The value of non echo planar, diffusion-weighted magnetic resonance imaging for the detection of residual or recurrent middle-ear cholesteatoma.

OBJECTIVE: To determine the value of non echo planar, diffusion-weighted magnetic resonance imaging for detection of residual and recurrent middle-ear cholesteatoma after combined-approach tympanoplasty. METHOD: The magnetic resonance imaging findings after primary surgery for cholesteatoma were compared with intra-operative findings at 'second-look' surgery or with clinical follow-up findings. RESULTS: Forty-eight magnetic resonance imaging studies were performed in 38 patients. Second-look surgery was performed 21 times in 18 patients. The remaining patients were followed up at the out-patient clinic. There were no false-positive findings with non echo planar, diffusion-weighted magnetic resonance imaging; however, there were four false-negative findings. The mean maximum diameter of recurrent cholesteatoma, as assessed using magnetic resonance imaging, was 11.7 mm (range, 4.4-25.3 mm). The sensitivity of non echo planar, diffusion-weighted magnetic resonance imaging for detecting cholesteatoma prior to second-look surgery was 0.76, with a specificity of 1.00. When clinical follow up of the non-operated ears was included in the analysis, sensitivity was 0.81 and specificity was 1.00. CONCLUSION: Recurrent cholesteatoma can be accurately detected using non echo planar, diffusion-weighted magnetic resonance imaging. Our study, however, also showed some false-negative results. Therefore, strict out-patient follow up is mandatory for those considering using this technique instead of standard second-look surgery.

Clinical course of pain in acute osteoporotic vertebral compression fractures.

PURPOSE: The authors prospectively determined the natural course of pain in patients with conservatively treated acute osteoporotic vertebral compression fractures (VCF). In addition, the type of conservative therapy that these patients received was assessed. MATERIALS AND METHODS: Patients older than 50 years, referred for spine radiography for acute back pain, were asked to complete a baseline clinical questionnaire. Patients with an acute VCF were followed up at 6 and 23 months with a questionnaire that included a Visual Analog Score (VAS) and type of pain medication and other conservative treatment. Significant pain relief was defined as a decrease in VAS of 50% or more. RESULTS: Forty-nine patients (mean age, 78 years; range, 51-95) with acute VCF were followed up for almost 2 years. Significant pain relief was noted in 22 of 35 patients (63%) at 6 months and in 25 of 36 (69%) at 23 months. In patients with persisting pain at 23 months (mean VAS 6.4), some decrease in VAS was apparent at 6 months but not in the 6-23 months interval. No predictors for significant pain relief could be identified. Patients with significant pain relief used less pain medication and had less physical therapy. CONCLUSIONS: In most patients with an acute VCF, pain decreases significantly with conservative therapy, predominantly in the first 6 months. However, almost 2 years after an acute VCF, a third of patients still had severe pain necessitating pain medication and physical therapy in the majority. No predictors for transition from acute to chronic pain could be identified.

Percutaneous vertebroplasty is not a risk factor for new osteoporotic compression fractures: results from VERTOS II.

BACKGROUND AND PURPOSE: PV is increasingly used as treatment for osteoporotic VCFs. However, controversy exists as to whether PV increases the risk for new VCFs during follow-up. The purpose of our research was to assess the incidence of new VCFs in patients with acute VCFs randomized to PV and conservative therapy. MATERIALS AND METHODS: VERTOS II is a prospective multicenter randomized controlled trial comparing PV with conservative therapy in 202 patients. Incidence, distribution, and timing of new VCFs during follow-up were assessed from spine radiographs. In addition, further height loss during follow-up of treated VCFs was measured. RESULTS: After a mean follow-up of 11.4 months (median, 12.0; range, 1-24 months), 18 new VCFs occurred in 15 of 91 patients after PV and 30 new VCFs in 21 of 85 patients after conservative therapy. This difference was not significant (P = .44). There was no higher fracture risk for adjacent-versus-distant vertebrae. Mean time to new VCF was 16.2 months after PV and 17.8 months after conservative treatment (logrank, P = .45). The baseline number of VCFs was the only risk factor for occurrence (OR, 1.43; 95% CI, 1.05-1.95) and number (P = .01) of new VCFs. After conservative therapy, further height loss of treated vertebrae occurred more frequently (35 of 85 versus 11 of 91 patients, P < .001) and was more severe (P < .001) than after PV. CONCLUSIONS: Incidence of new VCFs was not different after PV compared with conservative therapy after a mean of 11.4 months' follow-up. The only risk factor for new VCFs was the number of VCFs at baseline. PV contributed to preservation of stature by decreasing both the incidence and severity of further height loss in treated vertebrae.

VERTOS II: percutaneous vertebroplasty versus conservative therapy in patients with painful osteoporotic vertebral compression fractures; rationale, objectives and design of a multicenter randomized controlled trial.

BACKGROUND: The standard care in patients with a painful osteoporotic vertebral compression fracture (VCF) is conservative therapy. Percutaneous vertebroplasty (PV), a minimally invasive technique, is gaining popularity as a new treatment option. Many prospective and retrospective studies have reported on the effectiveness and safety of PV, but no large randomized controlled trial (RCT) has been published. OBJECTIVE: To estimate cost-effectiveness of PV compared to conservative therapy in terms of: pain reduction, quality of life, complications, secondary fractures and mortality. MATERIALS AND METHODS: The VERTOS II study is designed as a prospective, multicenter RCT. Patients with a painful VCF with bone edema on MR imaging, local back pain for 6 weeks or less, osteopenia and aged 50 years or older, after obtaining informed consent are included and randomized for PV or conservative therapy. In total 200 patients will be enrolled. Follow-up is at regular intervals during a 1-year period with standard questionnaires, addressing: clinical symptoms, pain medication, Visual Analogue Scale (VAS) score, quality of life and cost-effectiveness. Secondary fractures, necessary additional therapies and complications are recorded. CONCLUSION: The VERTOS II study is the first methodologically sound RCT designed to assess the cost-effectiveness of PV compared to conservative therapy in patients with an acute osteoporotic VCF. TRIAL REGISTRATION: http://www.clinicaltrials.gov, NCT00232466.

[Diagnostic image (91). A collapsing man with an aortic aneurysm. Ruptured aneurysm of the abdominal aorta]. / Diagnose in beeld (91). Een gecollabeerde man, bekend wegens een aorta-aneurysma. Gebarsten aneurysma aortae abdominalis.

A 73-year-old man had been diagnosed with an abdominal aortic aneurysm. Surgery was impossible due to poor cardiopulmonary condition. The patient collapsed due to rupture of the aneurysm.

[Diagnostic image (62). Pseudomyxoma peritonei]. / Diagnose in beeld (62). Pseudomyxoma peritonei.

In a 41-year-old man who suffered from an increasing abdominal diameter and weight loss, CT revealed signs of pseudomyxoma peritonei, which was confirmed by pathological investigation after surgical debulking.

[Diagnostic image (60) Chilaiditi syndrome]. / Diagnose in beeld (60). Syndroom van Chilaiditi.

In a 27-year-old man in whom an X-ray of the thorax was made, Chilaiditi syndrome (interposition of the colon between diaphragm and the liver) was diagnosed.

[Diagnostic image(58). Renal cell carcinoma]. / Diagnose in beeld (58). Niercelcarcinoom.

In a 38-year-old man with flank pain and macroscopic haematuria, CT revealed a renal mass of which the pathology diagnosis was: primary renal cell carcinoma.

Clinical features associated with internal carotid artery occlusion do not correlate with MRA cerebropetal flow measurements.

OBJECTIVES: The aetiology of clinical symptoms in patients with severe internal carotid artery (ICA) lesions may be thromboembolic or haemodynamic. The purpose was to assess whether changes in cerebropetal blood flow caused by an ICA occlusion have an effect on clinical symptoms and cerebral metabolism. METHODS: Forty three patients with an ICA occlusion who had hemispheric ischaemia (transient ischaemic attack or stroke), retinal ischaemia, or without symptoms, and 34 patients without significant ICA lesions with either hemispheric ischaemia or no symptoms were studied. Magnetic resonance angiography (MRA) was used to investigate total cerebropetal flow (flow in the ICAs plus basilar artery) and the flow in the middle cerebral arteries. Cerebral metabolic changes in the flow territory of the middle cerebral artery were determined with proton MR spectroscopy. RESULTS: Low total cerebropetal flow (r=-0.15, p<0.05) and low middle cerebral artery flow (r=-0.31, p<0.001) were found in patients with an ICA occlusion, but did not correlate with the clinical syndrome. By contrast, patients with prior symptoms of hemispheric ischaemia had decreased cerebral N-acetylaspartate/choline ratios (r=-0.35, p<0.001). However, the presence of an ICA occlusion (and subsequent low flow) did not correlate with low N-acetylaspartate/choline ratios. CONCLUSION: Neurological deficit caused by (transient) hemispheric ischaemia is associated with low N-acetylaspartate/choline ratios, whereas prior clinical features are not associated with low cerebropetal blood flow, as measured with MR angiography. As a result, differences in cerebropetal flow cannot explain why patients with similar carotid artery disease experience different neurological features.

Prognostic value of perfusion- and diffusion-weighted MR imaging in first 3 days of stroke.

The aim of this study was to evaluate the differences in cerebral perfusion seen on mean transit time (MTT) and cerebral blood volume (CBV) maps and to assess the subsequent prognostic value of the MTT-DWI (diffusion-weighted MRI) and CBV-DWI mismatch in the first three days of stroke on lesion enlargement and clinical outcome. In 38 patients, imaged 1-46 h after onset of symptoms, lesion volumes on proton-density (PD)-weighted MRI, DWI and PWI (both MTT and CBV maps) were compared with lesion volumes on follow-up PD-weighted scans, and to clinical outcome (National Institutes of Health Stroke Scale, Barthel index, and Rankin scale). The MTT-CBV, MTT-DWI and CBV-DWI mismatches were compared with change in lesion volume between initial and follow-up PD-weighted scans. Lesion volume on both DWI and PWI correlated significantly with clinical outcome parameters (p < 0.001) with strongest correlation for lesion volume on CBV. Perfusion-diffusion mismatches were found for both CBV and MTT and correlated significantly with lesion enlargement on PDweighted imaging with strongest correlation for the CBV-DWI mismatch. The CBV-DWI mismatch has the highest accuracy in predicting lesion size on follow-up imaging and in predicting clinical outcome. Lesion volume measurements on CBV maps have a higher specificity than on PD-weighted, MTT or DWI images in predicting clinical follow-up imaging and in predicting clinical outcome.

Circle of Willis collateral flow investigated by magnetic resonance angiography.

BACKGROUND AND PURPOSE: The circle of Willis (CW) is considered an important collateral pathway in maintaining adequate cerebral blood flow in patients with internal carotid artery (ICA) obstruction. We aimed to investigate the anatomic variation of the CW in patients with severe symptomatic carotid obstructive disease and to analyze diameter changes of its components in relation to varying grades of ICA obstruction and in relation to the presence or absence of (retrograde) collateral flow. METHODS: Seventy-five patients with minor disabling neurological deficits and with ICA stenoses or occlusions were categorized into 4 groups according to the severity of ICA obstruction. This patient population reflected a relatively favorable subgroup of cerebral infarction (considering their minor neurological deficits). All subjects underwent magnetic resonance angiography, including magnetic resonance angiography sensitive to flow direction. CW morphology and the size of its components were determined and compared with those values in control subjects (n=100). RESULTS: Compared with control subjects, patients demonstrated a significantly higher percentage of entirely complete CW configurations (55% versus 36%, P=0.02), complete anterior configurations (88% versus 68%, P=0.002), and complete posterior CW configurations (63% versus 47%, P=0.04). Patients with severe ICA stenosis did not show significantly increased CW vessel diameters. Patients with ICA occlusion demonstrated a high prevalence of collateral flow through the anterior CW and significantly increased diameters of the communicating channels. Patients with bilateral ICA occlusion relied on collateral flow via the posterior CW and demonstrated a bilateral increase in posterior communicating artery diameters (P<0.05). CONCLUSIONS: The anatomic and functional configuration of the CW reflects the degree of ICA obstruction.

Cerebral hemodynamics in relation to patterns of collateral flow.

BACKGROUND AND PURPOSE: We sought to investigate the relation between collateral flow via different pathways and hemodynamic parameters measured by dynamic susceptibility contrast-enhanced MRI in patients with severe carotid artery disease. METHODS: Dynamic susceptibility contrast-enhanced MRI was performed in 66 patients and 33 control subjects. Patients had severe stenosis (>70%, n=12), unilateral occlusion (n=38), or bilateral occlusion (n=16) of the internal carotid artery (ICA). Cerebripetal flow and collateral flow via the circle of Willis were investigated with MR angiography. Collateral flow via the ophthalmic artery was investigated with transcranial Doppler sonography. RESULTS: Patients with ICA stenosis had well-preserved cerebral perfusion and were in general not dependent on collateral supply. Patients with unilateral ICA occlusion had impaired cerebral perfusion. However, appearance time, peak time, and mean transit time in white matter were less increased in patients with than in patients without collateral flow via the circle of Willis (P<0.05). Furthermore, patients with collateral flow via both anterior and posterior communicating arteries had less increased regional cerebral blood volume than patients with collateral flow via the posterior communicating artery only (P<0.05). Patients with bilateral ICA occlusion had severely compromised hemodynamic status despite recruitment of collateral supply. CONCLUSIONS: In patients with unilateral ICA occlusion, the pattern of collateral supply has significant influence on hemodynamic status. Collateral flow via the anterior communicating artery is a sign of well-preserved hemodynamic status, whereas no collateral flow via the circle of Willis or flow via only the posterior communicating artery is a sign of deteriorated cerebral perfusion.

Assessment of borderzone ischemia with a combined MR imaging-MR angiography-MR spectroscopy protocol.

We attempted to assess whether magnetic resonance imaging (MRI)-MR angiography (MRA)-MR spectroscopy (MRS) measurements can be used in the differentiation of patients in whom severe carotid lesions result in chronically hypoperfused regions and in whom the collateral capacity is sufficient to maintain a normal cerebral blood flow. Sixty-six patients with severe stenosis of the internal carotid artery (ICA) and 19 control subjects underwent MRI, 1H MRS, and MRA. Anaerobic metabolic changes in the middle cerebral artery (MCA) territory were studied by assessing N-acetyl-L-aspartate (NAA)/choline and lactate/ NAA ratios. Quantitative flow was measured in the ICA, in the basilar artery, and in the MCA. Thirty-four patients had borderzone infarcts, 16 patients had territory infarcts, and 16 patients had no infarcts on MRI. Patients with border-zone infarcts had significantly reduced flow in the ICA (P < 0.001) and in the MCA (P < 0.05) and decreased NAA/ choline ratios (P < 0.001) in non-infarcted regions compared with control subjects (P < 0.001) but also compared with patients with territory infarcts (P < 0.05) and patients without infarcts (P < 0.05). Flow measurements in the ICA and MCA and metabolic measurements in the MCA territory can be applied to select patients in whom cerebral perfusion pressure is insufficient to maintain normal cellular integrity.

Diffusion-weighted magnetic resonance imaging in acute stroke.

BACKGROUND AND PURPOSE: Diffusion-weighted MRI (DWI) is highly sensitive in detecting early cerebral ischemic changes in acute stroke patients. In this study we compared the sensitivity of DWI with that of conventional MRI techniques. Furthermore, we investigated the prognostic value of the volume of ischemic lesions on DWI scans and of the apparent diffusion coefficient (ADC). METHODS: We performed DWI, fluid-attenuated inversion recovery, spin-echo T2-weighted MRI, and spin-echo proton density-weighted MRI in 42 patients with acute stroke and 15 control subjects. The volume of ischemic lesions was measured on early (<60 hours after onset) and follow-up MRI scans. Clinical outcome was measured 4 months after onset of symptoms with the National Institutes of Health Stroke Scale, the Barthel Index, and the Rankin Scale. RESULTS: With DWI, 98% of the ischemic lesions were detected, and with fluid-attenuated inversion recovery, 91% were detected, whereas with early T2-weighted or proton density-weighted scans, only 71% (P=0.002, chi2) and 80% (P=0.02, chi2) of lesions, respectively, were found. Lesion volume on early DWI scans correlated significantly with clinical outcome ratings (P<0.01). In patients with a first-ever stroke, a lesion volume of < or =22 mL on DWI predicted good outcome with a 75% sensitivity and a 100% specificity. The mean ADC of ischemic lesions was 29% lower than the ADC of normal-appearing parts of the brain (P<0.001). The ADC ratio correlated significantly with clinical outcome (P<0.05). CONCLUSIONS: DWI is a better imaging method than conventional MRI in detecting early ischemic lesions in stroke patients. Lesion size as measured on DWI scans and, to a lesser extent, ADC values are potential parameters for predicting clinical outcome in acute stroke patients.

Role of collateral flow on cerebral hemodynamics in patients with unilateral internal carotid artery occlusion.

The objective of this study was to evaluate the role of collateral blood flow via the anterior and posterior communicating arteries (ACoA and PCoA) and via the ophthalmic artery (OphA) on cerebral hemodynamics, metabolism, and border zone infarcts in 57 patients with unilateral symptomatic occlusions of the internal carotid artery. Collateral flow via the ACoA and PCoA was determined with magnetic resonance angiography (MRA) and collateral flow via the OphA with transcranial Doppler (TCD). Volume flow was studied with MRA, metabolism with 1H MR spectroscopy, CO2 reactivity with TCD, and the incidence of border zone infarcts with MRI. Compared with controls, patients had deteriorated volume flow, metabolism, and CO2 reactivity. No differences were found between patients with and patients without collateral flow through the ACoA and/or PCoA, or between patients with or without collateral flow via the OphA. Patients without collateral flow via any of these collaterals had decreased volume flow in the middle cerebral artery, decreased N-acetylaspartate/choline, and increased lactate/N-acetylaspartate, compared with the other patients. Patients with symptomatic internal carotid artery occlusion have deteriorated cerebral hemodynamics and metabolism. Different collateral flow patterns via the ACoA, PCoA, or OphA have no effect on the hemodynamic and metabolic parameters, as long as one of these pathways is present.

Overestimation of a stenosis in the internal carotid artery by duplex sonography caused by an increase in volume flow.

PURPOSE: The accuracy of duplex sonography in predicting the degree of an internal carotid artery (ICA) stenosis is decreased when a contralateral high-grade stenosis or occlusion is present. The purpose of this study was to determine whether this overestimation of the stenosis by duplex sonography is associated with an increase in volume flow through the ipsilateral ICA. METHODS: Forty-seven patients (89 vessels) with a symptomatic ICA stenosis or occlusion who underwent duplex sonography, intraarterial digital subtraction angiography, and magnetic resonance angiography flow quantification of the ICAs were evaluated. RESULTS: With the use of peak systolic velocity criteria, duplex overestimated stenoses more frequently (chi2: p = 0.03) in vessels with high volume flow (= mean volume flow in control group + 2 SD (>274 ml/min), 46% overestimation) than in vessels with normal or low volume flow (<274 ml/min, 20% overestimation). A correlation coefficient of 0.75 (p < 0.001) was found between volume flow and peak systolic velocity in the distal ICA, indicating that increased volume flow causes the peak systolic velocity to increase. Compared with volume flow in the control group (mean +/- SD = 198 +/- 38 ml/min), volume flow was increased in vessels with a 0% to 49% stenosis (mean +/- SD = 272 +/- 100 ml/min, p < 0.05) and in vessels with a 50% to 69% stenosis (mean +/- SD = 291 +/- 79 ml/min, p < 0.01) when the contralateral ICA had a 70% to 99% stenosis or occlusion. CONCLUSIONS: Increase in volume flow through the ICA frequently causes overestimation of stenoses in the ICA. Increased volume flow is frequently found in ICAs with a <70% stenosis that are contralateral to ICAs with a >70% stenosis or an occlusion.

MRA flow quantification in patients with a symptomatic internal carotid artery occlusion. The Dutch EC-IC Bypass Study Group.

BACKGROUND AND PURPOSE: Flow measurements in the collateral arteries of patients with internal carotid artery (ICA) occlusions may be important to estimate the risk of future stroke. Quantitative flow measurements in cerebropetal vessels can be reliably assessed by means of magnetic resonance angiography (MRA). METHODS: Fifty-four patients with transient or minor ischemic neurological deficits and an angiographically proven ICA occlusion and 16 control subjects underwent two-dimensional phase-contrast MRA quantitative flow measurements through the common carotid arteries, basilar artery, ICAs, and middle cerebral arteries (MCA). RESULTS: Patients with a unilateral ICA occlusion and a 0% to 69% stenosis of the contralateral ICA had increased flow in the contralateral ICA (P < .005) and in the basilar artery (P < .005) compared with control subjects. Even patients with a 70% to 99% stenosis contralateral to the ICA occlusion had increased flow in the ICA (P < .05) as well as increased flow in the basilar artery (P < .001). Total cerebropetal flow was not significantly different between these patients and control subjects. Patients with bilateral ICA occlusions had an increased flow in the basilar artery (P < .001), while the total cerebropetal flow was less than in control subjects (P < .001). In all patients, flow was decreased in the ipsilateral MCA (P < .001) and in the contralateral MCA (P < .05). CONCLUSIONS: The contralateral ICA is the main supplying artery in patients with an ICA occlusion. Total cerebropetal flow decreases only when both ICAs are occluded. In patients with symptomatic ICA occlusions, an open contralateral ICA is probably important to retain the cerebral blood flow within normal limits.

Determinants of in vivo MR imaging of slow axonal transport.

PURPOSE: To investigate specific surface characteristics of magnetic contrast agents based on a monocrystalline iron oxide nanoparticle (MION) that may determine their uptake and/or transport by axons. MATERIALS AND METHODS: MION were modified to have a range of surface charges or were covalently linked to wheat germ agglutinin (WGA), a neurotropic protein. Each agent was injected directly into the sciatic nerves or femoral arteries of rats (n = 22), and magnetic resonance (MR) images were obtained several days later. The imaging results then were correlated with results at postmortem histologic examination. RESULTS: Substantial uptake and/or transport by axons occurred only after intraneural injection and only if the agent had a strong surface charge or was covalently linked to WGA. The sciatic nerves appeared as uniformly hypointense structures having lengths proportional to the time from injection to imaging, and the calculated transport rates (4-7 mm/d) were consistent with slow axonal transport. Numerous Schwann cells and macrophages acquired large fractions of the injected agents and contributed substantially to the imaging results. CONCLUSION: Those characteristics of MION-based contrast agents that promote efficacy after intraneural injection may impede delivery to the nerve after intraarterial injection.