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Examples of the four types of hyperdense lesions on the non-contrast CT obtained immediately after intraarterial thrombolysis. A. An example of a 'cortical high density (HD)' showing the focal high densities limited to the cortices. B. An example of a 'soft HD' revealing a CT density of less than 80 HU without any bulging contour. C. An example of a 'metallic HD' showing a CT density of over 80 HU and a larger volume with a bulging contour. D. An example of a 'diffuse HD' with high density involving a large territory.
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Hyperdense lesions can frequently be observed on the CT obtained immediately after intra-arterial (IA) thrombolysis, and it is sometimes difficult to differentiate contrast extravasation from the hemorrhagic lesions. The purposes of this study are to classify the hyperdense lesions according to their morphologic features and to track the outcome of...
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... analyzed the morphologic characteristics of the hyperdense lesions noted on the post-procedure NCCT. The lesion location was categorized as cortical (Fig. 1A) or non-cortical (Figs. 1B D). The CT Hounsfield unit (HU) and the total volume were measured using a built-in calculation tool in the hospital's picture archiving and communication system (PACS, Petavision; Seoul, Korea). A rectangular region-of-interest (ROI: 25 mm 2 in area) was placed at the highest density area in the lesion to ...
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... analyzed the morphologic characteristics of the hyperdense lesions noted on the post-procedure NCCT. The lesion location was categorized as cortical (Fig. 1A) or non-cortical (Figs. 1B D). The CT Hounsfield unit (HU) and the total volume were measured using a built-in calculation tool in the hospital's picture archiving and communication system (PACS, Petavision; Seoul, Korea). A rectangular region-of-interest (ROI: 25 mm 2 in area) was placed at the highest density area in the lesion to measure the CT unit. In ...
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... retrospectively reviewing the findings of the hyperdense lesions observed on NCCT, it was possible to categorize them into four types according to their location in the brain parenchyma and their CT density, volume and shape. Cortical HD was defined as a hyperdense lesion that was limited to the cortices (Fig. 1A), soft HD was defined as a hyperdense lesion with a maximum CT unit measure- ment < 80 HU and a small volume without contour bulging (Fig. 1B), metallic HD was defined as a hyperdense lesion with a maximum CT unit measurement > 80 HU (Fig. 1C) and a larger volume with bulging contour, and diffuse HD was defined as a hyperdense area ...
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... to categorize them into four types according to their location in the brain parenchyma and their CT density, volume and shape. Cortical HD was defined as a hyperdense lesion that was limited to the cortices (Fig. 1A), soft HD was defined as a hyperdense lesion with a maximum CT unit measure- ment < 80 HU and a small volume without contour bulging (Fig. 1B), metallic HD was defined as a hyperdense lesion with a maximum CT unit measurement > 80 HU (Fig. 1C) and a larger volume with bulging contour, and diffuse HD was defined as a hyperdense area involving a large vascular territory (Fig. ...
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... volume and shape. Cortical HD was defined as a hyperdense lesion that was limited to the cortices (Fig. 1A), soft HD was defined as a hyperdense lesion with a maximum CT unit measure- ment < 80 HU and a small volume without contour bulging (Fig. 1B), metallic HD was defined as a hyperdense lesion with a maximum CT unit measurement > 80 HU (Fig. 1C) and a larger volume with bulging contour, and diffuse HD was defined as a hyperdense area involving a large vascular territory (Fig. ...
Context 6
... as a hyperdense lesion with a maximum CT unit measure- ment < 80 HU and a small volume without contour bulging (Fig. 1B), metallic HD was defined as a hyperdense lesion with a maximum CT unit measurement > 80 HU (Fig. 1C) and a larger volume with bulging contour, and diffuse HD was defined as a hyperdense area involving a large vascular territory (Fig. ...
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Citations
... The frequency of hyperdense lesions following MT on NCCT has been reported to range from 32 to 84% (9,10), significantly higher than the rates of postoperative HT, ranging from 35 to 49%. While about 30% of those who were judged HT using postoperative NCCT alone actually were lots in contrast extravasation (11). ...
Background
It is challenging yet critical to differentiate between hemorrhagic transformation (HT) and contrast extravasation on non-contrast-enhanced computed tomography (NCCT) scans following mechanical thrombectomy (MT) in patients with acute ischemic stroke. We propose a new method called the ratio of maximum density values (RMDV) to minimize the confusion of contrast extravasation and to evaluate the diagnostic significance of RMDV in predicting HT on immediate post-interventional NCCT scans.
Methods
We conducted a retrospective analysis of the prospective patients’ database who received MT for acute ischemic stroke caused by occlusion of the intracranial large artery and showed postinterventional cerebral hyperdensities (PCHDs) on NCCT scans immediately after MT. Based on the subsequent NCCT scans, we divided patients with PCHDs into the HT and the non-HT groups. The clinical characters and radiological details were collected and compared to the two groups. We assessed the ability of RMDV >1 to predict HT by analyzing the receiver operating characteristic curve.
Results
One hundred and three patients showed PCHDs; 58 (56.31%) were classified as HT, while 45 (43.69%) were classified as non-HT. The only notable distinction between the two groups was the proportion of RMDV >1 in the HT group. The correlation between HT and RMDV >1 with an area under the curve of 0.826 (95% confidence interval, 0.739 to 0.894). The sensitivity, specificity, positive, and negative predictive values of RMDV >1 on NCCT for predicting HT were 89.66, 75.56, 82.54, and 85.00%, respectively.
Conclusion
The utilization of RMDV >1 on immediate NCCT scans after MT can predict early HT with good sensitivity and specificity.
... Early differentiation is key, given most cases of postthrombolytics or post-MT reperfusion hemorrhagic transformation occurs in the rst 24 hours after intervention. 33,34 In our cohort, larger infarct burden demonstrated by ASPECTS on both conventional NCCT and VMIs was associated with HT, with iodine leakage in the deep structures also associated with HT. Commonly, HT after AIS can be asymptomatic; however, it has been shown to worsen 3 month outcomes measured by mRS, suggesting another potential pharmacological target aimed at avoidance of endothelial dysfunction, oxidative stress, leukocyte in ltration, and vascular activation. ...
Background & Purpose:
Ischemia affecting two thirds of the MCA territory predicts development of malignant cerebral
edema. However, early infarcts are hard to diagnose on conventional head CT. We hypothesize
that high-energy (190keV) virtual monochromatic images (VMI) from dual-energy CT (DECT)
imaging enables earlier detection of secondary injury from malignant cerebral edema (MCE).
Methods:
Consecutive LHI patients with NIHSS ≥ 15 and DECT within 10 hours of reperfusion from May 2020 to March 2022 were included. We excluded patients with parenchymal hematoma-type 2 transformation. Retrospective analysis of clinical and novel variables included VMI Alberta Stroke Program Early CT Score (ASPECTS), total iodine content, and VMI infarct volume. Primary outcome was early neurological decline (END). Secondary outcomes included hemorrhagic transformation, decompressive craniectomy (DC), and medical treatment of MCE. Fisher’s exact test and Wilcoxon test were used for univariate analysis. Logistic regression was used to develop prediction models for categorical outcomes.
Results:
Eighty-four LHI patients with a median age of 67.5 [IQR 57,78] years and NIHSS 22 [IQR 18,25] were included. Twenty-nine patients had END. VMI ASPECTS, total iodine content, and VMI infarct volume were associated with END. VMI ASPECTS, VMI infarct volume, and total iodine content were predictors of END after adjusting for age, sex, initial NIHSS, and tPA administration, with a AUROC of 0.691 [0.572,0.810], 0.877 [0.800, 0.954], and 0.845 [0.750, 0.940]. By including all three predictors, the model achieved AUROC of 0.903 [0.84,0.97] and was cross validated by leave one out method with AUROC of 0.827.
Conclusion:
DECT with high-energy VMI and iodine quantification is superior to conventional CT ASPECTS and is a novel predictor for early neurological decline due to malignant cerebral edema after large hemispheric infarction.
... However, the rate of symptomatic intracerebral haemorrhage after mechanical thrombectomy ranges from 0 to 7.7% [9]. Early haemorrhagic transformation after treatment may continue to evolve, leading to a marked deterioration in some patients [10][11][12]. Therefore, the early identification of intraparenchymal haemorrhage (IPH) after mechanical thrombectomy provides the possibility to limit haemorrhagic growth, which can provide significant value in the management of post-operative patients [12,13]. ...
... The identification of IPH after mechanical thrombectomy is of great significance for the adjustment of treatment [12,13]. In the early phase after mechanical thrombectomy, conventional CT has a limited ability to differentiate IPH from iodinated contrast extravasation [11,[39][40][41]. From a pathophysiological standpoint, contrast extravasation is caused by a breakdown of the blood-brain barrier [42]. ...
Objective:
To develop a nonenhanced CT-based radiomic signature for the differentiation of iodinated contrast extravasation from intraparenchymal haemorrhage (IPH) following mechanical thrombectomy.
Methods:
Patients diagnosed with acute ischaemic stroke who underwent mechanical thrombectomy in 4 institutions from December 2017 to June 2020 were included in this retrospective study. The study population was divided into a training cohort and a validation cohort. The nonenhanced CT images taken after mechanical thrombectomy were used to extract radiomic features. The maximum relevance minimum redundancy (mRMR) algorithm was used to eliminate confounding variables. Afterwards, least absolute shrinkage and selection operator (LASSO) logistic regression was used to generate the radiomic signature. The diagnostic performance of the radiomic signature was evaluated by the area under the curve (AUC), accuracy, specificity, sensitivity, positive predictive value (PPV), and negative predictive value (NPV).
Results:
A total of 166 intraparenchymal areas of hyperattenuation from 101 patients were used. The areas of hyperattenuation were randomly allocated to the training and validation cohorts at a ratio of 7:3. The AUC of the radiomic signature was 0.848 (95% confidence interval (CI) 0.780-0.917) in the training cohort and 0.826 (95% CI 0.705-0.948) in the validation cohort. The accuracy of the radiomic signature was 77.6%, with a sensitivity of 76.7%, a specificity of 78.9%, a PPV of 85.2%, and a NPV of 68.2% in the validation cohort.
Conclusions:
The radiomic signature constructed based on initial post-operative nonenhanced CT after mechanical thrombectomy can effectively differentiate IPH from iodinated contrast extravasation.
Key points:
• Radiomic features were extracted from intraparenchymal areas of hyperattenuation on initial post-operative CT scans after mechanical thrombectomy. • The nonenhanced CT-based radiomic signature can differentiate IPH from iodinated contrast extravasation early. • The radiomic signature may help prevent unnecessary rescanning after mechanical thrombectomy, especially in cases where contrast extravasation is highly suggestive.
... Postinterventional cerebral hyperdensity (PCHD) is fairly commonly seen in patients with acute ischemic stroke following intra-arterial treatment [1][2][3]. Recently, with advances in technology, intravascular stents have been widely used for acute stroke patients; however, there have been few studies on patients with PCHD after mechanical thrombectomy. Previous small-sample studies revealed that PCHD was a strong predictor for final infarction size [4,5] but was not a risk factor for symptomatic hemorrhage or poor prognosis [5,6]. ...
... However, there were no further investigations into the effect on clinical prognosis in that study. The classification standard of CT values was formulated in clinical trials evaluating arterial thrombolysis [3], and a later study of intra-arterial revascularization suggested that a CT value of >90 poorly predicted hemorrhagic transformation (HT) with low sensitivity (23%) [8]. There were no further studies of PCHD on clinical prognosis in people with mechanical thrombectomy. ...
... In our study, the incidence of PCHD after intra-arterial reperfusion therapy was 57.1%, which was consistent with the incidence of PCHD reported by others (32.9% to 84.2%) [1][2][3]15]. The incidence of HT in our study was 50.8% (HI = 31:2%; pH = 19:6%). ...
Background:
Postinterventional cerebral hyperdensity (PCHD) is commonly seen in acute ischemic patients after mechanical thrombectomy. We propose a new classification of PCHD to investigate its correlation with hemorrhagic transformation (HT). The clinical prognosis of PCHD was further studied.
Methods:
Data from 189 acute stroke patients were analyzed retrospectively. According to the European Cooperative Acute Stroke Study criteria (ECASS), HT was classified as hemorrhagic infarction (HI-1 and HI-2) and parenchymal hematoma (pH-1 and pH-2). Referring to the classification of HT, PCHD was classified as PCHD-1, PCHD-2, PCHD-3, and PCHD-4. The prognosis included early neurological deterioration (END) and the modified Rankin Scale (mRS) score at 3 months.
Results:
The incidence of HT was 14.8% (12/81) in the no-PCHD group and 77.8% (84/108) in the PCHD group. PCHD was highly correlated with HT (r = 0.751, p < 0.01). After stepwise regression analysis, PCHD and the National Institutes of Health Stroke Scale (NIHSS) score at admission were found to be independent factors for END (p < 0.001, p = 0.015, respectively). The area of curves (AUC) of PCHD, the NIHSS at admission, and the combined model were 0.810, 0.667, and 0.832, respectively. The optimal diagnostic cutoff of PCHD for END was PCHD > 2. PCHD, the NIHSS score at admission, and good vascular recanalization (VR) were independently associated with 3-month mRS (all p < 0.05). The AUC of PCHD, the NIHSS at admission, good VR, and the combined model were 0.779, 0.733, 0.565, and 0.867, respectively. And the best cutoff of PCHD for the mRS was PCHD > 1.
Conclusion:
The relationship of PCHD and HT suggested PCHD was an early risk indicator for HT. The occurrence of PCHD-3 and PCHD-4 was a strong predictor for END. PCHD-1 is considered to be relatively benign in relation to the 3-month mRS.
... Non-enhanced brain CT conducted immediately after AR often presents hyperdense lesions in the parenchyma [4,5]. Such hyperdense lesions have been reported and analyzed in various literature since 1993 [6]. However, it is still a tricky problem to determine whether the hyperdense lesions are contrast extravasation or cerebral hemorrhage [7]. ...
... However, intracranial hemorrhage, a complication associated with intravascular interventional procedures, poses a challenge to clinical diagnosis and treatment of AIS. Immediately after completing intra-arterial procedures, a non-enhanced CT is often performed to assess the progression of the AIS and whether hemorrhage has occurred [6]. Non-enhanced CT often detects hyperdense lesions in the parenchyma. ...
... Computational and Mathematical Methods in Medicine extravasation or cerebral hemorrhage [6,8]. So neurologists and neuroradiologists need to identify the true nature of the hyperdense lesions so that appropriate interventions can be taken in time, otherwise it will seriously affect the prognosis of patients. ...
Purpose:
To analyze the characteristics of hyperdense lesions on brain CT conducted immediately after arterial revascularization (AR) in patients with acute ischemic stroke (AIS), track the outcome of those lesions and investigate their clinical significance.
Materials and methods:
97 AIS patients were enrolled in our study. Among them, 52 patients showed hyperdense lesions and were divided into three categories: type I, type II and type III according to the morphologic characteristics of hyperdense lesions. All patients underwent several follow-up CT/MR examinations to visualize the outcomes of the lesions.
Results:
Among the 52 patients, 22 showed contrast extravasation, 23 displayed contrast extravasation combined with hemorrhagic transformation (HT) and 7 confirmed symptomatic intracranial hemorrhage (SICH) in follow-up CT/MR. Among the without hyperdense lesions group, only 7 converted to hemorrhage, and no SICH occurred. All type I lesions showed contrast extravasation; 23 type II lesions turned to hemorrhage, 2 revealed SICH and 6 were pure contrast extravasation; all of the type III developed into SICH.
Conclusion:
Hyperdense lesions on non-enhanced brain CT obtained immediately after arterial revascularization (AR) exhibited varying features. Type I indicated a pure contrast extravasation. Type II and type III hyperdense lesions suggested higher incidence of HT, the presence of type III lesions indicated an ominous outcome.
... Several studies reported that the presence of hyperdense area may be associated with higher risks of hemorrhage [16][17][18][19][20]. Some studies have indicated that only specific types of hyperdense area were related to specific types of intracranial hemorrhage [12,[21][22][23][24][25][26][27][28]. While, no significant association was found between hyperdense area and hemorrhage in other studies [29,30]. ...
... The selected studies were conducted between 2001 and 2020 in 6 countries. Of the 16 studies included, 8 studies [10,11,16,17,19,[21][22][23] reported the relationship between post-interventional hyperdense area and poor functional outcome, while 15 studies outlined the correlation between post-interventional hyperdense area and HT, along with 9 studies [10,11,16,19,20,23,24,29,34] for sICH, 8 studies [10,11,18,22,26,27,29,34] for PH and 6 studies [17,18,22,27,29,34] for PH2. Hemorrhagic transformation types were defined as the criteria used in the ECASS [32] test. ...
... However, Parrilla et al. [30] followed up with nonenhanced CT in the next 48-72 h. Jang et al. [24] set the follow-up time in 3-5 days later. Obviously, the studies of Xu et al. [26] and Rouchaud et al. [17] contributed the majority of OR value with a wide range of CI in the outcome of HT. ...
Objective:
We performed a systematic review and meta-analysis to investigate the clinical significance of hyperdense area after thrombectomy in patients with acute ischemic stroke (AIS).
Methods:
We searched Ovid MEDLINE(R) and Epub Ahead of Print, In-Process and other Non-Indexed, Cochrane Library Clinical Controlled Trials and Embase from inception to September 2020 and collected the cohort and case-control studies about the clinical significance of hyperdense area on different types of computed tomography (CT) after thrombectomy in patients with AIS. Outcomes were poor functional outcome (modified Rankin Scale [mRS] Score 3-6 at discharge or 90-day), mortality and subtypes of hemorrhage according to the European Cooperative Acute Stroke Study (ECASS).
Results:
1,999 patients from 16 studies were included in this meta-analysis. Pooled results indicated higher risk of symptomatic intracerebral hemorrhage (odds ratio [OR] = 3.02; 95% confidence interval [CI] 1.84-4.95; p < 0.0001, I2 = 0%) in patients with hyperdense area, and the subtype of parenchymal hematoma as well. There was also higher odds of poor functional outcome based on the mRS 3-6 at discharge or 90-day (OR = 1.92; 95% CI 1.35-2.73; p = 0.0003, I2 = 31%) and mortality (OR = 2.06; 95% CI 1.41-3.02; p = 0.0002, I2 = 0%) in patients with hyperdense area after thrombectomy compared with those without hyperdense area.
Conclusions:
Our results indicated that the presence of hyperdense area on CT after thrombectomy was associated with high risk of symptomatic intracerebral hemorrhage, poor functional outcome, as well as mortality in patients with AIS. However, further studies were needed to confirm these results. The meta-analysis was conducted in adherence with the PRISMA Statement and was registered at the International Prospective Register of Systematic Reviews (CRD42020164165). To the best of our knowledge, this study is the first meta-analysis investigating the effect of hyperdense area after endovascular therapy in patients with AIS.
... Our study found that 39.5% of patients (32/81) had hyperdense lesions after mechanical thrombectomy, which is in line with previous reports (from 30% to 87% using NC-CT [8][9][10][11][12][13][14][15] and 16% to 60% using FP-CT [16][17][18]). As HT is critical in the setting of therapy for AIS patients, we BioMed Research International attempted to investigate the potential of FP-CT in the prediction of HT. ...
Purpose:
Hyperdense lesions are frequently revealed on flat panel CT (FP-CT) immediately after endovascular thrombectomy in patients with acute ischemic stroke. This study is aimed at discriminating hyperdense lesions caused by extravasation plus hemorrhage from those caused by contrast extravasation alone.
Methods:
We retrospectively analyzed clinical and radiological data of patients who underwent an immediate postprocedure FP-CT scan and a follow-up noncontrast CT 24 hours after thrombectomy. We especially focused on the Maximum Hounsfield Units (HUmax) of each hyperdense lesion. A hyperdense lesion was judged to be hemorrhagic when it persisted on noncontrast CT and/or developed a mass effect.
Results:
Of 81 patients included in this study, 32 (39.5%) patients presented 41 hyperdense lesions on FP-CT. The chance of hemorrhagic transformation is higher in patients with hyperdense lesions on FP-CT than that in patients without hyperdense lesions (23/32 vs. 1/49, p < 0.001). The HUmax of hyperdensity on FP-CT can predict hemorrhagic transformation with an area under the curve of 0.805 (95% CI: 0.67-0.94, p = 0.02). The sensitivity, specificity, positive, and negative predictive values of hyperdensity on FP-CT for hemorrhagic transformation were 96%, 84%, 72%, and 98%, respectively. A HUmax of >600 predicted hemorrhagic transformation with a sensitivity of 50% and a specificity of 100%.
Conclusions:
The presence of hyperdensity on FP-CT can predict hemorrhagic transformation with a high sensitivity and negative predictive value. The measurement of HUmax of hyperdense lesion on FP-CT can be applied to the management of patients undergoing endovascular recanalization.
... There are some reports on the prognosis of IPH lesions by quantitative or qualitative analysis. Jang et al. (25) have categorized hyperdense lesions into four types: cortical, soft, metallic (>80 Hounsfield units), and diffuse highdensity. They reported that all metallic density lesions, 50% of the diffuse type, 46.1% of the soft type, and 0% of the cortical type progressed to hemorrhage. ...
Background:
To evaluate intraparenchymal hyperattenuation (IPH) on flat-panel computed tomography (FPCT) findings and their clinical usefulness for predicting prognosis after successful mechanical thrombectomy (MT) for acute occlusion of anterior circulation.
Methods:
A retrospective review was conducted for 158 consecutive patients undergoing mechanical thrombectomy during the last six years. After excluding those with posterior circulation occlusion or incomplete recanalization and those without FPCT, 82 patients were finally included. Immediate post-procedural IPH on FPCT was categorized into four patterns (none, striatal, cortical, or combined pattern). Follow-up magnetic resonance images or CT scans after 48 hours from MT were analyzed according to FPCT findings. The existence of hemorrhagic transformation, intracerebral hemorrhage, and brain swelling was evaluated. Functional clinical outcomes were accessed with post-procedural 3-month modified Rankin scales (mRS).
Results:
Of 82 patients, 34 patients were found to have IPH (16 with a striatal pattern, 8 with a cortical pattern, and 10 with a combined pattern). Hemorrhagic complication (P<0.001), brain swelling (P<0.001), and poor mRS scores (P=0.042) showed significant differences according to IPH patterns. Multivariate logistic regression analysis revealed that the presence of a striatal pattern (OR: 13.26, P<0.001), cortical pattern (OR: 11.61, P=0.009), and combined pattern (OR: 45.34, P<0.001) independently predicted hemorrhagic complications. The location of the occlusion (OR: 4.13, P=0.034), cortical pattern (OR: 5.94, P=0.039), and combined pattern (OR: 39.85, P=0.001) predicted brain swelling. Age (OR: 1.07, P=0.006) and the presence of a combined pattern (OR: 10.58, P=0.046) predicted poor clinical outcomes.
Conclusions:
FPCT is a rapid and effective tool for a prompt follow-up just after MT to predict prognosis. Those with striatal patterns showed relatively good clinical outcomes despite significant hemorrhage. Cortical IPH patterns independently predicted a high rate of post-procedural hemorrhage or brain swelling. Combined pattern is a strong predictor for both radiologic and poor clinical outcomes.
... Jang [16] How can we classify hyperdense lesions according to their morphologic features and what are the outcomes of those lesions? ...
Mechanical thrombectomy (MT) for cerebral revascularization in acute stroke is now considered standard of care in select patients. Patients are assessed routinely after MT with CT scanning. The phenomenon of contrast staining is well documented in the literature and is posited to be related to increased blood-brain barrier (BBB) permeability of susceptible and/or infarcting brain tissue allowing angiographic contrast to be visualized outside the normal cerebral vasculature. In some cases, this can progress to include frank blood/contrast extravasation or even more seriously lead to intraparenchymal hemorrhage (IPH) with less favorable clinical outcomes. The relationship of this staining phenomenon and how it may have a cause or effect relationship with progression to hemorrhage is unclear. Many studies have been performed trying to better characterize this radiographic finding in terms of accurate diagnosis and potential for influencing prognosis. A literature review included a glaring lack of standardization in the application of terminology and quantitative/qualitative analysis. Dual energy CT (DECT) appears to be the best imaging modality to differentiate blood from contrast, but its application is limited since it is not as available as conventional CT. The possibility that risk factors are associated with progression of mixed density (blood and contrast) extravasations to frank IPH with resultant poorer outcomes is suggested in some studies. Overall, there remains a lack of consensus on how to best interpret this radiographic finding in altering any future stroke treatment(s). Recommendations of how to overcome this are postulated by the authors, which include standardization of terminology, progression toward more DECT use.
... Brain Differentiating haemorrhage from contrast medium extravasation or staining after intra-arterial stroke therapy can be challenging as they both appear hyperdense on unenhanced CT. 7 Currently, conventional follow-up CT without contrast medium is needed to differentiate haemorrhage, as a major complication of the procedure, from contrast medium extravasation or staining due to bloodebrain barrier disruption. 7,8 Hyperdensity that persists on unenhanced follow-up CT obtained 24e48 h later is indicative of haemorrhage as it persists for several days to weeks. ...
... Brain Differentiating haemorrhage from contrast medium extravasation or staining after intra-arterial stroke therapy can be challenging as they both appear hyperdense on unenhanced CT. 7 Currently, conventional follow-up CT without contrast medium is needed to differentiate haemorrhage, as a major complication of the procedure, from contrast medium extravasation or staining due to bloodebrain barrier disruption. 7,8 Hyperdensity that persists on unenhanced follow-up CT obtained 24e48 h later is indicative of haemorrhage as it persists for several days to weeks. On the contrary, contrast medium extravasation or staining demonstrates early washout and usually resolves by 24 h and therefore does not persist on follow-up CT. 7,9 With the introduction of spectral CT, immediate differentiation of haemorrhage from contrast medium extravasation or staining could be possible with virtual noncontrast images and iodine density maps. ...
... 7,8 Hyperdensity that persists on unenhanced follow-up CT obtained 24e48 h later is indicative of haemorrhage as it persists for several days to weeks. On the contrary, contrast medium extravasation or staining demonstrates early washout and usually resolves by 24 h and therefore does not persist on follow-up CT. 7,9 With the introduction of spectral CT, immediate differentiation of haemorrhage from contrast medium extravasation or staining could be possible with virtual noncontrast images and iodine density maps. 9,10 Haemorrhage is seen as persisting hyperdense areas on virtual unenhanced images whereas contrast medium staining is demonstrated as hyperdense areas only on iodine-density/ An 86-year-old man presented with epigastric pain, jaundice, and weight loss. ...
Computed tomography (CT) has been the first choice of imaging technique in the emergency department and has a crucial role in many acute conditions. Since its implementation, spectral CT has gained widespread application with the potential to improve diagnostic performance and impact patient care. In spectral CT, images are acquired at two different energy levels allowing this technique to differentiate tissues by exploiting their energy-dependent attenuation properties. Dual-layer spectral CT provides additional information with its material decomposition applications that include virtual non-contrast imaging, iodine density, and effective atomic number (Zeff) maps along with virtual monoenergetic images without the need for preselection of a protocol. This review aims to demonstrate its added value in the emergency department in different organ systems enabling better evaluation of inflammatory and ischaemic conditions, assessment of organ perfusion, tissue/lesion characterisation and mass detection, iodine quantification, and the use of lower volumes of contrast medium. With improved diagnostic performance, spectral CT could also aid in rapid decision-making to determine the treatment method in many acute conditions without increased radiation dose to the patient.
