Question and Answer

50 yo AAF with PMH of breast CA is having bone pain. What is the best test to diagnose bone metastases?
The most commonly used test is bone scan, the best test is PET scan.

Bone scan - sensitivity 75-85%, specificity 95%

PET scan - sensitivity 91%, specificity 96%

X-rays - good for characterezing the lesions but not for initial diagnosis although very often this is the first test to be ordered.

CT scan - low sensitivity (similar to X-rays)

MRI - sensitivity 82-91%, specificity 62-92%

Compared with bone scan, MRI costs 2-3 times as much, and FDG PET, 8 times as much.

Source:
Comparison of whole-body FDG-PET to bone scan for detection of bone metastases - Lung Cancer. 2004 Jun;44(3):317-25
eMedicine


70 yo AAM with BPH has an acute urinary obstruction which is relieved with a Foley, and now he is having postobstructive polyuria. What is the mechanism behind the polyuria?
There are several mechanisms:
-PGE-mediated increase in medullary blood flow
-tubular damage with decreased Na+ reabsorption and impaired concentrating ability
-osmotic diuresis
-activation of natriuretic factors following ECF volume expansion

The resulting loss of fluid and electrolytes represents a major hazard.
Source: Pubmed


56 yo CM with LDL 145 is asking if he needs drug therapy. He was recently admitted to the hospital with CP and the catheterization showed "trivial CAD". What do you think?
You need to calculate his risk for CAD, and then to base the decision whether to treat or not on the calclulated risk.

A great starting point is the Quick Desk Reference based on ATP III from the NIH.

Source: NIH
Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III - ATP) - NIH - includes online calculators and PDA downloads