Different distribution patterns of cerebral microbleeds in acute ischemic stroke patients with and without hypertension.

BACKGROUND: Cerebral microbleeds (CMBs) were found in patients with and without hypertension. We aimed to investigate different distribution patterns of CMBs in patients with and without hypertension. METHODS: We examined acute ischemic stroke patients using a standardized MRI protocol that included T(1), T(2) and gradient-echo T(2)*. Clinical and imaging characteristics were collected from all patients. RESULTS: Among 998 patients, CMBs were detected in 273 patients (27.3%). Of these, 62 did not have hypertension (22.7%). The incidence of CMBs among patients without hypertension (62/335, 18.5%) was lower than among those with hypertension (211/663, 31.8%; p < 0.01). The location of CMBs in patients without hypertension was limited to the cortical-subcortical (CSC) region in 40.3% (25/62) compared to 20.4% of those with hypertension (43/211; p = 0.01). No significant difference was found between CMB locations within the intra-CSC region in both groups. The severity of white matter changes and systolic blood pressure on admission were found to be independent predictors for CMBs in patients without hypertension. CONCLUSIONS: CMBs in patients with and without hypertension have different distribution patterns and may have a different pathogenesis. Blood pressure controlling is important in both groups because systolic blood pressure is an independent predictor of CMBs in patients without hypertension.

Magnetic resonance imaging assessment of cardiac and liver iron load in transfusion dependent patients.

BACKGROUND: Magnetic resonance imaging (MRI) is an emerging tool to assess organ-specific iron load in patients with transfusion dependent anemia. OBJECTIVE: We performed MRI T2 star (T2*) assessment in 44 transfusion dependent patients to study the prevalence of cardiac and liver iron overload and the relationship of T2* measurement with various clinical and biochemical parameters. RESULT: Mean age of the study subjects was 19.9 years (range 8.8-32.3) and the mean cardiac T2* was 23.4 +/- 13.8 msec. Fifty percent of the subjects had abnormal cardiac T2* (below 20 msec). Cardiac T2* was not found to have any correlation with serum ferritin or liver T2*. Liver T2* value was abnormal in 79% of the subjects and it correlated inversely with both current and 12 months average serum ferritin (r = -0.44, P = 0.003; r = -0.46, P = 0.002). Clinical parameters including age, duration of transfusion, age starting iron chelation therapy, and ratio between transfusion volume and desferrioxamine dosage were not correlated with cardiac and liver T2*. CONCLUSION: We conclude that iron overload in heart and liver is common in our transfusion dependent patients. Liver T2* has inverse correlation with serum ferritin. Cardiac T2* does not have any correlation with the various clinical and biochemical parameters.

Symptomatic ostial vertebral artery stenosis: treatment with drug-eluting stents--clinical and angiographic results at 1-year follow-up.

PURPOSE: To evaluate the feasibility and preliminary results of using paclitaxel-eluting stents for angioplasty and to treat symptomatic atherosclerotic ostial vertebral artery (VA) stenosis. MATERIALS AND METHODS: Institutional review board approval and written informed consent were obtained for this prospective study. Nine men and one woman (average age, 65.9 years +/- 11.6 [standard deviation]) were included. Inclusion criteria were as follows: (a) Patients had angiographic evidence of VA ostial stenosis of 50% or more or stenosis of more than 45% if the contralateral VA was occluded. (b) Refractory vertebrobasilar ischemia, such as a stroke or transient ischemic attack, occurred while patients were taking one antiplatelet medication with optimal cardiovascular risk factor control. (c) Patients did not have another substantial vertebrobasilar stenotic lesion in the same territory. The primary end point was procedure safety, defined as mortality and permanent neurologic morbidity 30 days after stent placement. The secondary end point was clinical effectiveness, defined as recurrent vertebrobasilar ischemic symptoms within 12 months after stent placement and restenosis greater than or equal to 50% of the treated VA segment within 12 months after stent placement. RESULTS: The degree of stenosis ranged from 46% to 83% (mean, 67.3% +/- 11.9). The technical success rate was 100%. Procedure-related complication rate, mortality rate, and permanent neurologic morbidity rate at 30-day follow-up were 0%. At 12-month follow-up, no patient reported recurrent vertebrobasilar ischemic symptoms or had VA restenosis. CONCLUSION: This pilot study suggests that use of paclitaxel-eluting stents in angioplasty and to treat symptomatic atherosclerotic ostial VA stenosis are feasible and promising in terms of potential safety and effectiveness in prevention of recurrent ischemia and restenosis. These results could be helpful in the formulation of a larger prospective randomized controlled trial.

A T2* magnetic resonance imaging study of pancreatic iron overload in thalassemia major.

We studied the utility of pancreatic magnetic resonance imaging (MRI) in 72 thalassemia major patients (21 diabetic, 51 normoglycemic). Diabetic patients were significantly older (p<0.0001) and had smaller pancreas volume (p<0.0001). The two groups were comparable for ferritin and MRI-T2* heart, liver and pancreas. Pancreatic T2* signals were abnormal in 80% of both groups, and correlated with heart T2*. In normoglycemic patients, cardiac T2* and log-pancreatic T2* values correlated with homeostatic model assessments HOMA-B (beta cell reserve), HOMA-IR (insulin resistance) and fasting insulin/C-peptide levels. This suggested that improved chelation may improve beta cell reserve and prevent pancreatic atrophy.

Middle cerebral artery atherosclerosis: histological comparison between plaques associated with and not associated with infarct in a postmortem study.

BACKGROUND: Atherosclerotic stenosis of large intracranial arteries, especially the middle cerebral artery (MCA), is a common cause of stroke in Chinese patients. We aimed to describe the morphological features of atherosclerotic stenosis in the MCA and to investigate their relationship with cerebral infarcts from a postmortem series. METHODS: We studied the morphological features of the MCAs in consecutive postmortem adults aged 45 years or above. The following parameters were evaluated by a single observer blinded to the clinical history: (1) thickness of fibrous cap; (2) extent of lipid area; (3) degree of luminal stenosis; (4) presence of intraplaque hemorrhage, neovasculature, thrombus and calcification. A semiquantitative assessment of macrophage and T lymphocyte infiltration was made by immunohistochemical staining for CD68 and CD45RO. RESULTS: Seventy-six cases were recruited. Atherosclerotic plaques of more than 40% cross-sectional area luminal narrowing stenosis were found in 69 MCAs (45.4%, 69/152). The results demonstrated that the degree of luminal stenosis, the percentage of the plaques containing more than 40% lipid area and the prevalence of intraplaque hemorrhage, neovasculature and thrombus were higher in those plaques associated with infarct, and the mean index of both CD45RO and CD68 was higher among those associated with infarct (p < 0.01). Binary logistic regression showed that stenosis (p = 0.003; odds ratio, OR = 1.050), lipid area (p = 0.048, OR = 1.698) and presence of neovasculature (p = 0.040, OR = 3.471) were independent risk factors of MCA infarcts. CONCLUSIONS: Luminal stenosis caused by atherosclerotic plaque, percentage of lipid area and presence of intraplaque neovasculature may play a key role in leading to ischemic stroke.

Intracranial artery calcification: a newly identified risk factor of ischemic stroke.

BACKGROUND AND PURPOSE: Calcification in cerebral arteries is understudied, although frequently observed on computed tomography of the brain (CT brain). We aimed to assess the incidence of intracranial artery calcification in ischemic stroke patients and to evaluate its correlation with ischemic stroke. METHODS: Our study included ischemic stroke patients and age-gender-matched nonischemic stroke patients referred for CT brain. RESULTS: One hundred and seventy-five ischemic stroke patients and 182 controls were enrolled. The highest prevalence of calcification was seen in intracranial internal carotid artery (IICA) (80.4%), and less commonly in the vertebral artery (35.6%). There was a higher prevalence of intracranial artery calcification in ischemic stroke patients than controls (92.6% vs. 76.4%, P < .001). Hypertension (OR = 2.056, 95% CI: 1.129 approximately 3.745), diabetes (OR = 2.483, 95% CI: 1.233 approximately 5.001), smoking (OR = 2.844, 95% CI: 1.542 approximately 5.243), intracranial artery calcification (OR = 3.172, 95% CI: 1.252 approximately 8.036), hyperlipidemia (OR = 6.714, 95% CI: 3.302 approximately 13.650), and atrial fibrillation (OR = 7.941, 95% CI: 2.790 approximately 22.599) were found to be independently associated with ischemic stroke. CONCLUSIONS: We demonstrated a higher incidence of intracranial artery calcification in ischemic stroke patients. Besides traditional risk factors, intracranial artery calcification was found to be an independent risk factor of ischemic stroke.

Air-inflated magnetic resonance colonography in patients with incomplete conventional colonoscopy: Comparison with intraoperative findings, pathology specimens, and follow-up conventional colonoscopy.

BACKGROUND: To assess the usefulness of air-inflated magnetic resonance colonography (MRC) in patients with incomplete conventional colonoscopy (CC). METHODS: From September 2001 to December 2004, 51 patients (25 male and 26 female, age range 32 to 85 years) with incomplete colonoscopy were recruited to have MRC performed. Half-fourier single short turbo spin echo (HASTE) axial, coronal, and three dimensional fat suppressed gradient echo sequence (VIBE) coronal images in both the prone and supine positions were performed for each patient. MRC was reviewed by two radiologists for detection of synchronous colonic lesion. The location and size of lesions were recorded and were compared with the findings of CC. Patients were managed according to the clinical situation and intraoperative findings were compared with MRC findings. Follow-up colonoscopy was performed in 29 patients. The follow-up colonoscopy findings were then compared with the MRC findings. RESULTS: Forty-four patients had incomplete colonoscopy because of an obstructing tumor. The other seven patients had incomplete colonoscopy because of excessive bowel looping. Apart from one patient suffering from chronic obstructive airway disease with resulting nondiagnostic MRC, all other patients had MRC successfully performed. Each colon was divided into six bowel segments for analysis. All 300 segments were of diagnostic quality and were assessed by the MRC. MRC correctly identified all 44 obstructing tumors demonstrated by initial CC. Synchronous tumors in proximal colonic segments were identified in two patients by MRC. In addition, MRC identified two colonic tumors located in bowel segments inaccessible by CC because of excessive looping. CONCLUSIONS: MRC is useful for detection of colonic pathology and assessment of proximal colon in patients with colonic cancer after incomplete colonoscopy.

Diagnostic accuracy of MRI for middle cerebral artery stenosis: a postmortem study.

BACKGROUND AND PURPOSE: Magnetic resonance imaging (MRI) has been widely applied in detecting intracranial large artery stenosis, but there have been few validation studies to compare with histopathology. The aim of the postmortem study is to assess the accuracy of MRI in identifying middle cerebral artery (MCA) stenosis. METHODS: We recruited, consecutively, Chinese postmortem autopsies in our hospital during 19 months. MRI was performed in the postmortem brains to scan the cross-sections of MCAs with barium expanding the artery lumen. The MCAs were then removed for histopathologic studies. With histopathology as a reference standard, the accuracy of MRI was evaluated, and the correlation between MCA stenosis identified by MRI and radiologically or histopathologically evident brain infarcts was investigated. RESULTS: Seventy-six consecutive autopsies were recruited. The sensitivity and specificity of MRI in detecting more than 30% MCA stenosis were 38.6% and 92.2%, with a positive predictive value of 87.2% and negative predictive value of 52.2%, and the corresponding values of MRI in identifying more than 50% MCA stenosis were 57.1%, 90.8%, 50%, and 83.0%, respectively. Both more than 30% and more than 50% MCA stenosis identified by MRI were found to be associated with infarctions in the corresponding MCA territory (P= 0.001, odds ratio = 4.365, 95% CI: 1.684-11.313; and P= 0.039, odds ratio = 2.694, 95% CI: 1.139-6.377). CONCLUSIONS: Our study demonstrates the agreement between ex vivo MRI and histopathology in identifying MCA stenosis, and the correlation between the MCA stenosis identified by MRI and radiologically or histopathologically evident brain infarcts.

Role of fine needle aspiration and tru cut biopsy in diagnosis of mucinous carcinoma of breast--from a radiologist's perspective.

This study was to assess whether fine needle aspiration (FNA) or core biopsy would allow diagnosis of mucinous carcinoma of breast. In 37 mucinous carcinoma in 34 patients, 20 lesions had FNA and 24 lesions with core biopsy. FNA achieved a sensitivity of 66.7% in diagnosis of malignant lesions and 56% sensitivity in diagnosis of mucinous carcinoma. Core biopsy achieved 100% sensitivity and accuracy in the diagnosis of malignant lesions and mucinous carcinoma.

Radiology-Pathology conference: papillary carcinoma of the breast.

Papillary carcinoma of the breast is a rare breast carcinoma. It can be classified into invasive and noninvasive types. It can also be classified into intracystic and intraductal papillary carcinoma. Different radiological features are found to be associated with different histological types. Pitfalls are found to be associated with fine needle aspiration and core biopsy in the evaluation of papillary lesions. It is therefore important for radiologists to diagnose papillary carcinoma for proper management of the patients.

Magnetic resonance angiography of coronary arteries with a 3-dimensional magnetization-prepared true fast imaging with steady-state precession sequence compared with conventional coronary angiography.

BACKGROUND: The aim of the study was to compare the detection of clinically significant coronary artery stenosis using a magnetic resonance 3-dimensional (3D) breath-hold true fast imaging with steady-state precession (trueFISP) sequence with conventional coronary angiography. METHODS: Twenty-nine patients who were scheduled to undergo or had recently undergone diagnostic conventional coronary angiogram participated in this study. The left main, left anterior descending, left circumflex, and right coronary arteries were studied using the 3D breath-hold trueFISP technique. Each artery was imaged with 1 acquisition in 16 to 32 heartbeats. The image quality, vessel length, and presence or absence of stenosis were evaluated. A score of 1 to 3 (1 = noninterpretable, 2 = good, 3 = excellent) was used to assess image quality. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of magnetic resonance angiography in detecting significant coronary artery stenosis (> 50% luminal narrowing) on conventional coronary angiogram were calculated. RESULTS: Of 116 vessels, 108 were assessed in 29 patients. Twenty vessels that had image quality score of 1 were excluded from further evaluation. The mean lengths of vessels visualized were the following: left anterior descending 3.6 cm, left circumflex 3.4 cm, and right coronary 6.6 cm. The entire length of the left main coronary artery was visualized. For the visualized arterial segments, the sensitivity, specificity, accuracy, positive predictive value, and negative predictive value for detecting significant coronary artery stenosis were 92.8%, 95.3%, 95.0%, 68.4%, and 99.2%, respectively. CONCLUSIONS: The 3D breath-hold trueFISP technique, which uses the endogenous contrast of blood, is potentially useful in ruling out significant coronary artery stenosis but not yet sensitive enough as a screening tool.

Assessment of hyperacute stroke like symptoms by diffusion-weighted images.

We assessed the role of diffusion-weighted images in the evaluation of hyperacute stroke like symptoms in 18 patients. The volume of infarct measured by diffusion-weighted imaging (DWI) was correlated with the later computed tomography (CT) examinations. DWI had a sensitivity of 92%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 86% in detection of acute hemorrhagic and ischemic stroke. There is a good correlation with the volume of infarct measured by DWI and follow-up CT with a P < .05.

Hyperacute extensive middle cerebral artery territory infarcts. Role of computed tomography in predicting outcome.

OBJECTIVE: To assess the prognostic value of computed tomography (CT) in hyperacute middle cerebral artery (MCA) infarcts. METHODS: The CT features, total CT score, and National Institutes of Health Stroke Scale (NIHSS) score were correlated with the 30-day mortality in 16 patients with a hyperacute MCA infarct. RESULTS: Admission NIHSS scores were significantly lower in the survival group (P = 0.016). The extent of infarct, attenuation of corticomedullary differentiation, and total CT score were associated with 30-day mortality (P < 0.05). In prediction of mortality, extent of an infarct > 67% gave sensitivity, specificity, positive predictive value, and negative predictive value rates of 86%, 100%, 100%, and 90%, respectively. Attenuation of corticomedullary differentiation gave sensitivity, specificity, positive predictive value, and negative predictive value rates of 86%, 89%, 86%, and 89%, respectively. An NIHSS score > 28 gave sensitivity, specificity, positive predictive value, and negative predictive value rates of 86%, 67%, 67%, and 86%, respectively. A CT score > 4 gave sensitivity, specificity, positive predictive value, and negative predictive value rates of 86%, 78%, 75%, and 88%, respectively. CONCLUSIONS: Computed tomography features and the admission NIHSS score are important predictors of survival in hyperacute extensive MCA infarcts.

Cerebral blood flow measurement by color velocity imaging in radiation-induced carotid stenosis.

OBJECTIVE: To show whether there is any association between the development of neurologic symptoms and the total cerebral blood flow volume documented by color velocity imaging in patients with carotid stenosis that develops after radiotherapy. METHODS: Twenty-three patients with nasopharyngeal carcinoma (4 female and 19 male; age range, 39-69 years; mean age, 55.6 years) and major extracranial carotid stenosis underwent color velocity imaging. In this group, 8 patients had symptoms of a stroke or transient ischemic attack, and the other 15 patients were asymptomatic. The color velocity imaging results in the symptomatic group were then compared with those in the asymptomatic group. RESULTS: The cerebral blood flow in the symptomatic group was significantly lower than that in the asymptomatic group (224.1 +/- 89.0 versus 532.5 +/- 89.0 mL/min; P = .001). CONCLUSIONS: Cerebral blood flow as measured by color velocity imaging was lower in the symptomatic group. There is an association between the development of neurologic symptoms and blood flow volume.