Imablog

July 4, 2011July 10, 2025

Puzzling image artifact

It’s not often I run into problems when testing x-ray equipment, but when I do they’re usually puzzling ones.

While I was testing a cath lab today, the lateral plane was giving me images that looked like

Unusual image artifact with a bright diagonal centra region fading to dark at the edges

Ignore the grid pattern. That’s just one of my test objects.

At first I thought it was just a bolus filter getting in the way, but none of the usual buttons and joysticks for moving the filters made it go away. Wasn’t the bolus filters.

After giving it a little bit more thought, I realized it was the anti-scatter grid. It’s the exact type of artifact you expect to see for an upside down focused grid.

Popped the grid cover off to check, and sure enough the grid was put in backwards. Couldn’t figure out how to remove the grid to flip it around so I’ll have to leave it for the service guys to take care of. Coincidentally enough, the pages in the manual for inserting and removing the grid were missing.

In radiography, it’s not too unusual (although somewhat rare these days) to use a reversed focus grid as a kind of “poor man’s filter”, usually for chest imaging to even out the exposure differences between the lung fields and the mediastinum. I’ve never heard of this being this done for a fluoroscopy unit though. I don’t know if it was done deliberately or by accident.

July 2, 2011July 10, 2025

Property reassessment

Received a reassessment notice from the county in the mail today.
From last year’s property tax bill, the house had an appraised value of $227100 and an assessment of $9080 (4%).

The reassessment notice says the house now has an appraised value of $243000 (pretty much the original purchase price) and an assessment of $9720. If the millage rate stays the same as last year, this means my property taxes will probably go up about $160 this year (maybe a little less depending on how many tax credits show up on the bill).

Zillow.com’s estimate of my house’s value was $216000 last week, and jumped up to $227800 this week.

Estimated property value graph from Zillow.com

I have no idea what kind of strange voodoo or mathemagical incantations Zillow.com uses to derive their real estate values, but it sure does look strange.

Good thing I’m not planning on moving anytime soon.

June 28, 2011July 10, 2025

On dollar coins

There was a story on NPR this morning about $1B in dollar coins sitting unwanted in a vault. Presidential and Sacagawea $1 coins piling up returned and uncirculated in a Federal Reserve vault.

It leads me to the conclusion that the US Government’s attempts to make the use of a $1 coin widespread have been completely half-assed from the start.

Completely. Half. Assed.

From the Susan B Anthony dollar to the Sacagawea coin to the Presidential coins, the government has assumed that people will just adopt the coins and use them. Clearly that never happened.

First a $1 coin needs to be noticably different from other coins. The SBA dollar, unless you look closely looks and feels almost like the US quarter. That’s no good. The Sacagawea dollar does better being a different colour and with different edging.

Next, the paper dollar needs to go away. That’s all.

The Loonie was designed to be noticeably different from the Canadian quarter. It also sounds different when you jingle it with other coins.

Canada moved to dollar coins (the Loonie) and $2 coins nearly 25 years ago. There was some grumbling for a while, but it’s since become a part of the Canadian culture.

Perhaps the US Government and Federal Reserve should look at how Canada made the transition. They essentially said the loonie is replacing the paper dollar, and after a such-and-such date, we will stop circulating paper dollars. Get used to the dollar coin.

The US Government needs to do the same if they want dollar coins to do something other than sit useless in a vault.