[Needle crystal detector technology in mammography--relationship between image quality and dose depending on beam quality]. / Nadelkristalldetektor-Technologie in der Mammografie--Bildqualität und Dosisverhalten in Abhängigkeit von der Strahlenqualität.

PURPOSE: Compared with traditional CR storage phosphor plates, CR needle crystal technology used in mammography claims to allow for better image quality using a lower dose. Image quality and dose behavior are evaluated for multiple breast thicknesses (simulated with PMMA slabs) on the Agfa DX-M system with needle crystal detectors (HM5.0) and optimized for possible different beam qualities. MATERIALS AND METHODS: Technical image quality was determined using the CDMAM phantom with subsequent "automatic readout" by considering limiting values as specified in the EUREF guideline. For dose, the calculated average glandular dose was used. RESULTS: With CR needle crystal detectors, comparable image quality can already be achieved with an approximately 50% lower dose than required for traditional plates. In addition, CR needle crystal technology makes it possible to also reach the achievable EUREF limit values without exceeding the dose limit values specified in EUREF. It was also found that the usage of W/Rh instead of Mo/Rh is beneficial for a 50 mm as well as 70 mm PMMA with regards to better image quality and a lower dose. CONCLUSION: The needle crystal technology with the Agfa DX-M system supports equivalent CDMAM image quality with an approximately 50% lower AGD compared to powder-based CR. An additional dose reduction can be achieved by using W/Rh instead of Mo/Rh.

[Pathological changes of the hypopharynx in the focus of imaging]. / Pathologische Veränderungen des Hypopharynx im Brennpunkt der Bildgebung.

The spectrum of pathological changes in anatomical sections of the hypopharynx ranges from benign pathologies to hypopharyngeal carcinoma. Beside the clinical status and the endoscopic evaluation performed by ear, nose and throat specialists, imaging techniques play an important role in pre-therapeutic and post-therapeutic diagnostics and in the follow-up of pharyngeal disease patterns, especially for malignant lesions. A conventional x-ray swallow examination, contrast-enhanced multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI), as well as positron emission tomography (PET) and positron emission tomography computed tomography (PET-CT) are applied depending on the medical question and disease. Especially in radiological oncology, it is extremely important in regions which are clinically difficult to assess to determine the exact localization and extent of hypopharyngeal pathologies to plan the optimal therapy for the patient. This article demonstrates the radiological appearance of pathological changes of the hypopharynx and discusses in particular the hypopharynx carcinoma in the focus of pre-therapeutic and post-therapeutic imaging.

[Radiological normal anatomy of the larynx and pharynx and imaging techniques]. / Radiologische Normalanatomie des Larynx und Pharynx sowie bildgebende Techniken.

The larynx and the pharynx represent anatomically as well as functionally a very complex organ which serves as an airway and a nutrition channel. Knowledge of anatomy and anatomical topography is therefore a fundamental basis for the evaluation of any pathological process. Beside the clinical examination and endoscopy performed by ear, nose and throat specialists, imaging techniques play a crucial role in pre-therapeutic and post-therapeutic diagnostics. The radiologist employs a conventional x-ray swallow examination, as well as contrast-enhanced multidetector computed tomography (MDCT), magnetic resonance imaging (MRI), positron emission tomography (PET) and positron emission tomography-computed tomography (PET-CT), depending on the medical problem in question. The following article demonstrates the functional and especially the structural anatomy of the larynx and the pharynx. Furthermore, the broad range of imaging techniques in clinical use is discussed.

[Measurement instead of scoring in rheumatology: new quantitative imaging and processing methods in radiology]. / Messen statt scoren in der Rheumatologie : Neue quantitative Bildgebungs- und -verarbeitungsmethoden der Radiologie.

Many radiological methods to statistically evaluate progression of rheumatic diseases have been presented in recent years. This review article explains their basics as well as the background to the development of "imaging biomarkers" and their potential application in rheumatology.

[Overuse syndromes of the foot]. / Uberlastungssyndrome des Fusses.

Overuse syndromes due to lifestyle problems or sporting activities commonly lead to foot abnormalities. The tendons of the long flexor and extensor muscles are specifically prone to degeneration. The various disorders may be classified by a grading system that includes peritendinous inflammation, degenerative tendon disease, and ruptures. Bone marrow edema is another typical manifestation of overuse. It may be differentiated from inflammatory or traumatic forms of edema by its anatomic distribution. Systematic pattern recognition is based on the concept of musculotendinous and osseous kinetic chains.

[Computer assisted radiological diagnostics of arthritic joint alterations]. / Computerassistierte radiologische Diagnostik arthritischer Gelenkveränderungen.

Computer assisted diagnosis (CAD) schemes are currently used in the field of musculoskeletal diseases to quantitatively assess vertebral fractures, joint space narrowing, andr erosion. Most systems work semi-automatically, i.e. they are operator dependent in the selection of anatomical landmarks. Fully automatic programs are currently under development. Some CAD products have already been successfully used in clinical trials.

High-resolution 3 T MR microscopy imaging of arterial walls.

PURPOSE: To achieve a high spatial resolution in MR imaging that allows for clear visualization of anatomy and even histology and documentation of plaque morphology in in vitro samples from patients with advanced atherosclerosis. A further objective of our study was to evaluate whether T2-weighted high-resolution MR imaging can provide accurate classification of atherosclerotic plaque according to a modified American Heart Association classification. METHODS: T2-weighted images of arteries were obtained in 13 in vitro specimens using a 3 T MR unit (Medspec 300 Avance/Bruker, Ettlingen, Germany) combined with a dedicated MR microscopy system. Measurement parameters were: T2-weighted sequences with TR 3.5 sec, TE 15-120 msec; field of view (FOV) 1.4 x 1.4; NEX 8; matrix 192; and slice thickness 600 microm. MR measurements were compared with corresponding histologic sections. RESULTS: We achieved excellent spatial and contrast resolution in all specimens. We found high agreement between MR images and histology with regard to the morphology and extent of intimal proliferations in all but 2 specimens. We could differentiate fibrous caps and calcifications from lipid plaque components based on differences in signal intensity in order to differentiate hard and soft atheromatous plaques. Hard plaques with predominantly intimal calcifications were found in 7 specimens, and soft plaques with a cholesterol/lipid content in 5 cases. In all specimens, hemorrhage or thrombus formation, and fibrotic and hyalinized tissue could be detected on both MR imaging and histopathology. CONCLUSION: High-resolution, high-field MR imaging of arterial walls demonstrates the morphologic features, volume, and extent of intimal proliferations with high spatial and contrast resolution in in vitro specimens and can differentiate hard and soft plaques.

[Quantitative imaging in rheumatoid arthritis: from scoring to measurement]. / Quantitative Bildgebung bei rheumatoider Arthritis: Vom Scoring zur Messung.

The need of clinical sciences to measure therapy effects on chronic illness led to development, evaluation, and publication of several radiological methods to monitor disease progression of rheumatic diseases. This review article explains the basics and background of scoring and measurement. The radiologist thus learns to report more compactly and to communicate the results more specifically.

The role of multi-slice spiral CT angiography in patient management after endovascular therapy.

OBJECTIVES: To bring out the role of multi-slice spiral CT angiography (MS-CTA) in patient management after endovascular therapy of subclavian artery stenosis. METHODS: Twenty-one consecutive patients with clinically suspected restenosis after endovascular treatment of subclavian artery stenosis or occlusion were included in the study. Eleven patients had been treated with percutaneous transluminal angioplasty (PTA) alone and 10 with PTA and stenting. The mean follow-up period after PTA or stenting was 57 (+/-27 SD) months. CTA was performed using a bolus-triggered high-resolution protocol with biphasic intravenous contrast medium injection. Axial images and curved planar reformations (CPRs) were rated by three readers with regard to patency of supra-aortic vessels. Imaging findings were correlated with a standardized clinical assessment. RESULTS: All examinations were of diagnostic quality. Of 21 referred patients, 7 had significant reobstruction of the treated subclavian artery. Six of the 7 patients with significant restenosis on CTA were treated conservatively (antiplatelet agents), despite 2 of them being symptomatic on the standardized clinical assessment, which showed a sensitivity and specificity of 86% in predicting stenosis. One patient was treated with PTA and stent deployment because of strong subjective suffering. CONCLUSION: MS-CTA is useful for exclusion or quantification of clinically suspected restenosis in carefully selected patients after endovascular therapy where ultrasound is inconclusive and/or contrast-enhanced magnetic resonance angiography is contraindicated.

Quantification of axial alignment of the lower extremity on conventional and digital total leg radiographs.

The purpose was to assess axial alignment of the lower limb using mechanical axis measurements on conventional and digital radiographs. Total-leg radiographs of 24 patients, 8 male and 16 female, with a mean age of 68.6+/-10.2 years, were performed in a standardized anterior-posterior projection and standing position using a conventional and digital phosphor storage film screen radiography system. Knee joint angulation was assessed by measuring the angle between a line drawn from the center of the femoral head to the middle of the femoral condyles and a line drawn from the middle of the tibial condyles to the midpoint of the malleolus. On conventional leg radiographs, line drawing and angle measurement were performed manually with a transparent goniometer. Angle measurement on digital leg radiographs was performed on a PACS workstation using computer-assisted measurement software (IMPAX, AGFA-GEVAERT, Belgium). Evaluation time for both measurements was recorded. We diagnosed 14 varus and 10 valgus angulations of the knee joint. The mean individual difference between axis deviation of conventional digital leg radiographs was 0.93+0.6 degrees (min 0 degrees, max 2 degrees), the mean difference in varus angulation was 1.13+/-0.45 degrees (min 0.3 degrees, max 2 degrees), and the mean difference in valgus angulation was 0.65+/-0.71 degrees (min 0 degrees, max 2 degrees). Angle measurements on conventional and digital radiographs did not show any statistically significant difference. Mean time exposure was 4.9 min/patient for manual and 1.08 min/patient for computer-assisted angle measurement (P<0.001). Computer-assisted angle measurement on digital total-leg radiographs represents a reliable method with no significant angle differences compared to conventional radiographic systems and offers a significantly lower evaluation time.

The "X-Ray RheumaCoach" software: a novel tool for enhancing the efficacy and accelerating radiological quantification in rheumatoid arthritis.

BACKGROUND: Precise diagnosis and follow up treatment of rheumatoid arthritis (RA) requires objective quantification, which is still lacking. For this purpose, radiological analyses are considered to be the most appropriate method. OBJECTIVE: To develop computer assisted quantification software that is particularly applicable to joint scoring in rheumatic disorders. METHODS: 3914 radiographs from hands and feet of 190 patients with RA were collected, expertly examined, analysed, and statistically evaluated. Radiographs were quantified using the conventional Larsen score and the "X-Ray RheumaCoach" (XRRC) software. The XRRC is a Java stand alone application which can support and accelerate, but not fully automate, the scoring procedure in RA. The scorer can apply both the Larsen and the Ratingen-Rau scores. RESULTS: Compared with conventional scoring procedures, the XRRC software accelerated quantification time by approximately 25%. The program, which is now available on the internet free of charge, ran stably and proved to be a consistently valuable tool. CONCLUSIONS: Compared with conventional scoring methods, the XRRC software offers several advantages: (a) structured data analysis and input that minimises variance by standardisation; (b) faster and more precise calculation of sum scores and indices; (c) permanent data storing and fast access to the software's database; (d) the possibility of cross calculation to other scores; (e) "user friendly" technology and a dedicated help program; (f) fast access and data transfer through the internet if desired; and (g) reliable documentation of results in a specially designed printout.

Predictors of long-term results after treatment of iliac artery obliteration by transluminal angioplasty and stent deployment.

PURPOSE: To investigate initial and long-term success rate after percutaneous treatment of iliac artery occlusion with angioplasty and stent deployment. To investigate the influence of vascular comorbidity, lesion length, stent placement and lesion coverage as possible predictors of outcome. METHODS: Between January 1994 and December 1999, 80 iliac recanalizations were performed on 78 patients, median age 61.1 +/- 11.5 (SD) years. All patients were followed up by clinical examinations, duplex ultrasound and intravenous digital subtraction angiography. Mean follow-up time was 2.0 +/- 1.53 (SD) years. Multivariate Cox regression analysis was used to determine the influence of cofactors on patency. RESULTS: One, 2 and 4 years after recanalization, primary patency was 78.1%, 74.5% and 64.0%; secondary patency was 88.8%, 88.8% and 77.9%, respectively. Patients with shorter occlusions, complete lesion coverage and patent ipsilateral femoral arteries had significantly longer patency rates. Complications included inguinal hematoma (n=1), technical failure (n=3) aortic dissection (n=1), embolic occlusions (n=7), gluteal claudication (n=1) and genital necrosis after subsequent urethral surgery in one patient with contralateral occlusion and ipsilateral overstenting of the internal iliac artery with subsequent stenosis. Complications were of permanent clinical significance in seven of 78 (9%) of the patients. In 17 (22%) cases, percutaneous reintervention was performed with angioplasty in the stent (n=16) or deployment of a new stent (n=1). CONCLUSION: Endoluminal stent placement has its place in an interdisciplinary therapeutic approach as a viable therapeutic alternative to major transabdominal bypass surgery and can be performed with comparable complication rates. Patients with short occlusions, patent femoral arteries, and stents covering the entire occlusion have significant longer patency.

Endovascular treatment of aortic type B dissection and penetrating ulcer using commercially available stent-grafts.

OBJECTIVE: The purpose of our study was to investigate the clinical experience and efficiency of translumenl endovascular stent-graft insertion using commercially available vascular endoprotheses. We studied seven patients with descending aortic dissection (type B) and four patients with penetrating aortic ulcer over a median follow-up period of 254 days during the years 1997-2000, using cross-sectional CT to evaluate the extent of the dissection, the distance between the entry tear and the left subclavian artery, and the diameter of the true lumen and the false lumen. CONCLUSION: Endovascular treatment of acute and chronic aortic type B dissections and penetrating ulcer is a minimally invasive method with a low complication rate that could be considered a feasible alternative to surgical repair. Depending on the length of the dissection, we recommend the placement of two overlapping stent-grafts in the thoracic aorta to stabilize the affected thoracic aorta over a longer distance. This might provide a reliable sealing of the entry tear and should prevent further communication between the true lumen and the false lumen.

[Temporomandibular joint pain: radiological diagnosis]. / Der Kiefergelenksschmerz: radiologische Diagnostik.

Pain in the temporomandibular joint is often the result of internal derangement, other causes are traumatic, functional or inflammatory processes. Conventional radiography is indicated in case of suspected trauma or for specialised preoperative measurements to plan the treatment of various facial dysplasias. MRI and CT should be used in the context with the results of clinical investigation and of axiography to differentiate the various functional and morphological abnormalities of this joint.

[Radiologic quantification of joint changes. A methodological overview]. / Radiologische Quantifizierung von Gelenkveränderungen. Ein methodischer Uberblick.

Osteoarthritis as well as rheumatoid arthritis lead to chronical progressive destruction of diseased joints. As aggressive new treatments need to be evaluated, plenty of (semi-) quantitative methods for the radiological joint evaluation had been developed. They lack sufficient reproducibility due to their low objectivity. Modern approaches of computer-assisted radiological quantification should increase the reproducibility and efficiency of radiological scoring. Automatically calculated, computer-assisted measurements of joint space, cartilage- and synovial volume, periarticular assessment of bone mineral density and quantitative analysis of the subchondral plate will have major impact on the radiological routine of the future.

[Pulmonary perfusion, ventilation, and gas exchange during modified cobalt-60 teletherapy of operated on breast carcinomas]. / Lungenperfusion,-ventilation and Gaswechsel unter einer modifizierten Kobalt-60-Teletherapie operierter Mammakarzinome

Post ablationem mammae, 22 patients were exposed to a modified telecobalt-irradiation because of mammary carcinoma. (Tangential pendulum irradiation of the thoracic wall with deflection of the central beam off the pendulum axis, parasternal irradiation with pendulum fields, irradiation of the supraclavicular and axillar area with deflection of the central beam to lateral and cranial directions.) During radiation therapy and up to six months after its termination, periodical pulmonary function tests were accomplished, consisting in a radiogram of the thorax, in spirometric check-up and blood gas analysis, and in an examination of pulmonary perfusion and ventilation using radionuclide techniques. In one patient with metastases to the ribs, the spirographic and nulear-medical ventilatory results changed for the worse in the course of time, whereas the other 21 patients did not show any significantly abnormal alterations at follow-up examinations.