Nonvisualization of the Gallbladder with HIDA Scan

HIDA (Tc-99m hydroxy iminodiacetic acid) scan shows normal uptake in the liver with excretion into the extrahepatic bile duct (arrow) and in the bowel (arrowheads) at 25-30 minutes after radiotracer injection. Intravenous morphine was administered at 60 minutes. The images obtained up to 2 hours show no activity in the gallbladder.

Facts: HIDA scan

• Also known as hepatobiliary scan
• Liver uptakes HIDA and excretes it into bile that drains into the bowel
• Normal activity should be seen immediately in the liver, at one hour in gallbladder and into the bowel
• The scan can be done to help diagnose acute cholecystitis, postoperative bile leak
• Morphine can be utilized to shorten the examination time for the diagnosis of acute cholecystitis if the gallbladder is not seen at 1 hour but the bile duct and bowel activity is visualized.
• Cholecystokinin or fatty meal can be used to help diagnose chronic cholecystitis.

Findings on HIDA scan

Nonvisualization of gallbladder WITH bowel activity

• Acute cholecystitis
• Previous cholecystectomy
• Non-fasting patient (including IV feeding)
• Severe hepatic disease
• Chronic cholecystitis (usually fills after 1 hour)

Nonvisualization of gallbladder WITHOUT bowel activity

• Biliary obstruction of any cause
• Severe hepatic disease
• Opiates (because of their effect on the sphinctor of Oddi)

Our patient: acute cholecystitis confirmed at surgery

References:

1. Sharp PF, Gemmell HG, Murray AD. Practical nuclear medicine, 3rd edition, 2005.

2. Chapman S, Nakielny R. Aids to radiological differential diagnosis, 4th edition, 2003

Popliteal Artery Aneurysm

Figure 1: Gray-scale ultrasound of the let popliteal ultrasound shows a fusiform aneurysm of the popliteal artery, measuring 2 cm.
Figure 2: Color Doppler US image shows partial thrombosis of the aneurysm.

Facts:

• Most common peripheral artery aneurysm
• Most commonly due to atherosclerosis
• More common in male
• Commonly bilateral (need to examine the contralateral popliteal artery), and commonly associated with abdominal aortic and iliac artery aneurysm in about half of all cases.
• Presentation: cold lower extremity from acute thrombosis or distal embolization, asymptomatic pulsatile popliteal fossa mass, rarely rupture

Indication for Repair

1. Size 2 cm or greater
2. Intraluminal thrombus

Imaging Strategy

• Doppler US for diagnosis and follow up
• MDCT for planning of repair (surgical or endovascular): extent, location of associated peripheral vascular disease, nearby branch vessels, size and angulation of the aneurysm

References

1. Blackbourne LH. Surgical recall, 5th ed, 2008.

2. Funaki B, Lorenz J, Ha TV. Teaching atlas of vascular and non-vascular interventional radiology, 2007.

An Expert's Response to the Recent USPSTF Recommendations for Mammography

A recent release of the US Preventive Services Task Force (USPSTF) recommendations for breast cancer screening has brought about so many controversies. Below is the summary view of Dr. Daniel B. Kopans, a Mass General radiologist and Harvard professor, internationally known as a breast imaging expert:

Mass General Imaging believes that the USPSTF recommendations are based on flawed analysis of the data and continues to support the scientifically based recommendations of the American Cancer Society for the early detection of breast cancer:

1. Annual mammographic screening should begin at age 40
2. Women at high risk for developing breast cancer should have annual MRI screening in addition to mammography

View full article by Dr. Kopans (MGH Radiology Rounds) HERE

Read more controversies in the New York Times and Washington Post

Read where the American College of Radiology stands

Additional opinions from the New England Journal of Medicine (November 25, 2009)
- Screening mammography and the "R" word
- On mammography - more agreement than disagreement

New Guidelines for Cervical Cytology Screening Released

The American College of Obstetricians and Gynecologists (ACOG) released its new clinical management guidelines for cervical cytology screening today.

New Recommendations

• Screening should begin at age 21 years (previously at the age of first sexual intercourse)
• Frequency of screening: every two years for women aged 21-29 years; for women aged 30 and older -- if results have been negative for intraepithelial lesions and malignancy for three times they may be screened at every three years
• More frequent screening may be done in high-risk groups including: HIV infection, immunosuppression, exposure to diethylstilbestrol in utero, previously treated for CIN2, CIN3 or cancer
• Discontinue screening: at either 65 or 70 years in women with three or more negative cytology test results in a row and no abnormal results in the past 10 years; immediately after total hysterectomy for benign indications and no prior history of high-grade CIN
• Both liquid-based and conventional methods for cervical cytology are acceptable for screening
• Co-testing with a combination of cytology and HPV DNA testing: appropriate for women older than 30 years.

Full text from the ACOG (Free)

New York Times story (Free)

Updated Recommendation for Breast Cancer Screening

The update of the U.S. Preventive Services Task Force (USPSTF) recommendation statement on screening for breast cancer in the general population has been published today in the Annals of Internal Medicine.

The USPSTF Recommends

• Against routine screening mammography in women aged 40-49 years
• Biennial (every two years) screening mammography for women between the ages of 50 and 74 years

Based on the USPSTF review, the current evidence is insufficient to assess benefits and harms of ...

• Screening mammography in women 75 years or older
• Clinical breast examination beyond screening mammography in women 40 years or older
• Either digital mammography or magnetic resonance imaging instead of film mammography as screening modalities for breast cancer

What Has Changed from the Previous Recommendations, and Why?

• Recommendations against universal screening mammography for women aged 40 to 49 years, based in part on an updated systematic review of screening mammography randomized, controlled trials that showed lower yield of reduced breast cancer mortality and higher false-postive results with screening in this population
• Recommendation of biennial screening mammography for women aged 50 to 69. Based on statistical models, annual versus biennial screening showed similar degree of breast cancer mortality reduction and similar likelihood of late-stage disease at diagnosis.
• Extension of screening mammography to women aged 70 to 74 years. Models estimate that approximately 2 additional breast cancer deaths are averted per 1000 women screen at this age.

Read full text here (free)

Reference:

1. U.S. Preventive Services Task Force. Screening for breast cancer: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med 2009;151:716-726.

2. Kerlikokowske K. Evidence-based breast cancer prevention: the importance of individual risk. Ann Intern Med 2009;151:750-752.