Cone-beam Computed tomography

Principle:
CBCT scanners utilize a 2D detector and cone-shaped source of ionizing radiation allowing for a single rotation of gantry to generate a scan of the entire region of interest.
How does it work?

X-ray generation:
3D X-ray beam with circular collimation → Cone shaped beam

Image detection system:
Image intensifier tube/ charged coupled device combination or flat panel detector arrays

Image reconstruction:
Acquisition of single projection images known as “basis” images and reconstruction using Feldkamp software algorithm

Image display:
Axial, sagittal and coronal planes

Diagnostic value:
1. Dentomaxillofacial imaging
2. Orthodontic planning
3. Periodontal diseases
4. TMJ analysis
5. Cephalometric analysis
6. Jaw pathologies
7. Radiotherapy guidance
8. Implant site assessment
9. Impacted tooth evaluation

Medical applications:
1. Interventional radiography
2. Angiography
3. Mammography
4. Airway assessment

Benefits:
1. Size: reduced
2. Cost: ¼ to 1/5 of conventional CT
3. Rapid scan time: less than 30 seconds
4. Submillimeter resolution: 0.4 mm to as low as 0.125 mm
5. Patient dose reduction: 52-1025 ╬╝Sv = 4-77 digital panoramic radiographs
6. Interactive analysis: for real-time dimensional assessment and measurements
7. Image artifact: reduced

Limitations:
1. Image noise
2. Poor soft tissue contrast

Conclusion:

The ability of CBCT to provide images in three dimensions with a high level of detail makes it a very attractive method for many dental applications.
There is no doubt that cone-beam technology will become an important tool in dental and maxillofacial imaging over the coming decades.
 

Literature

  1. White SC, Pharoah MJ. Oral Radiology – principles and interpretation. 6th edn. India: Elsevier; 2009. p.225-243.
  2. Miracle AC, Mukherji SK. Conebeam CT of the head and neck, Part 2: clinical applications. Am J Neuroradiol 2009 Aug;30:1285–92.
  3. Scarfe WC, Farman AG. What is cone-beam CT and how does it work. Dent Clin North Am 2008;52:707-730.
     

Abbreviations

2D - 2 dimensional
CT - Computed tomography
CBCT - Cone-beam computed tomography

Graduation!

"Bukan pertama kali melangkah kaki ke atas pentas Auditorium ni untuk ambil Ijazah. Tapi bukan juga kali terakhir. Baru habis grade as SKG. Next grade gonna get a DRG title. Belum habis koas tak boleh nak berangan banyak-banyak. Selalunya bila dah habis grade orang pergi celebrate. Tapi aku terus balik rumah tidur. Penat sikit rasa."
I want to say sorry for being a jerk a little while ago. I did lose my cool for sometimes. When I realized it, it was too late. I had it in my hand yet I just let it go. So sorry. Never meant it to be like that. I wish we could start again.

thats all..

Fine! I'll do it!

"Hari ni bangun lambat. Pastu dah siap-siap, motor pulak buat hal. Susah bukan main time nak start. Nasib baik sampai jugak FKG. Tapi dah tak boleh nak absen. Nak buat apa lagi, lepak je lah kat kantin sebab kalau tak absen tak boleh buat kerja hari tu. Baru je nak mengadu betapa malangnya nasib diri, rupa-rupanya dosen semua takde kat dept sebab ada acara kat Nazir Alwi. Cantik. Tak lah rugi sangat pun kalau tak kerja hari ni. Balik pun awal sikit. Oh Yeah! Alhamdulillah."
I want to get more than what I have now. I need to stretch myself to achieve it. Just hoping I'm not overdoing it till I'm done.

thats all...

Night watch

"Banyak ragam manusia time malam2 nih. Sambil bawak motor sambil layan perangai manusia yang macam-macam.

Ragam 1 - Awek naik motor dengan balak dia. Dari belakang nampak macam cantik. Kaki licin, mulus, putih. Badan solid, slim. Rambut lawa beralun. Sekali dah sampai depan nampak tangan TENGAH KOREK IDUNG! Spoil gle. Haha.


Ragam 2 - Jalan punya besar tiba-tiba kereta semua slow. Apsal? Ada kucing melintas ke? Rupa nya ada accident kat tepi jalan. Semua berenti nak tengok. Siap parking kat tengah jalan. Elok-elok 2 lane, dah tinggal 1 lane je.


Ragam 3 - Motor kecik je tapi penumpang dia ada 5 orang. Satu family tu beb. Sorang anak duduk depan, Pastu dua orang lagi duduk antara parent dia. Sorang pun tak pakai helmet. Bahaya siut.


Ragam 4 - Sorang awek cun tengah tunggu nak naik angkut. Setiap 10 saat mesti ada mamat-mamat motor lalu kacau dia. Hon-hon sikit pastu jerit-jerit. Kejadah pompuan tu nak layan dia."

Weird things seems like normal thing. Its wrong,man. So wrong.

thats all..

Abundance of feeling

"Hari ni saje je lambat bangun pagi. Ingat nak buat cuti umum sendiri je. Sekali ada pasien call lak. Isk, time koas pun ade oncall ke? Pelik. Rupanya ni pasien yang pernah datang dulu. Lama dah tapi baru sekarang ada waktu. Nak buat perawatan katanya. harap-haraplah takde kasus yang susah-susah." 
By all means, I need some motivation. Got lazy again all of a sudden. I better shower now. Refresh my brain and body.

thats all..

Tickling Clock

"Abang aku dah bawa parent aku merisik gadis pilihan dia. Tak lama lagi dapat la sorang kakak lepas ni. Excited pulak rasanya nak dapat kakak ipar nih. Lepas tu turn adik pompuan aku lak nanti. Next year kot. Lepas tu baru la turn aku. Cantik."

Too tired today. Traveled about 20 km around Medan. Never get a chance to get rest. I should get some now.

thats all...

Behind behind

"Asal marah je nak menjerit. Asal marah je nak mencarut. Kena bencana sikit dah mengeluh panjang gle. Ada masa banyak tapi still buat kerja last minit. Setiap hari pun layan tenet sampai malam. Duit cepat je habis tak tau nak jimat cermat. Solat entah kemana, baca Quran lagi la. Baca buku malas tapi buat-buat bijak macam dah hafal satu buku. What the eL?"

There is always a room for improvement. Either we want it or not. I really want to change. I am.

thats all..

Curtain oh my curtain

Pejam mata. Celik mata. Pejam mata lagi. Tidur.

Malas betul nak pergi kerja. Tilam oh tilam, kenapa kau best sangat untuk tidur? Dah lah ujan renyai-renyai tadi. Sejuk betul. Rasa nak balut selimut pastu sambung tidur sampai petang.

safety~

thats all..

A lot of tears

Kerana kau wahai wisuda aku terpaksa merayu-rayu, menangis di khalayak ramai..hadoi..
Dapat juga akhirnya terdaftar sebagai peserta wisuda..penat mental, letih otak..
Syukur itu yang paling penting. Alhamdulillah..

Its been awhile since I cleane up my room. Everything is messed up like walking in a crime scene. I better start now.

thats all..

it gets hard

Wake up every morning feeling nothing. Open my eyes and asking myself why I took this course? Look to my right, I see a plain white wall that seems like my life, lame. Turn to my left, I sigh to all the unfinished works. I need a remedy. And I need it quick!

thats NOT all...

Why? (Kenapa?)


Sebelum ku kenali mu hidupku cukup dgn suka duka
Tak penah ku sangka semuanya akan berubah
Dikau bagaikan cahaya bagi jiwaku ini
Tak mungkin ku lupakan kata mu kan sentiasa disisi 

thats all..

Constructions

"Khouf (takut) itu ada tiga. Yaitu khouf orang awam, khouf khossah, dan khouf khossul khossoh. Sebagai orang awam, takut yang dinyatakan adalah takut kepada seksa neraka dan mengharap balasan syurga. Apabila datang kepadanya maksiat, maka jika dia takut untuk melakukannya, disitu ada khouf dalam dirinya. Kalau tidak ada takut dalam hatinya terhadap balasan seksa dari Allah atas perbuatan maksiatnya, maka samalah dia seperti binatang ternakan."



Some words I heard the other night makes me wanna cry again and again. How low have I been? I want to change. I want to be better than yesterday. Lets start now and never stop until I achieve it. There's never end for being better.

thats all..