12 radiographic signs of enlarged hematoma of intracerebral hemorrhage

Cerebral hemorrhage patients in China account for about 23.
4% of stroke patients, of which 46% die or are severely disabled
within 1 year of onset.
Enlargement of hematomas increases the long-term prognosis of the disease and the risk of
death.
Most studies defined haematoma enlargement as an increase in absolute haematoma volume of ≥6 cm or ≥ 33%
relative haematoma relative volume compared to baseline haematoma.

In recent years, many studies have shown that the presence of some specific imaging signs in non-contrast CT and CTA can predict the enlargement of
cerebral hemorrhage hematoma.

Non-contrast CT

1.
Low density within the hematoma

Proposed by Boulouis et al.
, it can be divided into the following four types:

Low density in hematoma is an independent risk factor for hematoma enlargement (OR=3.
42, 95%CI: 2.
21~5.
31), and can predict a poor prognosis of 90d (OR=1.
70, 95%CI: 1.
10~2.
65).

2.
Black hole sign

IT IS DEFINED AS A WELL-DEFINED LOW-DENSITY AREA WITHIN A HIGH-DENSITY HEMATOMA THAT IS NOT CONNECTED TO THE SURROUNDING BRAIN TISSUE, WHICH CAN BE ROUND, OVAL OR STRIP-SHAPED, AND DIFFER FROM THE CT VALUE OF THE PERIPHERAL HEMATOMA BY AT LEAST 28 HU.

A: IRREGULARLY SHAPED BLACK HOLE SIGN, WITH A DIFFERENCE OF 35 HU FROM THE SURROUNDING HEMATOMA; B: circular black hole sign; C: Bar black hole sign, the low-density area in the hematoma is separated from the brain tissue; D: Small round black hole
.

The sensitivity, specificity, positive predictive value, and negative predictive value of black hole sign are 33%, 94%, 73%, and 73%,
respectively.
The mechanism may be related to
different densities in the hematoma cavity representing different stages of bleeding.
Therefore, hematoma enlargement and poor prognosis
can be predicted.

3.
Vortex sign

Vortex signs are an important predictor
of acute active epidural bleeding.
Selariu et al.
applied this marker to patients with acute cerebral hemorrhage for the first time, defined as a low-density or isodense area in the high-density area of the hematoma, and its shape varies from round to strip or irregular shape
.
It is more common in patients with known poor prognosis, such as midline displacement and bleeding into the ventricles, and its incidence is closely related to the size of the hematoma (5-30ml: 41%, >30ml: 62%, P=0.
01; while only 6% of patients with 1-4ml of bleeding have a vortex sign), suggesting that the vortex sign may be a marker
for predicting hematoma enlargement.

A-c is manifested as three different forms of vortex signs: well-defined, irregular and striped.
d: left putamen hemorrhage without vortex sign; e: right frontal hemorrhage, arrow shows hematoma resorption, non-vortex sign: f: left frontal hemorrhage, arrow shows hematoma fluid level

4.
Mixed signs

It is defined as the presence of relatively high-density and low-density areas in the hematoma, with clear boundaries between the two, and a CT value difference of more than
18 HU.

A and B are mixed signs, and there is a clear boundary visible to the naked eye between the two density regions.
C has no obvious demarcation; D is the vortex sign that the high-density region completely envelops the low-density region

The mechanism of its formation is that the clotting blood clot in the hematoma appears to be of high density on CT, while the low-density area may be due
to the continued bleeding of the ruptured blood vessel and the blood has not yet clotting.
Therefore, it predicts hematoma enlargement and is associated with
a poor prognosis of 90 days.

5.
Island signs

That is, a small hematoma around the hematoma
on CT with a plain scan.
If none are connected to hematomas, the number of them is required to be 3 or more; If it is connected to a hematoma in whole or in part, the number of pieces is required to be 4 or more
.

A: In patients with basal ganglia hemorrhage, 3 scattered small hematomas can be seen, each of which is separated from the main hematoma;

B: In patients with putamena hemorrhage, 3 independent small hematomas can be seen, pay attention to the low signal area between the small hematoma and the main hematoma;

C: Patients with lobar hemorrhage, 4 scattered small hematomas can be seen

D: In patients with basal ganglia hemorrhage and protrusion into the ventricle, 4 vesicular or bud-like small hematomas can be seen connected to the main hematoma, and 1 separate scattered small hematoma

It may occur as the hematoma expands, causing damage to adjacent arterioles, causing islets around
the main hematoma.
The study showed that the sensitivity, specificity, positive and negative predictive values of "island sign" in predicting hematoma enlargement were 44.
7%, 98.
2%, 92.
7% and 77.
7%,
respectively.
Therefore, it can be used as a reliable indicator to predict the enlargement of early hematoma in patients with ICH, and is an independent risk factor for poor prognosis of 90 days (OR=3.
51, 95%CI: 1.
26~9.
81).

6.
Satellite signs

Proposed by Shimoda et al.
, it is an independent predictor of the prognosis of
intracerebral hemorrhage.
Defined as:

7.
Uneven density of hematomas and irregular shape of hematomas

Barras et al.
reported for the first time the predictive value of hematoma morphology and density under plain CT scanning for hematoma enlargement, and divided them into 5 types
according to the shape and density of hematoma.
As shown in the following figure (shape classification on the left and density classification on the right):

8.
Liquid level

Recent studies have also found that fluid level is associated
with enlarged hematomas and poor prognosis.
The presence of this sign can reflect abnormalities in the blood clotting process, which leads to early HDL deposition
.
Fluid level is less common in patients with bleeding, and its incidence has been reported to be about 1%~7%
in the past.

Combining the above non-contrast CT signs, some scholars proposed hematomas with an enlargement tendency, that is, one or more positive in mixed signs, black hole signs and island signs, which are strong predictors of hematoma enlargement (OR=28.
33, 95%CI: 12.
95~61.
98) and poor prognosis (OR=5.
67, 95%CI: 2.
82~11.
40
).

CTA

1.
Point sign

Defined as:

The sensitivity, specificity, positive and negative predictive values of CTA point sign in predicting hematoma enlargement were 63%, 90%, 73%, and 84%,
respectively.
And the more high-density "points", the higher
the risk of hematoma enlargement.

In addition, spot signs are associated with poor prognosis, early clinical deterioration, high mortality, and intraventricular hemorrhage, and are considered to be one of the most reliable predictors of
early hematoma enlargement and poor prognosis.

However, in clinical practice, it is necessary to be alert to false positive conditions
such as aneurysm, microarteriovenous malformation, moyamoya disease, tumor and choroid plexus calcification.

Then the point score is proposed:

The spot sign score is the strongest independent risk factor for predicting hematoma enlargement, suggesting that the number of enhanced spots and morphological indicators are related
to the risk of hematoma enlargement.
In addition, the point sign score also has predictive value
for nosocomial death and 3-month poor prognosis.

2.
Leakage signs

Japanese scholars proposed that the original arterial phase of CTA image and the delay period were compared to determine the region of interest with a diameter of 10mm on the delayed period image, and if the CT value increased by more than 10% compared with the arterial stage, it was judged to be positive
for leakage signs.
Its sensitivity for predicting hematoma enlargement was 93.
3% and specificity was 88.
9%.

3.
Iodine sign

Proposed by Chinese scholars, the diagnostic criteria for positive iodine signs on the original CTA image were determined by the synthesis of gem energy spectrum imaging technology to determine that the positive iodine sign was: 1 enhanced spot ≥ in the hematoma and the spot should be clearly visible to the naked eye, the iodine concentration in the spot should be > 7.
82 (100ug/ml) and the spot is not located in the normal vascular walking area
.

Iodine signs independently predicted hematoma enlargement (OR=53.
67, 95%CI : 11.
88~242.
42), and had higher sensitivity (91.
5% vs 63.
8%) and accuracy (85.
7% vs 75.
8%)
than point signs.

4.
Hyperemia signs

Proposed by Singaporean scholars, it refers to the leakage of contrast agent larger than 1mm*2mm in the hematoma, and in the shape
of a curved nozzle.
The results suggest that congestion is an independent risk factor
for hematoma enlargement (OR=6.
05, 95%CI: 1.
03~15.
95) and death (OR=3.
31, 95%CI: 1.
24~25.
41).