Microinfarcts in the Deep Gray Matter on 7T MRI: Risk Factors, MRI Correlates, and Relation to Cognitive Functioning-The SMART-MR Study.

BACKGROUND AND PURPOSE: The clinical relevance of cortical microinfarcts has recently been established; however, studies on microinfarcts in the deep gray matter are lacking. We examined the risk factors and MR imaging correlates of microinfarcts in the deep gray matter on 7T MR imaging and their relation to cognitive functioning. MATERIALS AND METHODS: Within the Second Manifestations of ARTerial disease-Magnetic Resonance (SMART-MR) study, 213 patients (mean age, 68 [SD, 8] years) had a risk-factor assessment, 7T and 1.5T brain MR imaging, and a cognitive examination. Microinfarcts on 7T MR imaging were defined as lesions of <5 mm. Regression models were used to examine the age-adjusted associations among risk factors, MR imaging markers, and microinfarcts. Cognitive function was summarized as composite and domain-specific z scores. RESULTS: A total of 47 microinfarcts were found in 28 patients (13%), most commonly in the thalamus. Older age, history of stroke, hypertension, and intima-media thickness were associated with microinfarcts. On 1.5T MR imaging, cerebellar infarcts (relative risk = 2.75; 95% CI, 1.4-5.33) and lacunes in the white (relative risk = 3.28; 95% CI, 3.28-6.04) and deep gray matter (relative risk = 3.06; 95% CI, 1.75-5.35) were associated with microinfarcts, and on 7T MR imaging cortical microinfarcts (relative risk = 2.33; 95% CI, 1.32-4.13). Microinfarcts were also associated with poorer global cognitive functioning (mean difference in the global z score between patients with multiple microinfarcts versus none = -0.97; 95% CI, -1.66 to -0.28, P = .006) and across all cognitive domains. CONCLUSIONS: Microinfarcts in the deep gray matter on 7T MR imaging were associated with worse cognitive functioning and risk factors and MR imaging markers of small-vessel and large-vessel disease. Our findings suggest that microinfarcts in the deep gray matter may represent a novel imaging marker of vascular brain injury.

Performance of knee image digital analysis of radiographs of patients with end-stage knee osteoarthritis.

OBJECTIVE: Knee Image Digital Analysis (KIDA) is standardized radiographic analysis software for measuring osteoarthritis (OA) characteristics. It was validated in mild OA, but used for severe OA as well. The current goal was to evaluate the performance of KIDA in severe OA. DESIGN: Of 103 patients, standardized radiographs were performed before and one and 2 years after treatment for severe OA. All radiographs were evaluated on subchondral bone density, joint space width (JSW), osteophytes, eminence height, and joint angle, twice within years by the same observer. Part of the radiographs were randomly selected for reevaluation twice within 1 month and evaluation by another observer. The intraclass correlation coefficient (ICC), smallest detectable difference (SDD) and coefficient of variation (CV) were calculated; the SDD and CV were compared to those in mild OA. The relation of severity with KIDA parameters and with observer differences was calculated with linear regression. RESULTS: Intra-observer ICCs were higher in the 98 severe radiographs reanalyzed within 1 month (all >0.8) than the 293 reanalyzed within years (all >0.5; most >0.8) and than inter-observer ICCs (all >0.7). SDDs and CVs were smaller when reanalyzed within a month and comparable to those in mild OA. Some parameters showed bias between readings. Severity showed significant relation with osteophytes and JSW parameters, and with the observer variation in these parameters (all P < 0.04). CONCLUSIONS: KIDA is a well-performing tool also for severe OA. In order to decrease variability and SDDs, images should be analyzed in a limited time frame and randomized order.

Radiographic evaluation of posttraumatic osteoarthritis of the ankle: the Kellgren-Lawrence scale is reliable and correlates with clinical symptoms.

OBJECTIVE: To assess reliability and construct validity of the Kellgren-Lawrence (K&L) scale in posttraumatic ankle osteoarthritis (OA); additionally evaluate the validity of including tibiotalar tilting in the scale. METHOD: One-hundred and fifty ankle radiographs (75 patients, unilateral malleolar fractures) evaluated at average of 18 years after surgery. American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot (HF) score and pain (visual analog scale) were recorded. Grading of OA according to K&L criteria and identification of OA features was performed on standardized radiographs by four physicians. Minimal joint space width, sclerosis, and talar tilt angle were quantified by digital measurements. A modified K&L scale including talar tilting is presented. Validity of original and modified scale was evaluated and expressed as ability to (1) Identify those with clinical symptoms of ankle OA; and (2) Distinguish between different degrees of fracture severity. RESULTS: Inter- and intra-observer reliability of OA assessment according to K&L were good (ICC 0.61 and 0.75). Original and modified K&L grades significantly increased with decreasing AOFAS ankle-HF scores and greater pain. A talar-tilt angle > 2° compared with ≤ 2° in grade 3 was associated with significantly higher pain levels (VAS pain 4.2 vs 1.4, respectively; mean difference 2.8, 95% CI 0.5-5.1). More severe fracture patterns at time of surgery were more often in patients with the highest K&L grades. CONCLUSIONS: The K&L scale is a valid and reliable radiographic grading system for assessment of ankle OA. Inclusion of the talar tilt angle might allow for better differentiation with respect to clinical outcomes.

Delayed gadolinium enhanced MRI of cartilage (dGEMRIC) can be effectively applied for longitudinal cohort evaluation of articular cartilage regeneration.

OBJECTIVE: Delayed gadolinium enhanced magnetic resonance imaging (MRI) of cartilage (dGEMRIC) facilitates non-invasive evaluation of the glycosaminoglycan content in articular cartilage. The primary aim of this study was to show that the dGEMRIC technique is able to monitor cartilage repair following regenerative cartilage treatment. DESIGN: Thirty-one patients with a focal cartilage lesion underwent a dGEMRIC scan prior to cartilage repair surgery and at 3 and 12 months follow-up. At similar time points clinical improvement was monitored using the Knee injury and Osteoarthritis Outcome Score (KOOS) and Lysholm questionnaires. Per MRI scan several regions-of-interest (ROIs) were defined for different locations in the joint. The dGEMRIC index (T1gd) was calculated for each ROI. Repeated-measures analysis of variance (RMANOVA) analysis was used to evaluate improvement in clinical scores and MRI T1gd over time. Also regression analysis was performed to show the influence of local repair on cartilage quality at distant locations in the knee. RESULTS: Clinical scores and the dGEMRIC T1gd per ROI showed a statistically significant improvement (P < 0.01), from baseline, at 12 months follow-up. Also, improvement from baseline in T1gd of the ROI defining the treated cartilage defect showed a direct relationship (P < 0.007) to the improvement of the T1gd of ROI at other locations in the joint. CONCLUSIONS: The dGEMRIC MRI protocol is a useful method to evaluate cartilage repair. In addition, local cartilage repair influenced the cartilage quality at other location in the joint. These findings validate the use of dGEMRIC for non-invasive evaluation of the effects of cartilage regeneration.

Cerebral small-vessel disease and progression of brain atrophy: the SMART-MR study.

OBJECTIVES: To investigate whether severity and progression of periventricular and deep white matter lesions (WML) and lacunar infarcts were associated with progression of brain atrophy. METHODS: Within the SMART-MR study, a prospective cohort on MRI changes in patients with symptomatic atherosclerotic disease, 565 patients (57 ± 9 years) without large infarcts had vascular screening and 1.5 T MRI at baseline and after a mean follow-up of 3.9 years. With automated brain segmentation, total brain, cortical gray matter, ventricular, and WML volumes were estimated and expressed relative to intracranial volume (%). Lacunar infarcts were rated manually. RESULTS: Using linear regression analyses adjusted for demographics and vascular risk factors, periventricular WML volume at baseline was associated with greater decrease in cortical gray matter volume (B = -1.73%, 95% confidence interval [CI] -3.15% to -0.30%, per 1% WML volume increase) and greater increase in ventricular volume (B = 0.12%, 95% CI 0.04% to 0.20%). Progression of periventricular WML volume corresponded with a greater decrease in cortical gray matter volume (B = -0.45%, 95% CI -0.9% to 0%) and greater increase in ventricular volume (B = 0.15%, 95% CI 0.1% to 0.2%). Presence of lacunar infarcts was associated with greater decline in total brain volume (B = -0.25%, 95% CI -0.49% to -0.01%) and progression of lacunar infarcts with a greater decrease of total brain (B = -0.30%, 95% CI -0.59% to 0.01%) and cortical gray matter volume (B = -0.81%, 95% CI -1.43% to -0.20%). CONCLUSIONS: In patients with symptomatic atherosclerotic disease, presence and progression of periventricular WML and lacunar infarcts is associated with greater progression of brain atrophy independent of vascular risk factors.

dGEMRIC as a tool for measuring changes in cartilage quality following high tibial osteotomy: a feasibility study.

OBJECTIVE: The high tibial osteotomy (HTO) is an effective strategy for treatment of painful medial compartment knee osteoarthritis. Effects on cartilage quality are largely unknown. Delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) enables non-invasive assessment of cartilage glycosaminoglycan content. This study aimed to evaluate if dGEMRIC could detect relevant changes in cartilage glycosaminoglycan content following HTO. DESIGN: Ten patients with medial compartment osteoarthritis underwent a dGEMRIC scan prior to HTO, and after bone healing and subsequent hardware removal. A dGEMRIC index (T1Gd) was used for changes in cartilage glycosaminoglycan content, a high T1Gd indicating a high glycosaminoglycan content and vice versa. Radiographic analysis included mechanical axis and tibial slope measurement. clinical scores [knee osteoarthritis outcome scale (KOOS), visual analogue score (VAS) for pain, Knee Society clinical rating system (KSCRS)] before, 3 and 6 months after HTO and after hardware removal were correlated to T1Gd changes. RESULTS: Overall a trend towards a decreased T1Gd, despite HTO, was observed. Before and after HTO, lateral femoral condyle T1Gd was higher than medial femoral condyle (MFC) T1Gd and tibial cartilage T1Gd was higher than that of femoral cartilage (P < 0.001). The MFC had the lowest T1Gd before and after HTO. Clinical scores all improved significantly (P < 0.01), KOOS Symptoms and QOL were moderately related to changes in MFC T1Gd. CONCLUSIONS: dGEMRIC effectively detected differences in cartilage quality within knee compartments before and after HTO, but no changes due to HTO were detected. Hardware removal post-HTO seems essential for adequate T(1)Gd interpretation. T(1)Gd was correlated to improved clinical scores on a subscore level only. Longer follow-up after HTO may reveal lasting changes. ClinicalTrials.gov registration ID: NCT01269944.

Influence of variation in semiflexed knee positioning during image acquisition on separate quantitative radiographic parameters of osteoarthritis, measured by Knee Images Digital Analysis.

OBJECTIVE: The clinical application of quantitative measurement of separate radiographic parameters of knee osteoarthritis (OA) might be hampered by a lack of reproducible semiflexed joint positioning during acquisition of radiographs. The influence of systematic variations in knee positioning on measurement of separate quantitative radiographic parameters was studied. METHODS: Five components of knee position during radiographic acquisition (beam height, lower and upper leg extension, internal rotation, and lateral shift) were systematically varied within a clinically relevant range, using three cadaver legs. The influence of these variations on the measurement of the separate quantitative radiographic parameters by Knee Images Digital Analysis (KIDA) was evaluated. Significant changes were validated in vivo. Changes were compared with differences during 2-year follow-up in a radiographic progression cohort of early OA. RESULTS: Systematic variation in upper and lower leg extension induced changes in the measurement of joint space width (JSW). Lower leg extension also influenced osteophyte area and eminence height measurement. Also bone density measurement was influenced by variation in all five position components. Variations were of clinical relevance compared with 2-year differences in knees with radiographic progression, and were confirmed in vivo. CONCLUSIONS: Variations in semiflexed knee positioning, which are considered to occur easily during image acquisition in trials and clinical practice despite standardization, are of significant influence on the quantitative measurement of most separate radiographic parameters of OA using KIDA. The additional value of quantitative measurement might improve significantly by better standardization during radiographic acquisition; with radiography still being the gold standard for structure-modification in OA.

Evaluation of separate quantitative radiographic features adds to the prediction of incident radiographic osteoarthritis in individuals with recent onset of knee pain: 5-year follow-up in the CHECK cohort.

OBJECTIVE: Detailed radiographic evaluation might enable the identification of osteoarthritis (OA) earlier in the disease. This study evaluated whether and which separate quantitative features on knee radiographs of individuals with recent onset knee pain are associated with incidence of radiographic OA and persistence and/or progression of clinical OA during 5-year follow-up. METHOD: From the Cohort Hip & Cohort Knee study participants with knee pain at baseline were evaluated. Radiographic OA development was defined as Kellgren & Lawrence (K&L) grade ≥ II at 5-year follow-up. Clinical OA was defined as persistent knee pain and as progression of Westen Ontario & McMaster Universities Osteoarthritis index (WOMAC) pain and function score during follow-up. At baseline radiographic damage was determined by quantitative measurement of separate features using Knee Images Digital Analysis, and by K&L-grading. RESULTS: Measuring osteophyte area [odds ratio (OR) =7.0] and minimum joint space width (OR=0.7), in addition to demographic and clinical characteristics, improved the prediction of radiographic OA 5 years later [area under curve receiver operating characteristic=0.74 vs 0.64 without radiographic features]. When the predictive score (based on multivariate regression coefficients) was larger than the cut-off for optimal specificity, the chance of incident radiographic OA was 54% instead of the prior probability of 19%. Evaluating separate quantitative features performed slightly better than K&L-grading (AUC=0.70). Radiographic characteristics hardly added to prediction of clinical OA. CONCLUSION: In individuals with onset knee pain, radiographic characteristics added to the prediction of radiographic OA development 5 years later. Quantitative radiographic evaluation in individuals with suspected OA is worthwhile when determining treatment strategies and designing clinical trials.

Radiographic features of knee and hip osteoarthritis represent characteristics of an individual, in addition to severity of osteoarthritis.

OBJECTIVE: To evaluate to what extent radiographic features of knees and hips that are normally related to osteoarthritis (OA) represent characteristics of an individual in addition to OA severity. METHODS: We studied a cohort of individuals (n = 1002) with very early signs of hip and knee OA, from the Cohort Hip and Cohort Knee (CHECK) study. Baseline radiographs were evaluated by digital analyses, using Holy's and Knee Images Digital Analysis (KIDA) software, providing distinct quantitative measures of radiographic OA features. In addition, conventional Kellgren and Lawrence (KL) grading was performed. Digital parameters were evaluated for correlations within participants between contralateral (left vs. right hip and left vs. right knee), ipsilateral (e.g. left hip vs. left knee), and diagonal joints (e.g. left hip vs. right knee). Analyses were performed separately for participants with KL grade 0-I and those with evident radiographic OA (KL grade II-III). Regression analyses determined whether demographic characteristics were related to radiographic features. RESULTS: Correlations between digital parameters and KL grade were moderate, and within each KL grade large variation was found. Within participants strong correlations were found for digital parameters between joints in individuals with KL grade 0-I (R = 0.60-0.89), strongest for contralateral comparison, but no statistically significant correlations were found for participants with KL grade II-III. The demographic characteristics age, gender, height, and weight were, to a limited extent (R(2) = 0.01-0.20) but statistically significant, related to radiographic characteristics. CONCLUSION: Using digital analyses of radiographic OA, strong correlations between joints within participants were found. These correlations diminished when OA became evident. This has implications for monitoring joint damage in (very) early OA with digital analyses.

Location and progression of cerebral small-vessel disease and atrophy, and depressive symptom profiles: the Second Manifestations of ARTerial disease (SMART)-Medea study.

BACKGROUND: The 'vascular depression' hypothesis states that brain changes located in frontal-subcortical pathways increase vulnerability for specific depressive symptom profiles, but studies examining locations of small-vessel and degenerative changes with individual symptoms are scarce. We examined whether location and progression of white-matter lesions (WMLs), lacunar infarcts and atrophy were associated with motivational and mood symptoms in patients with symptomatic atherosclerotic disease. METHOD: In 578 patients [63 (s.d.=8) years] of the Second Manifestations of ARTerial disease (SMART)-Medea study, volumes of WMLs and atrophy and visually rated infarcts were obtained with 1.5 T magnetic resonance imaging at baseline and after 3.9 (s.d.=0.4) years' follow-up. Depressive symptoms were assessed with Patient Health Questionnaire-9 at follow-up and categorized into motivational and mood symptoms. RESULTS: Regression analyses adjusted for age, gender, education, Mini-Mental State Examination, physical functioning, antidepressant use and vascular risk factors showed that location in mainly deep white-matter tracts and progression of WMLs were associated with symptoms of anhedonia, concentration problems, psychomotor retardation and appetite disturbance. Lacunar infarcts in deep white matter were associated with greater motivational [Incidence rate ratio (IRR) 1.7, 95% confidence interval (CI) 1.2-2.4] and mood (IRR 1.7, 95% CI 1.1-2.6) sumscores, and with symptoms of psychomotor retardation, energy loss and depressed mood; lacunar infarcts in the thalamus were associated with psychomotor retardation only. Cortical atrophy was associated with symptoms of anhedonia and appetite disturbance. Excluding patients with major depression did not materially change the results. CONCLUSIONS: Our findings suggest that disruption of frontal-subcortical pathways by small-vessel lesions leads to a symptom profile that is mainly characteristic of motivational problems, also in the absence of major depression.

Feasibility of bone density evaluation using plain digital radiography.

OBJECTIVE: For the radiographic evaluation of subchondral bone changes (sclerosis) in osteoarthritis (OA), bone density (BD) is commonly subjectively assessed. BD evaluation using plain digital radiography might be influenced by acquisition and post-processing (PP) settings. Objective of this study was to evaluate the effects of these settings on the measurement of BD using digital radiographs. METHODS: A bone density standard (BDS) of hydroxyapatite (HA) mimicked a BD range of 1.0-5.75 g/cm(2). Digital radiographs were acquired with variation in acquisition settings, and with clinical and minimal PP. An aluminum step wedge served as an internal reference to express the gray values of the BDS in mm aluminum equivalents (mmAl). The relation (R(2)) between actual BD and BD normalized to the reference wedge was evaluated with linear regression analyses for radiographs with variations in PP and acquisition settings. Precision of BD measurement of the BDS was evaluated for application in clinical practice. RESULTS: The correlation between actual BD and BD normalized to the reference was improved by changing PP from clinical (R(2)=0.96) to minimal (R(2)=0.98). Higher tube voltage [kilovolt (kV)] improved the correlation further. Even for clinical PP, average standard deviation (SD) was 0.97 mmAl, much smaller than the change of 2.51 mmAl clinically observed in early OA, which implies the feasibility of BD measurements on digital radiographs. CONCLUSION: Changing PP and acquisition settings in clinical practice can have profound effect on outcome. If done with care, accurate BD measurement is feasible using plain digital radiography.

Pelvic rotation and tilt can cause misinterpretation of the acetabular index measured on radiographs.

BACKGROUND: Radiographic diagnosis and followup studies of developmental dysplasia of the hip are commonly performed by measuring the acetabular index on radiographs using Hilgenreiner's method. The outcome of the measurement, however, depends on the orientation of the subject's pelvis relative to the xray source. The influence of pelvic rotation and tilt on the measurement error has been evaluated separately but not in combination. QUESTIONS/PURPOSES: We asked whether (1) combinations of pelvic rotation and tilt introduced systematic error in acetabular index measurement in a reproducible way, and (2) ratios proposed to evaluate either pelvic rotation (R(rotation)) or pelvic tilt (R(tilt)) are influenced by pelvic tilt and rotation, respectively. METHODS: Radiographic measurements of the acetabular index, R(rotation), and R(tilt) were performed on digitally reconstructed radiographs of one high-resolution three-dimensional CT dataset with various combinations of pelvic rotation and tilt. RESULTS: For rotations and tilt up to 12°, the average systematic errors in the acetabular index varied from -8.8° to 4.5°. Negative and positive error values can be interpreted as underestimations and overestimations of the acetabular index, respectively. Errors in acetabular index measurements were acceptable for R(rotation) values between 1.0 and 2.0 and R(tilt) values between 1.1 and 1.8. CONCLUSIONS: To limit the systematic error in assessing the acetabular index caused by pelvic misalignment, we recommend only radiographs acquired with ± 4° rotation and ± 4° tilt be considered acceptable.

Combined effect of cerebral hypoperfusion and white matter lesions on executive functioning - The SMART-MR study.

BACKGROUND/AIMS: It has been hypothesized that cerebral hypoperfusion may contribute to cognitive deterioration. Patients with white matter lesions (WML) may be more vulnerable to a decrease in cerebral blood flow (CBF) due to an impaired autoregulation. We investigated the association between CBF and cognitive performance and whether WML modified this relation. METHODS: Within the SMART-MR study, a cohort study among patients with manifest arterial disease, cross-sectional analyses were performed in 472 patients (mean age 57 +/- 10 years, 77% male). Total CBF was measured with magnetic resonance angiography in the internal carotid arteries and basilar artery, and was expressed per 100 ml brain volume. Neuropsychological tests assessing executive functioning and memory were performed and composite scores were calculated. We used linear regression analyses, adjusted for age, sex, education and intelligence, to investigate the association between CBF and cognitive performance. RESULTS: We found that WML modified the association between CBF and executive functioning (p for interaction <0.001); the association between lower CBF and worse performance on executive functioning became stronger and significant with increasing volumes of WML. Lower CBF was not associated with worse memory. CONCLUSION: Our results suggest that a combination of lower CBF and WML may impair executive functioning but not memory.

The influence of different types of stent grafts on aneurysm neck dynamics after endovascular aneurysm repair.

OBJECTIVE: Dynamic imaging provides insight into aortic shape changes throughout the cardiac cycle. These changes may be important for proximal aortic stent graft fixation, sealing and durability. The objective of this study is to analyse the influence of different types of stent grafts on dynamic changes of the aneurysm neck. METHODS: Pre- and postoperative electrocardiography (ECG)-gated computed tomographic angiography (CTA) scans were obtained in 30 abdominal aortic aneurysm (AAA) patients, 10 each from three different types of stent grafts (10 Talent, Endurant, and Excluder). Each dynamic CTA dataset consisted of eight reconstructed images over the cardiac cycle. Aortic area and radius changes during the cardiac cycle were determined at two levels: (A) 3 cm above and (B) 1 cm below the lowermost renal artery. Radius changes were measured over 360 axes, and plotted in a polar plot. An ellipse was fitted over the plots to determine radius changes over the major and minor axis for assessment of the asymmetric aspect and most prominent direction of distension. RESULTS: Baseline characteristics did not differ significantly between the three groups. Preoperatively, the aortic area increased significantly (p < 0.001) over the cardiac cycle in all patients at both levels: (A) mean increase 8.3 +/- 4.1% (2.0-17.3%); (B) mean increase 5.9 +/- 4.2% (1.9-12.4%). The postoperative aortic area increase over the cardiac cycle did not differ significantly from preoperative increases: (A) mean increase 9.9 +/- 2.2% (4.4-20.0%); (B) mean increase 7.7 +/- 2.4% (3.8-12.4%). The difference between radius change over the major and minor axis was significant both pre- and postoperatively for all three stent grafts, indicating asymmetric distension. Suprarenal, the distension showed a tendency to right-anterior and infrarenal to left-anterior. The distension and direction of the aortic expansion was preserved after stent grafting. There were no differences between the three types of stent grafts regarding their impact on the aortic distension or direction of this distension. CONCLUSION: The aorta expands significantly and asymmetrically throughout the cardiac cycle. After implantation of abdominal aortic stent grafts, the aortic distension and direction of distension remain equally preserved in all three groups. The three stent graft types studied seem to be able to adapt to the asymmetric dynamic aortic shape changes.

Validation of a Novel Semiautomated Segmentation Method for MRI Detection of Cartilage-Related Bone Marrow Lesions.

OBJECTIVE: To determine the relationship of bone marrow lesions (BMLs) with phenomena such as clinical symptoms, histological subchondral bone damage, and development of osteoarthritis, a reliable and reproducible method to localize and quantify BMLs accurately is indispensable. Therefore, the goal of the current study was to develop and validate a novel semiautomated segmentation method based on the KNN classification technique on T2-weighted (T2w) SPIR and proton density-weighted (PDw) magnetic resonance images (MRIs), as this would provide an accurate, reliable, and reproducible tool. MATERIALS AND METHODS: Twenty PDw and T2w SPIR MRIs were selected and manually segmented as a learning set for the software system. The manual segmentations were considered the gold standard. Automated segmentation based on the KNN classification technique was carried out on the same MRIs. To determine the accuracy and validity of the system, the automated segmentations were compared to the gold standard using the Dice Similarity Index (DSI). RESULTS: The KNN classification system resulted both visually and statistically in an accurate segmentation of BMLs on T2w SPIR MRIs with an excellent mean optimal DSI of 0.702 (±0.202; range, 0.409-0.908). Elimination of specific areas smaller than 10 voxels improved the accuracy. The accuracy was independent of BML size. The segmentation of BMLs on PDw MRIs was less reliable with a mean optimal DSI of 0.536 (±0.156). CONCLUSION: Although the applicability of this method is limited on PDw MRIs, the KNN classification system provides an accurate, reliable, and reproducible tool for semiautomated segmentation of BMLs in T2w SPIR MRIs of the knee.

Blood pressure and white matter lesions in patients with vascular disease: the SMART-MR study.

White matter lesions (WML) are a frequent finding on brain magnetic resonance imaging scans. Elevated blood pressure (BP) is consistently identified as risk factor for WML. However, it is unknown whether BP still is associated with WML in patients with manifest vascular disease. The aim of this cross-sectional study was to investigate associations between BP and WML in patients with manifest vascular disease. A total of 1030 patients with vascular disease (cerebrovascular disease (23%), coronary heart disease (59%), peripheral arterial disease (23%), abdominal aortic aneurysm (9%)) from the Second Manifestations of Arterial Disease study were included. WML volume was calculated using an automated quantitative volumetric method and subsequently divided into quartiles. We investigated associations between BP and WML and examined whether relations between BP and WML were modified by the localization of the symptomatic site or presence of diabetes. Participants had a mean age of 58.7 years. Median volume of WML was 1.70 ml. Mean BP was 141/82 mmHg and 69% suffered hypertension. No significant associations between systolic BP, diastolic BP, mean arterial pressure (MAP) or hypertension presence and moderate or large WML volumes were present. The relation between BP and WML was not modified by the localization of vascular disease or diabetes presence. Among patients with manifest vascular disease, BP was not associated with the presence of WML, irrespective of the presence of diabetes or the localization of vascular disease.

Aortic pulsatile distention in young healthy volunteers is asymmetric: analysis with ECG-gated MRI.

OBJECTIVE: Knowledge of aortic shape changes throughout the cardiac cycle can offer improved understanding of vascular pathophysiology and may have crucial impact on stentgraft design and EVAR durability. To understand underlying mechanisms of dynamic changes in aortic aneurysm (neck) morphology, the undiseased aorta has to be studied first. Objective is to visualize and characterize dynamic aortic shape changes in young healthy volunteers. MATERIALS AND METHODS: Fifteen healthy volunteers (7 male, median age 24 year, range 18-28) were scanned using ECG-gated balanced gradient-echo MRI, with 16 reconstructed cardiac phases. Transverse scans were made perpendicular to the aorta: (A) above the aortic bifurcation, (B) infrarenal, (C) juxtarenal, (D) suprarenal and (E) above the celiac trunk. After aortic lumen segmentation, radial changes during the cardiac cycle were measured, from the center of mass, over 360 degrees, and plotted. An ellipse was fitted over the distention plots, yielding the direction (AP:0 degrees, Right: -90 degrees, Left: 90 degrees ) and magnitude of radius change over the major and minor axis. RESULTS: Asymmetric distention was observed, with a variable rate per patient and level. Radius changes decreased from the proximal to distal aorta. Radius changes over the major axis ranged from 14% to 41%. At level A mean change in radius over the minor versus major axis was 1.4+/-0.2mm (17%) versus 1.6+/-0.2mm (20%), respectively. At B 1.7+/-0.4mm (22%) versus 2.0+/-0.4mm (25%), at C 1.7+/-0.4mm (22%) versus 2.2+/-0.4mm (27%) at D 2.0+/-0.4mm (25%) versus 2.4+/-0.5mm (30%) and at E 2.2+/-0.3mm (27%) versus 2.6+/-0.3mm (32%). Mean orientation of the major axis was (A) 0.8+/-23.3 degrees , (B) 1.8+/-31.3 degrees , (C) 14.0+/-15.5 degrees , (D) -28.8+/-48.0 degrees and (E) 18.4+/-22.2 degrees. CONCLUSIONS: Aortic pulsatile distention in young healthy volunteers is asymmetric, with up to 41% radius change in the descending aorta. This study offers a frame of reference for dynamic imaging studies in patients with aortic pathology and provides a valuable non-invasive tool for future research into aortic distention, development and localization of vascular pathology.

Digital scoring of haemophilic arthropathy using radiographs is feasible.

Radiographs are important tools to evaluate structural changes in many joint diseases. In the case of haemophilic arthropathy (HA), the Pettersson score is widely used. The rising of digital radiography enables evaluation of these changes in a more quantitative and detailed manner, potentially improving diagnosis and follow-up. The aim of this study was to evaluate whether digital image analysis in the case of HA is feasible, using a presently available method for radiographic changes in knee osteoarthritis (OA), knee image digital analysis (KIDA). Sixty-two knee radiographs were scored according to Pettersson and with KIDA, each by two independent observers. Inter-observer variation and correlations between the two scoring methods were determined. The inter-observer variation was smaller for KIDA than for Pettersson and for KIDA not significantly different from evaluation of OA joints. Good correlations were found for the two methods where comparison of parameters was appropriate. Importantly, for each of the parameters within one point in the ordinal Pettersson score, a large window still existed in the continuous KIDA grading. Digital analysis of radiographs to quantify joint damage in HA is feasible. The use of continuous variables, as used in a digital method such as KIDA has the advantage that it enables objective and much more sensitive detection of small changes than by use of an ordinal analogue method such as the Pettersson score. Based on the present results, it would be worthwhile to adapt the KIDA method for the specific characteristics of HA and to extend the method to elbow and ankle radiographs.

Cerebral perfusion in relation to cognitive function and type 2 diabetes.

AIM/HYPOTHESIS: Underlying mechanisms for decreased cognitive functioning in patients with type 2 diabetes are unclear. In the general population, cerebral hypoperfusion is a risk factor for cognitive dysfunction and dementia. Reduced cerebral perfusion may account for cognitive impairments in diabetic patients relative to controls. METHODS: A total of 98 patients with type 2 diabetes and 47 control participants underwent neuropsychological evaluation. Total cerebral blood flow (CBF) was assessed non-invasively by measuring the volume flow in the internal carotid arteries and basilar artery with two-dimensional phase-contrast magnetic resonance angiography. Relative total CBF, a measure of mean total cerebral perfusion, was obtained by expressing total CBF per 100 ml brain parenchyma volume. RESULTS: Patients with type 2 diabetes performed worse on neuropsychological tests (p < 0.05). Total CBF per 100 ml brain parenchyma volume did not differ between participants with and without diabetes (difference -2.3 ml min(-1) 100 ml(-1); 95% CI -6.0, 1.3). In the entire group, total CBF per 100 ml brain parenchyma volume was positively associated with cognitive functioning (0.09 SD increase in composite z score per 10 ml min(-1) 100 ml(-1) increase in relative total CBF). This association was not affected by type 2 diabetes. CONCLUSIONS/INTERPRETATION: Although total CBF per 100 ml brain parenchyma volume was associated with cognitive functioning, it did not explain cognitive impairments in patients with type 2 diabetes relative to controls.