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1.
AJNR Am J Neuroradiol ; 38(11): 2059-2066, 2017 Nov.
Article in English | MEDLINE | ID: mdl-28882862

ABSTRACT

BACKGROUND AND PURPOSE: Accurate follow-up of metastatic brain tumors has important implications for patient prognosis and management. The aim of this study was to develop and evaluate the accuracy of a semiautomated algorithm in detecting growing or shrinking metastatic brain tumors on longitudinal brain MRIs. MATERIALS AND METHODS: We used 50 pairs of successive MR imaging datasets, 30 on 1.5T and 20 on 3T, containing contrast-enhanced 3D T1-weighted sequences. These yielded 150 growing or shrinking metastatic brain tumors. To detect them, we completed 2 major steps: 1) spatial normalization and calculation of the Jacobian operator field to quantify changes between scans, and 2) metastatic brain tumor candidate segmentation and detection of volume-changing metastatic brain tumors with the Jacobian operator field. Receiver operating characteristic analysis was used to assess the detection accuracy of the algorithm, and it was verified with jackknife resampling. The reference standard was based on detections by a neuroradiologist. RESULTS: The areas under the receiver operating characteristic curves were 0.925 for 1.5T and 0.965 for 3T. Furthermore, at its optimal performance, the algorithm achieved a sensitivity of 85.1% and 92.1% and specificity of 86.7% and 91.3% for 1.5T and 3T, respectively. Vessels were responsible for most false-positives. Newly developed or resolved metastatic brain tumors were a major source of false-negatives. CONCLUSIONS: The proposed algorithm could detect volume-changing metastatic brain tumors on longitudinal brain MRIs with statistically high accuracy, demonstrating its potential as a computer-aided change-detection tool for complementing the performance of radiologists, decreasing inter- and intraobserver variability, and improving efficacy.


Subject(s)
Algorithms , Brain Neoplasms/diagnostic imaging , Brain Neoplasms/secondary , Image Processing, Computer-Assisted/methods , Magnetic Resonance Imaging/methods , Adult , Aged , Aged, 80 and over , False Negative Reactions , False Positive Reactions , Female , Humans , Male , Middle Aged , Observer Variation , ROC Curve , Retrospective Studies , Sensitivity and Specificity , Young Adult
2.
AJNR Am J Neuroradiol ; 38(1): 195-199, 2017 Jan.
Article in English | MEDLINE | ID: mdl-27884880

ABSTRACT

BACKGROUND AND PURPOSE: Spinal epidural AVFs are rare spinal vascular malformations. When there is associated intradural venous reflux, they may mimic the more common spinal dural AVFs. Correct diagnosis and localization before conventional angiography is beneficial to facilitate treatment. We hypothesize that first-pass contrast-enhanced MRA can diagnose and localize spinal epidural AVFs with intradural venous reflux and distinguish them from other spinal AVFs. MATERIALS AND METHODS: Forty-two consecutive patients with a clinical and/or radiologic suspicion of spinal AVF underwent MR imaging, first-pass contrast-enhanced MRA, and DSA at a single institute (2000-2015). MR imaging/MRA and DSA studies were reviewed by 2 independent blinded observers. DSA was used as the reference standard. RESULTS: On MRA, all 7 spinal epidural AVFs with intradural venous reflux were correctly diagnosed and localized with no interobserver disagreement. The key diagnostic feature was arterialized filling of an epidural venous pouch with a refluxing radicular vein arising from the arterialized epidural venous system. CONCLUSIONS: First-pass contrast-enhanced MRA is a reliable and useful technique for the initial diagnosis and localization of spinal epidural AVFs with intradural venous reflux and can distinguish these lesions from other spinal AVFs.


Subject(s)
Central Nervous System Vascular Malformations/diagnostic imaging , Epidural Space/diagnostic imaging , Magnetic Resonance Angiography/methods , Spinal Cord/diagnostic imaging , Aged , Angiography, Digital Subtraction/methods , Central Nervous System Vascular Malformations/pathology , Epidural Space/pathology , Female , Humans , Male , Middle Aged , Spinal Cord/pathology
3.
AJNR Am J Neuroradiol ; 38(1): 200-205, 2017 Jan.
Article in English | MEDLINE | ID: mdl-27811131

ABSTRACT

BACKGROUND AND PURPOSE: Catheter angiography is typically used for follow-up of treated spinal AVFs. The purpose of this study was to determine the diagnostic performance and utility of first-pass contrast-enhanced MRA in the posttreatment evaluation of spinal AVFs compared with DSA. MATERIALS AND METHODS: A retrospective review was performed of all patients at our tertiary referral hospital (from January 2000 to April 2015) who underwent spine MR imaging, first-pass contrast-enhanced MRA, and DSA after surgical and/or endovascular treatment of a spinal AVF. Presence of recurrent or residual fistula on MRA, including vertebral level of the recurrent/residual fistula, was evaluated by 2 experienced neuroradiologists blinded to DSA findings. Posttreatment conventional MR imaging findings were also evaluated, including presence of intramedullary T2 hyperintensity, perimedullary serpentine flow voids, and cord enhancement. The performance of MRA and MR imaging findings for diagnosis of recurrent/residual fistula was determined by using DSA as the criterion standard. RESULTS: In total, 28 posttreatment paired MR imaging/MRA and DSA studies were evaluated in 22 patients with prior spinal AVF and 1 patient with intracranial AVF with prior cervical perimedullary venous drainage. Six image sets of 5 patients demonstrated recurrent/residual disease at DSA. MRA correctly identified all cases with recurrent/residual disease with 1 false-positive (sensitivity, 100%; specificity 95%; P < .001), with correct localization in all cases without interobserver disagreement. Conventional MR imaging parameters were not significantly associated with recurrent/residual spinal AVF. CONCLUSIONS: First-pass MRA demonstrates high sensitivity and specificity for identifying recurrent/residual spinal AVFs and may potentially substitute for DSA in the posttreatment follow-up of patients with spinal AVFs.


Subject(s)
Central Nervous System Vascular Malformations/diagnostic imaging , Magnetic Resonance Angiography/methods , Adult , Aged , Angiography, Digital Subtraction/methods , Female , Humans , Male , Middle Aged , Retrospective Studies , Sensitivity and Specificity
4.
AJNR Am J Neuroradiol ; 38(1): 206-212, 2017 Jan.
Article in English | MEDLINE | ID: mdl-27811132

ABSTRACT

BACKGROUND AND PURPOSE: Different MRA techniques used to evaluate spinal dural arteriovenous fistulas offer unique advantages and limitations with regards to temporal and spatial resolution. The purpose of this study was to compare the efficacy and interobserver agreement of 2 commonly used contrast-enhanced spinal MRA techniques, multiphase time-resolved MRA and single-phase first-pass MRA, in assessment of spinal dural arteriovenous fistulas. MATERIALS AND METHODS: Retrospective review of 15 time-resolved and 31 first-pass MRA studies in patients with clinical suspicion of spinal dural arteriovenous fistula was performed by 2 independent, blinded observers. DSA was used as the reference standard to compare the diagnostic performance of the 2 techniques. RESULTS: There were 10 cases of spinal dural arteriovenous fistula in the time-resolved MRA group and 20 in the first-pass MRA group. Time-resolved MRA detected spinal dural arteriovenous fistulas with sensitivity and specificity of 100% and 80%, respectively, with 100% correct-level localization rate. First-pass MRA detected spinal dural arteriovenous fistulas with sensitivity and specificity of 100% and 82%, respectively, with 87% correct-level localization rate. Interobserver agreement for localization was excellent for both techniques; however, it was higher for time-resolved MRA. In 5 cases, the site of fistula was not included in the FOV, but a prominent intradural radicular vein was observed at the edge of the FOV. CONCLUSIONS: Multiphase time-resolved MRA and single-phase first-pass MRA were comparable in diagnosis and localization of spinal dural arteriovenous fistulas and demonstrated excellent interobserver agreement, though there were more instances of ambiguity in fistula localization on first-pass MRA.


Subject(s)
Central Nervous System Vascular Malformations/diagnostic imaging , Magnetic Resonance Angiography/methods , Adult , Aged , Contrast Media , Female , Humans , Male , Middle Aged , Retrospective Studies , Sensitivity and Specificity
5.
AJNR Am J Neuroradiol ; 37(11): 2026-2032, 2016 Nov.
Article in English | MEDLINE | ID: mdl-27313130

ABSTRACT

BACKGROUND AND PURPOSE: Signs suggestive of unexpected dural venous sinus thrombosis are detectable on routine MR imaging studies without MRV. We assessed performance characteristics and interrater reliability of routine MR imaging for the diagnosis of dural venous sinus thrombosis, focusing on the superior sagittal, transverse, and sigmoid sinuses. MATERIALS AND METHODS: This case series included 350 patients with MRIs performed with contrast-enhanced MRV and 79 patients with routine MRIs performed within 48 hours of a CTV from 2008 to 2014 (total, n = 429). Routine MR images were separated from the contrast-enhanced MRVs and CTVs. Three neuroradiologists, blinded to clinical data, independently reviewed the MRIs for signs of dural venous sinus thrombosis, including high signal on sagittal T1, loss of flow void on axial T2, high signal on FLAIR, high signal on DWI, increased susceptibility effects on T2*-weighted gradient recalled-echo imaging, and filling defects on axial contrast-enhanced spin-echo T1WI and/or volumetric gradient-echo T1WI. Two neuroradiologists independently reviewed contrast-enhanced MRVs and CTVs to determine the consensus gold standard. Interrater reliability was calculated by using the κ coefficient. RESULTS: Contrast-enhanced MRV and CTV confirmed that dural venous sinus thrombosis was present in 72 of 429 cases (16.8%). The combination of routine MR sequences had an overall sensitivity of 79.2%, specificity of 89.9%, and moderate interrater reliability (κ = 0.50). The 3 readers did not have similar performance characteristics. 69.4% of positive cases had clinical suspicion of dural venous sinus thrombosis indicated on imaging requisition. CONCLUSIONS: Routine MR images can suggest dural venous sinus thrombosis with high specificity in high-risk patients, even in cases without clinical suspicion.

6.
AJNR Am J Neuroradiol ; 36(12): 2285-91, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26471754

ABSTRACT

BACKGROUND AND PURPOSE: Good CTA collaterals independently predict good outcome in acute ischemic stroke. Our aim was to evaluate the role of collateral circulation and its added benefit over CTP-derived total ischemic volume as a predictor of baseline NIHSS score, total ischemic volume, hemorrhagic transformation, final infarct size, and a modified Rankin Scale score >2. MATERIALS AND METHODS: This was a retrospective study of 395 patients with stroke dichotomized by recanalization (recanalization positive/recanalization negative) and collateral status. Clot burden score was quantified on baseline CTA. Total ischemic volumes were derived from thresholded CTP maps. Final infarct size was assessed on follow-up CT/MRI. We performed uni-/multivariate analyses for each outcome, adjusting for rtPA status, using general linear (continuous variables) and logistic (binary variables) regression. Model comparison with collateral score and total ischemic volume was performed using the F or likelihood ratio test. RESULTS: Collateral presence independently and inversely predicted all outcomes except hemorrhagic transformation in patients who were recanalization negative and mRS >2 in patients who were recanalization positive. The greatest collateral benefit occurred in patients who were recanalization negative, contributing 16.5% and 19.2% of the variability for final infarct size and mRS >2. The collateral score model is superior to the total ischemic volume for mRS >2 prediction, but a combination of total ischemic volume and collateral score is superior for mRS >2 and final infarct prediction (24% and 28% variability, respectively). In patients who were recanalization positive, a model including collateral score and total ischemic volume was superior to that of total ischemic volume for hemorrhagic transformation and final infarct prediction but was muted compared with patients who were recanalization negative (11.3% and 16.9% variability). CONCLUSIONS: Collateral circulation is an independent predictor of all outcomes, but the magnitude of significance varies, greater in patients who were recanalization negative versus recanalization positive. Total ischemic volume assessment is complementary to collateral score in many cases.


Subject(s)
Brain/blood supply , Collateral Circulation/physiology , Stroke/pathology , Aged , Aged, 80 and over , Cerebral Angiography/methods , Female , Humans , Magnetic Resonance Imaging/adverse effects , Male , Middle Aged , Multivariate Analysis , Retrospective Studies , Stroke/diagnostic imaging , Stroke/drug therapy , Tissue Plasminogen Activator/therapeutic use , Tomography, X-Ray Computed/methods , Treatment Outcome
7.
AJNR Am J Neuroradiol ; 36(6): 1069-75, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25721075

ABSTRACT

BACKGROUND AND PURPOSE: Lacunar infarcts account for approximately 25% of acute ischemic strokes. Compared with NCCT alone, the addition of CTP improves sensitivity for detection of infarcts overall. Our aim was to systematically evaluate the diagnostic benefit and interobserver reliability of an incremental CT protocol in lacunar infarction. MATERIALS AND METHODS: Institutional review board approval and patient consent were obtained. One hundred sixty-three patients presenting with a lacunar syndrome ≤4.5 hours from symptom onset were enrolled. Images were reviewed incrementally by 2 blinded readers in 3 separate sessions (NCCT only, NCCT/CTA, and NCCT/CTA/CTP). Diagnostic confidence was recorded on a 6-point scale with DWI/ADC as a reference. Logistic regression analysis calculated differences between actual and observed diagnoses, adjusted for confidence. Predictive effects of observed diagnostic accuracy and confidence score were quantified with the entropy r(2) value. Sensitivity, specificity, and confidence intervals were calculated accounting for multiple readers. Receiver operating characteristic analyses were compared among diagnostic strategies. Interobserver agreement was established with Cohen κ statistic. RESULTS: The final study cohort comprised 88 patients (50% male). DWI/ADC-confirmed lacunar infarction occurred in 59/88 (67%) with 36/59 (61%) demonstrating a concordant abnormal finding on CTP. Sensitivity for definite or probable presence of lacunar infarct increased significantly from 9.3% to 42.4% with incremental protocol use, though specificity was unchanged (range, 91.9%-95.3%). The observed diagnosis was significantly related to the actual diagnosis after adjusting for CTP confidence level (P = .04) and was 5.1 and 2.4 times more likely to confirm lacunar infarct than NCCT or CTA source images. CTP area under the curve (0.77) was significantly higher than that of CTA source images (0.68, P = .006) or NCCT (0.55, P < .001). CONCLUSIONS: CTP offers an improved diagnostic benefit over NCCT and CTA for the diagnosis of lacunar infarction.


Subject(s)
Cerebral Angiography/methods , Multimodal Imaging/methods , Stroke, Lacunar/diagnostic imaging , Tomography, X-Ray Computed/methods , Adult , Aged , Aged, 80 and over , Cohort Studies , Diagnosis, Differential , Female , Humans , Male , Middle Aged , Observer Variation , Reproducibility of Results , Sensitivity and Specificity
8.
AJNR Am J Neuroradiol ; 36(4): 646-52, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25572947

ABSTRACT

BACKGROUND AND PURPOSE: Stroke Prognostication by Using Age and NIHSS score (SPAN-100 index) facilitates stroke outcomes. We assessed imaging markers associated with the SPAN-100 index and their additional impact on outcome determination. MATERIALS AND METHODS: Of 273 consecutive patients with acute ischemic stroke (<4.5 hours), 55 were characterized as SPAN-100-positive (age +NIHSS score ≥ 100). A comprehensive imaging review evaluated differences, using the presence of the hyperattenuated vessel sign, ASPECTS, clot burden score, collateral score, CBV, CBF, and MTT. The primary outcome assessed was favorable outcome (mRS ≤ 2). Secondary outcomes included recanalization, lack of neurologic improvement, and hemorrhagic transformation. Uni- and multivariate analyses assessed factors associated with favorable outcome. Area under the curve evaluated predictors of favorable clinical outcome. RESULTS: Compared with the SPAN-100-negative group, the SPAN-100-positive group (55/273; 20%) demonstrated larger CBVs (<0.001), poorer collaterals (P < .001), and increased hemorrhagic transformation rates (56.0% versus 36%, P = .02) despite earlier time to rtPA (P = .03). Favorable outcome was less common among patients with SPAN-100-positive compared with SPAN-100-negative (10.9% versus 42.2%; P < .001). Multivariate regression revealed poorer outcome for SPAN-100-positive (OR = 0.17; 95% CI, 0.06-0.38; P = .001), clot burden score (OR = 1.14; 95% CI, 1.05-1.25; P < .001), and CBV (OR = 0.58; 95% CI, 0.46-0.72; P = .001). The addition of the clot burden score and CBV improved the predictive value of SPAN-100 alone for favorable outcome from 60% to 68% and 74%, respectively. CONCLUSIONS: SPAN-100-positivity predicts a lower likelihood of favorable outcome and increased hemorrhagic transformation. CBV and clot burden score contribute to poorer outcomes among high-risk patients and improve stroke-outcome prediction.


Subject(s)
Brain Infarction/diagnosis , Stroke/diagnosis , Aged , Aged, 80 and over , Cerebral Angiography/methods , Female , Humans , Image Processing, Computer-Assisted , Intracranial Thrombosis/diagnosis , Male , Middle Aged , Multivariate Analysis , Prognosis , Retrospective Studies , Severity of Illness Index , Stroke/complications , Stroke/diagnostic imaging , Treatment Outcome
9.
AJNR Am J Neuroradiol ; 34(1): 146-52, 2013 Jan.
Article in English | MEDLINE | ID: mdl-22700751

ABSTRACT

BACKGROUND AND PURPOSE: Recanalization may not result in better clinical outcomes after ischemic stroke. We determined the incidence and significant predictors of CMR, defined as CT angiographic recanalization and a good clinical outcome, after IV-rtPA in acute ischemic stroke. A CMR score was devised and tested. MATERIALS AND METHODS: One hundred twenty-six consecutive patients with anterior circulation ischemic stroke receiving IV-rtPA were retrospectively reviewed. Imaging included a baseline NCCT and CTA. Recanalization was assessed on a 24-hour CTA. Clinical outcome was determined by the 90-day mRS. CMR was defined as CTA recanalization and a good clinical outcome (mRS ≤2). Logistic regression analysis determined predictors of CMR. The predictive ability of a CMR score was tested with AIC. RESULTS: CMR occurred in 29% (36/126). Patients with CMR had fewer neurologic deficits (P = .001) and higher ASPECTS (P = .041) at baseline than those without CMR. Baseline NIHSS score did not predict proximal occlusion (OR 0.959; 95% CI [0.907-1.014]; P = .141). Multivariate analysis showed admission NIHSS score (P = .001) and the site of vessel occlusion (P = .022) to be significant CMR predictors. CMR was significantly less likely in patients with proximal occlusions (ICA, P = .005; proximal M1, P = .021). A CMR score better predicted CMR than either NIHSS or vessel occlusion site alone (P < .0001). CONCLUSIONS: Milder baseline stroke deficit and distal vessel occlusion are significant predictors of CMR. A combination of these parameters better predicts CMR than either parameter alone.


Subject(s)
Brain Ischemia/diagnostic imaging , Brain Ischemia/prevention & control , Cerebral Angiography/statistics & numerical data , Stroke/diagnostic imaging , Stroke/prevention & control , Tissue Plasminogen Activator/administration & dosage , Aged , Brain Ischemia/epidemiology , Comorbidity , Fibrinolytic Agents/administration & dosage , Humans , Ontario/epidemiology , Outcome Assessment, Health Care/methods , Outcome Assessment, Health Care/statistics & numerical data , Prevalence , Prognosis , Recombinant Proteins/administration & dosage , Reproducibility of Results , Retrospective Studies , Risk Factors , Sensitivity and Specificity , Stroke/epidemiology , Tissue Plasminogen Activator/genetics , Treatment Outcome
10.
AJNR Am J Neuroradiol ; 34(4): 773-9, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23079406

ABSTRACT

BACKGROUND AND PURPOSE: Contrast extravasation within spontaneous intracranial hemorrhage is a well-described predictor of hematoma growth, poor clinical outcome, and mortality. The purpose of this study was to assess the prognostic value of contrast extravasation in acute traumatic intracranial hematomas. MATERIALS AND METHODS: In our institution, CTA (including PCCT) is the primary screening technique for cervical vascular injuries. Sixty consecutive patients with at least 1 acute intracranial hematoma (ICH, subdural hematoma, and/or epidural hematoma) meeting predefined size criteria, with CTA/PCCT performed within 24 hours of admission and follow-up CT within 72 hours of admission, were retrospectively evaluated for CE by 2 observers. The predictive value of CE for a composite outcome (hematoma expansion, need for hematoma evacuation, in-hospital mortality) was evaluated on a per-patient basis. Interobserver agreement for CE and the association between baseline variables and outcome were also examined. Different patterns of extravasation were evaluated on a per-lesion basis, with outcomes including hematoma expansion and evacuation. RESULTS: CE was present in 30 (50%) patients with almost perfect interobserver agreement (κ=0.87; 95% CI, 0.74-0.99). The per-patient multivariate analysis showed independent association of midline shift (P=.020), Glasgow Coma Scale score≤8 (P=.024), and CE (P=.017), with poor outcome and demonstrated a trend toward poor outcome prediction for age 65 years or older (P=.050). In the per-lesion analysis, only extravasation identified on CTA (active and contained extravasation) was associated with hematoma expansion and evacuation. CONCLUSIONS: Contrast extravasation within intracranial hematomas predicts poor in-hospital outcome in the setting of acute traumatic intracranial injuries.


Subject(s)
Extravasation of Diagnostic and Therapeutic Materials/diagnostic imaging , Hematoma, Epidural, Cranial/diagnostic imaging , Hematoma, Subdural, Acute/diagnostic imaging , Intracranial Hemorrhage, Traumatic/diagnostic imaging , Tomography, X-Ray Computed/methods , Acute Disease , Adult , Aged , Aged, 80 and over , Disease Progression , Extravasation of Diagnostic and Therapeutic Materials/mortality , Female , Glasgow Coma Scale , Hematoma, Epidural, Cranial/mortality , Hematoma, Subdural, Acute/mortality , Hospital Mortality , Humans , Intracranial Hemorrhage, Traumatic/mortality , Male , Middle Aged , Observer Variation , Predictive Value of Tests , Prognosis , Retrospective Studies , Tomography, X-Ray Computed/statistics & numerical data
12.
AJNR Am J Neuroradiol ; 32(11): 2132-5, 2011 Dec.
Article in English | MEDLINE | ID: mdl-21903915

ABSTRACT

BACKGROUND AND PURPOSE: CTA provides high-resolution imaging of the head and neck vasculature but also of the soft tissues and bones. This results in a large volume of information to be interpreted. This study examines interpretation errors with head and neck CTAs and assesses whether double reading reduces miss rates. MATERIALS AND METHODS: Consecutive CTAs of the neck and intracranial circulation were retrospectively identified and reviewed for vascular and nonvascular findings by a consensus of 2 neuroradiologists. The results were compared with the official report. Significant discrepancies were considered those that would have influenced follow-up or management. RESULTS: We reviewed 503 studies; 144 were originally reported by a staff neuroradiologist alone, 209 by staff and diagnostic radiology resident, and 150 by staff and neuroradiology fellow. Twenty-six significant discrepancies were discovered in 20 studies, corresponding to 4.0% of studies with at least 1 miss, and an overall miss rate per study of 5.2%. There was at least 1 miss in 6.3% of studies interpreted by a staff neuroradiologist alone, 3.3% by staff and resident, and 2.7% by staff and fellow. The miss rate differences were not statistically significant. The most common misses were small aneurysms (50% of misses). CONCLUSIONS: CTA neck and head datasets are now large, and there is a potential for missed findings. Significant discrepancies can occur with a low but not insignificant rate. Arterial pathology accounted for most discrepancies. This study emphasizes the need for careful systematic scrutiny for both vascular and nonvascular pathology regardless of indication. Double reading reduces error rates.


Subject(s)
Angiography/methods , Artifacts , Carotid Artery Diseases/diagnostic imaging , Cerebral Arterial Diseases/diagnostic imaging , Image Enhancement/methods , Stroke/diagnostic imaging , Tomography, X-Ray Computed/methods , Adult , Aged , Aged, 80 and over , Female , Head/blood supply , Head/diagnostic imaging , Humans , Male , Middle Aged , Neck/blood supply , Neck/diagnostic imaging , Observer Variation , Reproducibility of Results , Sensitivity and Specificity
13.
AJNR Am J Neuroradiol ; 32(10): 1879-84, 2011.
Article in English | MEDLINE | ID: mdl-21885714

ABSTRACT

BACKGROUND AND PURPOSE: For patients with ICH, knowing the rate of CT contrast extravasation may provide insight into the pathophysiology of hematoma expansion. This study assessed whether the PCT-derived PS can measure different rates of CT contrast extravasation for admission CTA spot signs, PCCT, PCL, and regions without extravasation in patients with ICH. MATERIALS AND METHODS: CT was performed at admission and at 24 hours for 16 patients with ICH with/without contrast extravasation seen on CTA and PCCT. PCT-PS was measured at admission. The Wilcoxon rank sum test with a Bonferroni correction was used to compare PS values from the following regions of interest: 1) spot sign lesions only (9 foci), 2) PCL lesions only (9 foci), 3) hematoma excluding extravasation, 4) regions contralateral to extravasation, 5) hematoma in patients without extravasation, and 6) an area contralateral to that in 5. Additionally, hematoma expansion was determined at 24 hours defined by NCCT. RESULTS: PS was 6.5 ± 1.60 mL · min(-1) × (100 g)(-1), 0.95 ± 0.39 mL · min(-1) × (100 g)(-1), 0.12 ± 0.39 mL · min(-1) × (100 g)(-1), 0.26 ± 0.09 mL · min(-1) × (100 g)(-1), 0.38 ± 0.26 mL · min(-1) × (100 g)(-1), and 0.09 ± 0.32 mL · min(-1) × (100 g)(-1) for the following: 1) spot sign lesions only (9 foci), 2) PCL lesions only (9 foci), 3) hematoma excluding extravasation, 4) regions contralateral to extravasation, 5) hematoma in patients without extravasation, and 6) an area contralateral to that in 5. PS values from spot sign lesions and PCL lesions were significantly different from each other and all other regions, respectively (P < .05). Hematoma volume increased from 34.1 ± 41.0 mL to 40.2 ± 46.1 mL in extravasation-positive patients and decreased from 19.8 ± 31.8 mL to 17.4 ± 27.3 mL in extravasation-negative patients. CONCLUSIONS: The PCT-PS parameter measures a higher rate of contrast extravasation for CTA spot sign lesions compared with PCL lesions and hematoma. Early extravasation was associated with hematoma expansion.


Subject(s)
Cerebral Hemorrhage/diagnostic imaging , Cerebral Hemorrhage/metabolism , Extravasation of Diagnostic and Therapeutic Materials/diagnostic imaging , Extravasation of Diagnostic and Therapeutic Materials/metabolism , Iodine/pharmacokinetics , Tomography, X-Ray Computed/methods , Aged , Cerebral Hemorrhage/complications , Contrast Media/pharmacokinetics , Extravasation of Diagnostic and Therapeutic Materials/etiology , Female , Humans , Male , Metabolic Clearance Rate , Middle Aged
14.
Diabet Med ; 28(2): 175-8, 2011 Feb.
Article in English | MEDLINE | ID: mdl-21219425

ABSTRACT

AIMS: To investigate the impact of wound fluid lactate concentration on diagnosing soft-tissue infection in diabetic foot ulcers. METHODS: Lactate concentration in wound fluid obtained from diabetic foot ulcers was determined using a lactate analyser and compared with clinical examination findings. RESULTS: Overall median wound fluid lactate concentration was 21.03 mm (5.58-80.40 mm). Wound lactate levels were significantly higher in infected compared with non-infected diabetic foot ulcers (P=0.001). Non-infected diabetic foot ulcers that healed within 6 months of treatment showed a significantly lower wound fluid lactate concentration at baseline as opposed to those that did not heal (P=0.007). CONCLUSIONS: Non-healing diabetic foot ulcers are characterized by high wound fluid lactate levels. Assessment of wound fluid lactate concentration might be helpful for confirming the suspicion of soft tissue infection, particularly when clinical signs are atypical.


Subject(s)
Body Fluids/metabolism , Diabetes Mellitus, Type 2/metabolism , Diabetic Foot/metabolism , Lactic Acid/metabolism , Soft Tissue Infections/diagnosis , Soft Tissue Infections/metabolism , Wounds and Injuries/metabolism , Adult , Aged , Aged, 80 and over , Amputation, Surgical , Biomarkers/metabolism , Body Fluids/microbiology , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/microbiology , Diabetic Foot/diagnosis , Diabetic Foot/microbiology , Female , Humans , Male , Middle Aged , Soft Tissue Infections/microbiology , Wound Healing , Wounds and Injuries/microbiology
15.
AJNR Am J Neuroradiol ; 32(2): 359-64, 2011 Feb.
Article in English | MEDLINE | ID: mdl-21051518

ABSTRACT

BACKGROUND AND PURPOSE: CTA-SI have been previously reported to correlate with CBV. We hypothesized that CTA-SI performed by modern multisection CT scanners are CBF-, not CBV-weighted. MATERIALS AND METHODS: Sixty-four consecutive patients with anterior circulation stroke symptoms were selected from a stroke data base between June 2007 and January 2009. Two independent blinded readers calculated defect volumes of CTA-SI and PCCT, CBF, and CBV images. Spearman correlation of lesion volumes was performed. Linear regression and residual analysis demonstrated factors associated with outliers for CTA or PCCT for CBF and CBV volumes. RESULTS: We found a strong positive correlation between CTA with CBF (r = 0.89, P < .0001) and between PCCT and CBV (r = 0.79, P < .0001). CTA to CBV (r = 0.5, P < .0001) and PCCT to CBF (r = 0.52, P < .0001) correlations were weaker. Positive CTA outliers had lower ASPECTS (P = .01), larger baseline CTA (149 ± 46 cm(3) versus 83 ± 32 cm(3); P = .002, respectively), and final infarct (190 ± 100 cm(3) versus 80 ± 50 cm(3); P = .09, respectively) volumes than nonoutliers. No baseline features were significantly related to PCCT outliers. There was no difference in the vessel occlusion sites for positive or negative outliers for CTA or PCCT (P = .55 and P = 1.00, respectively). CONCLUSIONS: Our results indicate that CTA-SI are CBF- rather than CBV-weighted.


Subject(s)
Blood Volume/physiology , Cerebral Angiography/methods , Cerebrovascular Circulation/physiology , Infarction, Anterior Cerebral Artery/diagnostic imaging , Tomography, X-Ray Computed/methods , Databases, Factual , Humans , Infarction, Anterior Cerebral Artery/physiopathology , Linear Models
16.
Eur Arch Psychiatry Clin Neurosci ; 260 Suppl 2: S81-9, 2010 Nov.
Article in English | MEDLINE | ID: mdl-20945070

ABSTRACT

Obstetric complications play a role in the pathophysiology of schizophrenia. However, the biological consequences during neurodevelopment until adulthood are unknown. Microarrays have been used for expression profiling in four brain regions of a rat model of neonatal hypoxia as a common factor of obstetric complications. Animals were repeatedly exposed to chronic hypoxia from postnatal (PD) day 4 through day 8 and killed at the age of 150 days. Additional groups of rats were treated with clozapine from PD 120-150. Self-spotted chips containing 340 cDNAs related to the glutamate system ("glutamate chips") were used. The data show differential (up and down) regulations of numerous genes in frontal (FR), temporal (TE) and parietal cortex (PAR), and in caudate putamen (CPU), but evidently many more genes are upregulated in frontal and temporal cortex, whereas in parietal cortex the majority of genes are downregulated. Because of their primary presynaptic occurrence, five differentially expressed genes (CPX1, NPY, NRXN1, SNAP-25, and STX1A) have been selected for comparisons with clozapine-treated animals by qRT-PCR. Complexin 1 is upregulated in FR and TE cortex but unchanged in PAR by hypoxic treatment. Clozapine downregulates it in FR but upregulates it in PAR cortex. Similarly, syntaxin 1A was upregulated in FR, but downregulated in TE and unchanged in PAR cortex, whereas clozapine downregulated it in FR but upregulated it in PAR cortex. Hence, hypoxia alters gene expression regionally specific, which is in agreement with reports on differentially expressed presynaptic genes in schizophrenia. Chronic clozapine treatment may contribute to normalize synaptic connectivity.


Subject(s)
Brain/metabolism , Carboxypeptidases/metabolism , Gene Expression Regulation/physiology , Hypoxia/pathology , Neuropeptide Y/metabolism , Receptors, Cell Surface/metabolism , Synaptosomal-Associated Protein 25/metabolism , Syntaxin 1/metabolism , Animals , Animals, Newborn , Antipsychotic Agents/pharmacology , Antipsychotic Agents/therapeutic use , Brain/drug effects , Brain/pathology , Carboxypeptidases/genetics , Clozapine/pharmacology , Clozapine/therapeutic use , Disease Models, Animal , Gene Expression Profiling/methods , Gene Expression Regulation/drug effects , Hypoxia/drug therapy , Hypoxia/physiopathology , Neural Inhibition/drug effects , Neural Inhibition/physiology , Neuropeptide Y/genetics , Oligonucleotide Array Sequence Analysis/methods , Rats , Rats, Sprague-Dawley , Receptors, Cell Surface/genetics , Synaptosomal-Associated Protein 25/genetics , Syntaxin 1/genetics
17.
AJNR Am J Neuroradiol ; 31(8): 1403-7, 2010 Sep.
Article in English | MEDLINE | ID: mdl-20466799

ABSTRACT

BACKGROUND AND PURPOSE: Calcium can potentially shorten T1, generating high signal intensity in GREs. Because IPH appears as high signal intensity in MRIPH and the surface effects of calcium can potentially shorten T1 of surrounding water protons, the purpose of this study was to evaluate whether the high signal intensity seen on MRIPH could be attributed solely to IPH and not calcification. MATERIALS AND METHODS: Eleven patients undergoing carotid endarterectomy were imaged by using MRIPH. Calcification was assessed by scanning respective endarterectomy specimens with a tabletop MicroCT. MRIPH/MicroCT correlation used an 8-segment template. Two readers evaluated images from both modalities. Agreement between MRIPH/MicroCT was measured by calculating Cohen κ. RESULTS: High signal intensity was seen in 58.8% and 68.9% (readers 1 and 2, respectively) of MRIPH segments, whereas calcification was seen in 44.7% and 32.1% (readers 1 and 2, respectively) of MicroCT segments. High signal intensity seen by MRIPH showed very good but inverse agreement to calcification (κ = -0.90; P < .0001, 95% CI, -0.93 to -0.86, reader 1; and κ = -0.74; P < .0001; 95% CI, -0.81 to -0.69, reader 2). Most interesting, high signal intensity demonstrated excellent agreement with lack of calcification on MicroCT (κ = 0.92; P < .0001; 95% CI, 0.89-0.94, reader 1; and κ = 0.97; P < .0001; 95% CI, 0.96-0.99, reader 2). In a very small number of segments, high signal intensity was seen in MRIPH, and calcification was seen on MicroCT; however, these represented a very small proportion of segments with high signal intensity (5.9% and 1.6%, readers 1 and 2, respectively). CONCLUSIONS: High signal intensity, therefore, reliably identified IPH, known to describe complicated plaque, rather than calcification, which is increasingly recognized as identifying more stable vascular disease.


Subject(s)
Calcinosis/pathology , Carotid Artery Diseases/pathology , Cerebral Hemorrhage/pathology , Echo-Planar Imaging/methods , Aged , Aged, 80 and over , Calcinosis/diagnostic imaging , Calcinosis/surgery , Carotid Arteries/diagnostic imaging , Carotid Arteries/pathology , Carotid Arteries/surgery , Carotid Artery Diseases/diagnostic imaging , Carotid Artery Diseases/surgery , Cerebral Hemorrhage/diagnostic imaging , Cerebral Hemorrhage/surgery , Echo-Planar Imaging/standards , Endarterectomy, Carotid , Female , Humans , Male , Reproducibility of Results , X-Ray Microtomography
18.
AJNR Am J Neuroradiol ; 30(7): 1435-9, 2009 Aug.
Article in English | MEDLINE | ID: mdl-19321627

ABSTRACT

BACKGROUND AND PURPOSE: The CT grading system for otosclerosis was proposed by Symons and Fanning in 2005. The purpose of this study was to determine if this CT grading system has high interobserver and intraobserver agreement. MATERIALS AND METHODS: All 997 petrous bone CTs performed between December 2000 and September 2007 were reviewed. A total of 81 subjects had CT evidence of otosclerosis on at least 1 side; 68 (84%) had bilateral disease. Because otosclerosis was clinically suspected in both ears of all 81 subjects even if CT evidence was only unilateral, both petrous bones (162 in total) were included. Two blinded neuroradiologists independently graded disease severity using the Symons/Fanning grading system: grade 1, solely fenestral; grade 2, patchy localized cochlear disease (with or without fenestral involvement) to either the basal cochlear turn (grade 2A), or the middle/apical turns (grade 2B), or both the basal turn and the middle/apical turns (grade 2C); and grade 3, diffuse confluent cochlear involvement (with or without fenestral involvement). One reviewer repeat-graded the petrous bone CTs to determine intraobserver agreement with a 7-month intervening delay to mitigate recall bias. RESULTS: There were 154 agreements (95%) comparing the first grading of reviewer 1 with that of reviewer 2 (kappa = 0.93). When the repeat 7-month delayed grading of reviewer 1 was compared with that of reviewer 2, there were 151 (93%) agreements (kappa = 0.90). Therefore, mean interobserver agreement was excellent (mean kappa = 0.92). There were 155 agreements (96%) comparing the original grading of reviewer 1 with the delayed grading (kappa = 0.94), demonstrating excellent intraobserver agreement. CONCLUSIONS: A recently published CT grading for otosclerosis on the basis of location of involvement yielded excellent interobserver and intraobserver agreement.


Subject(s)
Otosclerosis/diagnostic imaging , Petrous Bone/diagnostic imaging , Tomography, X-Ray Computed/methods , Female , Humans , Male , Observer Variation , Reproducibility of Results , Sensitivity and Specificity
19.
Curr Oncol ; 16(1): 62-6, 2009 Jan.
Article in English | MEDLINE | ID: mdl-19229374

ABSTRACT

Brain metastasis is increasingly common, affecting 20%-40% of cancer patients. After diagnosis, survival is usually limited to months in these patients. Treatment for brain metastasis includes whole-brain radiation therapy, surgical resection, or both. These treatments aim to slow progression of disease and to improve or maintain neurologic function and quality of life.Although less common, primary brain tumours produce symptoms that are similar to those of brain metastasis. Glioblastoma, the most common malignant tumour of the brain, has a median survival of less than 12 months. Patients are often treated with surgical resection followed by radical radiation therapy and chemotherapy.Here, we present 2 separate cases of lesions in the brain radiologically compatible with brain metastasis. In both cases, no primary cancer site had been established, and neurosurgical intervention was sought to obtain a pathologic diagnosis. Both cases were pathologically confirmed as glioblastoma. These cases demonstrate the importance of differentiation between brain metastases and primary brain tumours to ensure that the appropriate management strategy is implemented.

20.
AJNR Am J Neuroradiol ; 30(3): 525-31, 2009 Mar.
Article in English | MEDLINE | ID: mdl-19147716

ABSTRACT

BACKGROUND AND PURPOSE: Clot extent, location, and collateral integrity are important determinants of outcome in acute stroke. We hypothesized that a novel clot burden score (CBS) and collateral score (CS) are important determinants of clinical and radiologic outcomes and serve as useful additional stroke outcome predictors. MATERIALS AND METHODS: One hundred twenty-one patients with anterior circulation infarct presenting within 3 hours of stroke onset were reviewed. The Spearman correlation was performed to assess the correlation between CBS and CS and clinical and radiologic outcome measures. Patients were dichotomized by using a 90-day modified Rankin scale (mRS) score. Uni- and multivariate logistic regression models were used to assess variables predicting favorable clinical and radiologic outcomes. Receiver operating characteristic and intraclass correlation coefficient (ICC) analyses were performed. Diagnostic performance of a CBS threshold of >6 was assessed. RESULTS: There were 85 patients (mean age, 70 +/- 14.5 years). Patients with higher CBS and CS demonstrated smaller pretreatment perfusion defects and final infarct volume and better clinical outcome (all, P < .01). CBS (P = .009) and recanalization (P = .015) independently predicted favorable outcome. A CBS >6 predicted good clinical outcome with an area under the curve of 0.75 (95% confidence interval [CI], 0.65-0.84; P = .0001), sensitivity of 73.0 (95% CI, 55.9-86.2), and specificity of 64.6 (95% CI, 49.5-77.8). The recanalization rate with intravenous recombinant tissue plasminogen activator was higher in patients with CBS >6 (P = .04; odds ratio, 3.2; 95% CI, 1.1-9.4). The ICC was 0.97 (95% CI, 0.95-0.98) and 0.87 (95% CI, 0.80-0.91) for CBS and CS, respectively. CONCLUSIONS: CBS and CS are useful additional markers predicting clinical and radiologic outcomes.


Subject(s)
Cerebral Angiography/methods , Collateral Circulation , Infarction, Middle Cerebral Artery/diagnostic imaging , Intracranial Thrombosis/diagnostic imaging , Tomography, X-Ray Computed , Aged , Aged, 80 and over , Cerebral Revascularization , Cerebrovascular Circulation , Female , Humans , Infarction, Middle Cerebral Artery/therapy , Intracranial Thrombosis/therapy , Logistic Models , Male , Middle Aged , Multivariate Analysis , Predictive Value of Tests , ROC Curve , Retrospective Studies , Sensitivity and Specificity , Severity of Illness Index , Treatment Outcome
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