Utility of Hounsfield Unit: Haematocrit Ratio in Diagnosing Acute Cerebral Venous Sinus Thrombosis on Unenhanced Computed Tomography
Introduction: The non-invasive imaging technique of choice in diagnosing Cerebral Venous Sinus Thrombosis (CVST) is Magnetic Resonance Imaging (MRI), but it has its own set of limitations like not being available universally in the acute setting. Computed Tomography (CT) Venography (CTV) can be...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
JCDR Research and Publications Pvt. Ltd.
2021-01-01
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| Series: | International Journal of Anatomy Radiology and Surgery |
| Subjects: | |
| Online Access: | http://www.ijars.net/articles/PDF/2612/44951_CE[Ra1]_F(SHU)_PF1(ShG_SHU)_PFA(SHU_ShG_KM)_GC(SHU)_PN(SHU).pdf |
| Summary: | Introduction: The non-invasive imaging technique of choice
in diagnosing Cerebral Venous Sinus Thrombosis (CVST) is
Magnetic Resonance Imaging (MRI), but it has its own set
of limitations like not being available universally in the acute
setting. Computed Tomography (CT) Venography (CTV) can be
used as an alternative diagnostic modality with an advantage of
being more readily available which can be comparable to MRI
in diagnostic accuracy.
Aim: To determine the value of Hounsfield unit: haematocrit
(H:H) ratio on unenhanced brain CT scans in diagnosing acute
CVST and to determine an optimal cut-off value for sensitivity
and specificity based on the Receiver Operating Characteristic
Curve (ROC) curve.
Materials and Methods: This was a retrospective case-control
study on 60 adults, divided into two groups A and B consisting
of 30 each. Group A consisted of 30 healthy controls who
came for unrelated complaints, in whom the imaging findings
for CVST were negative, which was confirmed on contrast
CTV. Group B consisted of 30 Test subjects with imaging
findings of CVST confirmed on CTV. For control images,
attenuation was measured in 3 random, but different, venous
sinuses in plain CT images. For study group, thrombosed
venous sinus was measured on three different locations in
the respective sinus by using the cursor. The location and
densities of the thrombus was also documented. The nonenhanced CT brain images of both the groups were assessed
for the attenuation of the dural sinus. CTV was utilised only
to confirm the presence or absence of dural thrombosis. The
statistical software namely SPSS 22.0, and R environment
ver.3.2.2 were used for the analysis of the data.
Results: The average sinus attenuation in the study group of
acute CVST (M=84.5 HU, SD=6.1 HU) compared to the control
group (M=65.2 HU, SD=4.3HU) demonstrated significant
difference of p<0.0001. The average H: H ratio in the study
group of acute CVST (M=2.3, SD=0.4) compared to the control
group without CVST (M=1.6, SD=0.1); demonstrated significant
difference of p<0.0001. On the basis of ROC curves, with 72 HU
as cut-off value, the study determined a sensitivity of 100% and
a specificity of 96.6%. The study determined a cut-off H: H ratio
of 1.8 for 100% sensitivity and a specificity of 96.6%.
Conclusion: Both density measurement in the venous sinus and
calculation of the H:H ratio will increase the confidence of the
radiologist in a setting where CT is the only available modality.
Determining the H:H ratio on a per case basis helps in clinical
scenarios of such blood disorders like anemia, polycythemia,
while considerably reduced the risk of a false negative or a
positive diagnosis. The present study is just an attempt to equip
the radiologist with another tool at his disposal in cases where he
is not able to access MRV/CTV either due to logistical or patient
contraindications. Although in this study H:H ratio was accurate
and sensitive enough, further large multicenter studies might be
needed before utilising H: H ratio parameter for acute CVST. |
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| ISSN: | 2277-8543 2455-6874 |