The Uniform Cortex Sign: A Diagnostic Sign of Diffuse Cortical Injury at MR Imaging of the Brain Presentation #: EP-79 Authors: Apurva Patel, Basem Bahakeem, Andrew Leung
18
Embed
The Uniform Cortex Sign: A Diagnostic Sign of Diffuse Cortical Injury at MR Imaging of the Brain Presentation #: EP-79 Authors: Apurva Patel, Basem Bahakeem,
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Slide 1
The Uniform Cortex Sign: A Diagnostic Sign of Diffuse Cortical
Injury at MR Imaging of the Brain Presentation #: EP-79 Authors:
Apurva Patel, Basem Bahakeem, Andrew Leung
Slide 2
No disclosures
Slide 3
Background Identification of the central sulcus on MR imaging
is important for accurate anatomic localization of motor and
sensory cortices, especially in patients undergoing surgical
treatment Several topographic features can be utilized on CT and MR
imaging to localize the central sulcus One such feature is thin
cortex sign (TCS), described as the greatest difference in cortical
thickness between gyri banking a single sulcus which is found along
the central sulcus
Slide 4
Purpose The TCS has been described in earlier studies using T1
and T2 weighted sequences in normal patients and in patients with
neoplasms who can have marked distortion of normal anatomy We
propose that the TCS is lost in cases of diffuse cortical injury
which results in the novel uniform cortex sign (UCS) We also
investigate the utility of axial T2, DWI and FLAIR; sagittal FLAIR;
and coronal FLAIR sequences in qualitatively identifying the
TCS
Slide 5
Materials and Methods From July 2014 to November 2014: The UCS
group was formed from patients with diffuse cortical abnormality on
MRI The TCS control group was formed from asymptomatic patients
undergoing MR examination for aneurysm screening 9 patients with
TCS and 8 patients with UCS were obtained
Slide 6
Materials and Methods Radiologist training Using selected MR
images from two control (TCS) and one UCS subject, three fellowship
trained Neuroradiologists were given a tutorial on the TCS and UCS
Two Ax T2, two Ax DWI, two Ax FLAIR, one Sag FLAIR and seven
contiguous Cor FLAIR images were shown for all three tutorial
patients The remaining seven control and seven UCS subjects were
used to determine the utility of the UCS in identifying patients
with diffuse cortical injury Each reader was given selected
deidentified images (same as above) from the database of 14
patients in random order Each reader was asked to identify and mark
the TCS on each image if present If readers felt that the TCS was
absent, they were asked to say that a UCS was present
Slide 7
TCS Tutorial Case Cor FLAIR Axial FLAIR Axial DWI Axial T2 Can
you identify the TCS?
Slide 8
TCS Tutorial Case Cor FLAIR Axial FLAIR Axial DWI Axial T2
Cortical thickness along anterior and posterior banks of the
central sulcus is less than that of adjacent sulci Furthermore, the
cortical thickness of the posterior bank is less than that of the
anterior bank Generalized cortical thinning is qualitatively
observed on coronal FLAIR imaging as the pre- and postcentral
cortices travel obliquely through the coronal plane
Slide 9
UCS Tutorial Case Axial FLAIR Cor FLAIR Axial DWI Sag
FLAIR
Slide 10
UCS Tutorial Case Axial FLAIR Cor FLAIR Axial DWI Sag FLAIR
There is loss of the normal thin cortex banking the central sulcus
All cortices appear uniform in thickness, giving rise to the UCS
(Each red oval marks the region of the central sulcus which was
identified using other anatomic landmarks in the absence of
TCS)
Slide 11
Results TCS correctly identified PatientAgeGenderIndication for
exam Reader 1Reader 2 Reader 3 TCS 129FFHxA. Rule out aneurysm YY Y
TCS 246FFHxA. Rule out aneurysm YY Y TCS 355FFHxA. Rule out
aneurysm YY Y TCS 456MFHxA. Rule out aneurysm YY Y TCS 526FFHxA.
Rule out aneurysm YY Y TCS 652MFHxA. Rule out aneurysm YY Y TCS
713MFHxA. Rule out aneurysm YY Y UCS correctly identified
PatientAgeGenderIndication for examReader 1 Reader 2Reader 3 UCS
112FHIE due to hangingY YY UCS 216MViral encephalitisN NN UCS
355FHIE due to cardiac arrestY YY UCS 475MHIE due to cardiac
arrestY NY UCS 514FHIE due to hangingY YY UCS 649FHIE due to
cardiac arrestY YY UCS 718MTCA overdoseY YY TCS correctly
identified in all 7 control cases by all three readers UCS
correctly identified in 5/7 cases by all readers UCS2 All readers
thought a TCS was present UCS4 Reader 2 thought a TCS was present
HIE, hypoxiemic ischemic injury; FHxA, family history of
intracranial aneurysms; TCA, tricyclic antidepressants
Results UCS and Severity of Cortical Injury Axial T2 images of
patients with mild, moderate and severe cortical injury demonstrate
that the UCS is more conspicuous in cases of severe injury UCS2
UCS4 UCS7 Mild Moderate Severe
Slide 15
Results Follow-up exam of Patient UCS 2 All three readers
failed to correctly identify the UCS in Patient UCS 2 who presented
with mild diffuse cortical injury in the setting of viral
encephalitis Comparison of the initial MR to the post-treatment MR
confirms that the UCS was indeed present on the initial exam which
is no longer evident on the post-treatment exam Initial Exam
Post-treatment Exam
Slide 16
Results SequenceReader 1Reader 2Reader 3Average Axial DWI89%
(25/28)100% (28/28) 96% Axial T2100% (28/28) 100% Axial FLAIR100%
(24/24)92% (22/24)100% (24/24)97% Sagittal FLAIR100% (7/7) 100%
Coronal FLAIR100% (7/7) 100% The TCS was correctly identified by
all 3 readers on all the axial T2, sagittal FLAIR and coronal FLAIR
images Axial DWI TCS correctly identified 81/84 times (96%) Axial
FLAIR TCS correctly identified 70/72 times (97%)
Slide 17
Conclusion We confirm that the TCS can be used as a tool to
identify the central sulcus in normal patients The UCS is a
reliable indicator of diffuse cortical injury The extent of
cortical swelling is variable depending on the severity of cortical
injury The sensitivity of UCS may be lower in the setting of mild
diffuse cortical injury
Slide 18
References Biega TJ, Lonser RR, Butman JA. Differential
cortical thickness across the central sulcus: A method for
identifying the central sulcus in the presence of mass effect and
vasogenic edema. AJNR 2006;27:1450-1453 Togao O, Yoshiura T, Mihara
F, et al. Cortical thickness difference across the central sulcus
visualized in the presence of vasogenic edema. EJR 2008:66;274- 281
Meyer JR, Sudipta R, Russell EJ, et al. Localization of the central
sulcus via cortical thickness of the precentral and postcentral
gyri on MRI. AJNR 1996:17;1699-1706 Wagner M, Jurcoane M, Hattingen
E. The U sign: Tenth landmark to the central region on brain
surface reformatted MR imaging. AJNR 2013:34;323-326