MRI safety questionnaire added to Protocols and Guidelines Section

For the benefit of our patients, and the convenience of our esteemed customers, the MRI saftey questionnaire can now be downloaded from the "guidelines and protocols" section of this site.
To go straight to the page, click here .

Build your own PACS using free open-source software

From Antoine Rosset, developer of Osirix.
This is based on Apple Mac components but the all software is open source, and can be downloaded from the internet.

Full step-by -step instructions here.

You can work out the cost of the hardware (in the UK) by visiting the Apple Store.

From today's CT list

Small bowel obstruction due to left inguinal hernia

Sonosite portable ultrasound machines on eBay

I look on eBay for medical equipment from time to time, out of idle curiosty. SonoSite portable ultrasound machines are frequently on sale, and there were more than ususal today: one SonoSite 180 plus, one SonoSite 180, one MicroMaxx, one Titan, one Sonoheart, as well as a linear SonoSite probe.


Our old SonoSite 180 could do with replacement, and that linear probe would come in handy. If I recall correctly, our SonoSite originally cost £18 000 with one probe only.

PIOPED II

Recommendations formulated on the basis of the results of the Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED) II trial have recently been published. Some of our current protocols are at variance with these.

For instance, we currently image patients with a moderate clinical probability of PE and a negative d-dimer. The PIOPED II investigators recommend that in such patients no further testing is necessary.

I won't go into all the other details, but it makes interesting reading, and we'll be reviewing our practice in consultation with the physicians.

Diagnostic Pathways in Acute Pulmonary Embolism: Recommendations of the PIOPED II Investigators.
Stein PD,Woodard PK,Weg JG,Wakefield TW,Tapson VF,Sostman HD,Sos TA,Quinn DA,Leeper KV Jr,Hull RD,Hales CA,Gottschalk A,Goodman LR,Fowler SE,Buckley JD.
Radiology. 2007 Jan;242(1):15-21.
http://intl-radiology.rsnajnls.org/cgi/content/full/242/1/15
MEHTRadiology citation
(A similar version of this editorial was published in the December 2006 issue of the American Journal of Medicine)

Also by the same authors:
Multidetector computed tomography for acute pulmonary embolism
N Engl J Med. 2006 Jun 1;354(22):2317-27.
CONCLUSIONS: In patients with suspected pulmonary embolism, multidetector CTA-CTV has a higher diagnostic sensitivity than does CTA alone, with similar specificity. The predictive value of either CTA or CTA-CTV is high with a concordant clinical assessment, but additional testing is necessary when the clinical probability is inconsistent with the imaging results.

Digital Dictation and Voice Recognition: Not ready for prime time?

Our digital dictation system consists of a Philips Speech Mike linked in to our RIS (TC-RAD, McKesson). For plain film reporting, after using it for a year or two, I have switched back to using cassette tapes, and guess what? I estimate that my productivity is up 20%, and fatigue levels reduced by 50%. Other colleagues have reported similar experiences.

The problem with our digital dictation system is that it involves numerous mouse clicks and aiming a cursor several times during the dictation process, and this increases the total amount of work very substantially if the report is very brief (e.g. "Normal appearances"). Also, transcription of reports by secretaries from digital dictation involves more steps and is inherently less efficient than transcription from tape.

There are advantages to digital dictation, and it's OK for longer reports like CT and MRI reports. It allows secretaries to retrieve and locate dictated reports more easily. However, at least in our version, there are very serious inadequacies.

As for voice recognition (VR), I tried that too, for several months, and put enormous effort into training the system, which was created by bolting the Dragon dictation system (which seems to have nothing but outstanding reviews in PC magazines) onto our digital dictation system. I came to the conclusion that I would have been better served by doing a touch typing course.

Here's an online article that describes in great detail the experiences of many users with radiological voice recognition systems. I concur with the opinions expressed.
Voice, I mean Speech Recognition, Buggy Whips, and OODA Loops

If VR makes sense on an accountant's spreadsheet in terms of staffing levels and turnaround times, this may be because the spreadsheet has not recorded all of the variables. I am now extremely sceptical about the practicalities and costs of these systems in their current form.

From personal experience I am wary of verbal or published recommendations for VR systems and other software products, especially those designed for medical use, where standards and expectations are often extremely low. Someone who has spent vast sums of money on a poor quality product may be reluctant to admit (even to himself, let alone to the outside world) that it was all a big mistake.

Drinking barium to protect the fetus during CT pulmonary angiography

This phantom study suggests that ingestion of barium will shield the fetus of a woman undergoing CT pulmonary angiography.
It's cheap, harmless and seems logical, so why not?

Yousefzadeh DK, Ward MB, Reft C.
Internal barium shielding to minimize fetal irradiation in spiral chest CT: a phantom simulation experiment.
Radiology. 2006 Jun;239(3):751-8.

Simpler CT reporting for clnical trials?

"In the majority of patients with hepatic metastases of colorectal cancer, measuring the maximal diameter of the single largest lesion yielded the same treatment-response classification as measuring up to five target lesions. This result suggests that it may be possible to reduce the number of lesions measured in clinical trials."

CT of Colon Cancer Metastases to the Liver Using Modified RECIST Criteria: Determining the Ideal Number of Target Lesions to Measure
Zacharia, Saini, Halpern and Sumner. AJR April 2006; 186:1067-1070

Now wouldn't that make life so much easier?

http://www.ajronline.org/cgi/content/abstract/186/4/1067

Barium enemas on the cover of Radiology!

Makes a change from virtual colonoscopy :-)

Unlike other authors, this group found that in their series, technical errors were more common than perceptual errors, and the majority of missed polyps were in the proximal colon.

Thompson, Foster, Paulson et al
Causes of Errors in Polyp Detection at Air-Contrast Barium Enema Examination
Radiology April 2006;239:139-148.

CiteULike: FREE Online reference manager

I discovered this site through a link on our hospital intranet.
It's free, online and easy to use.
You can also set up a "group" for your department or colleagues so you can share references, as we have done.

http://www.citeulike.org/
http://www.citeulike.org/group/MEHTRadiology

Free software for CT and MRI cerebral perfusion and breast MRI

I came across this website offering free software, developed in conjunction with the University of Dusseldorf, for analysng CT and MRI cerebral perfusion studies, (stroketool-CT and stroketool) and contrast enhanced breast MRI studies (mammatool).

We already have equivalents of stroketool and mammatool in our MRI unit so we would have no real use for this software, but someone might find it fun to play with.

On the other hand, stroketool-CT might be useful, since we don't have cerebral perfusion software installed on our CT workstation. However I can't think of a way round the ethical and legal issues, i.e. giving iv contrast to stroke patients just to play around with free software that, according to the website "may not be used for diagnosis or patient treatment".

http://www.digitalimagesolutions.de/

I found the software via http://www.idoimaging.com/.

Study shows PC monitors equivalent to PACS workstation for detecting wrist fractures

A recent study reports equivalent performance for detection of wrist fractures between a 17" PC monitor with a web browser, and a 2 MP diagnostic quality Barco monitor with a PACS workstation.

The authors concluded that:
there is no difference in the accuracy of observer performance in the detection of wrist fractures on digital radiographs with a standard PC compared with that with a high-quality workstation. In our opinion, important factors in achievement of this result are the use of image magnification to employ the maximum spatial resolution of the original digital image and the use of an environment with low ambient light.

In the UK a 17" PC monitor of the type they describe costs about 300 GBP, compared to about 2000 GBP for the 2MP Barco. The PACS workstation probably costs another 10 000 GBP at least, whereas web browser displays run off standard PCs.

Of course for large volume reporting, high resolution monitors make sense, otherwise you'd have to zoom everything right up and pan around a lot, but in other situations, e.g. casualty departments, PC monitors are probably fine (provided the viewing area is dark, which is another story)


Personal Computer versus Workstation Display: Observer Performance in Detection of Wrist Fractures on Digital Radiographs
Anthony J. Doyle,, James Le Fevre, and Graeme D. Anderson
Radiology Dec 2005;237:872-877

Ultrasound poor (herniography good) at detecting clinically occult hernias

In this study, ultrasound had a sensitivity of 29% and specificity of 90% compared with the herniography. Correlation with surgical findings showed ultrasound to have a sensitivity of 33% and a specificity of 100%.

I'm not surprised about the ultrasound results. I can't comment on the herniography part, since I've only ever done one (many years ago), but maybe I'll need to start practising.

Adeeb Alam, Colin Nice and Raman Uberoi
The accuracy of ultrasound in the diagnosis of clinically occult groin hernias in adults
European Radiology 2005 (Dec) 15 (12): 2457 - 2461

Fantasy Health Minister: I'm on the high scorers list

As described in a previous post, it's an online game where you get to be the Health Minister and select from a range of policy decisions.

I scored 8851 on my last attempt, which made me the seventh highest scorer. Note that I got the health of the nation to 96%, but some of the higher scorers did not do as well. This is because the score also depends on popularity, and you have to please everyone, including the private sector.

At present, I'm the only Authoritarian on the high scorers' list.
(I'm "dr_lee_xray"' in case you were wondering).
Most of the others are Idealists...Pah!!

Fantasy Health Minister

CT vs MR cholangiography for biliary calculi

In our hospital we tend to use CT cholangiography (CTCh) more often than than MR cholangiopancreatography (MRCP) for the non-invasive detection of common bile duct stones because CT is more readily available, and we find CTCh a simpler and more robust test. Of course MRCP has no radiation and does not need any injections, but how do the two tests compare in terms of diagnostic accuracy?

A recent paper addresses this question. 40 patients had both CTCh and MRCP, with the following results:

For detection of choledochal stones the two tests were comparable:
CTCh: sens 87%, spec 96%
MRCP: sens 80%, spec 88%

For detection of gallstones MRCP was a bit better,
CTCh: sens 78%, spec 100%
MRCP: sens 94%, spec 88%
(The reduced sensitivity of CTCh was due to non-opacification of the gall bladder due a stone being stuck in the gall bladder neck)

CTCh demonstrated bile leakage in one patient, and air in the biliary tree in two patients, which were not detected on MRCP.
CTCh also has the advantage over MRCP in demonstrating anastomotic patency, since opacification in CTCh reflects flow, whereas MRCP only demonstrates the presence of fluid.

I've never been able to figure out why are there so few papers on CTCh compared to MRCP. According to the article, Biliscopin (the contrast agent used for CTCh) is not approved for use in the USA. I didn't realise this but perhaps that's part of the reason. (As an aside, it's odd how some substances are permitted in one country but not another, for no obvious reason. Buscopan, for instance, is not licensed for use in the USA either).

Okada M, Fukada J, Toya K, Ito R, Ohashi T, Yorozu A.
The value of drip infusion cholangiography using multidetector-row helical CT in patients with choledocholithiasis.
Eur Radiol. 2005 Oct;15(10):2140-5

Want to run the National Health Service?

Here's an online game where you get to be the Health Minister and select from a range of policy decisions, which in turn have an effect on the health of the Nation, your budget, and your popularity.

On my last attempt I got the health of the nation up to 96% (you start at 43%), kept within budget, and increased my popularity. You also get an indication of your political complexion. Mine varies but so far it's usually 'authoritarian', occasionally 'idealist' or 'realist', but never 'liberal'.

Fantasy Health Minister

Hospital to install OsiriX: open source diagnostic workstation

A small private hospital where I do a bit of work will be buying an iMac to run OsiriX, an open source diagnostic workstation developed at UCLA and the University of Geneva.

It's not as sophisticated or as fast as the expensive Vitrea workstations we use in the big NHS hospital, but those cost about £35000, compared to £2000 for the iMac, and would not be financially viable for a small hospital with a relatively low volume of work.

An iMac with 2G of RAM will be adequate for our requirements and the software is downloaded for free from the OsiriX website, so it's excellent value for money.

Incidentally, one commercial company did offer us an outrageously expensive workstation with no multiplanar or 3D capability, that could not even read the discs produced by a CT scanner from their own company.

Upgrades for OsiriX are frequent and free, the instruction manuals are on wiki, and excellent applications support is provided by the online community on a yahoo discussion group.

As an open source product, anyone with the skills and interest can contribute to its development, and many people do.

You can also plug your iPod straight into your Mac workstation and save files and pictures to it. (I'm not sure how radiology images on an iPod photo are of any real use, but I guess some people might think they look cute).
Or download music from iTunes more easily than from your home PC .... oooops!

For a lot more money, you can buy the most expensive available PowerMac, with lots and lots of RAM, and install a VolumePro board from TeraRecon, for which a special version of Osirix is available. This is meant to provide much better 3D performance but I haven't seen it myself. It's still cheaper than the commercial products though.

The public healthcare sector might like to keep an eye on this, especially now that many state hospitals are feeling the squeeze financially. OsiriX is NOT a replacement for commercial 3D workstations, but it does have a lot of functionality at a low price, and is in continuous development.

Disclaimer:
I am a PC user. I do not own a Mac. My mother has a Mac: I think it's fine, and I have nothing against Macs. I do not have an iPod either: I have a Zen Neeon, which does not work with Macs.


Links:
Osirix
Apple
TeraRecon
Definition of Open Source
Vitrea Diagnostic Workstation from Vital Images Inc.
Zen Neeon Cheaper and better than the iPod
Hospital bosses ordered to cut debts The Guardian 16 Sep 2005

One third of the population mistakenly believes that an anaesthetist is not a doctor, according to a BBC Radio 4 programme I am listening to right now.

http://www.bbc.co.uk/radio4/science/casenotes.shtml

I bet that's not the case with radiologists :-)

Ultrasound instead of chest x-rays for nasogastric tube localisation

I was giving a talk to our staff on "looking for medical information on the internet". There was a live demo on using PubMed, and the topic of nasogastric tubes was suggested by someone who clearly found the whole business of doing chest x-rays for localisation a bit tedious.

This is an article we found:

Sonography as an alternative to radiography for nasogastric feeding tube location.
Vigneau C, Baudel JL, Guidet B, Offenstadt G, Maury E
Intensive Care Med. 2005 Sep 20; [Epub ahead of print]
Bedside sonography performed by nonradiologists is a sensitive method for confirming the position of weighted-tip feeding nasogastric feeding tubes. It is more rapid than conventional radiography and can easily be taught to ICU physicians. Conventional radiography could be reserved for cases in which sonography is inconclusive.

Whoopee! Our ICU physicians have said they want to get their own ultrasound machine.

We'll see.

Making Gadolinium DTPA in your kitchen

According to a lecturer (a chemist) at recent MRI course I attended, Gadolinium DTPA (the fabulously expensive contrast agent used in MRI scanning) is a very simple compound that any first year chemistry student could make at home.

In China, they are not too concerned with copyrights and patents, I was told, so the pharmaceutical companies have started factories there to protect themselves. Enough said.

My sister studied chemistry at university, but unfortunately that was some time ago and she is unable to assist our department in obtaining cheap supplies.