Wednesday, January 29, 2014

What Role Does CT Play in Screening for Lung Cancer?

The short answer is: depends

In December 2013, the United States Preventive Services Task Force (USPSTF) released a conditional recommendation for lung cancer screening. The Grade B recommendation states:
The USPSTF recommends annual screening for lung cancer with low-dose computed tomography in adults ages 55 to 80 years who have a 30 pack-year smoking history and currently smoke or have quit within the past 15 years. Screening should be discontinued once a person has not smoked for 15 years or develops a health problem that substantially limits life expectancy or the ability or willingness to have curative lung surgery.

For more information about what this means from a radiology perspective, here is an interview from ARRS InPractice:
Why did the USPSTF come to these conclusions?
Lung cancer is a serious public health problem, causing one in four cancer deaths. It is estimated that seven percent of people born today will develop lung cancer in their lifetimes. Eighty-five percent of lung cancer is caused by smoking; 85 percent of lung cancer is fatal. 
The randomized, multicenter, National Lung Screening Trial (NLST) trial [1], which compared three annual LDCT scans with three annual posterior-anterior chest radiographs at 33 sites in the United States, found that LDCT screening correlated with significant reductions in lung cancer (20%) and all-cause (6.7%) mortality.

Is CT the best method for lung cancer screening?
The NLST trial showed such a major advantage for LDCT over radiography for lung cancer screening —a 20% reduction in lung cancer mortality—that the trial was stopped early. Thus, CT is currently the only available examination for effective lung cancer screening.

How low can the patient radiation exposure be reduced for effective lung cancer screening?
In published trials [2], estimated radiation doses using LDCT have been between 0.60 and 1.75 mSv per exam. It is predictable that satisfactory LDCT results can be achieved with submSv doses, equivalent to less than 4 months of ambient radiation (assuming the natural occurrence of 3 mSv per year).

Check out InPractice for the rest of the interview with Dr. Patrick Colletti.  The USPSTF Statement wording is interesting - if screening is conditional on 'willingness to have curative lung surgery', should providers have a discussion with patients about treatment options if cancer is discovered prior to screening? Does this extend to other screening modalities such as mammograms? As the latter experience has shown, screening is not always benign. Hopefully future recommendations further clarify when and for whom screening should be undertaken. The real question now is: will insurance companies reimburse for lung cancer screening scans?

Monday, August 13, 2012

Ultrasound Technology Continues to Evolve

The promise of ultrasound has always been in its ability to visualize tissues dynamically without the use of radiation. Today's guest post by Michelle Brunet tells us about the road ahead for ultrasound:

Cardiovascular technicians, diagnostic medical sonographers, radiologic technologists and other healthcare professionals are increasingly incorporating ultrasound as an imaging tool for both diagnosis and treatment. Due to the fact that the equipment is relatively cost effective and it does not rely on radiation, it is becoming more and more important in a range of healthcare departments. Often referred to as the “stethoscope of the future,” Health Imaging’s Editor Lisa Fratt predicts that ultrasound technology, as it continues to become more compact and transportable, will indeed replace the medical tool we are accustomed to seeing around a doctor’s neck.

The advancements have already begun in terms of shrinking or portability, potentially allowing ultrasound machines to be employed in field hospitals and other temporary medical facilities (i.e. in Third World Countries or war settings), but also in point-of-care or beside scenarios. One such example of portability is the development of a wearable ultrasound machine developed upon the encouragement of Master Sergeant Cheryl Vance back in 2002. An instructor at the Sheppard Air Force Base in Texas, Vance began implementing the new form of technology to teach her students how to perform ultrasounds in an efficient manner. Weighing less than four pounds, it consisted of a central processing unit-vest with an attachable probe, a wristband with a mouse and keyboard and an eyepiece displaying the system’s interface.

Recently, the first ultrasound smart phone came out onto the market. In the fall of 2011, Mobisante released the MobiUS SP1. Like other smart phones, it acts as a conventional communications device with typical Internet/e-mail and telephone functions. But once attachable probe is inserted into the device’s USB port it transforms into a mini ultrasound machine. “Ultrasound imaging is safe, effective and can save lives, however more than 70% of the world’s population does not have access to ultrasound because it is expensive and not portable enough,” states Mobisante’s website. The company is hoping its new product (that was approved by the FDA) will allow even the most remote medical clinics to benefit from sonography as a diagnostic and therapeutic tool.

In addition to ultrasound technology becoming more compact and portable, there have also been advancements in performance and capabilities. For example, Philips’ iU22 xMATRIX ultrasound system is capable of switching between two-dimensional and three-dimensional imaging with the click of a button. It also comes equipped with a special transducer that can image two distinct planes at the same time, allowing for a more thorough examination. The Siemens ACUSON S2000 ultrasound system is another example. This particular machine not only performs conventional ultrasounds but also acoustic radiation force impulse (ARFI) imaging to help diagnose masses in the neck, liver, intestinal tract and other areas of the body.

The use of ultrasound is expected to increase in terms of diagnostic and therapeutic methodologies but also in terms of settings, including point-of-care and temporary medical locations. With this in mind, technology will continue to become more sophisticated and portable to meet the growing demand.


Michelle Brunet completed a BSc in biology and environmental studies and a BEd in secondary education. After a short teaching career, she realized writing was her passion and now pursues this full time, contributing to various online and print media, including writing for ultrasoundschoolsinfo.com

Saturday, July 28, 2012

Periostitis Differential Diagnosis

Periostitis is an important finding on a musculoskeletal imaging study. It represents inflammation within the periosteum, a layer of connective tissue which surrounds bone. Various forms exist, which typically reflect the aggressiveness of the underlying process. No good mnemonic here (Roentgen Ray Reader referenced below has one, but it is quite long), but the major categories are:

DiseaseNotes

Physiologic Periostitis
  • Appears around age 3 mos
  • Resolves by 6 mos

Caffey's Disease
  • Infantile cortical hyperostosis
  • Involves mandible
  • Occurs before 6 mos

Arthritis
  • Typically psoriatic or reactive

Pachydermioperiostitis
  • Autosomal dominant disorder 
  • Skin thickening

Fluorosis
  • Symmetric 
  • Sclerotic bones

Hypervitaminosis A

Infection (Osteomyelitis)
  • Involucrum - thick irregular new bone that forms from periosteum
  • Sequestra - avascular dead bone from cortical blood supply disruption

Fractures
  • Can be seen in regular fractures or stress fractures

Tumor
  • Osteosarcoma (Codman's triangle, sunburst)
  • Ewing's sarcoma (Lamellated, hair-on-end)
  • Chondroblastoma (age<20)

Eosinophilic granuloma

Hypertrophic Pulmonary Osteoarthropathy

Venous stasis
  • Thick, undulating reaction
  • Also see edema, phleboliths
Sunburst reaction of osteosarcoma
Source: AJR

References:

Monday, June 18, 2012

Small Bowel Aneurysmal Dilatation Differential Diagnosis

Small bowel aneurysmal dilatation is a common pattern of disease in the small bowel. It consists of a focal segment of dilated small bowel associated with a mass. The mass is typically circumferential. The mnemonic MALL can be used to recall the common diagnoses.

DiseaseNotes
MMalignant GISTLymphadenopathy absent; obstruction common
AAdenocarcinoma of small bowel
LLymphomaLymphadenopathy present; obstruction uncommon
LLeiomyosarcomaLincoln

Lymphoma
Source: AJR
Metastatic disease can also present with small bowel aneurysmal dilatation. The most common primary is melanoma, followed by lung, breast, and colon cancer. Metastases tend to be multifocal and necrotic.

Friday, June 15, 2012

Radiology Salary: Cautious Optimism?

The American Medical Group Association (AMGA) recently released their 24th annual survey of physician groups. The Annual Medical Group Compensation and Financial Survey was a mixed bag of results. Almost 70% of groups noted an increase in compensation, but the increase was quite small on average: 2.4%.

The question I bet you're wondering though: how did radiology salaries do? All told, not bad, but not spectacular either. The top five specialties were: cardiothoracic surgery ($532,567), interventional cardiology ($504,099), orthopedic surgery ($501,808), interventional radiology ($492,102), and diagnostic radiology ($354,917). However, of the five, interventional radiology had the second highest growth of 2.95%, just behind the interventional cardiologists' 4.13%. The cardiothoracic surgeons actually experienced a decline!

The main figure to watch though is the relative value unit, or RVU. An RVU is the primary measure of a physician's productivity for the majority of participating medical groups. Medicare decides that each procedure is worth a certain number of RVUs. That value is then adjusted by the geographic location / practice environment of the physician. The adjusted RVU is then multiplied by the a dollar conversion factor to arrive at the amount Medicare will re-imburse. Most HMOs in the U.S. use this value as a basis for their repayments. Many physician groups charge up to 300% of this value, and then recoup 60-80% of that amount. For example, take a procedure generally worth one RVU. In Manhattan, this might be adjusted to 2 RVUs. At a conversion factor of $50, Medicare would reimburse $100 for this procedure. The physician group may charge up to $300 to a private insurance company, and could expect to collect roughly $180 to $240 on average.

In radiology, RVUs have been falling, so radiologists have had to work harder (complete more RVUs) to maintain the same salary level. This trend is likely to continue, regardless of whether the Affordable Care Act ("Obamacare") passes in full or in part. Healthcare reform of some shape or another will occur. Radiologists will likely face even further decreases in compensation. The real question is: how will radiologists respond? No one is quite sure yet, other than there will certainly be change.

But going back to the title of the post - what cause is there for optimism about radiology salaries? Well, whatever optimism is there, it is indeed a cautious one. Looking further back in the data, salaries tend to stay flat for a few years, then advance, then flatten again, in a step-wise fashion. Radiology salaries have been fairly flat since 2008, so the field is due for a step up. Whether that happens in 2013 or 2015 though, is anyone's guess. Any future gains are contingent on the broader economy advancing. Til then, keep knocking out those RVUs!