Abnormal Magnetic Resonance Angiography Research Articles

Association of Elevated Tricuspid Regurgitation Velocity with Kidney and Cerebrovascular Disease in Children with Sickle Cell Disease

Introduction: Adult patients with sickle cell disease (SCD) develop progressive end-organ injury leading to multi-organ disease and increased mortality. It is plausible that this multi-organ damage begins in pediatric patients. Tricuspid regurgitation velocity (TRV), measured by echocardiography is a surrogate marker for pulmonary hypertension that is a poor prognostic factor in adults with SCD. The utility of screening echocardiograms as a marker of disease severity is being studied in pediatrics. In this study, we assessed associations between elevated TRV with early development of chronic kidney disease (albuminuria), and cerebrovascular disease (CVD). Methods: We performed an IRB approved cross-sectional study to evaluate the prevalence of elevated TRV ≥ 2.5 m/s and its associations with albuminuria and CVD in patients with SCD ages 1-21 years. We included children with a diagnosis of SCD who had at least one echocardiogram performed during an outpatient clinic visit at steady-state for screening for pulmonary hypertension. We categorized patients as receiving either transfusion therapy (chronic transfusion for >12 months), SCD modifying therapy (hydroxyurea, voxelotor, crizanlizumab, or L-glutamine), or no therapy. Patients on both transfusion and a SCD modifying therapy were defined as being on transfusion therapy. We defined albuminuria as patients with two of three consecutive albumin creatinine ratios ≥30mg/g measured during standard clinic visits. Cerebrovascular disease was defined as having either 1) an overt stroke, 2) silent cerebral stroke defined by MRI, 3) vasculopathy by abnormal magnetic resonance angiography (MRA), 4) transient ischemic event defined by stroke symptoms that resolved within 24 hours, or 5) abnormal TCD (>200 cm/second). We performed bivariate analysis utilizing t-test (or Kruskal-Wallis test) and Cochran-Mantel-Haenszel test for continuous and categorical variables respectively. To determine the association between elevated TRV and albuminuria, and elevated TRV and CVD, logistic regression was fit and adjusted for variables that were significant in the bivariate analysis. Using the TRV <2.5m/sec as the reference group, adjusted odds ratios with their accompanying confidence intervals were calculated for those with albuminuria and those with CVD in separate models. All reported P values were 2-sided. Statistical significance was defined as p<0.05. All analyses were performed using Statistical Analysis Software 9.4, (SAS Institute, Cary, NC). Results: Among 166 children with echocardiography, the prevalence of an elevated TRV was 21%. On bivariate analysis, elevated TRV was significantly associated with persistent albuminuria (OR 2.85 (95% CI: 1.27-6.43) and cerebrovascular disease (OR: 2.46 (95% CI: 1.09-5.53) (Table 1). An elevated TRV was also significantly associated with increased age (15.6 vs 12.9 yrs, p=0.005), lower hemoglobin F% (2.5 vs 4.6%, p=0.01), higher absolute reticulocyte count (0.5 vs 0.4 x 106/ µL p=0.005) and chronic transfusion therapy (p=0.04). After adjusting for age, absolute reticulocyte count, HbF and treatment in a multivariable logistic regression, the associations between elevated TRV with either persistent albuminuria (OR: 1.82 (0.71 - 4.67)) and cerebrovascular disease (OR: 1.15 (0.43-3.10)) were no longer statistically significant (Table 1). Our data suggests that with an odds ratio of 2.9 and a prevalence of elevated TRV of 20%, a prospective study of 166 adolescent patients with SCD would be needed to detect the association between elevated TRV and persistent albuminuria with 80% power and 233 children would be needed to detect this difference with 90% power. Conclusion: This data provides additional evidence that around 20% of pediatric patients have an elevated TRV and those patients may also have an increased risk for developing chronic kidney disease and cerebrovascular disease. A larger, prospective cohort study should be conducted to confirm these findings and determine the role of screening echocardiography in pediatric SCD. At minimum, our data suggests that pediatric patients with known chronic kidney disease or cerebrovascular disease should be screened for cardiac complications. Furthermore, longitudinal studies are needed to evaluate the association between elevated TRV in children with early end-organ complications in adults. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Does Advanced Imaging Aid in the Preoperative Evaluation of Patients With Moyamoya Disease?

Background Moyamoya disease is characterized by progressive nonatherosclerotic stenosis and eventual occlusion of the supraclinoid cerebral arteries with the associated development of abnormal collateral vessels. Treatment of moyamoya disease revolves around restoring cerebral blood flow (CBF) distal to the steno-occlusive disease. Numerous modalities can be used to assess hemodynamic parameters. We sought to determine the impact of preoperative imaging on surgical decision-making. Methods A retrospective review was performed of all patients seen with the diagnosis of moyamoya. Patients were grouped on presentationbased on CT/MRI findings of infarction, hemorrhage, or normal. Patients who did not have all of the preoperative tests were excluded. Preoperative radiological results were dichotomized as either normal or abnormal. Results During a five-year period, 34 patients with moyamoya met the inclusion criteria. All patients had an abnormal magnetic resonance angiography (MRA) Non-invasive Optimal Vessel Analysis (NOVA; VasSol, Inc, River Forest, IL). Three patients had normal initial MRI. All symptomatic patients had abnormal preoperative workup and underwent revascularization, as all were found to have abnormal single photon emission computed tomography (SPECT). The only occasion where the decision for surgery or type of surgery was influenced by imaging findings was in patients with nonclassical or minimal symptoms. Conclusion Although hemodynamic imaging studies can aid in establishing a preoperative baseline of CBF and cerebral vascular reserve (CVR) for follow-up studies, the true implication of these tests in the preoperative evaluation of clearly symptomatic moyamoya patients is debatable. In asymptomatic/mildly symptomatic patients, hemodynamic studies are necessary to determine the need for treatment. For symptomatic patients, surgery can be performed without an exhaustive and costly preoperative hemodynamic evaluation.

Hydroxyurea Therapy to Prevent Incident Stroke Among Children with Sickle Cell Anaemia in Jamaica: The Extend Trial

Hydroxyurea Therapy to Prevent Incident Stroke Among Children with Sickle Cell Anaemia in Jamaica: The Extend Trial

Transcranial Doppler and Magnetic Resonance in Tanzanian Children With Sickle Cell Disease.

Background and Purpose- We determined prevalences of neurological complications, vascular abnormality, and infarction in Tanzanian children with sickle cell disease. Methods- Children with sickle cell disease were consecutively enrolled for transcranial Doppler; those with slightly elevated (>150 cm/s), low (<50 cm/s) or absent cerebral blood flow velocity (CBFv) were invited for brain magnetic resonance imaging and magnetic resonance angiography. Results- Of 200 children (median age 9; range 6-13 years; 105 [2.5%] boys), 21 (11%) and 15 (8%) had previous seizures and unilateral weakness, respectively. Twenty-eight (14%) had elevated and 39 (20%) had low/absent CBFv, all associated with lower hemoglobin level, but not higher indirect bilirubin level. On multivariable analysis, CBFv>150 cm/s was associated with frequent painful crises and low hemoglobin level. Absent/low CBFv was associated with low hemoglobin level and history of unilateral weakness. In 49 out of 67 children with low/absent/elevated transcranial Doppler undergoing magnetic resonance imaging, 43% had infarction, whereas 24 out of 48 (50%) magnetic resonance angiographies were abnormal. One had hemorrhagic infarction; none had microbleeds. Posterior circulation infarcts occurred in 14%. Of 11 children with previous seizure undergoing magnetic resonance imaging, 10 (91%) had infarction (5 silent) compared with 11 out of 38 (29%) of the remainder ( P=0.003). Of 7 children with clinical stroke, 2 had recurrent stroke and 3 died; 4 out of 5 had absent CBFv. Of 193 without stroke, 1 died and 1 had a stroke; both had absent CBFv. Conclusions- In one-third of Tanzanian children with sickle cell disease, CBFv is outside the normal range, associated with frequent painful crises and low hemoglobin level, but not hemolysis. Half have abnormal magnetic resonance angiography. African children with sickle cell disease should be evaluated with transcranial Doppler; those with low/absent/elevated CBFv should undergo magnetic resonance imaging/magnetic resonance angiography.

Utility of diagnostic cerebral angiography in the management of suspected central nervous system vasculitis

Vasculitis of the central nervous system is a rare and poorly understood disease of the brain and spinal cord. Cerebral angiography is the radiological gold standard for diagnosis in patients with compatible clinical findings. However, advances in the quality of noninvasive neuroimaging techniques of cerebral and spinal vasculature such as magnetic resonance angiography (MRA) and computed tomography angiography (CTA) may obviate the need for invasive catheter angiography. We reviewed our institutional experience at Jackson Memorial Hospital between 2011 and 2016 to assess the utility of performing a cerebral digital subtraction angiogram (DSA) in the management of suspected vasculitis. In 16 (59%) of the 27 patients who underwent both noninvasive imaging and DSA, neither imaging studies showed any evidence of vasculitis. Despite these negative studies, 2 patients were treated empirically with immunosuppressants based on clinical symptoms and laboratory findings. 10 (37%) patients demonstrated irregularities on MRA and findings were confirmed by DSA in 6 of these patients. All 6 of these patients were treated, however, 2 of the 4 patients with abnormal MRA and normal DSA were also started on immunosuppressive therapy despite negative DSA. In conclusion, invasive catheter-based angiography may be of limited benefit in the diagnosis and management of PCNSV when considered in the context of clinical and laboratory findings and MRA or CTA results. Further large studies are necessary to determine whether non-invasive imaging can replace DSA.

Arterial Wall Imaging in Pediatric Stroke.

Arteriopathy is common in childhood arterial ischemic stroke (AIS) and predicts stroke recurrence. Currently available vascular imaging techniques mainly image the arterial lumen rather than the vessel wall and have a limited ability to differentiate among common arteriopathies. We aimed to investigate the value of a magnetic resonance imaging-based technique, namely noninvasive arterial wall imaging (AWI), for distinguishing among arteriopathy subtypes in a consecutive cohort of children presenting with AIS. Children with confirmed AIS and magnetic resonance angiography underwent 3-Tesla AWI including T1-weighted 2-dimensional fluid-attenuated inversion recovery fast spin echo sequences pre- and post-gadolinium contrast. AWI characteristics, including wall enhancement, wall thickening, and luminal stenosis, were documented for all. Twenty-six children with AIS had AWI. Of these, 9 (35%) had AWI enhancement. AWI enhancement was associated with anterior circulation magnetic resonance angiography abnormality and cortical infarction in 8 of 9 (89%) children and normal magnetic resonance angiography with posterior circulation subcortical infarction in 1 (1 of 9; 11%) child. AWI enhancement was not seen in 17 (65%), 10 (59%) of whom had an abnormal magnetic resonance angiography. Distinct patterns of pre- and postcontrast signal abnormality were demonstrated in the vessel wall in the region of interest in children with transient cerebral arteriopathy, arterial dissection, primary central nervous system angiitis, dissecting aneurysm, and cardioembolic stroke. AWI is a noninvasive, high-resolution magnetic resonance AWI technique, which can be successfully used in children presenting with AIS. Patterns of AWI enhancement are recognizable and associated with specific AIS pathogeneses. Further studies are required to assess the additional diagnostic utility of AWI over routine vascular imaging techniques, in childhood AIS.

Maximal and submaximal mouth opening with mouth gags in cats: Implications for maxillary artery blood flow

The use of spring-loaded mouth gags in cats can be associated with the development of central neurological deficits, including blindness. In this species, the maxillary arteries are the main source of blood supply to the retinae and brain. Spring-loaded gags generate constant force after placement that could contribute to bulging of the soft tissues between the mandible and the tympanic bulla. Under these circumstances, the maxillary arteries can become compressed as they course between these osseous structures. Smaller gags that might apply less force to the mouth were investigated to determine if they preserved maxillary artery blood flow. Six healthy adult cats were anesthetized. Electroretinography (ERG) and magnetic resonance angiography (MRA) were performed without the use of a mouth gag and during submaximal (plastic mouth gags of 20, 30 and 42mm in length between canine teeth) and maximal mouth opening.Maximal mouth opening produced alterations in ERG waveforms consistent with circulatory compromise in 1/6 cats and reductions in signal intensity during MRA in 4/6 cats. Placement of a 42mm plastic gag produced a reduction in MRA signal in 1/6 cats. No changes were observed with smaller gags. The force applied against the mouth was significantly higher with the spring-loaded gag than with any other gags. The use of a smaller mouth gags was associated with fewer alterations of indicators of maxillary artery blood flow. Nevertheless, a 42mm plastic gag, equivalent to the size of a needle cap, resulted in an abnormal MRA in one cat.

The Spectrum of Lesions and Clinical Results of Arthroscopic Stabilization of Acute Anterior Shoulder Instability

PurposeThe purpose of this study is to investigate and analyze accom-panying lesions including injury types of anteroinferior labrum lesion in young and active patients who suffered traumatic anterior shoulder dislocation for the first time.Meterials and MethodsThe study used magnetic resonance angiography (MRA) to 40 patients with acute anterior shoulder dislocation from April 2004 to April 2008, and of those, 36 with abnormal MRA finding were treated with arthroscopy.ResultsThere was a total of 25 cases of anteroinferior glenoid labrum lesions. A superior labrum anterior-posterior lesion (SLAP) lesion was observed in 8 cases. For bony lesions, 22 cases of Hill-sachs lesions, 4 cases of lesions in greater tuberosity fracture of humerus, and 4 cases of loose body were found. For lesions involving rotator cuff, partial articular side rupture was found in 2 cases and 2 cases were found to have a complete rupture.ConclusionUnder MRA and arthroscopy performed on patients with acute anterior shoulder dislocation, it was observed to have varying types of anteroinferior labrum lesions such as Perthes, Bankart, ALPSA, and bony Bankart lesion. that MRA is a remar-kably useful tool to classify various lesions in acute anterior dislocation of the shoulder and to make a diagnosis, making it a useful tool to decide a treatment method while consulting patients and their families.

Absence of Association Between TNF α Polymorphysm and Cerebral Large Vessel Abnormalities in Adults with Sickle Cell Anemia

Purpose: Stroke is a common and serious complication of sickle cell disease (SCD) affecting children as well as adults. Recent reports suggested that promoter region polymorphism in the tumour necrosis factor alpha (TNF-α) gene at position −308 is an important risk factor for large vessel stroke in children with SCD. The role of TNF-α polymorphism in the frequency of magnetic resonance angiography (MRA) abnormalities in adults with SCD is still uncertain. Our objective was to evaluate TNF-α polymorphism in adults with SCD from a tertiary University-based hospital in Sao Paulo, Brazil and correlate them to brain magnetic resonance imaging (MRI) and MRA findings.Casuistic and Methods: The determination of the G-308A polymorphism of the TNF-α gene was performed in forty-nine adult patients with SCD followed in our outpatient clinic. All subjects were evaluated with brain MRI and MRA to determine the presence of previous stroke, arterial tortuosity and intracranial stenosisResults: Thirty-three patients (67.3%) had abnormal brain MRA scans (intracranial stenosis or arterial tortuosity). Eight patients (16.3%) had intracranial stenosis on MRA and 29 (59.2%) showed arterial tortuosity. Forty one patients (83.7%) had the GG TNF-α (−308) genotype and eight had the GA genotype. There were no cases of AA genotype. There was no correlation between homozygosis for the TNF-α (−308) G allele and MRA abnormalities.Conclusion: Although TNF-α (−308) polymorphism has been considered a potential predictor of genetic risk for stroke in children with SCA, we found no association between the polymorphism and large vessel abnormalities in adults with sickle cell disease. (FAPESP: 04/04498-4)

Change over Time of Transcranial Doppler Cerebral Blood Flow Velocity and the Relationship with Turbulence on Magnetic Resonance Angiography in Patients with Sickle Cell Anemia.

Cerebrovascular disease (CVD) involving the circle of Willis and documented using time-averaged maximum velocity (TAMM) on transcranial Doppler (TCD) and on magnetic resonance angiography (MRA), is common in sickle cell anemia (SCA). Few studies have examined the natural history of CVD. The relationship between TAMM and MRA turbulence is also unclear. We aimed to examine time trends in TAMM and any relationship with clinical stroke and silent infarction (SI) on MRI. We also wanted to determine (a) the degree of MRA turbulence associated with TCD V>200 cm/sec (b) the TCD signature of MRA occlusion and (c) the proportion of patients with no TCD signal who did not have MRA occlusion. TCD was performed in a cohort of 169 patients with highest TAMM measured in either internal carotid/middle cerebral artery recorded (time point 1). Studies were categorised as follows: 0=normal TAMM, 1=170–200cm/sec (conditional TAMM), 2=>200cm/sec, 3=<50cm/sec. The median age was 8 (range 1–25) years. Six (4%) patients had an abnormal scan with TAMM>200cm/sec; 3 had not been screened for SCD neonatally. 11 (7%) patients had abnormally low TAMM <50cm/sec. In the neonatally screened cohort, the median for the highest TAMM ever recorded was 124 (range 33–258 cm/s) at a median age of 9 (1–25 years). 91 patients had repeat TCD at time point 2 (median 5 years later). 63 patients remained normal throughout and 16 with initially normal TAMM changed to TAMM<50cm/s at time point 2. 3/5 patients with TAMM>200cm/s at time point 1 had TAMM<50cm/s at time point 2 and 3/5 patients with TAMM<50cm/s at time point 1 remained low at time point 2. Patients with abnormally high or low TAMM at time point 1 were more likely to have abnormally low TAMM at time point 2 (x2, p= 0.001). Although clinical stroke (x2, p=0.001)and SI were commoner in those with abnormal TCD, the latter relationship was not significant (x2, p=0.94). 92 patients had both TCD and MRA within 1 month. The results were analysed for symptomatic (n=63) and asymptomatic (n=29) groups. There was no difference between groups for age (median 13; range 0–27 years). MRAs were examined for evidence of MCA turbulence graded as none, mild, moderate, severe or occlusion. There was a significant association between TAMM and MRA turbulence for the whole (ANOVA, right p=0.0001, left p=0.001), and symptomatic groups (ANOVA, right p=0.01, left p=0.025). All patients with TAMM>200 cm/sec had severe MCA turbulence but 2/3 with TAMM>170<200 cm/sec had normal MRA. The highest TAMM seen in a patient with occlusion was 80 cm/sec. Eighteen patients had no TCD signal, of whom 11 had abnormal MRA (3 occlusion). There is progressive CVD in children with SCD over time as evidenced by an increase in the number of children with abnormally low TCD. Patients with low TAMM or no signal may require MRA to document the severity of their CVD. Patients with TAMM>80 cm/sec are unlikely to have occlusion. As silent infarction is not predicted by TCD, MRA has a role as an additional tool to identify high risk patients, particularly in those with low TAMM. TAMM>200cm/sec appears to be a screen for severe turbulence, although this condition may represent specific pathophysiology rather than part of a spectrum.

The Relationship of Vascular Glycolipid Storage to Clinical Manifestations of Fabry Disease

Fabry disease is a rare X-linked lysosomal storage disorder caused by deficient activity of alpha-galactosidase A (alpha-Gal A) resulting in the storage of glycosphingolipids, especially globotriaosylceramide (Gb3), in cells throughout the body, causing life-threatening renal, cardiac, and cerebrovascular complications in hemizygous males and some heterozygous females. Disease manifestations in heterozygotes are being recognized increasingly, but quantitative prospective data on their extent and severity are limited. Prospective clinical and laboratory assessments were performed in a 7-day study of 61 women with signs and symptoms of Fabry disease. Analyses included medical history and physical, neurologic, cardiac, and ophthalmologic assessments; laboratory assessments; renal function tests; magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) of the head; and Fabry-related blood and urine tests, including Gb3 levels in blood and urine, skin biopsies, and DNA genotype analysis of the alpha-Gal A gene to identify causative mutations. Quality of life, pain and concomitant medication were documented using validated questionnaires and diaries. All patients had normal Gb3 levels in plasma; only 1 patient had visible storage material in the superficial dermal vascular endothelial cells. Cardiac, renal, or cerebrovascular abnormalities were documented in 52 of the 57 patients (91%) with confirmed Fabry genotypes. These included electrocardiographic abnormalities in 38 of 52 patients (73%), echocardiographic abnormalities in 8 of 57 (14%), proteinuria (>150 g protein/24-h urine) in 23 of 38 (61%), low estimated glomerular filtration rate (<90 mL/min per 1.73 m) in 24 of 57 (42%), abnormal MRI in 4 of 54 (7%), and abnormal MRA in 10 of 50 patients (20%). Angiokeratomas and corneal epitheliopathy were documented in 63% and 82% of the 57 patients, respectively. Despite the virtual absence of storage material in plasma and skin vascular endothelial cells, this population of women with Fabry disease exhibited a wide spectrum of clinical abnormalities. Useful outcome measures for assessment of specific therapies need to be developed. Studies limited to homogeneously affected subjects may be possible.