This technical note describes the use of dynamic MRI in the diagnosis of groin herniations. A review of the anatomy of the groin is presented and 4 representative cases are described. This paper indicates that dynamic MRI can be used to confirm the diagnosis in patients with clinically evident groin herniations. [ABSTRACT FROM AUTHOR]

Pancreatic carcinoma is increasing in its incidence, and despite advances in surgical treatment and chemotherapy, its prognosis remains extremely poor. Realistic therapy is targeted primarily at the relief of obstruction of the biliary tract and the duodenum, as well as the relief of pain. This paper discusses the indications and techniques for palliation and illustrates the critical team approach between radiologist, endoscopist and surgeon. [ABSTRACT FROM AUTHOR]

The aim of this paper is to describe clinical and imaging findings in three patients with ventral dural defects and herniation of the spinal cord or cauda equina. The literature is reviewed and the clinical, radiological and operative findings are compared. Three patients with ventral dural defects of different etiologies are presented. One patient gave a longstanding history of ankylosing spondylitis, the second patient presents 37 years after spinal trauma, and the third patient presents with spontaneous spinal cord herniation. All patients had typically slowly progressive neurological symptoms with multiple hospitalizations until diagnosis was made. Characteristic findings in postmyelographic CT included a ventral or ventrolateral displacement with deformation of the spinal cord or the cauda equina. Sagittal MRI showed this abrupt and localized anterior deviation of the spinal cord or the cauda equina to the posterior portions of a vertebral body with or without a bony vertebral defect optimally. Additionally, due to the ventral displacement of the spinal cord, the dorsal subarachnoid space was relatively enlarged without evidence of an arachnoid cyst, in all patients. Magnetic resonance imaging and postmyelographic CT can diagnose ventral dural defects with spinal cord herniation or nerve root entrapment. Dural defects must be considered in the presence of neurological symptoms in cases of longstanding ankylosing spondylitis, late sequelae of fractures of vertebral bodies, and without history of spinal trauma or surgery. [ABSTRACT FROM AUTHOR]

The sensitivity of MR imaging for detection of pulmonary metastases was evaluated in 23 patients. The MR imaging was performed with T2-weighted turbo-spin-echo (TSE) sequences at 1.5 T. The MR images were compared with spiral volumetric CT which served as the radiological standard. All MR images were interpreted by two radiologists without knowledge of CT findings. The MR imaging technique initially enabled correct identification of altogether 286 of 340 metastases (84 %) resulting in sensitivities of 36 % (size of nodules < 5 mm), 83 % (size of nodules 5-10 mm), 92 % (size of nodules 10-15 mm), and 100 % (size of nodules > 15 mm). Retrospectively with knowledge of CT findings an additional 39 metastases were visible; 15 remained undetected even retrospectively. The results of this paper suggest that MRI still does not have a role for screening for pulmonary metastases. It proves, however, that the incidental diagnosis of a pulmonary lesion on T2-weighted TSE images is highly reliable in representing a pulmonary nodule also visible on CT. However, thus far the malignant nature especially of small nodules detected by MRI (as by CT) remains uncertain even in patients with known malignant neoplasm. [ABSTRACT FROM AUTHOR]

Because of its high intrinsic contrast resolution, magnetic resonance imaging (MRI) has largely replaced computed tomography (CT) in the diagnosis of central nervous system (CNS) diseases, and the use of contrast media in MRI of the CNS has increased progressively, gadolinium chelates being, by far, the most used ones. Our paper will focus on the current indications for contrast-enhanced MR imaging of the CNS and will outline the current role and the future trends in contrast medium (CM) administration in the diagnosis of CNS disease. Gadolinium chelates are now routinely employed in MRI of the brain and spine and have been shown to be relatively safe and well tolerated at standard doses of 0.1 mmol/kg b. w. Although there is general consensus on the usefulness of CM administration in MRI of the CNS, some controversy still persists on the type of CM to be used, on the administration scheme, and on the imaging protocol. The current trend is toward selective employment of CM, the effect of which can be enhanced by Magnetization Transfer (MT) techniques, to increase the sensitivity of the procedure. Double or triple doses of CM can be useful in the detection of small parenchymal lesions with faint enhancement, in functional/dynamic studies of the brain parenchyma and in MR angiography. Gadoteridol (ProHance(R)) closely resembles the features of an optimal CM, because it is non-ionic, has a low osmolality and a low viscosity, and may be particularly efficacious when high doses are required. [ABSTRACT FROM AUTHOR]

MR angiography (MRA) is a technique under ongoing discussion. Its non-invasiveness and sensitivity to flow irregularities make it an investigational technique which is easy to apply but which does not always lead to comprehensive results. It requires special skill to perform and also experience for correct interpretation of the results. The lengthiness of the procedure combined with certain physical properties tends to limit its use to mostly neurovascular applications. With the introduction of ultrafast MRA in conjunction with peripheral bolus-injection of extracellular contrast media, a new approach to the imaging of such regions as the thoracic and abdominal vasculature not to mention other vascular territories has become possible. In this paper, considerations of bolus and measurement optimization and timing protocols for dedicated indications are presented together with an overview on the experience acquired to date for CE-MRA of the carotid artery, mediastinal and pulmonary vessels, abdominal vasculature, and peripheral vessels. The main advantage of ultrafast CE-MRA is that patients are subjected to much more tolerable breath-hold investigations with the result that physiological motion such as peristalsis or major pulsation is minimised. [ABSTRACT FROM AUTHOR]

Techniques developed in computer vision and automated pattern recognition can be applied to assist radiologists in reading mammograms. With the introduction of direct digital mammography this will become a feasible approach. A radiologist in breast cancer screening can use findings of the computer as a second opinion, or as a pointer to suspicious regions. This may increase the sensitivity and specificity of screening programs, and it may avoid the need for double reading. In this paper methods which have been developed for automated detection of mammographic abnormalities are reviewed. Programs for detecting microcalcification clusters and stellate lesions have reached a level of performance which makes application in practice viable. Current programs for recognition of masses and asymmetry perform less well. Large-scale studies still have to demonstrate if radiologists in a screening situation can deal with the relatively large number of false positives which are marked by computer programs, where the number of normal cases is much higher than in observer experiments conducted thus far. [ABSTRACT FROM AUTHOR]

Preoperative diagnosis of primary small intestinal neoplasms can be a challenge for both clinicians and radiologists. As a result of their infrequent occurrence, they invariably present difficult problems in diagnosis and management. These problems are reflected mainly in the delayed treatment and a very poor prognosis for such malignant tumours. Their morphological changes, however, shown in enteroclysis and CT, correlate almost perfectly with the lesions identified in the gross pathological specimens. This ability to accurately image a small intestinal neoplasm, independently of its size, anatomical localization and growing tendency, represents a major improvement in the diagnosis and management of these neoplasms. This paper, based on a large series of patients with primary small intestinal neoplasms, focuses on the recognition of their detailed radiological appearances when evaluated by enteroclysis and CT. [ABSTRACT FROM AUTHOR]

At the end of 1995, a pilot project of a year and a half was successfully completed. The project had two main objectives. On the one hand, the aim was to have a performant analogue X-ray system replaced by a digital system. On the other, modalities of various manufacturers had to be integrated and evaluation had to be done on-screen. Within the scope of QA, this paper deals with a comparative study on the hard- and soft copy evaluation of 90 selected intensive thorax radiographs. A further element in our study was the adjusted work-flow of radiological technical assistants as well as a comparison of dose measurements in conventional and digital systems. [ABSTRACT FROM AUTHOR]

In this paper we compare a semi-automated delineation method with totally manual delineation for area quantification, with respect to efficiency, quality, and intra- and interobserver variability. Liver lesions on 28 CT images were delineated by three observers, twice using completely manual delineation and twice using a semi-automated method. Quantitative comparisons were performed with respect to delineated area and time required for the delineation tasks. Subjective comparisons were performed with respect to efficiency and perceived quality of the semi-automated method. The areas obtained using semi-automated delineation were significantly smaller (11 %) than those obtained using totally manual delineation. Intraobserver and interobserver variability with the semi-automated method were approximately three times lower than with manual delineation. Efficiency of the semi-automated method was subjectively rated favorable, although further improvements are possible. With respect to quality, the semi-automated method was ranked better than the manual method in 73 % of cases. [ABSTRACT FROM AUTHOR]

Conventional post-processing of digital subtraction angiography (DSA) by 3D spiral CT, 3D MRI and 2D DSA is often hampered by extended artefacts due to patient movements during examination. In this paper an image registration procedure prior to the digital subtraction is introduced allowing an enhanced visualization of the contrast agent. The object displacement is detected by analysis of image deformations in small local regions. The motion pattern is used to compute a new synthetic mask of maximum congruence with the contrast medium image. This new mask image is then used in the subsequent subtraction. The algorithm works fully automatically and does not need any interactive placement of landmarks. Results obtained from subtraction of uncorrected and corrected sequences were compared with each other. The registration procedure provided good results in the suppression of subtraction artefacts and in the enhancement of vascular structures. Results are presented from subtraction of 2D and 3D data from CTA, MR mammography and coronary angiography. [ABSTRACT FROM AUTHOR]

The segmental anatomy of the human liver has become a field of increasing interest to radiologists during the past few years. The number of different terminologies which have been used since the topic has been systemically investigated is, however, a source of serious confusion. The present paper describes the reasons why the authors plead for an international working nomenclature which distinguishes a right hemiliver consisting of a right posterior and a right anterior segment, formed by subsegments 6 and 7, and 5 and 8, respectively, and a left hemiliver consisting of a left medial and a left lateral segment, the former corresponding to segment 4, and the latter to subsegments 2 and 3. This basic concept, however, must be carefully tailored to the highly variable individual anatomy of each patient. Furthermore, some aspects of hepatic segmentation are not yet understood and require additional anatomical investigation. [ABSTRACT FROM AUTHOR]

The purpose of this paper was to compare manganese-DPDP (Mn-DPDP) and gadolinium chelate (Gd-DTPA) contrast agents for enhancement of the normal pancreas. A total of 14 patients with focal liver disease underwent Mn-DPDP- and Gd-DTPA-enhanced 1.5 T MR examinations using spoiled gradient-echo (FLASH) technique at two separate times. Contrast agents were injected according to the currently recommended practices; Gd-DTPA was injected as a rapid bolus injection in a dosage of 0.1 mmol/kg, and Mn-DPDP was injected as a slow IV injection in a dosage of 5 mumol/kg. Quantitative region of interest measurements were made in 11 patients, and percent contrast enhancement of the pancreas and pancreas-fat signal-to-noise ratios (SNR) were determined for each agent. Images were also evaluated qualitatively by consensus reading of two investigators and overall scan quality was rated on a scale from 1 (poor) to 4 (very good). Enhancement of the pancreas immediately post Gd-DTPA was significantly higher than 15 min post Mn-DPDP (73.3 vs 36.3%; p = 0.003). On postcontrast images the pancreas-fat SNR measurements were 7.7 (i.e., pancreas higher in signal than fat) and -6.1 for Gd-DTPA and Mn-DPDP, respectively, which was significantly different (p < 0.001). Image quality was rated as 3.1 and 2.5 for Gd-DTPA- and Mn-DPDP-enhanced images, respectively. The normal pancreas enhances significantly more with Gd-DTPA than with Mn-DPDP administered under the conditions of this study. Overall image quality is also greater on the Gd-DTPA-enhanced images. [ABSTRACT FROM AUTHOR]

Staging prostate cancer is a systematic classification of the extent of disease based on clinical and pathological criteria. Despite general acceptance of the TNM staging system, a lot of controversy and uncertainty with respect to staging still exists. This paper gives an overview of different staging modalities and emphasizes the need for incorporation of prognostic factors, such as tumour grade and volume, in the staging system. [ABSTRACT FROM AUTHOR]

In this methodological paper the authors report the stereotactic correlation of different magnetic resonance imaging (MRI) techniques [MR angiography (MRA), MRI, blood bolus tagging (STAR), and functional MRI] in 10 patients with cerebral arteriovenous malformations (AVM) and its application in precision radiotherapy planning. The patient's head was fixed in a stereotactic localization system that is usable at the MR and the linear accelerator installations. By phantom measurements different materials (steel, aluminium, titanium, plastic, wood, ceramics) used for the stereotactic system were tested for mechanical stability and geometrical MR image distortion. All metallic stereotactic rings (closed rings made of massive metal) led to a more or less dramatic geometrical distortion and signal cancellation in the MR images. The best properties-nearly no distortion and high mechanical stability-are provided by a ceramic ring. If necessary, the remaining geometrical MR image distortion can be "corrected" (reducing displacements to the size of a pixel) by calculations based on modeling the distortion as a fourth-order two-dimensional polynomial. Using this method multimodality matching can be performed automatically as long as all images are acquired in the same examination and the patient is sufficiently immobilized. Precise definition of the target volume could be performed by the radiotherapist either directly in MR images or in calculated projection MR angiograms obtained by a maximum-intensity projection algorithm. As a result, information about the hemodynamics of the AVM was provided by a three-dimensional (3D) phase-contrast flow measurement and a dynamic MRA with the STAR technique leading to an improved definition of the size of the nidus, the origin of the feeding arteries, and the pattern of the venous drainage. In addition, functional MRI was performed in patients with lesions close to the primary motor cortex area leading to an improved definition of structures at risk for high-dose application in radiosurgery. The different imaging techniques of MR provide a sensitive, noninvasive, 3D method for defining target volume, critical structures, and for calculating dose distributions for radiosurgery of cerebral arteriovenous malformations, because dose calculation of radiosurgery at sufficient accuracy can be based on 3D MR data of the geometrical conformation of the patient's head. [ABSTRACT FROM AUTHOR]

This paper presents the case of a 36-year-old male with congenitally corrected transposition of great vessels (CTGV). This is a rare cardiac anomaly characterized by atrioventricular and ventriculoarterial discordance, occuriing in less than 1% of all congenital heart diseases. This was diagnosed by echocardiography and MRI. The MRI findings demonstrated cardiac abnormality. [ABSTRACT FROM AUTHOR]

Hamartoma of the breast is a relatively rare, well-circumscribed benign breast tumour that lacks a true capsule, and is composed primarily of dense, fibrous tissue with associated ducts and a variable amount of fat. A typical mammographic finding is a well-delineated, non-homogeneous mass containing mottled densities corresponding to fat, epithelium and connective tissue. Ultrasonographically, hamartoma has a well-circumscribed heterogeneous internal echo pattern corresponding to areas of fat and soft tissue components. This is the first original paper to describe the MRI findings of hamartomas. Mammography and ultrasonography usually enable a diagnosis of hamartoma; however, gadolinium-DTPA enhanced dynamic MRI is the only method in the preoperative management of atypical hamartomas that allows the exclusion of malignancy elsewhere in the breast and hamartoma. [ABSTRACT FROM AUTHOR]

Human exposure to man-made radiation sources is largely due to diagnostic X-ray examinations, and the overall effect depends on the frequency and close of every single procedure. This paper deals with the evaluation of the frequencies of different types of examinations. As the method of investigation in the former German Democratic Republic (GDR) the consumption of X-ray films combined with the statistical registration of all examinations in 3 of 15 districts of the GDR was used for the basic estimation. In former West Germany (FRG) we used data from the cost-covering institutions and from the diagnosis and therapy index of a commercial data bank. As a result in the GDR we discovered, for 17 million people. 13 million examinations, plus .5 million photofluorographs of the lung and 2.5 million dental films. In the FRG the frequency was, for 65 million people, almost 99 million examinations, including 17.5 million dental films. The most frequent X-ray examinations in both parts of the country involve the skeletal system, followed by examinations of the lung. In Germany the examination frequency is high despite the rather broad use of alternative diagnostic methods. A more strictly controlled indication could reduce the number of examinations without loss in quality. [ABSTRACT FROM AUTHOR]

The term micrencephaly refers to apparent diminution of brain volume in the presence of normal calvarial bones. This paper presents a 25-day-old neonate with widespread infarction in the territories of internal carotid arteries due to dessiminated intravascular coagulation who developed micrencephaly over the next 75 days. This type of micrencephaly, which developed well beyond the perinatal period, here labeled as 'acquired micrencephaly' compared to the micrencephaly usually resulting from perinatal or congenital events. [ABSTRACT FROM AUTHOR]

Monochromatic X-ray beam produced by synchrotron radiation may be considered an ideal probe in some fields of diagnostic radiology. In this paper the potential of monochromatic synchrotron radiation X-ray beam in mammography is analyzed. The image quality of four different phantom radiographs, obtained using two different energies equal to 17 and 18 keV, respectively, and a mammographic film/screen system, is assessed. The doses have been determined for both energies by using thermoluminescent dosimeters and a 5-cm thick phantom having a composition of 50% water and 50% fat. The results have been compared with those obtained in the same manner using a mammographic unit equipped with a molybdenum anode, molybdenum filter tube and antiscanner grid. The radiographs obtained with synchrotron radiation show higher contrast and less blur than those obtained with a conventional mammographic system. The average breast doses, 1.55 and 0.80 mGy at 17 and 18 keV, respectively, are comparable with the dose (1.51 mGy) of the conventional technique. [ABSTRACT FROM AUTHOR]

Interest in telemedicine is being driven by the rapid advances in the availability of high-speed, multimedia. telecommunications services, and the ever-growing requirement in medicine to be able to consult experts who may be located in distant hospitals. Research in Berlin in the past 5 years has led to the development and clinical trials of several telemedicine scenarios, involving the use of video conferencing and digital image communication via B-ISDN and other networks. This paper presents an overview of the current state of the technology, the projects carried out, the resulting experience, and an outlook for future trends in telemedicine. [ABSTRACT FROM AUTHOR]

The knee joint is frequently affected by trauma as well as degenerative and inflammatory disorders, involving the internal structures (i.e. ligaments, menisci, cartilage, synovial membrane) and the adjacent bones. Plain radiographs represent an indispensable basis for diagnosis. For further analysis magnetic resonance imaging (MRI) has become the method of choice, and has widely replaced computed tomography, arthrography and stress examinations. Extensive experience has been accumulated in MRI of the knee joint in recent years. In addition, advances in MRI technology have had a major impact on diagnostic accuracy. In this paper, diagnosis of various lesions of the knee joint, such as meniscal and ligamental injuries, aseptic necrosis, lesions of the hyaline cartilage, occult fractures and inflammatory lesions will be discussed. [ABSTRACT FROM AUTHOR]

In I European Radiology i , Ongena and colleagues [[1]] have developed a standardised questionnaire to evaluate the patient perspective on the implementation of artificial intelligence in radiology. The paper found a patient preference for AI to look at all parts of the body, and for AI to do more opportunistic imaging and predictive analysis. [Extracted from the article]

A Correction to this paper has been published: https://doi.org/10.1007/s00330-021-07733-z [ABSTRACT FROM AUTHOR]

A Correction to this paper has been published: https://doi.org/10.1007/s00330-021-07704-4 [ABSTRACT FROM AUTHOR]