Forensic age assessment by 3.0 T MRI of the wrist: adaption of the Vieth classification.

OBJECTIVES: In order to find a reliable method to correctly assess majority in both sexes by MRI, a study was conducted to evaluate the applicability of the recently presented Vieth classification in wrist MRI, after it had originally been proposed for knee MRI. METHODS: After receiving a positive vote by the ethics committee, the left-hand wrists of 347 male and 348 female volunteers of German nationality in the age bracket 12-24 years were scanned. Before conducting the prospective, cross-sectional examinations, an informed consent was obtained from each volunteer. A 3.0 T MRI scanner was used, acquiring a T1 turbo spin-echo sequence (TSE) and a T2 TSE sequence with fat suppression by spectral presaturation with inversion recovery (SPIR). The images were assessed by applying the Vieth classification. Minimum, maximum, mean ± standard deviation, and median with lower and upper quartiles were defined. Intra- and interobserver agreements were determined by calculating the kappa coefficients. Differences between the sexes were analyzed using the Mann-Whitney U test. RESULTS: By applying the unmodified Vieth classification with corresponding schematics, it was possible to assess majority in both sexes via the epiphyseal-diaphyseal fusion of the distal radius and in males also via the epiphyseal-diaphyseal fusion of the distal ulna. The Mann-Whitney U test implied significant sex-related differences for all stages. For both epiphyses, the intra- and interobserver agreement levels were very good (κ > 0.8). CONCLUSION: If confirmed by further studies, it would be possible to determine the completion of the 18th year of life in both sexes by 3.0 T MRI of the wrist and using the Vieth classification. KEY POINTS: • The Vieth classification allows determining majority in males and females alike based on the distal radius' epiphysis by 3.0 T MRI of the wrist. • The Vieth classification also allows determining majority in males based on the distal ulna's epiphysis by 3.0 T MRI of the wrist, but not in females. • The presented data can be deemed referential within certain discussed boundaries.

Uni-hemispheric hyperperfusion in the early postictal state: case report.

BACKGROUND: In the emergency setting of acute ischemic stroke, seizures have been reported in up to 4% of patients. In the absence of arterial occlusion, seizures may also cause abnormalities in CT perfusion in 78% of cases when the time window from onset to imaging is short. Both hyperperfusion and hypoperfusion in the postictal state have been described. Also, though rarely reported, postictal perfusion changes can be uni-hemispheric. In these cases, perfusion maps should be analyzed thoroughly, since perfusion reconstruction software relies heavily on a "normal" contralateral perfusion status. CASE PRESENTATION: A 39-year-old man was found on the ground with a minor head injury. On admission, his reactions were generally slow, but there were no other neurological symptoms, and blood pressure was low. The patient had a history of primary generalized epilepsy and admitted to dropping off his anti-epileptic medication. He was transferred to the radiological department for imaging but shortly before began to experience generalized onset tonic-clonic seizures which were brought under control by intravenous therapy with 10 mg diazepam. After approximately 15 min, a multimodal CT scan was performed, revealing marked changes in the perfusion of the brain hemispheres and posterior fossa, with sharp delimitation at the midline. Blood gas analysis was congruent with respiratory acidosis. Clinically, the patient remained awake without developing any new symptoms. He gradually recovered over the following 3 h and, against our medical recommendation, discharged himself from the hospital. CONCLUSIONS: To the authors' knowledge, this is the first report of an early postictal state describing sharply delimited uni-hemispheric hyperperfusion and hemispheric alteration of the cerebellum with an equally split rhombencephalon. Surprisingly, these changes were not associated with any focal neurological signs. To prevent misdiagnosis of perfusion alterations in seizures, radiologists and neurologists should be aware of the limitations of CT perfusion maps and software reconstructions. Novel use of CT perfusion reconstruction using peak enhancement helped in identifying the cerebral pathology.

[Response of dermatomyositis with lung involvement to Janus kinase inhibitor treatment]. / Ansprechen einer Dermatomyositis mit Lungenbeteiligung auf eine Januskinase-Inhibitor-Therapie.

We report on a 32-year-old male patient presenting with anti-MDA-5 and anti-Ro52 antibody positive hypomyopathic dermatomyositis (CADM) with clinically leading interstitial pulmonary involvement. Under several immunosuppressive treatment regimens including high-dose steroids, cyclophosphamide, rituximab, immunoglobulins, plasmapheresis, ciclosporin and mycophenolate mofetil, pulmonary involvement was refractory to progressive. Based on the detection of a clear-cut interferon signature by flow cytometric determination of SIGLEC-1 as an interferon-dependent marker, treatment with the Janus kinase inhibitor tofacitinib was initiated. This resulted in a response to treatment with a significant increase in physical performance, an ameliorated skin condition and computed tomographic (CT) morphologically improved interstitial lung disease with overall good tolerability.

Low rates of recanalization for wide-necked aneurysms treated with stenting after balloon-assisted coiling: combination of techniques delivers stable and improved results during follow-up.

PURPOSE: In the treatment of wide-necked aneurysms, stenting may be required after balloon-assisted coiling (BAC) for reconstructing the lumen/flow of the parent artery in cases of coil herniation. The potential benefits and complications of both techniques remain unclear when used together. Our aim was to assess the safety and long-term angiographic outcomes of stenting after BAC. METHODS: Retrospective review of 87 unruptured wide necked aneurysms (in 80 patients) treated with BAC and requiring stent placement at the final stage of the procedure due to coil prolapse. Aneurysm characteristics, technical issues, clinical records, and MR results were assessed. Post-treatment and follow-up angiograms were evaluated by two independent reviewers and categorized as "stable," "further thrombosis," or "recanalization." RESULTS: The mean maximum diameter was 9.1 ± 4.7 mm and aspect ratio 1.20 ± 0.47. Complete and near-complete initial occlusion were observed in 53 (60.9%) and 28 (32.2%) of all treated aneurysms, respectively. Angiographic follow-up (80 aneurysms; mean, 34.68 ± 25.26 months) revealed stability and further thrombosis in 92.4% (74/80). Recanalization was observed in six cases (7.5%, 6/83), four of which were retreated. No significantly different outcomes were found in terms of aneurysm size (p = 0.641). Transient and reversible procedure-related complications occurred in eight (9.2%), minor permanent deficits in 2.3%, and major deficits, including death, in four cases (4.6%). CONCLUSION: Our results suggest that treatment of wide-necked aneuryms with stent placement after BAC yields low recanalization rates and enhanced angiographic outcomes in long-term follow-up.

[Cystic lesions of the pancreas]. / Zystische Tumoren des Pankreas.

Due to the widespread use of computed tomography (CT) and magnetic resonance imaging (MRI) of the abdomen, the incidence of cystic pancreatic lesions as an incidental finding in asymptomatic patients is increasing; however, most of these lesions are less than 2 cm in size at the time of diagnosis making a correct classification difficult. A more differentiated understanding of the pathophysiology of these lesions has been developed during recent years. Technical improvements in imaging techniques have resulted in an increase in image resolution and has enabled radiologists to differentiate between intraductal papillary mucinous neoplasms (IPMN), serous cystic neoplasms (SCN) and mucinous cystic neoplasms (MCN). A correct classification, including the differentiation from malignant pancreatic tumors, can only be achieved by combining the knowledge of lesion pathophysiology and basic epidemiological data, such as age and sex distribution with modern imaging techniques. In conjunction with the correct diagnosis, the radiologist has to decide on the further management of the newly found lesion. This differs greatly depending on the biological behavior, especially the potential for malignant transformation, e.g. in main duct IPMN. This review gives an overview of the different cystic pancreatic lesions, their underlying pathophysiology and imaging characteristics along with recommendations for the further clinical management.

[Nonocclusive mesenteric ischemia (NOMI): Modern diagnostic and therapeutic interventional strategies from a radiological point of view]. / Nichtokklusive mesenteriale Ischämie (NOMI) : Moderne diagnostische und therapeutisch interventionelle Strategien aus radiologischer Sicht.

BACKGROUND: Nonocclusive mesenteric ischemia (NOMI), a rare form of mesenteric perfusion, is associated with a high mortality rate, especially when the diagnosis is delayed. OBJECTIVE: Optimizing the diagnostic workup and the use of modern diagnostic possibilities are needed to reduce mortality and morbidity. RECOMMENDED APPROACH: Recent studies recommend not yet standardized integration of computed tomography into the diagnostic workup. This paper gives an overview of the current data for the diagnosis of NOMI.

Abdominal and pelvic CT: is positive enteric contrast still necessary? Results of a retrospective observational study.

PURPOSE: Evaluation of diagnostic accuracy of abdominal CT depending on the type of enteric contrast agent. METHODS AND MATERIALS: Multislice CTs of 2,008 patients with different types of oral preparation (positive with barium, n = 576; neutral with water, n = 716; and no enteric contrast, n = 716) were retrospectively evaluated by two radiologists including delineation of intestinal segments and influence on diagnosis and diagnostic reliability exerted by the enteric contrast, using a three-point scale. Furthermore, diagnostic reliability of the delineation of selected enteric pathologies was noted. CT data were assigned into groups: oncology, inflammation, vascular, pathology, trauma and gastrointestinal pathology. RESULTS: Delineation of the bowel was clearly practicable across all segments irrespective of the type of enteric contrast, though a slight impairment was observed without enteric contrast. Although delineation of intestinal pathologies was mostly classified "clearly delimitable" more difficulties occurred without oral contrast (neutral/positive/no contrast, 0.8 %/3.8 %/6.5 %). Compared to examinations without enteric contrast, there was a significant improvement in diagnosis that was even increased regarding the reader's diagnostic reliability. Positive opacification impaired detection of mucosal enhancement or intestinal bleeding. CONCLUSION: Water can replace positive enteric contrast agents in abdominal CTs. However, selected clinical questions require individual enteric contrast preparations. Pathology detection is noticeably impaired without any enteric contrast.

Comparison of manual and semi-automatic measuring techniques in MSCT scans of patients with lymphoma: a multicentre study.

OBJECTIVES: Multicentre evaluation of the precision of semi-automatic 2D/3D measurements in comparison to manual, linear measurements of lymph nodes regarding their inter-observer variability in multi-slice CT (MSCT) of patients with lymphoma. METHODS: MSCT data of 63 patients were interpreted before and after chemotherapy by one/two radiologists in five university hospitals. In 307 lymph nodes, short (SAD)/long (LAD) axis diameter and WHO area were determined manually and semi-automatically. Volume was solely calculated semi-automatically. To determine the precision of the individual parameters, a mean was calculated for every lymph node/parameter. Deviation of the measured parameters from this mean was evaluated separately. Statistical analysis entailed intraclass correlation coefficients (ICC) and Kruskal-Wallis tests. RESULTS: Median relative deviations of semi-automatic parameters were smaller than deviations of manually assessed parameters, e.g. semi-automatic SAD 5.3 vs. manual 6.5 %. Median variations among different study sites were smaller if the measurement was conducted semi-automatically, e. g. manual LAD 5.7/4.2 % vs. semi-automatic 3.4/3.4 %. Semi-automatic volumetry was superior to the other parameters (2.8 %). CONCLUSIONS: Semi-automatic determination of different lymph node parameters is (compared to manually assessed parameters) associated with a slightly greater precision and a marginally lower inter-observer variability. These results are with regard to the increasing mobility of patients among different medical centres and in relation to the quality management of multicentre trials of importance. KEY POINTS: • In a multicentre setting, semi-automatic measurements are more accurate than manual assessments. • Lymph node volumetry outperforms all other semi-automatically and manually performed measurements. • Use of semi-automatic lymph node analyses can reduce the inter-observer variability.

Radiological evaluation of the therapeutic response of malignant diseases: status quo, innovative developments and requirements for radiology.

UNLABELLED: In consequence of the rapid development of newer targeted and personalized tumor therapies, radiology as an essential component of the treatment concept of numerous malignant diseases needs to improve in order to adequately capture and evaluate the effects, but also the side effects of these novel therapeutic agents. The early recognition of therapy response or failure is crucial for the optimal planning of the further treatment and can therefore have direct impact on the chances of recovery and the survival time of oncological patients. In previous years, the goal of medical imaging was to just qualitatively assess the increase or reduction in the size of tumors and their metastases, which was often achieved by a simple subjective estimation of the tumor findings by the diagnosing radiologist. Nowadays, radiology is faced with the challenge of evaluating changes during therapy quantitatively and of visualizing therapeutic effects that are more discrete (e. g. necrosis, altered tumor perfusion). The importance of an adequate assessment of therapy response is further underlined by the fact that in these days, a good portion of oncological patients are enrolled in clinical trials, in which the quantitative radiological evaluation of malignant disorders is an important surrogate parameter. On the basis of this development, the demands for radiology to provide more sophisticated assessments of therapy response and documentation of imaging findings have been constantly growing. The following article provides an overview of the established and still widely spread but in particular also the latest imaging modalities and evaluation criteria with regard to oncological diseases as well as of the increasing demands on radiology that result from these developments. Beyond that, future advancements in tumor imaging are taken into account and the new challenges these developments will bring are discussed. KEY POINTS: • In the era of personalized medicine, evaluation criteria that are individually adapted to the respective patient are required.• Radiology needs to substantially contribute to oncological treatment concepts and the evaluation of therapeutic response.

Therapy response evaluation of malignant lymphoma in a multicenter study: comparison of manual and semiautomatic measurements in CT.

PURPOSE: Comparison of manual one-/bi-dimensional measurements versus semi-automatically derived one-/bi-dimensional and volumetric measurements for therapy response evaluation of malignant lymphoma during CT follow-up examinations in a multicenter setting. MATERIALS AND METHODS: MSCT data sets of patients with malignant lymphoma were evaluated before (baseline) and after two cycles of chemotherapy (follow-up) at radiological centers of five university hospitals. The long axis diameter (LAD), the short axis diameter (SAD) and the bi-dimensional WHO of 307 target lymph nodes were measured manually and semi-automatically using dedicated software. Lymph node volumetry was performed semi-automatically only. The therapeutic response was evaluated according to lymphoma-adapted RECIST. RESULTS: Based on a single lymph node, semi-automatically derived multidimensional parameters allowed for significantly more accurate therapy response classification than the manual or the semi-automatic unidimensional parameters. Incorrect classifications were reduced by up to 9.6%. Compared to the manual approach, the influence of the study center on correct therapy classification is significantly less relevant when using semi-automatic measurements. CONCLUSION: Semi-automatic volumetry and bi-dimensional WHO significantly reduce the number of incorrectly classified lymphoma patients by approximately 9.6% in the multicenter setting in comparison to linear parameters. Semi-automatic quantitative software tools may help to significantly reduce wrong classifications that are associated with the manual assessment approach. KEY POINTS: ► Semi-automatic volumetry and bi-dimensional WHO significantly reduce the number of incorrectly classified lymphoma patients ► Manual lymph node evaluation with uni-dimensional parameters is inferior to semi-automatic analysis in a multicenter setting ► Semi-automatic quantitative software tools should be introduced in clinical study evaluation.

Cognitive impairment in HIV infection is associated with MRI and CSF pattern of neurodegeneration.

BACKGROUND AND PURPOSE: Biomarkers as indicators for the progression of human immunodeficiency virus (HIV)-associated neurocognitive disorders (HAND) remain still elusive. We performed a cross-sectional study to analyze the correlation between cognitive impairment, abnormalities in magnetic resonance imaging (MRI), and cerebrospinal fluid (CSF) markers of neurodegeneration in HIV-infected patients. METHODS: We enrolled 94 patients (82 men and 12 women; mean age 45 ± 10 years) with HIV infection, but without opportunistic infections of the CNS. All patients underwent MRI and CSF analysis. The global pattern of white matter signal intensity abnormalities, the index of atrophy, the severity of periventricular white matter abnormalities, and the severity of basal ganglia signal changes were analyzed. We measured CSF markers of neurodegeneration (total tau, phospho-tau, beta-amyloid). The findings of this evaluation were correlated with demographic and infection parameters of the patients in blood and CSF. RESULTS: We found a highly significant correlation between the severity of global brain atrophy, basal ganglia signal changes, and cognitive impairment in HIV-infected patients. Furthermore, cognitive impairment was significantly correlated with total tau, but not with phospho-tau or A-beta-amyloid in CSF analysis. CONCLUSIONS: Our results confirm the significant correlation between MRI changes and cognitive impairment in HIV infection. Furthermore, we could show that global brain atrophy and signal changes in basal ganglia are the typical MRI pattern in HAND. The correlation between cognitive impairment and total tau, but not phospho-tau, supports the hypothesis that HAND are not a subtype of Alzheimer's dementia.

[Hygienic aspects in radiology: what the radiologist should know]. / Hygiene in der Radiologie: Was der Radiologe wissen sollte.

Hospital hygiene is of pivotal importance in radiology departments, where patient throughput is high and staff come into direct contact with both inpatients and outpatients. Every member of the medical and technical team should be aware of all the general and specific hygiene requirements and ensure that they are considered during the daily routine. Failure to do so on the part of just one individual can result in bacterial contamination in the department, exposing both patients and staff to the risk of infection. For the purposes of performing examinations and interventions in infectious patients, the hospital hygienist and medical hygiene officer should introduce appropriate organisational structures to ensure that an appropriate level of hygiene is guaranteed and can be adapted to each patient. This will ensure a minimal degree of disruption to work flow in the radiology department. It is of particular importance that medical and technical staff receive regular hygiene training and instruction. Such training ensures that members of staff are fully aware of the hygiene requirements, are responsibly engaged and that they each possess the expertise and confidence to deal with general and specific hygiene issues in any particular case.

MSCT follow-up in malignant lymphoma: comparison of manual linear measurements with semi-automated lymph node analysis for therapy response classification.

PURPOSE: Assignment of semi-automated lymph node analysis compared to manual measurements for therapy response classification of malignant lymphoma in MSCT. MATERIALS AND METHODS: MSCT scans of 63 malignant lymphoma patients before and after 2 cycles of chemotherapy (307 target lymph nodes) were evaluated. The long axis diameter (LAD), short axis diameter (SAD) and bi-dimensional WHO were determined manually and semi-automatically. The time for manual and semi-automatic segmentation was evaluated. The ref. standard response was defined as the mean relative change across all manual and semi-automatic measurements (mean manual/semi-automatic LAD, SAD, semi-automatic volume). Statistical analysis encompassed t-test and McNemar's test for clustered data. RESULTS: Response classification per lymph node revealed semi-automated volumetry and bi-dimensional WHO to be significantly more accurate than manual linear metric measurements. Response classification per patient based on RECIST revealed more patients to be correctly classified by semi-automatic measurements, e. g. 96.0 %/92.9 % (WHO bi-dimensional/volume) compared to 85.7/84.1 % for manual LAD and SAD, respectively (mean reduction in misclassified patients of 9.95 %). Considering the use of correction tools, the time expenditure for lymph node segmentation (29.7 ± 17.4 sec) was the same as with the manual approach (29.1 ± 14.5 sec). CONCLUSION: Semi-automatically derived "lymph node volume" and "bi-dimensional WHO" significantly reduce the number of misclassified patients in the CT follow-up of malignant lymphoma by at least 10 %. However, lymph node volumetry does not outperform bi-dimensional WHO.

Diagnostic and radiological management of cystic pancreatic lesions: important features for radiologists.

Cystic pancreatic neoplasms are often an incidental finding, the frequency of which is increasing. The understanding of such lesions has increased in recent years, but the numerous types of lesions involved can hinder differential diagnosis. They include, in particular, intraductal papillary mucinous neoplasms (IPMN), serous cystic neoplasms (SCN), and mucinous cystic neoplasms (MCN). Knowledge of their histological and radiological structure, as well as distribution in terms of localization, age, and sex, helps to differentiate such tumours from common pancreatic pseudocysts. Several types of cystic pancreatic neoplasms can undergo malignant transformation and, therefore, require differentiated radiological management. This review aims to develop a broader understanding of the pathological and radiological characteristics of cystic pancreatic neoplasms, and provide a guideline for everyday practice based on current concepts in the radiological management of the given lesions.

[Thoracic radiology in the intensive care unit]. / Thoraxradiologie auf der Intensivstation.

The clinical evaluation of the intensive care unit patient is based upon multiple parameters, including portable chest x-ray examination. Knowledge of the methods, capabilities, and limitations is prerequisite for a legally correct and medically reasonable approach. This report provides basic knowledge about pleural und pulmonary pathologies, e.g., pneumothorax, pleural effusion, atelectasis, aspiration, pneumonia, lung edema, and acute respiratory distress syndrome.

Liver lesion segmentation in MSCT: effect of slice thickness on segmentation quality, measurement precision and interobserver variability.

PURPOSE: To evaluate the effect of slice thickness on semi-automated liver lesion segmentation. MATERIALS AND METHODS: In this retrospective study, liver MSCT scans from 60 patients were reconstructed at a slice thickness of 1.5 mm, 3 mm and 5 mm. 106 liver lesions (8 - 64 mm, mean size 25 ± 13 mm) were evaluated independently by two radiologists using semi-automated segmentation software (OncoTreat®). Lesions were classified as cystic, hypodense and hyperdense according to their contrast-to-noise ratio (CNR). The long axis diameter (LAD), short axis diameter (SAD) and volume were measured. The necessity for manual correction (NOC = relative difference between uncorrected and corrected volume) and the relative interobserver difference (RID) were determined. Precision was calculated in terms of relative measurement deviations (RMD) from the reference standard (mean of 1.5 mm data sets). Wilcoxon test, t-test and intraclass correlation coefficients (ICC) were employed for statistical analysis. All statistical analyses were intended to be exploratory. RESULTS: Regardless of the liver lesion subtype, the NOC was found to be significantly higher for 5 mm than for 3 mm (p = 0.035) and 1.5 mm (p = 0.0002). The RID was consistently low for metric and volumetric parameters with no difference in any of the slice thicknesses for all subtypes (ICC > 0.89). The RMD increased significantly for the LAD, SAD and volume at a slice thickness of 5 mm (p < 0.01), e. g. volume: 0.5 % at 1.5 mm, 5.5 % at 3.0 mm and 7.6 % at 5.0 mm. CONCLUSION: Since the deviations in measurements are significant, and manual corrections made during semi-automated assessment of the liver lesions are considerable, a slice thickness of 1.5 mm, and no more than 3.0 mm, should be used for reconstruction for inconsistently vascularized liver lesions.

[Differential diagnosis and radiological management of cystic pancreatic lesions]. / Differenzialdiagnose und radiologisches Management von zystischen Tumoren des Pankreas.

Cystic pancreatic lesions are often discovered incidentally as an asymptomatic finding, at a rate which is increasing considerably. In recent years the understanding of such tumors has become clearly differentiated. The spectrum of relevant lesions includes in particular the intraductal papillary mucinous neoplasm (IPMN), serous cystic neoplasm (SCN) and mucinous cystic neoplasm (MCN). With certain knowledge of their histological and radiomorphological structure as well as their distribution in terms of location, age and sex, such tumors are easy to differentiate and demarcate from common pancreatic pseudocysts. This also implies the fundamental understanding of complementary endoscopic procedures such as endosonography, which enables aspiration of the content of the cyst. A number of cystic pancreatic lesions have the potential to undergo malignant transformation along the adenoma-carcinoma sequence and therefore necessitate a differentiated approach to their radiological management. This review aims to develop a broad understanding of the pathological and radiomorphological characteristics of cystic pancreatic lesions and provides advice regarding procedures, particularly with respect to incidentally detected lesions.

Bone subtraction CTA for transcranial arteries: intra-individual comparison with standard CTA without bone subtraction and TOF-MRA.

AIM: To evaluate the impact of bone subtraction computed tomography angiography (BS-CTA) for the assessment of transcranial arteries in comparison with standard CTA (S-CTA) without bone removal and time-of-flight magnetic resonance angiography (TOF-MRA). MATERIALS AND METHODS: Cranial unenhanced CT and S-CTA were performed in 53 patients with suspected cerebrovascular disease. BS-CTA datasets were reconstructed from the S-CTA and unenhanced CT source images. TOF-MRA was performed within 24h after CTA on a 1.5 T MRI system. Two radiologists, in consensus, evaluated the segments of the internal carotid artery (C2-C7), the vertebral artery (V4), and the basilar artery for the degree of stenosis. A five-step scale (0-49, 50-69, 70-89, 90-99% and occlusion) for the degree of stenosis was applied for all segments. Wilcoxon's signed rank test was used for statistical analysis. RESULTS: Seven hundred and fifty vessel segments (ICA:636, VA:106, BA:53) were analysed. The degree of stenosis on S-CTA was consistent with TOF-MRA in all segments. BS-CTA showed a trend towards higher stenosis scores in cases of calcified plaques compared to S-CTA (p=0.11) and TOF-MRA (p=0.09), which was not statistically significant. In transcranial segments, BS-CTA revealed equivalent scores compared to S-CTA and TOF-MRA (p=0.25; p=0.20). CONCLUSION: BS-CTA produced similar results to TOF-MRA and S-CTA and can be applied as a non-invasive imaging method for the transcranial arteries. However, BS-CTA shows a trend towards overestimation of the degree of stenosis.

Prediction of lymph node metastases in NSCLC. Three dimensional anatomical parameters do not substitute FDG-PET-CT.

PURPOSE: To distinguish between benign and malignant mediastinal lymph nodes in patients with NSCLC by comparing 2D and semi-automated 3D measurements in FDG-PET-CT. PATIENTS, MATERIAL, METHODS: FDG-PET-CT was performed in 46 patients prior to therapy. 299 mediastinal lymph-nodes were evaluated independently by two radiologists, both manually and by semi-automatic segmentation software. Longest-axial-diameter (LAD), shortest-axial-diameter (SAD), maximal-3D-diameter, elongation and volume were obtained. FDG-PET-CT and clinical/FDG-PET-CT follow up examinations and/or histology served as the reference standard. Statistical analysis encompassed intra-class-correlation-coefficients and receiver-operator-characteristics-curves (ROC). RESULTS: The standard of reference revealed involvement in 87 (29%) of 299 lymph nodes. Manually and semi-automatically measured 2D parameters (LAD and SAD) showed a good correlation with mean intraclass coefficients of .80 and .72, respectively. Semi-automated prediction revealed the highest areas-under-the-ROC-curve for volume (.75, 95%CI: .69-81) and SAD (.75, 95%CI: .70-.81). AUC for LAD and maximal-3D diameter were about .68. Substantially lower accuracies were found for elongation (.57, 95%CI: .50-.64). CONCLUSION: Optimized semi-automated three dimensional parameters by CT cannot approximate reported data on FDG-PET-CT for lymph node assessment in NSCLC. SAD remains the most accurate and at the same time simple to achieve anatomical criterion for definition of NSCLC target lesions.