Radiology sheet #1 by Dyala Al-Armouti

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Radiology sheet #1 by Dyala Al-Armouti

Post by Dyala Al-Armouti on 4/10/2012, 5:27 am

Last edited by Dyala Al-Armouti on 5/10/2012, 5:08 am; edited 2 times in total
Dyala Al-Armouti

عدد المساهمات : 639
النشاط : 16
تاريخ التسجيل : 2009-09-06
العمر : 26

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Re: Radiology sheet #1 by Dyala Al-Armouti

Post by Dyala Al-Armouti on 4/10/2012, 5:30 am

بسم الله الرحمن الرحيم
Radiology sheet #1
Dr. Abeer Al-Hadidi
This course will be different than the one we took before.
In that course we talked about the basics, (how radiographs are made, how radiographs were taken, some pitfalls of geometric errors, processing errors, etc.)
You need to know these basics so you know when your assistant has done something different than what you have expected.
The DENTIST in regular life is the one who DIAGNOSE radiographs>> so, you have to come up with the decision>> is this normal or not 
You should recognize what you are looking at >> is it an artifact, or normal anatomy, or a disease!
 This course is divided into modules, we’re going to meet twice over the same subject (let’s say cyst), in the 1st lecture we’ll talk about cysts (definition, types, radiographic signs, etc.)
In that day, a power point presentation of 8 to 10 cases will be uploaded on the e-learning website, with objective and subjective questions.
You have to look at these cases before the next lecture, which will be a CRC session (Clinical Radiographic Conference), in which we will discuss the cases using a uniform language that we will set up today. We’ll talk about description, localization, differential diagnosis, and management.
** E-learning website: > the username and password will be given later, it may be the same that you use in the registration website.
This website will contain documents, online quizzes, discussion forum, and other things!

 So, we are concerned now about the radiographic perspective from a decision point of view.
 If you can recognize abnormal things (again for example a cyst>> the management of cysts from a general practitioner point of view will be the same). So the important thing here is to recognize malignant lesions from benign ones>> not to have malignant lesion and do RCT for the adjacent tooth, or to have a benign lesion and do complete resection of the mandible!

 Interpretation: is the ability to see and understand.
You have to follow the following simple principles to be a safe dentist (as a minimum), and then build up on it to be a good diagnostician.
(Interpretation principles)
1- Importance of recognizing normal anatomy.
When I know that what I see in the radiograph is anatomy or variation of anatomy I won’t freak out that it does look like a disease! And vice versa.
This goes for intraoral radiographs, panoramic radiographs, etc.
2- The independence of radiographic signs.
This means that the signs are general.
You know that there are intraoral radiographs, extra-oral radiographs (panoramic and skull views), and advanced imaging (CT , MRI).
In all these types you can use a common language, this means that if you have a well-defined lesion, it will be well-defined in all of them.
3- The principle of symmetry.
If the two sides of the radiograph (right & left) are not symmetrical, this raise up a question! Is it pathology?? Or is it just variation of anatomy??

4- Terminology
5- Description
6- Categorization.
If someone calls me and wants to describe a radiographic lesion by phone, he should use this terminology and go through certain aspects when describing the lesion, so that I know exactly what he’s saying, and can imagine the radiograph just like if I’m looking at it!
(Universal terminology and description and signs of radiographic interpretation)
 Viewing sequence:
You should follow this sequence in order to make things easier and less complicated.

1- Global:
 Assess symmetry of form and density.
 Follow cortical boundaries.
 Count teeth.
2- Local:
 Assess periodontal ligament space and lamina dura.
 Evaluate root form and canal structure
 Assess crowns for caries or abnormality.

Pay attention that radiographs come after full history and examination of the patient, and application of the selection criteria to determine what types of radiographs we need.
 Systematic approach:
1- Patient’s information:
- Age, sex, race.
2- History
3- Symptoms
4- Clinical examination
5- Existing diagnostic radiographs
This systematic approach will help us in the differential diagnosis because sometimes you see two lesions that are similar from radiographic perspective, but if seen in the maxilla >> it may be certain type of lesion that is different from that if it’s seen in the mandible.
As well, if the radiograph is for an old gentleman of anglo-saxonian race, the differential diagnosis will be different than that of the same radiograph of a middle aged lady of African American descendant 
So, all these details will help us to make the picture complete.

** Terminology:
Things are divided into two major categories:
1- Radiolucent (black)
2- Radiopaque (white)

 Radiolucent lesions:
There are different categories:
1- Corticated unilocular radiolucent lesion.
2- Non-corticated unilocular radiolucent lesion.
3- Multilocular radiolucent lesion.
4- Multifocal confluent radiolucent lesion.
5- Moth eaten radiolucent lesion.
Each one of these types tells you that it’s a certain category of diseases.
For example when you see moth eaten radiolucent lesion>> no way to be a cyst!
So by this I’m narrowing my differential diagnosis.

1- Corticated unilocular radiolucent lesion
There is intact white sharp line surrounding it.

2- Non-corticated unilocular radiolucent lesion
(Loss of cortication has a pathophysiological cause)

3- Multilocular radiolucent lesion:
It looks like grapes! It’s a single lesion that consists of multiple locules of different sizes (some are too big, some are too small).

4- Multifocal confluent radiolucent lesion:
It consists of multiple lesions, but they are close to each other.
Q: how to differentiate between the multilocular and multifocal lesions?
A: it’s related to something called the EPICENTER!
Multilocular lesion>> single lesion>> one epicenter
Multifocal >> multiple lesions >> each one has its own center.

5- Moth-eaten radiolucent lesion:
It has ill-defined margin, and wide zone of transition.

 The location of each of these lesions is very important!
For example, if we have corticated unilocular radiolucent lesion associated with an unerupted tooth>> there are top three choices of the differential diagnosis!

Description + Location = narrows down the differential diagnosis
(This applies for the radiopaque and radiolucent lesions)

 Radiopaque lesions:
1- Focal radiopaque lesion >> homogenous lesion.
2- Target radiopaque lesion.
3- Multifocal confluent radiopaque lesion.
Ex. Mature stage of PCOD (Periapical Cemento-Osseous Dysplasia)
4- Irregular or ill-defined radiopaque lesion.
Ill- defined lesions are always bad>> either radiolucent or radiopaque!
5- Ground glass radiopaque lesion>>> orange peel, finger print, etc.
Ex. Fibrous dysplasia lesion, it has ill-defined margin, and it’s usually unilateral
6- Mixed density lesions> radio-opacity and radiolucency:
In these lesions, the radio-opacity is made by the lesion itself! (The lesion makes the radiopaque component inside it).
Ex. Ameloblastic fibrodentinoma.
7- Soft tissue radiopaque lesion

Back to interpretation 
- You just have to use signs to interpret radiographs!
GENERAL SIGNS>> just as the general signs that you look at when you meet a new person, or you go to a new city, or look at a photograph or a painting from certain century!
There are radiographic signs that you have to go over when you describe a radiograph
Radiographic signs
1- Radiographic density:
Lucent vs. opaque
2- Margin characteristics:
Well-defined vs. ill-defined
Corticated vs. non-corticated
3- Shape.
4- Location and distribution:
In the maxilla, mandible, premolar, molar, etc.
Multi focal, multi locolar, unilocular, etc.
This is important, for example when we say that there is a mixed density lesion, well-defined, associated with an impacted canine in a young male patient>> the doctor is thinking about adenomatoid odontogenic tumor >> straight forward 

5- Size
6- Internal architecture:
Mixed or not, with septa? What’s the shape of these septa? Etc.!
7- Effect on surrounding tissues:
Is the lesion pushing teeth? Or did it cause root resorption?
** It’s very important to differentiate benign conditions from malignant conditions.
When we say benign or malignant>> we mean management wise!
So, here malignant conditions are the ones that need aggressive management.

Benign conditions
Malignant conditions

More variation Mostly radiolucent, except:
1- Metastasis (breast and prostate cancer)
2- Osteogenic carcinoma

Margins 1- Well-defined
2- Narrow zone of transition
3- Smooth, regular
4- corticated 1- Ill-defined
2- Wide zone of transition
3- Ragged
4- Moth-eaten

Oval or round

Effect on surrounding structure - Cortical bone expansion
- Displacement of teeth and maxillary sinus
- Thinning - Erosion and destruction of bone

ID canal
- Displacement of the canal
- No neurosensory deficit
- Invasion and destruction
- Anesthesia and/or parasthesia


Root resorption
Horizontal root resorption -more variable
-Vertical root resorption
-spiked roots
-sometimes no root resorption

Squamous cell carcinoma

** Regarding the zone of transition, when we say wide zone of transition, this means that I cannot see where the bad lesion stops and where the bone begins>> which is known as infiltrative lesion.
Think about it from pathophysiology point of view!
Cancer and acute inflammation >> infiltrative lesions>> ill-defined, moth-eaten, wide zone of transition
While benign tumors and cysts >> exert pressure >> have enough time to push bone slowly and make margins.
** spiked roots >> undergone vertical resorption (in all dimensions!)
Spiked>> مبري
Q: why is it horizontal root resorption with benign lesions? while vertical with malignant lesions?
A: because in benign lesions we said that there is pressure exerted by the lesion with causes the horizontal resorption of all affected roots.
While in the malignant lesions, it’s infiltrative>> so the lesion is destructing the roots all around! Because it’s not a systematic activity, it’s rather a haphazard!
However, nowadays we’re having much better access of patients to health care providers, and they get early management and treatment, so it’s rare to see radiographs of spiked roots >> actually we see it in the early stage as blunting all around.
Q: did you know from the radiographs that this benign lesion is ameloblastoma and that malignant one is SCC??
A: no! from the radiograph I knew that this is a benign lesion (the one that has pushed the canal), and the other is a malignant or acute inflammation (the one by which the canal is destructed).
I could perform excisional biopsy for the benign one, but not for the malignant!
So the radiograph tells me what further investigation do I need, but it doesn’t tell me that this is a SCC.

** Lamina dura and PDL space:
It’s the second most important thing after cortical bone.
The worrying sign of the PDL >> is to have asymmetric widening of PDL space and loss of lamina dura, because it can be a sign of malignant tumors, such as:
1- Osteosarcoma
2- Chondrosarcoma
3- Lymphoma
How does it occur? As they are infiltrative lesion >> cells look for the weakest points and go through them >> on one side of the root>> asymmetric widening.

While it can be also caused by:
1- Scleroderma >> causes asymmetrical widening of PDL on all teeth

2- Vertical root fracture
3- Orthodontic treatment
(If these three conditions are not there>> asymmetric widening is a very bad sign!)

The last thing  >> the most important sign >> THE CORTICAL BONE
You have to follow cortices, which are:
1- The lower border of the mandible
2- The superior and inferior borders of the inferior alveolar nerve canal
3- Lamina dura
4- The floor of the maxillary sinus
(1 &2&3 are the cortical bone in the mandible,, 3&4 in the maxilla )
If we can see interruption in any of these >> it’s not a good sign and further action should be taken!
That’s it 
Best wishes
Dyala Kh. Al-Armouti
Radiology sheet #1 – Dr.Abeer Al-Hadidi
Dyala Al-Armouti

عدد المساهمات : 639
النشاط : 16
تاريخ التسجيل : 2009-09-06
العمر : 26

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