Option: Medical (1 Viewer)

[bottle01]

my optional question was on medical physics

the question was quite straight forward. some were even similar to the past CSSA papers. i was soooooo surprised in the exam.


how did you find it?

 

[mica]

went fairly well . Although i didnt know a bone scan was a PET scan... so i did a bit of jabbering on about xrays and ct scans

I thought question 29) a) ii took a fair amount of time to write about and then do the calculations

Physics is over..Hooray

 

[MrMe]

Yeah i thought it was pretty good. But thats why i chose medical... its pretty straight forward. YAY its over!!

 

[zeek]

wtf was up with that "bone" scan image....

 

[ianc]

Medical physics is the greatest! There wasn't even any technical stuff like working out net spin or stuff like that!

Best option ever

 

[XcarvengerX]

And the 7 marker question is the exact copy of CSSA 2006 7 marker, except it is "assess" not "compare", and because I only read CSSA answers once long time ago, I totally forgot about radio wave being used in MRI, but otherwise my assessment for the "assess" is pretty good I believe.

 

[peteryan57]

my optional question was on medical physics

the question was quite straight forward. some were even similar to the past CSSA papers. i was soooooo surprised in the exam.


how did you find it?

"but the wine and the song like the seasons all have gone"

 

[moeydalati88]

i loved the option! i actually enjoyed answering the Q's since they were so easy! i wrote two whole booklets!!!

 

[dartm2]

went fairly well . Although i didnt know a bone scan was a PET scan... so i did a bit of jabbering on about xrays and ct scans

Bone scans are different to PET arn't they, bone scans release gamma rays directly to gamma cameras over a long period of time to find high activity on BONES, where as Pet scans emitt positrons with anialate with electrons and release gamma from there. thats what i thought anyway

 

[Bricnic]

Did anyone else trip over the very first question, speed of sound in fat? According to the formula given in the back, Z = pv, and if I'm not mistaken, Z is the acoustic impedance, p is the density of the medium and v is the speed at which sound travels. However, if you sub in the values they gave for AIR, you get a horrendously incorrect measurement of the speed of sound in air- the table gave these values:
Material_____Acoustic impedance____Density
___Air__________0.0004____________1.3
..and if you sub these into the formula:
0.0004 = 1.3 * 340 (speed of sound in air is 340m/s, as given in the data sheet)
But this is clearly wrong? 1.3 * 340 = 442 as far as I can see...
Well if you used the formula z = pv for speed of sound in fat, you probably would have gotten something around the 1000m/s mark. Annoyingly, the question asked for the velocity of sound in fat, which is stupid because velocity has both speed and direction, but clearly we can only calculate a speed with this data.

BTW, I messed with the given values a bit, and found that density (1.3) divided by acoustic impedance (0.0004) was close to the correct speed of sound in air, but off by a factor of 10, which led me to believe that perhaps the acoustic impedance of air was really 0.004. I can't check either 'cause I've returned my physics textbook now anyway

 

[helper]

PET scans may be used for bone scans but normally they are just a measure of a direct radioisotope.

 

[helper]

Did anyone else trip over the very first question, speed of sound in fat? According to the formula given in the back, Z = pv, and if I'm not mistaken, Z is the acoustic impedance, p is the density of the medium and v is the speed at which sound travels. However, if you sub in the values they gave for AIR, you get a horrendously incorrect measurement of the speed of sound in air- the table gave these values:
Material_____Acoustic impedance____Density
___Air__________0.0004____________1.3
..and if you sub these into the formula:
0.0004 = 1.3 * 340 (speed of sound in air is 340m/s, as given in the data sheet)
But this is clearly wrong? 1.3 * 340 = 442 as far as I can see...

The units at the top of the table state x 10⁶
That is why it is worth 2 marks, a lot of students won't correct the units from the table

 

[donrob15]

yeh i didnt know what a bone scan was. i said it was an ultrasound used to measure bone density. and what about the pictures? i said the bone scan was the first, xray second, and CAT scan the third? what did you think?
and the seven marker, only had bout 6 minutes, and i wrote about Xray, cat scan, the radio side of MRI, and gamma, and how an undertanding of these phenomena has allowed them to be utiliesed in the medical technologies used to investigate the body. still probably only got max 4/7 though.
i dont thinki went into enough detail with the comparison of uses of xray/cat and bone scan, but i think i made up for it.

 

[Bricnic]

The units at the top of the table state x 10⁶
That is why it is worth 2 marks, a lot of students won't correct the units from the table

Wow, that explains it. Just did the calculations quickly, and you're of course correct. Damn that, as if they'd trick us by deliberately giving wrong units. Curse them all to heck.

 

[MrMe]

How can you not know what a bone scan is? it seems to come up in half the questions i do. I'm pretty sure (or atleast i put) they use technetium 99m on phosphate ions because they accumulate around bone in about an hour. But they accumulate more where there is areas of high blood flow... i.e. diseased areas. This releases gamma rays and yeah an image is produced!or somthing like that... i'm trying to forget now!!

 

[HayleyRGardiner]

yeah i thought medical was excellent! i was expecting it to go into more detail for some kind of scan but it was pretty general (except for MRI) and it was good that you could cover a lot in the electromagnetic spectrum question. the last bit was good - some pretty cruisy marks. Definitely my favourite part of the exam!

 

[Edge_Head]

I nearly screwed up d) i)
when its all identify the images...etc. and im sitting there thinking that they mean what is the picture of like a hand/wrist and i even wrote that, it wasnt untill the last minute that i realised, that they ment either X-Ray, CAT, or bone scan. lol that was close
Really the actual last minute, the final count down, type o stuff.

 

[bottle01]

And the 7 marker question is the exact copy of CSSA 2006 7 marker, except it is "assess" not "compare", and because I only read CSSA answers once long time ago, I totally forgot about radio wave being used in MRI, but otherwise my assessment for the "assess" is pretty good I believe.

i know!!!! i just did that question the day before the exam...
however, i was asked 'pens down' when attempting the third paragraph on that question...

misery...:mad1:

 

[MrMe]

i know!!!! i just did that question the day before the exam...
however, i was asked 'pens down' when attempting the third paragraph on that question...

misery...:mad1:

Ah serious? So you didn't get to finish?

 

[switchfootfan]

twas ok,
cant remember it i corrected the units in the first question
and i couldn't think straight off how to do the very last question and only remembered with 30 seconds to go....darn
besides that it was good