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In 2016, I wrote the first short article on Yimaitong on a night of overtime work, "Progressive Supranuclear Palsy MRI Features Only Know the Hummingbird Sign? "——That was the first article written on Yimaitong, naive and immature.
Probably last year, Teacher Li Kai contacted me and said that the Parkinson’s Syndrome Index (MRPI) in the article was calculated incorrectly, and it was found that it was indeed wrong.
At that time, he was just a little P boy in the second year of graduate school.
Now he is about to work independently, with great responsibilities, and hopes to correct his mistakes.
Author: Chen Xiaohui This article is the author's permission NMT Medical publish, please do not reprint without authorization.
Since 2016, there have been some new structural imaging markers for progressive supranuclear palsy (PSP), including MRPI version 2.
0 and pontine midbrain ratio 2.
0.
I will sort out and explain it below.
Overview PSP structure images can be summed up in four words: midbrain atrophy.
Almost all image signs and indicators reflect midbrain atrophy.
As for the T2 and Flair hyperintensities in the midbrain tectum, research reports have high specificity and low sensitivity.
Among the more than 10 cases of PSP patients I have collected, there is no case of midbrain tectum hyperintensity.
Qualitative description of midbrain atrophy-Hummingbird sign, Penguin side sign, Mickey Mouse sign, Morning glory sign 1.
Hummingbird sign Hummingbird sign is the most well-known sign of brain atrophy in PSP, which is manifested as a flat or sunken upper edge of the midbrain.
Let's put the picture again.
If the upper edge is flat, it should be considered as a suspicious positive hummingbird sign.
The B on the right of the figure below is also often seen in MSA and PD.
Only when the upper edge is sunken can it be considered a positive hummingbird sign, which has a high specificity for the diagnosis of PSP.
.
2.
Penguin side sign Another similar image is the "Penguin side sign", which is also due to atrophy of the midbrain.
The midbrain looks like a small penguin head and the pons looks like a big penguin belly. The difference between the two is that the observation point is atrophy of the upper edge of the midbrain and the overall area of the midbrain.
A specific patient can be positive for the hummingbird sign and negative for the penguin side sign.
As shown in the figure below, a 64-year-old male patient with a course of 2.
5 years has a depression in the upper edge of the midbrain, a slight decrease in the overall area of the midbrain in the sagittal view, and the ratio of midbrain/pons <1/2.
Axial midbrain atrophy is obvious, with suspicious "morning glory sign" and an indirect sign of midbrain atrophy-third ventricle enlargement (the signs mentioned here will be discussed later).
3.
The third qualitative sign of Morning Glory Sign is Morning Glory Sign.
The so-called Morning Glory Sign is the atrophy of the midbrain tectum observed in the axial position.
As shown in the figure below, make a horizontal line through the midbrain aqueduct, and draw a straight line from its intersection with the edge of the midbrain and the junction of the base of the midbrain and tegmental.
If the tegmental edge of the midbrain is outside the second straight line, it indicates No atrophy of the midbrain tectum—"Morning Glory Sign" is negative; if it just falls on the line, the "Morning Glory Sign" is suspiciously positive; if its edge is recessed due to atrophy, the edge of the midbrain tectum is located in the second straight line The inner side-"Morning Glory Sign" is positive.
4.
The last qualitative sign of the Mickey Mouse sign is the "Mickey Mouse sign", which is also observed in the axial position.
It can be seen that the distance between the feet of the brain is widened due to the atrophy of the base of the midbrain.
At the same time, the atrophy of the midbrain tectum causes similar drag.
The midbrain tegment area of the cow flower sign is inverted, and the brain feet are shaped like Mickey Mouse ears.
But the interpretation of this sign requires certain experience.
Quantitative midbrain atrophy-midbrain pons internal diameter ratio, midbrain pons area (area) ratio, third ventricle/intracranial diameter ratio, MRPI, MRPI2.
0, etc.
1.
The first is the midbrain pons internal diameter ratio, which is very personal to me I like a quantitative method.
The article was published in Neurology in 2013.
I like it because the method is simple, clinically feasible, accurate data, and available to Chinese people.
The reason for saying this is that I have roughly collected some patient images myself, and I feel that this indicator is quite accurate.
As for how to measure, first observe in the middle of the axis, draw two ellipses, one along the long axis of the midbrain, one along the long axis of the pons (thin line in the figure), and then make it perpendicular to the two long axes.
Vertical line, measure the maximum inner diameter of the transverse axis of the midbrain and the transverse axis of the pons. Note: Does not include the midbrain tectum (quadruplex) and the pons tectum area.
The critical value reported in the literature is 0.
52, which is less than that for PSP patients.
As for the midbrain diameter of 9.
35 as the critical value mentioned in the same article, the diagnostic value is slightly lower in the data compiled by myself, because MSA will also have a certain degree of midbrain atrophy, which is between PSP and PD/normal controls.
2.
The second is the MR Parkinson's Syndrome Index (MRPI), which is what I want to correct.
I wrote earlier "MRI Features of Progressive Supranuclear Palsy, Only Know the Hummingbird Sign? "The method of measuring the upper foot of the cerebellum is wrong, I am very sorry.
First of all, the calculation formula is as follows (click on the picture to enlarge) and the specific measurement method is as follows: draw a line (line A) that passes through the upper pons and the lower edge of the quadruple.
The second line runs parallel to the first line through the subpontine notch (line B).
Midbrain area = the midbrain area above the A line, excluding the tetracass.
Pons area = area of the area between the front and rear edges of the pons and the A and B lines.
The inner diameter of the midfoot of the cerebellum is the most obvious area of the midfoot on both sides of the cerebellum in the sagittal position.
Measure both sides to calculate the average; the upper foot of the cerebellum is in the coronal position where the hypothalamus and the upper foot of the cerebellum first separate as the starting level , Scan 3 layers continuously (under the premise of 3D-T1, the layer thickness is 1mm), calculate the inner diameter of the upper foot of the cerebellum on each layer, and calculate the average value.
The ratio of the third ventricle to the frontal angle added by MRPI2.
0 is relatively simple, but the axial position is required to be scanned along the front and back joints.
At the anterior and posterior joint level, measure the largest inner diameters of the third ventricle in the anterior, middle, and posterior positions, and calculate the average value, which is the third ventricle diameter; and then measure the distance between the outermost side Distance, as shown below.
Having said so much and the calculation is so complicated, is there any clinical value? According to my own calculations, MRPI2.
0 is significantly better than the original version of MRPI.
It is understandable because the enlargement of the third ventricle itself is an indirect sign of midbrain atrophy, which is equivalent to measuring the index of midbrain atrophy through midbrain atrophy/frontal angle distance.
Strengthened. In the literature, the specificity and sensitivity of MRPI and MRPI2.
0 can reach more than 90%, but it is unclear whether this cut-off value is suitable for Chinese people, and this measurement is complicated and its clinical application is limited.
3.
Finally, a third ventricle/cranial diameter ratio: This is a new indicator published in "Movement disorders" in 2020.
The original text says that the axis is parallel to the head of the corpus callosum and the lower edge of the pressure part.
Scanning, personally feel that this is not very different from scanning along the AC-PC direction.
Scanning in this direction can see the third ventricle resembling a rectangular regular shape.
It is better to see the third ventricle.
The method is very simple (click on the picture to enlarge) The role of SWI in identifying Parkinson’s syndrome should not be underestimated.
SWI is a very good sequence for observing iron deposition.
In PD and normal aging, iron deposition is often mild inside the globus pallidus The iron deposits are limited in scope and not serious.
In MSA-P patients, linear iron deposition on the dorsolateral putamen is a characteristic iron deposition pattern.
As the disease progresses, iron deposition can develop anterior and medially, but it is still the most prominent on the dorsolateral putamen.
It is somewhat similar to the putamen fissure sign.
The typical iron deposition pattern of PSP patients is diffuse and severe iron deposition in the basal ganglia, substantia nigra, and red nucleus, as shown in the figure below.
But in fact, this picture is not particularly clear.
Below are the pictures of the three patients, which will be more clear.
Written at the end and finally corrected the error.
There are a few points I want to mention: 1.
The various indicators need to be combined.
The specificity and sensitivity of a single indicator are limited.
If the patient has multiple indicators at the same time to indicate PSP, the power will be greater; 2.
Combined with clinical practice .
All diagnosis must be combined with clinical, structural imaging is only a part of assisting diagnosis, and its diagnostic value for you also depends on your personal experience; 3.
Once again, sorry for bringing everyone into the ditch 5 years ago. References: 1.
Quattrone A, Nicoletti G, Messina D, et al.
MR imaging index for differentiation of progressive supranuclear palsy from Parkinson disease and the Parkinson variant of multiple system atrophy.
Radiology.
2008;246(1):214-221.
2 Quattrone A, Morelli M, Nigro S, et al.
A new MR imaging index for differentiation of progressive supranuclear palsy-parkinsonism from Parkinson's disease.
Parkinsonism Relat Disord.
2018;54:3-8.
3.
Quattrone A, Antonini A, Vaillancourt DE , et al.
A New MRI Measure to Early Differentiate Progressive Supranuclear Palsy From De Novo Parkinson's Disease in Clinical Practice: An International Study.
Mov Disord.
2020.
4.
Massey LA, Jager HR, Paviour DC, et al.
The midbrain to pons ratio: a simple and specific MRI sign of progressive supranuclear palsy.
Neurology.
2013;80(20):1856-1861.
5.
Oba H, Yagishita A, Terada H,et al.
New and reliable MRI diagnosis for progressive supranuclear palsy.
Neurology.
2005;64(12):2050-2055.
6.
Adachi M, Kawanami T, Ohshima H, Sugai Y, Hosoya T.
Morning glory sign: a particular MR finding in progressive supranuclear palsy.
Magn Reson Med Sci.
2004;3(3):125-132.
Probably last year, Teacher Li Kai contacted me and said that the Parkinson’s Syndrome Index (MRPI) in the article was calculated incorrectly, and it was found that it was indeed wrong.
At that time, he was just a little P boy in the second year of graduate school.
Now he is about to work independently, with great responsibilities, and hopes to correct his mistakes.
Author: Chen Xiaohui This article is the author's permission NMT Medical publish, please do not reprint without authorization.
Since 2016, there have been some new structural imaging markers for progressive supranuclear palsy (PSP), including MRPI version 2.
0 and pontine midbrain ratio 2.
0.
I will sort out and explain it below.
Overview PSP structure images can be summed up in four words: midbrain atrophy.
Almost all image signs and indicators reflect midbrain atrophy.
As for the T2 and Flair hyperintensities in the midbrain tectum, research reports have high specificity and low sensitivity.
Among the more than 10 cases of PSP patients I have collected, there is no case of midbrain tectum hyperintensity.
Qualitative description of midbrain atrophy-Hummingbird sign, Penguin side sign, Mickey Mouse sign, Morning glory sign 1.
Hummingbird sign Hummingbird sign is the most well-known sign of brain atrophy in PSP, which is manifested as a flat or sunken upper edge of the midbrain.
Let's put the picture again.
If the upper edge is flat, it should be considered as a suspicious positive hummingbird sign.
The B on the right of the figure below is also often seen in MSA and PD.
Only when the upper edge is sunken can it be considered a positive hummingbird sign, which has a high specificity for the diagnosis of PSP.
.
2.
Penguin side sign Another similar image is the "Penguin side sign", which is also due to atrophy of the midbrain.
The midbrain looks like a small penguin head and the pons looks like a big penguin belly. The difference between the two is that the observation point is atrophy of the upper edge of the midbrain and the overall area of the midbrain.
A specific patient can be positive for the hummingbird sign and negative for the penguin side sign.
As shown in the figure below, a 64-year-old male patient with a course of 2.
5 years has a depression in the upper edge of the midbrain, a slight decrease in the overall area of the midbrain in the sagittal view, and the ratio of midbrain/pons <1/2.
Axial midbrain atrophy is obvious, with suspicious "morning glory sign" and an indirect sign of midbrain atrophy-third ventricle enlargement (the signs mentioned here will be discussed later).
3.
The third qualitative sign of Morning Glory Sign is Morning Glory Sign.
The so-called Morning Glory Sign is the atrophy of the midbrain tectum observed in the axial position.
As shown in the figure below, make a horizontal line through the midbrain aqueduct, and draw a straight line from its intersection with the edge of the midbrain and the junction of the base of the midbrain and tegmental.
If the tegmental edge of the midbrain is outside the second straight line, it indicates No atrophy of the midbrain tectum—"Morning Glory Sign" is negative; if it just falls on the line, the "Morning Glory Sign" is suspiciously positive; if its edge is recessed due to atrophy, the edge of the midbrain tectum is located in the second straight line The inner side-"Morning Glory Sign" is positive.
4.
The last qualitative sign of the Mickey Mouse sign is the "Mickey Mouse sign", which is also observed in the axial position.
It can be seen that the distance between the feet of the brain is widened due to the atrophy of the base of the midbrain.
At the same time, the atrophy of the midbrain tectum causes similar drag.
The midbrain tegment area of the cow flower sign is inverted, and the brain feet are shaped like Mickey Mouse ears.
But the interpretation of this sign requires certain experience.
Quantitative midbrain atrophy-midbrain pons internal diameter ratio, midbrain pons area (area) ratio, third ventricle/intracranial diameter ratio, MRPI, MRPI2.
0, etc.
1.
The first is the midbrain pons internal diameter ratio, which is very personal to me I like a quantitative method.
The article was published in Neurology in 2013.
I like it because the method is simple, clinically feasible, accurate data, and available to Chinese people.
The reason for saying this is that I have roughly collected some patient images myself, and I feel that this indicator is quite accurate.
As for how to measure, first observe in the middle of the axis, draw two ellipses, one along the long axis of the midbrain, one along the long axis of the pons (thin line in the figure), and then make it perpendicular to the two long axes.
Vertical line, measure the maximum inner diameter of the transverse axis of the midbrain and the transverse axis of the pons. Note: Does not include the midbrain tectum (quadruplex) and the pons tectum area.
The critical value reported in the literature is 0.
52, which is less than that for PSP patients.
As for the midbrain diameter of 9.
35 as the critical value mentioned in the same article, the diagnostic value is slightly lower in the data compiled by myself, because MSA will also have a certain degree of midbrain atrophy, which is between PSP and PD/normal controls.
2.
The second is the MR Parkinson's Syndrome Index (MRPI), which is what I want to correct.
I wrote earlier "MRI Features of Progressive Supranuclear Palsy, Only Know the Hummingbird Sign? "The method of measuring the upper foot of the cerebellum is wrong, I am very sorry.
First of all, the calculation formula is as follows (click on the picture to enlarge) and the specific measurement method is as follows: draw a line (line A) that passes through the upper pons and the lower edge of the quadruple.
The second line runs parallel to the first line through the subpontine notch (line B).
Midbrain area = the midbrain area above the A line, excluding the tetracass.
Pons area = area of the area between the front and rear edges of the pons and the A and B lines.
The inner diameter of the midfoot of the cerebellum is the most obvious area of the midfoot on both sides of the cerebellum in the sagittal position.
Measure both sides to calculate the average; the upper foot of the cerebellum is in the coronal position where the hypothalamus and the upper foot of the cerebellum first separate as the starting level , Scan 3 layers continuously (under the premise of 3D-T1, the layer thickness is 1mm), calculate the inner diameter of the upper foot of the cerebellum on each layer, and calculate the average value.
The ratio of the third ventricle to the frontal angle added by MRPI2.
0 is relatively simple, but the axial position is required to be scanned along the front and back joints.
At the anterior and posterior joint level, measure the largest inner diameters of the third ventricle in the anterior, middle, and posterior positions, and calculate the average value, which is the third ventricle diameter; and then measure the distance between the outermost side Distance, as shown below.
Having said so much and the calculation is so complicated, is there any clinical value? According to my own calculations, MRPI2.
0 is significantly better than the original version of MRPI.
It is understandable because the enlargement of the third ventricle itself is an indirect sign of midbrain atrophy, which is equivalent to measuring the index of midbrain atrophy through midbrain atrophy/frontal angle distance.
Strengthened. In the literature, the specificity and sensitivity of MRPI and MRPI2.
0 can reach more than 90%, but it is unclear whether this cut-off value is suitable for Chinese people, and this measurement is complicated and its clinical application is limited.
3.
Finally, a third ventricle/cranial diameter ratio: This is a new indicator published in "Movement disorders" in 2020.
The original text says that the axis is parallel to the head of the corpus callosum and the lower edge of the pressure part.
Scanning, personally feel that this is not very different from scanning along the AC-PC direction.
Scanning in this direction can see the third ventricle resembling a rectangular regular shape.
It is better to see the third ventricle.
The method is very simple (click on the picture to enlarge) The role of SWI in identifying Parkinson’s syndrome should not be underestimated.
SWI is a very good sequence for observing iron deposition.
In PD and normal aging, iron deposition is often mild inside the globus pallidus The iron deposits are limited in scope and not serious.
In MSA-P patients, linear iron deposition on the dorsolateral putamen is a characteristic iron deposition pattern.
As the disease progresses, iron deposition can develop anterior and medially, but it is still the most prominent on the dorsolateral putamen.
It is somewhat similar to the putamen fissure sign.
The typical iron deposition pattern of PSP patients is diffuse and severe iron deposition in the basal ganglia, substantia nigra, and red nucleus, as shown in the figure below.
But in fact, this picture is not particularly clear.
Below are the pictures of the three patients, which will be more clear.
Written at the end and finally corrected the error.
There are a few points I want to mention: 1.
The various indicators need to be combined.
The specificity and sensitivity of a single indicator are limited.
If the patient has multiple indicators at the same time to indicate PSP, the power will be greater; 2.
Combined with clinical practice .
All diagnosis must be combined with clinical, structural imaging is only a part of assisting diagnosis, and its diagnostic value for you also depends on your personal experience; 3.
Once again, sorry for bringing everyone into the ditch 5 years ago. References: 1.
Quattrone A, Nicoletti G, Messina D, et al.
MR imaging index for differentiation of progressive supranuclear palsy from Parkinson disease and the Parkinson variant of multiple system atrophy.
Radiology.
2008;246(1):214-221.
2 Quattrone A, Morelli M, Nigro S, et al.
A new MR imaging index for differentiation of progressive supranuclear palsy-parkinsonism from Parkinson's disease.
Parkinsonism Relat Disord.
2018;54:3-8.
3.
Quattrone A, Antonini A, Vaillancourt DE , et al.
A New MRI Measure to Early Differentiate Progressive Supranuclear Palsy From De Novo Parkinson's Disease in Clinical Practice: An International Study.
Mov Disord.
2020.
4.
Massey LA, Jager HR, Paviour DC, et al.
The midbrain to pons ratio: a simple and specific MRI sign of progressive supranuclear palsy.
Neurology.
2013;80(20):1856-1861.
5.
Oba H, Yagishita A, Terada H,et al.
New and reliable MRI diagnosis for progressive supranuclear palsy.
Neurology.
2005;64(12):2050-2055.
6.
Adachi M, Kawanami T, Ohshima H, Sugai Y, Hosoya T.
Morning glory sign: a particular MR finding in progressive supranuclear palsy.
Magn Reson Med Sci.
2004;3(3):125-132.
