Magnetic resonance imaging characteristics in patients with histopathologically proven fibrous dysplasia-a systematic review.

OBJECTIVE: To examine the demographics, lesion location, and characteristic magnetic resonance imaging (MRI) findings in patients with histopathologically proven fibrous dysplasia (FD). MATERIALS AND METHODS: A systematic literature search of the MRI findings in patients with histologically proven FD was performed. Altogether, 76 articles with 136 patients were evaluated. RESULTS: The mean age of the patients was 35.0 + - 18.5 years (range 1 month-75 years). Fifty-eight of the cases were females, 51 males, and in 27 gender was not defined. The most common locations were craniofacial (n = 55 (40%)), long bones (n = 31 (23%)), and spine (n = 24 (18%)). The monostotic form of FD was the most common. Signal intensities (SI) on T1-weighted images were predominantly hypointense (n = 46 (37%)). The SI was highly variable on T2-weighted images with hyperintensity being most common (n = 22 (18%)). Contrast enhancement was found in 75 (55%) FD patients. Secondary aneurysmal bone cysts (ABCs) and malignant transformation in patients without prior radiotherapy was found in some patients. CONCLUSION: Current knowledge of the MRI findings in patients with FD is based mainly on case reports. SI in patients with FD is variable and contrast enhancement is common. FD may explain etiology of spinal bone tumor in some patients. FD with malignant transformation should be considered also in patients without prior radiotherapy. Further studies are needed to clarify if FD displays specific characteristics allowing it to be distinguished from other bone tumors.

Quantification of porcine myocardial perfusion with modified dual bolus MRI - a prospective study with a PET reference.

BACKGROUND: The reliable quantification of myocardial blood flow (MBF) with MRI, necessitates the correction of errors in arterial input function (AIF) caused by the T1 saturation effect. The aim of this study was to compare MBF determined by a traditional dual bolus method against a modified dual bolus approach and to evaluate both methods against PET in a porcine model of myocardial ischemia. METHODS: Local myocardial ischemia was induced in five pigs, which were subsequently examined with contrast enhanced MRI (gadoteric acid) and PET (O-15 water). In the determination of MBF, the initial high concentration AIF was corrected using the ratio of low and high contrast AIF areas, normalized according to the corresponding heart rates. MBF was determined from the MRI, during stress and at rest, using the dual bolus and the modified dual bolus methods in 24 segments of the myocardium (total of 240 segments, five pigs in stress and rest). Due to image artifacts and technical problems 53% of the segments had to be rejected from further analyses. These two estimates were later compared against respective rest and stress PET-based MBF measurements. RESULTS: Values of MBF were determined for 112/240 regions. Correlations for MBF between the modified dual bolus method and PET was rs = 0.84, and between the traditional dual bolus method and PET rs = 0.79. The intraclass correlation was very good (ICC = 0.85) between the modified dual bolus method and PET, but poor between the traditional dual bolus method and PET (ICC = 0.07). CONCLUSIONS: The modified dual bolus method showed a better agreement with PET than the traditional dual bolus method. The modified dual bolus method was found to be more reliable than the traditional dual bolus method, especially when there was variation in the heart rate. However, the difference between the MBF values estimated with either of the two MRI-based dual-bolus methods and those estimated with the gold-standard PET method were statistically significant.

Fibrosis and wall thickness affect ventricular repolarization dynamics in hypertrophic cardiomyopathy.

BACKGROUND: Hypertrophic cardiomyopathy (HCM) is characterized by ventricular repolarization abnormalities and risk of ventricular arrhythmias. Our aim was to study the association between the phenotype and ventricular repolarization dynamics in HCM patients. METHODS: HCM patients with either the MYBPC3-Q1061X or TPM1-D175N mutation (n = 46) and control subjects without mutation and hypertrophy (n = 35) were studied with 24-hr ambulatory ECG recordings by measuring time intervals of rate-adapted QT (QTe), maximal QT, and T-wave apex to wave end (TPE) intervals and the QTe/RR slope. Findings were correlated to specified echocardiographic and cardiac magnetic resonance imaging (CMRI) findings. RESULTS: Rate-adapted QTe interval was progressively longer in HCM patients with decreasing heart rates compared to control subjects (p = 0.020). The degree of hypertrophy correlated with measured QTe values. HCM patients with maximal wall thickness higher than the mean (20.6 mm) had longer maximum QTe and median TPE intervals compared to control subjects and HCM patients with milder hypertrophy (p < 0.001 and p = 0.014, respectively). HCM patients with late gadolinium enhancement (LGE) on CMRI had steeper QTe/RR slopes compared to HCM patients without LGE and control subjects (p = 0.044 and p = 0.001, respectively). LGE was an independent predictor of QTe/RR slope (p = 0.023, B = 0.043). CONCLUSION: Dynamics of ventricular repolarization in HCM are affected by hypertrophy and fibrosis. LGE may confer an independent effect on QT dynamics which may increase the arrhythmogenic potential in HCM.

Novel electrocardiographic features in carriers of hypertrophic cardiomyopathy causing sarcomeric mutations.

OBJECTIVES: The sensitivity and specificity of the conventional 12-lead ECG to identify carriers of hypertrophic cardiomyopathy (HCM) - causing mutations without left ventricular hypertrophy (LVH) has been limited. We assessed the ability of novel electrocardiographic parameters to improve the detection of HCM mutation carriers. METHODS: We studied 140 carriers (G+) of the TPM1-Asp175Asn or MYBPC3-Gln1061X pathogenic variants for HCM: The G+/LVH+ group (n = 98) consisted of mutation carriers with LVH and the G+/LVH- group (n = 42) without LVH. The control group consisted of 30 subjects. The standard 12-lead ECG was comprehensively analyzed and two novel ECG variables were introduced: RV1RV3 and septal remodeling. A subset of 65 individuals underwent cardiac magnetic resonance imaging and 2D strain echocardiography. RESULTS: Conventional major ECG criteria were sensitive (90%) and specific (97%) in identifying G+/LVH+ subjects. RV1RV3 and septal remodeling were more prevalent in the G+/LVH- subjects compared to the control group (33% vs 3%, p = 0.005 and 45% vs 3%, p < 0.001, respectively). The combination of RV1RV3 and Q waves and repolarization abnormalities (QR) differentiated between the G+/LVH- subjects and the control group with a sensitivity of 52% and specificity of 97%. The combination of septal remodeling and QR differentiated between G+/LVH- subjects and the control group with a sensitivity of 64% and specificity of 97%. CONCLUSIONS: The novel ECG-parameters RV1RV3 and septal remodeling were effective in identifying G+/LVH- subjects and could be useful in the diagnostics of new suspected HCM patients and in the screening and follow-up of HCM families.

Cardiovascular magnetic resonance of mitral valve length in hypertrophic cardiomyopathy.

BACKGROUND: Previous data suggest that mitral valve leaflets are elongated in hypertrophic cardiomyopathy (HCM), and mitral valve leaflet elongation may constitute a primary phenotypic expression of HCM. Our objective was to measure the length of mitral valve leaflets by cardiovascular magnetic resonance (CMR) in subjects with HCM caused by a Finnish founder mutation in the myosin-binding protein C gene (MYBPC3-Q1061X), carriers of the same mutation without left ventricular hypertrophy, as well as in unselected consecutive patients with HCM, and respective controls. METHODS: Anterior mitral valve leaflet (AML) and posterior mitral valve leaflet (PML) lengths were measured by CMR in 47 subjects with the Q1061X mutation in the gene encoding MYBPC3 and in 20 healthy relatives without the mutation. In addition, mitral valve leaflet lengths were measured by CMR in 80 consecutive non-genotyped patients with HCM in CMR and 71 age- and gender-matched healthy subjects. RESULTS: Of the subjects with the MYBPC-Q1016X mutation, 32 had left ventricular hypertrophy (LVH, LV maximal wall thickness ≥ 13 mm in CMR) and 15 had no hypertrophy. PML was longer in patients with the MYBPC3-Q1061X mutation and LVH than in controls of the MYBPC group (12.8 ± 2.8 vs 10.6 ± 1.9 mm, P = 0.013), but the difference between the groups was not statistically significant when PML was indexed for BSA (P = 0.066), or when PML length was adjusted for BSA, age, gender, LV mass and ejection fraction (P = 0.195). There was no significant difference in the PML length in mutation carriers without LVH and controls (11.1 ± 3.4 vs 10.6 ± 1.9, P = 0.52). We found no difference in AML lengths between the MYBPC mutation carriers with or without hypertrophy and controls. In 80 consecutive non-genotyped patients with HCM, there was no difference either in AML or PML lengths in subjects with HCM compared to respective control subjects. CONCLUSIONS: In subjects with HCM caused by the Q1061X mutation in the MYBPC3 gene, the posterior mitral valve leaflets may be elongated, but mitral valve elongation does not constitute primary phenotypic expression of the disease. Instead, elongated mitral valve leaflets seem to be associated with body size and left ventricular remodeling.

Visually assessed severity of lumbar spinal canal stenosis is paradoxically associated with leg pain and objective walking ability.

BACKGROUND: Lumbar spinal stenosis (LSS) is the common term used to describe patients with symptoms related to the anatomical reduction of the lumbar spinal canal size. However, some subjects may have a markedly narrowed canal without any symptoms. This raises the question of what is the actual role of central canal stenosis in symptomatic patients. The purpose of this study was to compare radiological evaluations of LSS, both visually and quantitatively, with the clinical findings of patients with LSS. METHODS: Eighty patients [mean age 63 (11) years, 44% male], with symptoms severe enough to indicate LSS surgery, were included in this prospective single-center study. Lumbar magnetic resonance imaging was performed and one experienced neuroradiologist classified patients into three groups: 0 = normal or mild stenosis, 1 = moderate stenosis, and 2 = severe stenosis. In addition, the same observer measured the minimal dural sac area level by level from the inferior aspect of L1 to the inferior aspect of S1. The association between radiological and clinical findings were tested with Oswestry Disability Index, overall visual analog pain scale, specific low back pain, specific leg pain, Beck Depression Inventory, and walking distance on treadmill exercise test. RESULTS: In the visual classification of the central spinal canal, leg pain was significantly higher and walking distance achieved was shorter among patients with moderate central stenosis than in patients with severe central stenosis (7.33 (2.29) vs 5.80 (2.72); P = 0.008 and 421 (431) m vs 646 (436) m; P = 0.021, respectively). Patients with severe stenosis at only one level also achieved shorter walking distance than patients with severe stenosis of at least two levels. No correlation between visually or quantitatively assessed stenosis and other clinical findings was found. CONCLUSIONS: There is no straightforward association between the stenosis of dural sac and patient symptoms or functional capacity. These findings indicated that dural sac stenosis is not the single key element in the pathophysiology of LSS.

Correlation of lateral stenosis in MRI with symptoms, walking capacity and EMG findings in patients with surgically confirmed lateral lumbar spinal canal stenosis.

BACKGROUND: To evaluate the clinical significance of lateral lumbar spinal canal stenosis (LLSCS), found by magnetic resonance imaging (MRI), through correlating the imaging findings with patient symptoms, walking capacity and electromyography (EMG) measurements. METHOD: 102 patients with symptoms of LSS referred for operative treatment were studied in this uncontrolled study. Of these patients, subjects with distinct only lateral LSS were included. Accordingly, 140 roots in 14 patients (mean age 58, range 48-76 years, male 43%) were evaluated. In MR images the entrance and mid zones of the lateral lumbar nerve root canal were graded as normal, narrowed but not compressed, or compressed. In quantitative analysis, the minimal widths of the lateral recess and mid zone area were measured. Clinical symptoms were recorded with the Oswestry Disability Index (ODI), overall Visual Analogue Scale (VAS), specific low back pain (LBP; NRS-11), specific leg pain (LP NRS-11), Beck Depression Inventory (BDI) and walking distance in the treadmill test. Lumbar paraspinal (L2- L5) and lower limb (L3 - S1) needle EMG studies were performed. The findings were classified root by root as 1 = normal, 2 = abnormal. The associations between radiological, EMG and clinical findings were tested with each other. RESULTS: EMG findings were normal in 92 roots and abnormal in 48 roots. All of the patients had at least one abnormal nerve root finding. Severity of the mid zone stenosis in MRI correlated with abnormal EMG findings (p = 0.015). Patients with abnormal EMG had also higher scores in the VAS (41.9 ± 25.7 vs 31.5 ± 18.1; p = 0.018), NRS leg pain (7.5 ± 1.5 vs 6.3 ± 2.1; p = 0.000) and BDI (9.8 ± 3.8 vs 8.0 ± 3.9; p = 0.014). However, no statistically significant correlations between MRI findings and clinical symptoms or walking capacity were found. CONCLUSIONS: Among persons previously selected for surgery, lateral stenosis seen on MRI correlates with EMG, and thus may be a clinically significant finding. Our EMG findings were also associated with patient symptoms. However, no relationships between the MRI findings and symptoms or walking capacity were found, suggesting their multifactorial etiology.

Effect of middle cerebral artery territory ischemic stroke on QT interval.

BACKGROUND: Prolonged QT interval associates with increased risk for sudden cardiac death after acute ischemic stroke. However, pathophysiology of prolonged QT interval after stroke is poorly elucidated. In this study, we investigated whether QT interval dynamics is different in patients with right and left middle cerebral artery (MCA) territory stroke. METHOD: Electrocardiogram (ECG) intervals were compared between baseline (retrieved retrospectively from medical records) and admission (acquired at the acute hospital admission) in 33 patients (65 ± 9.5 years) with right or left MCA territory ischemic stroke. Head computed tomography (CT), cardiac ultrasound, and cardiac CT scans were undertaken. RESULTS: Stroke was located in the right MCA territory in 21 (64%) and in the left MCA territory in 12 (36%) patients. Patients with right and left MCA stroke were similar with respect to time interval between baseline and admission ECG recordings, positive history of heart disease, and left ventricular dimensions. Increase in heart rate-corrected QT interval (QTc) from baseline to admission was demonstrated to occur more often in patients with right (16 of 21; 76%) than in patients with left (3 of 12; 25%; P < .01) MCA stroke. ΔQTc between baseline and admission was significantly longer in patients with right (23 ± 23 milliseconds) than in patients with left (-11 ± 19 milliseconds; P < .0001) MCA stroke. Percent ΔQTc between baseline and admission was longer in patients with right (5.5% ± 5.5%) than in patients with left (-2.6% ± 4.7%; P < .001) MCA stroke. CONCLUSIONS: Right MCA ischemic stroke results in prolongation of QT interval. Findings indicate cerebral asymmetry in brain-heart interaction during acute ischemic stroke.

Central Obesity is Associated with Increased Left Ventricular Maximal Wall Thickness and Intrathoracic Adipose Tissue Measured with Cardiac Magnetic Resonance.

INTRODUCTION: Central obesity (CO), characterized by an increased waist circumference increases the risk of cardiovascular disease (CVD) and morbidity, yet the underlying mechanisms are not fully understood. CO is often associated with general obesity, hypertension, and abnormal glucose tolerance, confounding the independent contribution of CO to CVD. AIM: We investigated the relationship of CO (without associated disorders) with left ventricular (LV) characteristics and intrathoracic adipose tissue (IAT) by cardiac magnetic resonance. METHODS: LV characteristics, epicardial (EAT), and mediastinal adipose tissue (MAT) were measured from 29 normoglycemic, normotensive males with CO but without general obesity (waist circumference >100 cm, body mass index (BMI) <30 kg/m2) and 18 non-obese male controls. RESULTS: LV maximal wall thickness (LVMWT) and IAT but not LV mass or volumes were increased in CO subjects compared to controls (LVMWT, 12.3±1.2 vs. 10.7±1.5 mm, p < 0.001; EAT, 5.5±3.0 vs. 2.2±2.0 cm2, p = 0.001; MAT, 31.0±12.8 vs. 15.4±10.7 cm2, p < 0.001). The LVMWT was ≥12 mm in 69% of subjects with CO and 22% of controls (p = 0.002). In CO suspects, EAT correlated inversely with LV end-diastolic volume index (r = - 0.403, p = 0.037) and LV stroke volume (SV) (r = - 0.425, p = 0.027). MAT correlated inversely with SV (r = - 0.427, p=0.026) and positively with LVMWT (r = 0.399, p = 0.035). Among CO subjects, the waist-to-hip ratio (WHR) was an independent predictor of LVMWT (B = 22.4, ß = 0.617, p < 0.001). The optimal cut-off with Youden's index for LV hypertrophy was identified at WHR 0.98 (sensitivity 85%, specificity 89%). CONCLUSIONS: CO independent of BMI is associated with LV hypertrophy and intrathoracic adipose tissue contributing to cardiovascular burden.

Computed tomography and echocardiography together reveal more high-risk findings than echocardiography alone in the diagnostics of stroke etiology.

BACKGROUND: Cardioembolic stroke carries a major risk of stroke recurrence, which can be markedly reduced by early initiation of appropriate secondary prevention. We investigate whether combined examination of the heart, aorta, and cervicocranial arteries with computed tomography (CACC-CT) may improve the diagnosis of stroke etiology. METHODS: Patients with suspected cardiogenic ischemic stroke or transient ischemic attack (n = 140; mean age 60 ± 10 years; 95 males) underwent CACC-CT and standard diagnostics including transthoracic and transesophageal echocardiography (TTE/TEE). Patients with atrial fibrillation were excluded because cardiac imaging will not affect to anticoagulant treatment. Imaging findings with a potential cardioembolic source were analyzed. Aortic and cardiac risk findings were evaluated independently. Consensus reading of 2 experts using the findings of both approaches and complemented by cardiac MRI when needed served as the reference standard. RESULTS: In 101 patients (72%) the clinical diagnosis was stroke, and transient ischemic attack was confirmed in the remaining patients. Imaging findings associated with highly increased cardioembolic risk were detected in 22 patients (16%). Nine high-risk findings in 140 patients were found by TTE/TEE and this number rose to 25 high after performing both echocardiography and CACC-CT. No difference was found between CACC-CT and TTE/TEE in detecting patients with of at least one high-risk findings (sensitivity 68 vs. 41%, p = 0.052; specificity 98 vs. 99%; overall accuracy 94 vs. 90%). Combined use of CACC-CT and TTE/TEE was more sensitive than TTE/TEE alone for detecting patients with at least one cardiac or aortic high-risk finding (sensitivity 91 vs. 41%, p < 0.001; specificity 98 vs. 99%; overall accuracy 97 vs. 90%). TTE/TEE was insufficient for diagnosing myocardial infarction with left ventricular aneurysm, whereas the accuracy of CACC-CT was high. In 9 patients (6%) with normal or mild hypokinesia in TTE/TEE, CACC-CT and MRI showed myocardial infarction large enough to indicate anticoagulant therapy. In contrast, CACC-CT was not suitable for diagnosing small left artrial thrombi, patent foramen ovale or to measure left ventricular ejection fraction. CONCLUSION: CACC-CT and TTE/TEE alone show limited accuracy for the diagnostics of stroke etiology. Therefore, CACC-CT could be a valuable tool in patients with cryptogenic stroke despite standard stroke diagnostics.

Accuracy and reproducibility of a retrospective outcome assessment for lumbar spinal stenosis surgery.

BACKGROUND: Retrospective assessment of surgery outcome is considered problematic. The aims of this study were to evaluate the reproducibility and accuracy of a retrospective outcome assessment of lumbar spinal stenosis surgery with reference to prospective outcome scale measurements. METHOD: Outcome of surgery from 100 lumbar spinal stenosis (LSS) patients was evaluated retrospectively from patient files of a 3-month outpatient visit performed according to a standard clinical protocol by two independent researchers. In the retrospective analysis, outcome was graded as 2 = good if the clinical condition had clearly improved, 1 = moderate if it had just slightly improved, 0 = poor if it had not improved or was even worse than before the surgical treatment (Retrospective 3- point scale). A prospectively assessed Oswestry Disability Index questionnaire (ODI), Visual analogue pain scale (VAS) and a patient satisfaction questionnaire were used as references of standards. Reproducibility of the measurements was evaluated. RESULTS: The retrospective 3-point scale correlated with ODI (r = 0.528; P < 0.001) and VAS (r = 0.368; P < 0.001). The agreement was better in the good and poor outcome than in the moderate outcome. Retrospective 3-point scale demonstrated substantial intra-rater and inter-rater repeatability (κ = 0.682, P < 0.001 and κ = 0.630, P < 0.001, respectively). CONCLUSIONS: Retrospective assessment of spinal surgery outcome is highly reproducible. Accuracy is highest in the patients with poor and good surgical result.

Cardiac MRI assessed left ventricular hypertrophy in differentiating hypertensive heart disease from hypertrophic cardiomyopathy attributable to a sarcomeric gene mutation.

OBJECTIVE: To evaluate the value of cardiac magnetic resonance imaging (CMRI)-assessed left ventricular hypertrophy (LVH) in differentiating between hypertensive heart disease and hypertrophic cardiomyopathy (HCM). METHODS: 95 unselected subjects with mild-to-moderate hypertension, 24 patients with HCM attributable to the D175N mutation of the α-tropomyosin gene and 17 control subjects were studied by cine CMRI. Left ventricular (LV) quantitative and qualitative characteristics were evaluated. RESULTS: LV maximal end-diastolic wall thickness, wall thickness-to-LV volume ratio, end-diastolic septum thickness and septum-to-lateral wall thickness ratio were useful measures for differentiating between LVH due to hypertension and HCM. The most accurate measure for identifying patients with HCM was the LV maximal wall thickness ≥ 17 mm, with a sensitivity, specificity, negative predictive value, positive predictive value, and accuracy of 90%, 93%, 86%, 95% and 91%, respectively. LV maximal wall thickness in the anterior wall, or regional bulging in left ventricular wall was found only in patients with HCM. LV mass index was not discriminant between patients with HCM and those with LVH due to hypertension. CONCLUSION: LV maximal thickness measured by CMRI is the best anatomical parameter in differentiating between LVH due to mild-to-moderate hypertension and HCM attributable to a sarcomeric mutation. CMRI assessment of location and quality of LVH is also of value in differential diagnosis.

Visual and quantitative assessment of lateral lumbar spinal canal stenosis with magnetic resonance imaging.

BACKGROUND: Lateral lumbar spinal canal stenosis is a common etiology of lumbar radicular symptoms. Quantitative measurements have commonly demonstrated better repeatability than visual assessments. We are not aware of any studies examining the repeatability of quantitative assessment of the lateral canal. PURPOSE: To evaluate the repeatability of visual assessments and newly developed quantitative measurements of lateral lumbar spinal canal stenosis using magnetic resonance imaging (MRI). MATERIAL AND METHODS: Twenty-eight patients with lateral lumbar spinal canal stenosis or prior spinal surgery with recurrent symptoms were imaged with MRI. A radiologist, a neurosurgeon and a spine research trainee graded visually and quantitatively subarticular (n = 188) and foraminal zones (n = 260) of the lateral spinal canal. Quantitative measurements included the minimal subarticular width and the cross-sectional area of the foramen. RESULTS: The repeatability of visual assessment at the subarticular zone and foraminal zones between raters varied from 0.45-0.59 and 0.42-0.53, respectively. Similarly, the intraclass correlation coefficients for the quantitative measurements varied from 0.67-0.71 and 0.66-0.76, respectively. The intra-rater repeatability for the visual assessments of the subarticular and foraminal zones was 0.70 and 0.62, respectively, while the corresponding intraclass correlation coefficients for quantitative measurements were 0.83 and 0.81, respectively. CONCLUSION: Inter-rater repeatability of visual assessments of lateral stenosis is moderate, whereas quantitative measurements of both subarticular width and the cross-sectional area of the foramen have substantial reproducibility and may be particularly useful for longitudinal studies and research purposes. The clinical value of these parameters requires further study.

Sample size for prospective studies of hip joint space width narrowing in osteoarthritis by the use of radiographs.

OBJECTIVE: To determine the number of participants required in controlled clinical trials investigating the progression of osteoarthritis (OA) of the hip as evaluated by the joint space width (JSW) on radiographs and to evaluate the reproducibility of the JSW measurement methods. MATERIALS AND METHODS: Anteroposterior radiographs of hip were taken from 13 healthy volunteers and from 18 subjects with radiographic hip OA. The reproducibility of the JSW was determined from four segments using digital caliper measurements performed on film radiographs and using semiautomatic computerized image analysis of digitized images. Pearson correlation coefficient, coefficient of variability [CV (%)], and sample size values were calculated. RESULTS: It was found that 20 was a typical number of patients for a sufficiently powered study. The highest sample size was found in subjects with OA in the lateral segment. The reproducibility of the semiautomatic computerized method was not significantly better than the digital caliper method. CONCLUSION: The number of study subjects required to detect a significant joint space narrowing in follow-up studies is influenced by the baseline hip joint OA severity. The JSW measurements with computerized image analysis did not improve the reproducibility and thus performing JSW measurements with a digital caliper is acceptable.

Quantification of Myocardial Blood Flow by Machine Learning Analysis of Modified Dual Bolus MRI Examination.

Contrast-enhanced magnetic resonance imaging (MRI) is a promising method for estimating myocardial blood flow (MBF). However, it is often affected by noise from imaging artefacts, such as dark rim artefact obscuring relevant features. Machine learning enables extracting important features from such noisy data and is increasingly applied in areas where traditional approaches are limited. In this study, we investigate the capacity of machine learning, particularly support vector machines (SVM) and random forests (RF), for estimating MBF from tissue impulse response signal in an animal model. Domestic pigs (n = 5) were subjected to contrast enhanced first pass MRI (MRI-FP) and the impulse response at different regions of the myocardium (n = 24/pig) were evaluated at rest (n = 120) and stress (n = 96). Reference MBF was then measured using positron emission tomography (PET). Since the impulse response may include artefacts, classification models based on SVM and RF were developed to discriminate noisy signal. In addition, regression models based on SVM, RF and linear regression (for comparison) were developed for estimating MBF from the impulse response at rest and stress. The classification and regression models were trained on data from 4 pigs (n = 168) and tested on 1 pig (n = 48). Models based on SVM and RF outperformed linear regression, with higher correlation (R SVM 2 = 0.81, R RF 2 = 0.74, R linear_regression 2 = 0.60; ρSVM = 0.76, ρRF = 0.76, ρlinear_regression = 0.71) and lower error (RMSESVM = 0.67 mL/g/min, RMSERF = 0.77 mL/g/min, RMSElinear_regression = 0.96 mL/g/min) for predicting MBF from MRI impulse response signal. Classifier based on SVM was optimal for detecting impulse response signals with artefacts (accuracy = 92%). Modified dual bolus MRI signal, combined with machine learning, has potential for accurately estimating MBF at rest and stress states, even from signals with dark rim artefacts. This could provide a protocol for reliable and easy estimation of MBF, although further research is needed to clinically validate the approach.

Preinterventional quantitative magnetic resonance imaging predicts uterus and leiomyoma size reduction after uterine artery embolization.

PURPOSE: To investigate the relationship between magnetic resonance imaging (MRI) measures and uterus and leiomyoma size reductions after uterine artery embolization (UAE). MATERIALS AND METHODS: Fifty-two women with leiomyomas underwent selective UAEs. Uterine and dominant leiomyoma sizes were measured with preinterventional MRI and a 6-month follow-up MRI. Four MRI measures of the dominant leiomyoma were recorded: T1 time; T2 time; leiomyoma-to-skeletal muscle T2 SI-ratio; and percentage of contrast enhancement. To evaluate the predictive value of MRI measures we used Spearman rank correlation, area under the receiver operating characteristic (ROC) curve (A(z)), and values for diagnostic performance. RESULTS: Uterus and dominant leiomyoma size reductions were highly variable. Leiomyoma size reductions of >or=75% were accurately predicted with leiomyoma-to-skeletal muscle T2 SI-ratio (ROC curve A(z) = 0.930; 95% confidence interval [CI]: 0.853, 1.000). Leiomyoma size reductions >or=75% were predicted by leiomyoma-to-skeletal muscle T2 SI-ratio >or=3.5 and T1-time >or=750 msec with 100% and 86% sensitivities and 67% and 72% specificities, respectively. Uterus size reduction >or=50% were identified by dominant leiomyoma-to-skeletal muscle T2 SI-ratio >or=2.5. CONCLUSION: Uterus and dominant leiomyoma size reductions after UAE were predicted with preoperative MRI measures of the dominant leiomyoma.

Uterine artery embolisation versus hysterectomy for leiomyomas: primary and 2-year follow-up results of a randomised prospective clinical trial.

OBJECTIVE: To compare uterine artery embolisation (UAE) and hysterectomy for the treatment of leiomyomas at 2-year follow-up in a prospective, randomised, single-centre study. METHODS: Fifty-seven symptomatic patients were randomised to UAE (n = 27) or hysterectomy (n = 30). Complications, recovery, reinterventions and satisfaction with treatment were recorded. Primary endpoint was improvement of symptoms. Analyses were performed by intent-to-treat and per protocol. RESULTS: Two hysterectomy patients (7%) developed major complications. Hospital discharge occurred earlier after UAE than after hysterectomy (p < 0.001). Length of sick leave was longer after hysterectomy than after UAE (p < 0.001). Twenty-two (82%) UAE patients and 28 (93%) hysterectomy patients reported overall relief of symptoms (p = 0.173). In 12/18 (67%) UAE patients menorrhagia was completely resolved or reduced. Improvement of pressure symptoms was reported significantly more by UAE patients than by hysterectomy patients (19/20 [95%] versus 18/26 [69%], respectively; p = 0.029). Five (19%) UAE patients underwent additional interventions due to worsening symptoms. Twenty-four (89%) UAE patients and 29 (97%) hysterectomy patients would have chosen treatment again (p = 0.336). CONCLUSION: UAE gave relief of symptoms (apart from menorrhagia) comparable to hysterectomy with less severe complications, but with an increased rate of secondary interventions. UAE may be the preferable treatment especially for patients with pressure symptoms.

Pain after uterine fibroid embolisation is associated with the severity of myometrial ischaemia on magnetic resonance imaging.

The purpose of the study was to evaluate uterine ischaemia after uterine artery embolisation (UAE) using magnetic resonance imaging and the role of myometrial and fibroid ischaemia in the pathogenesis of post-procedural pain. T1-weighted gradient echo imaging before and after contrast agent was performed on 62 women before and 24 h after UAE. We assessed the severity (mild, moderate, severe) of myometrial ischaemia, and the percentage and volume of ischaemic tissue in myometrium and fibroids. The Verbal Rating Scale was used to assess in-hospital post-procedural pain (1-3 mild, 4-6 moderate, 7-10 severe). Mean maximal pain was 7.7. Myometrial ischaemia was mild, moderate and severe in 29, 23 and 10 patients, respectively. Moderate or severe myometrial ischaemia (p = 0.041), the percentage (p = 0.037) and volume (p = 0.012) of ischaemic tissue in the myometrium, and a large volume of embolic material (p = 0.038) correlated with severe pain. In summary, pain following UAE is common and partly explained by myometrial ischaemia.

CMR derived left ventricular septal convexity in carriers of the hypertrophic cardiomyopathy-causing MYBPC3-Q1061X mutation.

This manuscript has not been published before and is not currently being considered for publication elsewhere. Increased septal convexity of left ventricle has been described in subjects with hypertrophic cardiomyopathy (HCM) -causing mutations without left ventricular hypertrophy (LVH). Our objective was to study septal convexity by cardiac magnetic resonance (CMR) in subjects with the Finnish founder mutation Q1016X in the myosin-binding protein C gene (MYBPC3). Septal convexity was measured in end-diastolic 4-chamber CMR image in 67 study subjects (47 subjects with the MYBPC3-Q1061X mutation and 20 healthy relatives without the mutation). Septal convexity was significantly increased in subjects with the MYBPC3-Q1061X mutation and LVH (n = 32) compared to controls (11.4 ± 4.3 vs 2.7 ± 3.2 mm, P < 0.001). In mutation carriers without LVH, there was a trend for increased septal convexity compared to controls (4.9 ± 2.5 vs 2.7 ± 3.2 mm, P = 0.074). When indexed for BSA, septal convexity in mutation carriers without LVH was 2.8 ± 1.4 mm/m2 and 1.5 ± 1.6 mm/m2 in controls (P = 0.036). In all mutation carriers, septal convexity correlated significantly with body surface area, age, maximal LV wall thickness, LV mass, and late gadolinium enhancement. Subjects with the MYBPC3-Q10961X mutation have increased septal convexity irrespective of the presence of LVH. Septal convexity appears to reflect septal remodeling, and could be useful in recognizing LVH negative mutation carriers.

Early familial dilated cardiomyopathy: identification with determination of disease state parameter from cine MR image data.

PURPOSE: To characterize early changes in cardiac anatomy and function for lamin A/C gene (LMNA) mutation carriers by using magnetic resonance (MR) imaging and to develop tools to analyze and visualize the findings. MATERIALS AND METHODS: The ethical review board of the institution approved the study, and informed written consent was obtained. The patient group consisted of 12 subjects, seven women (mean age, 36 years; age range, 18-54 years) and five men (mean age, 28 years; age range, 18-39 years) of Finnish origin, who were each heterozygotes with one LMNA mutation that may cause familial dilated cardiomyopathy (DCM). All the subjects were judged to be healthy with transthoracic echocardiography. The control group consisted of 14 healthy subjects, 11 women (mean age, 41 years; range, 23-54 years) and three men (mean age, 45 years; range, 34-57 years), of Finnish origin. Cine steady state free precession MR imaging was performed with a 1.5-T system. The volumes, wall thickness, and wall motion of both left ventricle (LV) and right ventricle were assessed. A method combining multiple MR image parameters was used to generate a global cardiac function index, the disease state parameter (DSP). A visual fingerprint was generated to assess the severity of familial DCM. RESULTS: The mean DSP of the patient group (0.69 +/- 0.15 [standard deviation]) was significantly higher than that of the control group (0.32 +/- 0.13) (P = .00002). One subject had an enlarged LV. CONCLUSION: Subclinical familial DCM was identified by determination of the DSP with MR imaging, and this method might be used to recognize familial DCM at an early stage.