With the introduction of computed tomography(CT) followed by other
digital diagnostic imaging modalities in the 1970's,and the increasing
use of computers in clinical applications , the American College of
Radiology(ACR) and the National Electrical Manufacturers
Association(NEMA) recognized the emerging need for a standard method
for transferring images and associated information between devices
manufactured by various vendors.
I think that the words 'that is', are elided from the bold section like this:
- the introduction of computed tomography (CT) that is followed by other digital diagnostic imaging modalities
You cannot add that is to this clause. Otherwise, you will have two finite verbs in the sentence, making it ungrammatical.
Do you understand the structure? Apparently not, if you think that is can be added to it. This is one sentence with one independent clause; the independent clause has the finite verb (recognized) and may stand on its own:
the American College of Radiology (ACR) and the National Electrical Manufacturers Association (NEMA) recognized the emerging need for a standard method for transferring images and associated information between devices manufactured by various vendors.
The portion that comes before is two nonfinite clauses separated by a comma:
With the introduction of computed tomography (CT) followed by other digital diagnostic imaging modalities in the 1970's, and the increasing use of computers in clinical applications,
Notice that there is no other finite verb in the entire sentence, including the introductory portion; that is the way it should be in a single sentence.
And the sentence means that CT was introduced in 1970's, and the other modalities followed CT.
Is it right?
That is probably what the sentence means. Although in the 1970's could possibly modify only the clause that comes right before it (followed by other digital diagnostic imaging modalities), meaning that CT was introduced earlier than the 1970's.
Now I'm getting a little confusion about the word 'followed by'.
I thought it should be 'Be followed by'.And that is what my learned before.
But I searched 'follow by' on Google.Then I found this sentence :
"To follow by faith alone is to follow blindly." -Benjamin Franklin
So the word 'follow by' here is a ... fixed phrase?It's not a ... passive voice?
followed by is not a fixed phrase. It is a participle (followed) plus a preposition (by). This combination may be used often, but that does not make it a "fixed phrase" anymore than sent by is a fixed phrase.
Yes, followed is in the passive voice. For example, I was followed by John (compare I was sent by John.)
And more importantly, what comes first ?
I have no idea what you mean.