Search tips
Search criteria

Results 1-4 (4)

Clipboard (0)

Select a Filter Below

Year of Publication
Document Types
1.  Clot length Distribution and Predictors in Anterior Circulation Stroke: Implications for IA Therapy 
Background and Purpose
Thin-section non-contrast CT (NCCT) images can be used to measure hyperdense clot length in acute ischemic stroke (AIS). Clots ≥8mm have a very low probability of IV-tPA recanalization, and hence may benefit from a bridging intra-arterial approach. To understand the prevalence of such clots, we sought to determine the distribution and predictors of clot lengths in consecutive anterior circulation proximal artery occlusions.
Of 623 consecutive AIS patients, fifty-three met inclusion criteria: presentation <8 hours from onset; intracranial ICA-terminus or proximal-MCA occlusion; admission thin-slice NCCT (≤2.5mm); and no IV-tPA pre-treatment. For each patient, hyperdense clot length was measured and recorded along with additional relevant imaging and clinical data.
Mean age was 70 years, and mean time-to-CT was 213 minutes. Median baseline NIHSS was 16.5. Occlusions were located in the ICA-terminus (34% [18/53]), MCA M1 (49%[26/53]) and M2 segments (17% [9 of 53]). Hyperdense thrombus was visible in 96%, with mean and median clot lengths (mm) of 18.5 (±14.2) and 16.1 (7.6-25.2), respectively. Occlusion location was the strongest predictor of clot length (multivariate p=0.02). Clot length was ≥8mm in 94%, 73%, and 22% of ICA-terminus, M1, and M2 occlusions, respectively.
The majority of anterior circulation proximal occlusions are ≥8mm long, helping to explain the low published rates of IV-tPA recanalization. ICA-terminus occlusion is an excellent marker for clot length ≥8mm; vessel-imaging status alone may be sufficient. Thin-section NCCT appears useful for patients with MCA occlusion due to the wide variability of clot lengths.
PMCID: PMC3927722  PMID: 24105699
Stroke; Hyperdense MCA; Clot-length; Intra-Arterial Therapy; IV-tPA
2.  Optimal Brain MRI Protocol for New Neurological Complaint 
PLoS ONE  2014;9(10):e110803.
Patients with neurologic complaints are imaged with MRI protocols that may include many pulse sequences. It has not been documented which sequences are essential. We assessed the diagnostic accuracy of a limited number of sequences in patients with new neurologic complaints.
996 consecutive brain MRI studies from patients with new neurological complaints were divided into 2 groups. In group 1, reviewers used a 3-sequence set that included sagittal T1-weighted, axial T2-weighted fluid-attenuated inversion recovery, and axial diffusion-weighted images. Subsequently, another group of studies were reviewed using axial susceptibility-weighted images in addition to the 3 sequences. The reference standard was the study's official report. Discrepancies between the limited sequence review and the reference standard including Level I findings (that may require immediate change in patient management) were identified.
There were 84 major findings in 497 studies in group 1 with 21 not identified in the limited sequence evaluations: 12 enhancing lesions and 3 vascular abnormalities identified on MR angiography. The 3-sequence set did not reveal microhemorrhagic foci in 15 of 19 studies. There were 117 major findings in 499 studies in group 2 with 19 not identified on the 4-sequence set: 17 enhancing lesions and 2 vascular lesions identified on angiography. All 87 Level I findings were identified using limited sequence (56 acute infarcts, 16 hemorrhages, and 15 mass lesions).
A 4-pulse sequence brain MRI study is sufficient to evaluate patients with a new neurological complaint except when contrast or angiography is indicated.
PMCID: PMC4208779  PMID: 25343371
3.  Using Keynote to Present Radiology Images 
Journal of Digital Imaging  2010;24(5):844-847.
Numerous articles have offered instructions for working with advanced radiology images in Microsoft PowerPoint (Redmond, WA); however, no articles have detailed instructions to do the same on alternative presentation software. Apple Macintosh (Cupertino, CA) computers are gaining popularity with many radiologists, due in part to the availability of a powerful, free, open-source Digital Imaging and Communications in Medicine (DICOM) viewing and manipulating software OsiriX ( Apple’s own presentation software, Keynote, is particularly effective in dealing with medical images and cine clips. This article demonstrates how to use Apple’s Keynote software to present radiology images and scrollable image stacks, without third-party add-on software. The article also illustrates how to compress media files and protect patient information in Keynote presentations. Lastly, it addresses the steps to converting between PowerPoint and Keynote file formats. Apple’s Keynote software enables quick and efficient addition of multiple static images or scrollable image stacks, compression of media files, and removal of patient information. These functions can be accomplished by inexperienced users with no software modifications.
PMCID: PMC3180549  PMID: 20978920
Computers in medicine; Radiology Information Systems (RIS); Radiology teaching file; Image processing; Image display; Productivity; Keynote
4.  The Massachusetts General Hospital acute stroke imaging algorithm: an experience and evidence based approach 
Journal of Neurointerventional Surgery  2013;5(Suppl 1):i7-i12.
The Massachusetts General Hospital Neuroradiology Division employed an experience and evidence based approach to develop a neuroimaging algorithm to best select patients with severe ischemic strokes caused by anterior circulation occlusions (ACOs) for intravenous tissue plasminogen activator and endovascular treatment. Methods found to be of value included the National Institutes of Health Stroke Scale (NIHSS), non-contrast CT, CT angiography (CTA) and diffusion MRI. Perfusion imaging by CT and MRI were found to be unnecessary for safe and effective triage of patients with severe ACOs. An algorithm was adopted that includes: non-contrast CT to identify hemorrhage and large hypodensity followed by CTA to identify the ACO; diffusion MRI to estimate the core infarct; and NIHSS in conjunction with diffusion data to estimate the clinical penumbra.
PMCID: PMC3623036  PMID: 23493340

Results 1-4 (4)