Role Of Susceptibility-weighted Imaging Research Articles

The role of susceptibility-weighted imaging & contrast-enhanced MRI in the diagnosis of primary CNS vasculitis: a large case series.

Primary CNS Vasculitis (PCNSV) is a rare, diverse, and polymorphic CNS blood vessel inflammatory condition. Due to its rarity, clinical variability, heterogeneous imaging results, and lack of definitive laboratory markers, PCNSV diagnosis is challenging. This retrospective cohort analysis identified patients with histological diagnosis of PCNSV. Demographic data, clinical presentation, neuroimaging studies, and histopathologic findings were recorded. We enrolled 56 patients with a positive biopsy of CNS vasculitis. Most patients had cerebral hemisphere or brainstem symptoms. Most brain MRI lesions were bilateral, diffuse discrete to confluent white matter lesions. Frontal lobe lesions predominated, followed by inferior cerebellar lesions. Susceptibility-weighted imaging (SWI) hemorrhages in 96.4% (54/56) of patients, either solitary microhemorrhages or a combination of micro and macrohemorrhages. Contrast-enhanced T1-WIs revealed parenchymal enhancement in 96.3% (52/54 patients). The most prevalent pattern of enhancement observed was dot-linear (87%), followed by nodular (61.1%), perivascular (25.9%), and patchy (16.7%). Venulitis was found in 19 of 20 individuals in cerebral DSA. Hemorrhages in SWI and dot-linear enhancement pattern should be incorporated as MINOR diagnostic criteria to diagnose PCNSV accurately within an appropriate clinical context. Microhemorrhages in SWI and venulitis in DSA, should be regarded as a potential marker for PCNSV.

PERANAN SEQUENCE SWI (SUSCEPTIBILITY WEIGHTED IMAGING) PADA PEMERIKSAAN MRI BRAIN KLINIS PARKINSON

The Role of SWI (Susceptibility Weighted Imaging) Sequence in Clinical Parkinson’s MRI Brain Imaging. Magnetic Resonance Imaging (MRI) is a technique for imaging body crossings based on the principle of magnetic resonance of hydrogen atoms. Brain MRI examination aims to see anatomy and abnormalities within the brain to establish clinical diagnosis, pathological abnormalities, tumors, and surrounding abnormalities. Imaging examinations are also conducted to find other causes of Parkinsonism. Head MRI is one of the non-invasive examinations performed to help confirm the diagnosis of Parkinson's disease. This study aims to determine the procedure for Brain MRI examination with Parkinson's clinical and to determine the sequence information SWI (Susceptibility Weighted Imaging) can establish clinical diagnosis of Parkinson's. This study is qualitative descriptive with a case study approach. The subject consists of three patients with clinical Parkinson's. All subjects performed MRI brain 3 tesla examinations to determine the procedure and sequence information used. The research results were obtained according to the theory using an additional 2 mm sequence, while in the field using 0.9 mm sequence the examination was conducted using the head coil of the patient's position, namely supine, head first. Sequences used in field inspections are AAHead Scout, t1 fl2d transversal, t2 tse (time spin echo) dark fluid transversal, t2 tse (time spin echo) transversal, ep2d diff (diffusion) 4scan trace, asl 3d transversal, tof cs carotids, flow pc3d MRV (magnetic resonance venography), tof brain MRA (magnetic resonance angiography), t2 swi (susceptibility weighted imaging) 3d transversal 0.9 mm. The thin axial sequence of 0.9 mm is more likely to see Parkinson's anatomical abnormalities, higher SNR and better spatial resolution than using a 2 mm slice thickness.

SWI as a promising tool comparable to CT perfusion in evaluation of acute cerebral infarction

BackgroundThe recent advances in magnetic resonance imaging techniques have improved the assessment of acute stroke. Susceptibility weighted imaging (SWI) has a crucial role in the management plan of cerebral ischemia. This study was aimed to assess the role of susceptibility-weighted imaging in assessment of area at risk (pneumbra) compared to CT perfusion in patients with acute ischemic infraction.ResultsWe found the mean aspect score for SWI 4 ± 1.4 and mean aspect for DWI 7.6 ± 1.2; in addition, mean aspect for CTP was 4.6 ± 1.3. Significant difference is noted between the SWI and DWI with significant p value. But there is no significant difference between the SWI and CTP ASPECT scores.ConclusionSWI is a promising technique and comparable to CT perfusion is evaluation of penumbra in the settings of acute infarction.

Potential role of susceptibility-weighted imaging in the diagnosis of non-neoplastic pediatric neurological diseases

BackgroundThis study aimed to assess the added value and current applications of SWI in the diagnosis of pediatric non-neoplastic neurological diseases, including its ability to characterize hemorrhage in various brain lesions and its important role in the evaluation of both arterial as well as venous ischemic brain lesions.ResultsForty pediatric patients with a median age of 9 years were included in our prospective study; 23 were males and 17 females. SWI had a significantly higher detection rate than conventional MRI for traumatic brain injury (TBI) lesions, hemorrhagic lesions in acute necrotizing encephalopathy (ANEC), and cavernoma lesions (p = 0.005, p = 0.038, and p = 0.046, respectively). The sensitivity, specificity and accuracy of SWI for the detection of venous ischemic insult was 88.9%, 50%, and 76.9% respectively. SWI was significantly better than the conventional MRI (p = 0.046) for the detection of chronic ischemic brain insults and ischemic lesions with added hemorrhagic components.ConclusionSWI is a technique with reasonable acquisition time that could improve the diagnostic performance of MRI for the evaluation of various pediatric non-neoplastic neurological diseases.

Susceptibility-Weighted Imaging in Neurodegenerative Disorders: A Review.

As human life expectancy increases, there is an increased prevalence of neurodegenerative disorders and dementia. There are many ongoing research trials for early diagnosis and management of dementia, and neuroimaging is a critical part of such studies. However, conventional neuroimaging often fails to provide enough diagnostic findings in patients with neurodegenerative disorders. In this context, different MRI sequences are currently under investigation to facilitate the accurate diagnosis of such disorders. Susceptibility-weighted imaging (SWI) is an innovative MRI technique that utilizes "magnitude" and "phase" images to produce an image contrast that is sensitive for the detection of susceptibility differences of the tissues. As many neurodegenerative disorders are associated with accelerated iron deposition and/or microhemorrhages in different parts of the brain, SWI can be applied to detect these diagnostic clues. For instance, in cerebral amyloid angiopathy, SWI can demonstrate cortical microhemorrhages, which are predominantly in the frontal and parietal regions. Or in Parkinson disease, abnormal swallow-tail sign on high-resolution SWI is highly diagnostic. Also, SWI is a useful sequence to detect the low signal intensity of precentral cortices in patients with amyotrophic lateral sclerosis. Being familiar with SWI findings in neurodegenerative disorders is critical for an accurate diagnosis. In this paper, the authors review the technical parameters of SWI, physiologic, and pathologic iron deposition in the brain, and the role of SWI in the evaluation of neurodegenerative disorders in daily practice.

The role of susceptibility-weighted imaging (SWI) in neuroimaging in children with focal epilepsy

Aim. To approve of diagnostic effectiveness of SWAN (SWI) images in revealing of calcium containing epileptogenic substrates in children with resistant focal epilepsy.Materials and methods. The results of MRI in children with refractory focal epilepsy obtained in the Radiology Department of the Russian State Children Hospital in the period from 2018 to 2020 were observed retrospectively. High-resolution epileptological MR protocol used for investigation of 67 children. SWAN was applied in all cases for identification of calcium containing epileptogenic substrates, including cavernomas, DVA syndrome, cortical gangliogliomas, Sturge-Weber syndrome and tuberous sclerosis complex. All images were received by using MRI 3T 750 W Discovery GE.Results. In 17 cases (25%) SWAN provided important diagnostic information about the nature of the of epileptogenic lesion, its prevalence and borders. Additional earlier invisible structural changes were revealed in 2 cases of SWS and 1 cases of FCD; and in 13 cases SWAN gave us possibility to avoid CT for approving calcium in epileptogenic focus.Conclusion. We believe that adding SWAN in to the epileptological MR protocol is the necessary step for optimizing calcium and blood degradation products identification in the structure of potential epileptogenic focuses. Moreover, it would be very effective instrument for differential diagnosis of cerebral structural changes, specifying its etiology and, hence, would have influence on the therapeutic tactic and surgical strategy in children with focal epilepsy.

Role of Susceptibility-Weighted Imaging in Detecting Retinal Hemorrhages in Children with Head Trauma.

This study was carried out to evaluate the utility of susceptibility-weighted imaging (SWI) in demonstrating retinal hemorrhages (RH) in pediatric head trauma. Over a period of 7 years 67children (age 0-4years) with head trauma and MRI were included as either abusive head trauma (AHT) (n = 23), non-abusive head trauma (NAHT) (n = 38), or indeterminate (n = 6). Two pediatric neuroradiologists jointly reviewed the MR images for the presence of RH and sensitivity and specificity of SWI and T2WI were calculated. The dilated fundoscopic examination (DFE) was positive for RH in 18/23 (78.3%) of the AHT group, 5/38 (13.2%) in the NAHT group, and 4/6 (66.7%) in the indeterminate group. Regarding the SWI MRI findings, SWI was positive for RH in 13/23 (%56.5), while T2WI was positive in 6/23 (%26.1) of the AHT group. Based on utilizing DFE as astandard, the sensitivity and specificity of SWI in the detection of RH was 63% and 100%, respectively and 30% and 100%, respectively on T2WI. Our results suggest that SWI is auseful diagnostic tool for detection of RH in pediatric head trauma in whom DFE is difficult to perform.

Role of magnetic susceptibility-weighted imaging in characterization of cerebral microbleeds in acute ischemic stroke Egyptian obese patients

ObjectiveThe study was done to investigate the role of susceptibility-weighted imaging (SWI) in characterization of cerebral microbleeds (CMBs) and incidence of CMBs in acute ischemic stroke obese patients.Materials and methodsWe recruited 120 acute ischemic stroke obese patients. All participants or their relatives gave written informed consent. MRI of the brain with SWI sequences was done for all patients.ResultsSWI showed 30% of the patients have CMBs. The total numbers of CMBs were statistically significant higher in small vessel diseases (SVDs) than large vessel diseases (LVDs) (P = 0.008). According to the severity scale, CMBs were more prominent in patients with grade 0 (70%) followed by grade III (25.8%) then grade II (4.2%). BMI was independent risk factors for developing CMBs as shown in simple regression analysis (х2 = 6.008, P = 0.002). SVDs and hypertension were statistically significant independent predictors and had higher odds to exhibit CMBs. Patients with SVDs had 5.3 times higher odds to exhibit CMBs (P = 0.002) while patients with hypertension had 3.9 times higher odds to exhibit CMBs (P = 0.032).ConclusionSWI is a gold standard MR imaging technique in diagnosis and characterization of CMBs with more prevalence especially in obese patients suffering from acute ischemia stroke due to SVDs. Hypertension was an independent risk factor for development of CMBs but IHD, use of antiplatelet medications, increased BMI, and dyslipidemia must be taken into consideration.

Role of susceptibility-weighted imaging in patients with idiopathic intracranial hypertension.

To evaluate the role of susceptibility-weighted imaging (SWI) in patients with idiopathic intracranial hypertension (IIH). A prospective study was done on 55 patients with IIH who underwent SWI of the brain. The images were evaluated by two independent readers for cerebral microbleeds (CMBs) and the interobserver agreement between both readers was calculated. The graphic rating scale (GRS) for headache was calculated. CMBs were found in 16 (29%) of patients with IIH for both readers with excellent interobserver agreement (K = 0.8, p = 0.001). There was excellent interobserver agreement for location (K = 0.8, p = 0.001) and side of CMBs (K = 0.8, p = 0.001). There was good interobserver agreement for size of CMBs (K = 0.75, p = 0.002) and number (K = 0.6, p = 0.006). The mean GRS for headache in patients with CMBs (5.61 ± 1.3) was significantly higher (p = 0.02) than that of patients without CMBs (4.9 ± 0.8). We concluded that SWI can detect CMBs in patients with IIH especially in patients with higher GRS for headache.

Role of susceptibility-weighted imaging and intratumoral susceptibility signals in grading and differentiating pediatric brain tumors at 1.5 T: a preliminary study.

Susceptibility-weighted imaging (SWI) is useful for glioma grading and discriminating between brain tumor categories in adults, but its diagnostic value for pediatric brain tumors is unclear. Here we evaluated the usefulness of SWI for pediatric tumor grading and differentiation by assessing intratumoral susceptibility signal intensity (ITSS). We retrospectively enrolled 96 children with histopathologically diagnosed brain tumors, who underwent routine brain MRI exam with SWI (1.5T scanner). Each tumor was assigned an ITSS score by a radiology resident and an experienced neuroradiologist, and subsequently by consensus. Statistical analyses were performed to differentiate between low-grade (LG) and high-grade (HG) tumors, histological categories, and tumor locations. Inter-reader agreement was assessed using Cohen's kappa (κ). The interobserver agreement was 0.844 (0.953 between first reader and consensus, and 0.890 between second reader and consensus). Among all tumors, we found a statistically significant difference between LG and HG for ITSS scores of 0 and 2 (p = 0.002). This correlation was weaker among astrocytomas alone, and became significant when considering only off-midline astrocytomas (p = 0.05). Scores of 0 and 2 were a strong discriminating factor (p = 0.001) for astrocytomas (score 0) and for embryonal, choroid plexus, germ-cell, pineal, and ependymoma tumors (score 2). No medulloblastoma showed a score of 0. Our preliminary ITTS results in pediatric brain tumors somewhat differed from those obtained in adult populations. These findings highlight the potential valuable role of ITSS for tumor grading and discriminating between some tumor categories in the pediatric population.

Role of SWI in Early Detection of Hemorrhagic Transformation in Acute Cerebral Ischemia

Background: The advent of new magnetic resonance imaging (MRI) techniques has improved acute stroke diagnosis. Susceptibility weighted imaging (SWI) has an important role in the management of cerebro-vascular strokes. Patients and Method: The study was conducted upon 50 patients clinically diagnosed with cerebro-vascular strokes and referred to department of radio-diagnosis, Faculty of Medicine, Minia University. Computed tomography (CT) was done at first then magnetic resonance imaging was performed on a 1.5T Philips MR system using conventional MRI sequences as fluid attenuated inversion recovery (FLAIR), T2-weighted, T1-weighted and advanced sequences as susceptibility-weighted imaging (SWI) with the parameters including slice thickness, voxel size, field of view (FOV) and matrix,. They were done after the approval of ethical committee of our institution. Informed written consents were taken from the patients or their relatives. Results : In our study, we found that 35 patients presented with acute non hemorrhagic infarction even on SWI and 15 patients presented with hemorrhagic infarction noted in SWI. Only ten of those patients with hemorrhagic infarction detected in CT. We found that detection rate of hemorrhage in SWI sequence was (100%). Detection rate of hemorrhage in CT was (33.3%). In SWI as regarding detection of different signs of acute ischemic strokes we found that of hemorrhage was (88%), detection rate of prominent cortical veins in vicinity of infarct was (62%) and detection rate of dark vessel sign was 6%. Comparative studies between them were done revealed that hemorrhage was the most important sign detected at SWI. Conclusion : From this study we concluded that new imaging SWI MRI modality is a valuable MRI sequence in imaging hemorrhagic transformation in ischemic stroke.

Adult acute hemorrhagic leukoencephalitis: role of susceptibility-weighted imaging in diagnosis and importance of aggressive early immunotherapy. (P1.2-027)

Adult acute hemorrhagic leukoencephalitis: role of susceptibility-weighted imaging in diagnosis and importance of aggressive early immunotherapy. (P1.2-027)

The Role of Susceptibility-Weighted Imaging and Dedicated MRI Protocols in the Diagnostic Evaluation of Patients with Drug-Resistant Epilepsy

Background: Near one-third of epileptic cases never achieve remission, despite optimal medication use. In these patients, various surgical procedures can be helpful. However, surgical success is directly associated with the ability to localize precisely the region of seizure onset. Objectives: The goal of this study was to evaluate the role of susceptibility weighted imaging (SWI) in detecting intracerebral lesions and localizing epileptogenic zones in addition to conventional MRI with routine epilepsy protocol in drug-resistant epileptic patients. Methods: The study was carried out at an academic medical center in a major metropolitan city, and all participants underwent conventional MRI assessment with seizure protocol and SWI evaluation. Results: During the study period, 59 cases met the criteria. Thirty-four were male (57.6%) and twenty-five were female. Mean age of participants was 30 years, and mean age at the time of epilepsy onset was 11. In 50 cases (85%), there was evidence of brain abnormalities in conventional MRI and/or SWI. Brain abnormalities were also evident in conventional MRI evaluation of 47 cases (79%). In three out of twelve cases with normal conventional MRI with routine epilepsy protocol, SWI showed brain abnormalities. In 20 cases (40%), the same lateralization or localized lesions were detected in EEG and MRI. More information from SWI was reported in 13 patients (22%). In two cases, in which EEG showed evidence of partial seizures, conventional MRI showed no abnormality while SWI showed abnormal vascular cluster. In one of these two cases, caput medusa, in agreement with developmental venous anomaly, was reported. In one case, conventional MRI was normal while SWI showed evidence of cavernoma. In another patient, in addition to the lesion detectable in conventional MRI, SWI found two other lesions in agreement with cavernomas. Conclusions: Susceptibility weighted imaging can be helpful in localizing epileptogenic zones, which are not detectable by conventional MRI with routine epilepsy protocol, in patients with drug-resistant epilepsy.

Visualizing Central Vessels of Hepatic Angiomyolipoma Devoid of Fat Using a 2D Multi-Breath-Hold Susceptibility-Weighted Imaging.

Epithelioid hepatic angiomyolipoma (Epi-HAML) is a rare benign mesenchymal tumor with malignant potential. Most of Epi-HAML contains no or only a minimal amount of adipose tissue and poses a diagnostic challenge. Central vessels are characteristic imaging finding of Epi-HAML, which usually were displayed by dynamic contrast imaging. In this paper, we displayed the central vessels of Epi-HAML invisible on conventional MR images using a new developed abdominal susceptibility-weighted imaging (SWI). To the best of our knowledge, this is the first description for the role of SWI in characterization of Epi-HAML.

Quantitative T2 Changes and Susceptibility-Weighted Magnetic Resonance Imaging in Murine Pregnancy

Objective: To evaluate gestational age-dependent changes in the T2 relaxation time in normal murine placentas in vivo. The role of susceptibility-weighted imaging (SWI) in visualization of the murine fetal anatomy was also elucidated. Methods: Timed-pregnant CD-1 mice at gestational day (GD) 12 and GD17 underwent magnetic resonance imaging. Multi-echo spin echo and SWI data were acquired. The placental T2 values on GD12 and GD17 were quantified. To account for the influence of systemic maternal physiological factors on placental perfusion, maternal muscle was used as a reference for T2 normalization. A linear mixed-effects model was used to fit the normalized T2 values, and the significance of the coefficients was tested. Fetal SWI images were processed and reviewed for venous vasculature and skeletal structures. Results: The average placental T2 value decreased significantly on GD17 (40.17 ± 4.10 ms) compared to the value on GD12 (55.78 ± 8.13 ms). The difference in normalized T2 values also remained significant (p = 0.001). Using SWI, major fetal venous structures like the cardinal vein, the subcardinal vein, and the portal vein were visualized on GD12. In addition, fetal skeletal structures could also be discerned on GD17. Conclusion: The T2 value of a normal murine placenta decreases with advancing gestation. SWI provided clear visualization of the fetal venous vasculature and bony structures.

Clinical Vignette: Role of Susceptibility-Weighted Imaging in Predicting Stroke Evolution

Clinical Vignette: Role of Susceptibility-Weighted Imaging in Predicting Stroke Evolution

Clinical applications of susceptibility-weighted imaging in detecting and grading intracranial gliomas: a review

Susceptibility-weighted imaging (SWI) is a technique that exploits the susceptibility difference between tissues to provide contrast for different regions of the brain. In essence, it uses the deoxygenated hemoglobin of veins, hemosiderin of hemorrhage, etc. as intrinsic contrast agents, allowing for much better visualization of blood and microvessels even without administration of an external contrast agent. It is a fast-evolving field that is being constantly improved and increasingly implemented with updates in relevant technology. Multiple studies have been done on the role of SWI in the management of various neurologic disorders and it is also being seen as a further step in the neuroradiologist’s goal of being able to noninvasively grade tumors in order to influence therapy. This article briefly reviews the evolution of SWI since its conception and provides the reader with a comprehensive summary of various studies that have been done on its application for detecting and grading intraaxial brain tumors, specifically gliomas. Other useful magnetic resonance techniques that have shown promise in grading gliomas are also discussed.

Cerebral Thromboembolism: Value of Susceptibility-Weighted Imaging in the Initial Diagnosis of Acute Infarction

Susceptibility-weighted imaging (SWI) is commonly used to diagnose cerebral hemorrhage, calcification, and other T2* lesions. Its role in the detection of cerebral thromboemboli has been suggested for emboli of the anterior division of the middle cerebral artery (MCA). The purpose of our study was to determine SWI's accuracy and sensitivity in detection of all sites of cerebral thromboemboli, not just MCA emboli. Two neuroradiologists retrospectively reviewed consecutive MRI brain examinations with SWI for cerebral thromboemboli in 100 patients with clinical suspicion for stroke determined by the NIH Stroke Scale (NIHSS) score. FLAIR, MRA, CT, and catheter angiography were reviewed for thromboemboli in the same patients. Thromboembolic sites included: the internal carotid artery (ICA) terminus, anterior MCA, posterior MCA, any other cerebral artery, or if not present. The exclusion criteria included: no magnetic resonance angiogram (MRA) or catheter angiogram for comparison, lack of restricted diffusion, lacunar infarcts, and the presence of massive hemorrhage. The accuracy, sensitivity, and specificity of each imaging modality were determined. Twenty-four patients were excluded based on the aforementioned criteria. Cerebral thromboemboli were identified in 35 of the remaining 76 patients. Of the 35 patients with thromboemboli, 30 were identified on SWI. FLAIR detected 22/35 emboli, MRA 30/33, CT 18/35, and catheter angiography 12/12. The accuracies for SWI, FLAIR, and CT were 97%, 84%, and 74%, respectively. The sensitivities for SWI, FLAIR, and CT were 85%, 61%, and 52%, respectively. The specificities for SWI, FLAIR, and CT were 100%, 98%, and 93%, respectively. There is an adjunctive role of SWI to identify cerebral thromboemboli in patients with acute infarction. SWI is superior to FLAIR and CT, and complementary to MRA and catheter angiography in emboli detection. This study supports SWI detection of MCA emboli, but also emphasizes its utility in emboli detection of other arteries based on a high accuracy and sensitivity.