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September 2 , 2011

ARDMS Updates and Headlines in the News:

ARDMS: Important Testing Center Update

ARDMS Call for Item Writers: Musculoskeletal (MSK) Credentialing Examination

CT, PET-CT, MRT and Transthoracic Ultrasound in Lung Cancer Staging

Ultrasound-based Risk Scores Predicts Thyroid Malignancy

Optical Diffusion Breast Imaging Boosts Ultrasound Performance

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ARDMS: Important Testing Center Update

• At the test center, you must present two current, valid signature IDs, one of which must be a non-expired government-issued photo ID with your signature; see the accepted list of IDs here.
• The name on this application must EXACTLY MATCH the name on both current, valid signature IDs.
• Jane R. Doe and Jane Rachel Doe DO NOT EXACTLY MATCH.
• Failure to present two acceptable IDs will prevent your admission to the test center. If this happens, you will be marked absent and you will forfeit the entire examination fee and seat.
• If the names do not EXACTLY MATCH, update your ARDMS name of record. 

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ARDMS Call for Item Writers: Musculoskeletal (MSK) Credentialing Examination

ARDMS is looking for item writers for the upcoming Musculoskeletal (MSK) examination as part of the development of the new Registered in Musculoskeletal™ (RMSK™) sonography credential. If you are interested in this exclusive opportunity, please send an email to itemdevelopment@ardms.org. Please provide your first and last name, ARDMS number and telephone number.

For more information on the responsibilities of an item writer and other volunteer opportunities with ARDMS, click here.

CT, PET-CT, MRT and Transthoracic Ultrasound in Lung Cancer

Dr. Helmut Prosch, at the University Clinic for Radio-Diagnostics, Vienna, Austria, is examining the role of imaging in lung cancer diagnosis and staging. The key message of his presentation in the session EUS and EBUS vs. CT, MR and PET-CT in the staging of lung cancer is that the modalities do not compete with one another – as the title suggests – but are perfectly complimentary in the diagnostic flow.
                                                 
"In lung cancer, prognosis as well as therapy is to a large extent dependent upon tumor size at the time of diagnosis," Dr. Prosch explained. "CT is the modality of choice to assess size and localization of the primary tumor. Whether the tumor can be surgically resected is above all dependent upon the presence of metastases in the lymph nodes and within or without the chest. Surgery is indicated when only ipsilateral and hilar lymph nodes are involved and, in many cases, where ipsilateral mediastinal metastases occur after neoadjuvant chemotherapy. "However," he added, "if the cancer has spread to contralateral mediastinal or supraclavicular lymph nodes, a curative therapy is no longer an option."

Non-invasive imaging is frequently inadequate to detect lymph node metastases because, in these cases, CT offers a sensitivity of only 51% and a specificity of 86%. The metabolic information PET-CT provides are a valuable complement because increased metabolic activity indicates the presence of a tumor."‘However,’ the expert point out, ‘inflammatory processes also require more glucose. Consequently, a mere increase in glucose in the lymph nodes is no clear evidence of metastases. If the lymph nodes are large enough and negative in PET-CT we can exclude metastases with a residual probability of five percent."

If PET-CT findings are positive, further examinations are necessary – and that is where minimally invasive procedures, such as endobronchial ultrasound, come in. In this procedure, tissue samples are taken during the examination, which means that imaging results can be supported by histological information.

Transoesophageal ultrasound is used to assess lymph nodes that cannot be reached via endobronchial ultrasound. "By combining these two options most lymph node metastases in the mediastinum can be well assessed and invasive methods, such as mediastinoscopy, are not necessary," he explained.

To evaluate supraclavicular lymph nodes, frequently involved in lung cancer, percutaneous ultrasound plays an important role. Dr Prosch: "The routine ultrasound examination of these lymph node stages offers a higher sensitivity than CT. An additional advantage is the fact that we can perform a biopsy during this procedure, which means that, with minimal intervention, we can diagnose the primary tumor at an inoperable stage."

MRI is suited above all to brain metastases detection and the evaluation of Pancoast tumors or mediastinal infiltration.

Dr. Prosch emphasized the interaction of these imaging modalities as the precondition for any meaningful diagnosis: "Ultrasound doesn’t compete with other modalities. Rather, it is an instrument in an orchestra and the clinician has to know when which instrument has to be played in order for the concerto to be successful." Thus, in many cases after initial CT scans the interdisciplinary tumor board, made up of radiologists, nuclear and internal medicine specialists and pathologists, will discuss further diagnostic steps.

View the article online.

Article written by staff at european-hospital.com, and adapted for the purposes of this newsletter.

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Ultrasound-based Risk Score Predicts Thyroid Malignancy

A relatively simple and practical thyroid imaging reporting and data system (TIRADS) based on the number of suspicious ultrasound (US) features can be applied to risk stratify thyroid nodules, according to a study published in the September issue of Radiology.

Widespread use of ultrasound has resulted in an increase in the detection of thyroid nodules. However, less than 10 percent of these nodules are malignant.

Deciding which patients should undergo fine needle aspiration biopsy (FNAB) presents a diagnostic dilemma as the same nodule may be classified differently using different guidelines. "Appropriate criteria are necessary to avoid an increase of rather unnecessary benign cytologic results in thyroid nodules," wrote Jin Young Kwak, MD, from the department of radiology, research institute of radiological science at Yonsei University of College of Medicine in Seoul, South Korea.

Previous TIRADS have been complex and difficult to apply in practice, according to the researchers. Thus, they sought to develop a practical TIRADS to stratify malignancy risk and devised a retrospective study of 1,658 thyroid nodules which were biopsied via ultrasound guidance from May 2008 to December 2008. The study population included 1,373 women and 265 men.

Seven radiologists performed real-time ultrasound on the patients and categorized nodules according to the internal component, echogenicity, margins, evidence of calcifications and shape. Following the ultrasound study, the same radiologists performed US-guided FNAB. Results were analyzed and compared according to sex and ultrasound features.

Kwak and colleagues reported 275 malignant nodules. Benign nodules were significantly larger than malignant nodules (mean size, 20.7 mm vs. 15.5 mm, respectively), and patients with benign nodules tended to be older.

According to the univariate analysis, several ultrasound features demonstrated a significant association with malignancy. These were: solid component, hypoechogenicity, marked hypoechogenicity, microlobulated or irregular margins, microcalcification and taller-than-wide shape.

The risk and probability of malignancy increased as the number of suspicious features increased, the researchers said.

The authors used the findings to create TIRADS categories, which were defined as:

• Category 3—no suspicious features;
• Category 4a—one suspicious feature;
• Category 4b—two suspicious features;
• Category 4c—three or four suspicious features;
• Category 5—five suspicious features.

The authors acknowledged a few shortcomings to the study. Namely, only a subset of the population was followed, the study was single-site design and limited to nodules that underwent FNAB, researchers did not account for false-negative and false-positive cytologic results and the malignancy probabilities have a fairly wide range. The researchers did not examine cost-effectiveness of the approach. Finally, although TIRADS risk of malignancy is similar to BI-RADS categories, the clinical aggressiveness and prevalence of the two nodule types differs.

Despite these issues, the researchers emphasized the practical utility of the risk score. "This new TIRADS can be easily applied in the clinical field because it is not difficult for those who perform US to count the number of suspicious US features," wrote Kwak.

View the article online.

Article written by staff at healthimaging.com and adapted for the purposes of this newsletter.

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Optical Diffusion Breast Imaging Boosts Ultrasound Performance

Optical diffusion breast imaging improves the diagnostic accuracy of conventional ultrasound in distinguishing between malignant and benign breast lesions, according to a new study published in the September issue of the American Journal of Roentgenology.

Researchers from Asan Medical Center in South Korea evaluated the diagnostic accuracy of optical diffusion breast imaging in patients who underwent conventional ultrasound followed by surgery or biopsy. They found that using optical diffusion improved ultrasound's specificity, positive predictive value, and accuracy.

Breast ultrasound is a commonly used diagnostic tool for further evaluation of abnormal mammographic findings, but its specificity leaves a bit to be desired, according to lead author Dr. Jin Hee Moon and colleagues.

"The partially overlapping appearance of benign and malignant lesions on breast ultrasound can make it difficult for radiologists to make a confident diagnosis," the authors wrote.

Optical diffusion imaging uses diffused light in the near-infrared spectrum. Because it calculates the total hemoglobin and oxygen saturation levels of tumors as markers of tumor angiogenesis or hypoxia, it can provide supplemental information to conventional ultrasound results that helps clinicians determine the status of a tumor.

Moon and colleagues performed optical diffusion breast imaging after conventional ultrasound on 193 women with 217 lesions, using a handheld probe that consisted of both an ultrasound transducer and a near-infrared source-detector light guided by optical fibers. The ultrasound transducer was used to find the targeted lesion, and then the probe's mode was shifted to optical diffusion imaging. On the outside of the probe, the optical system included two light sources and nine light emission fibers, while the receiving side of the probe featured 10 photomultiplier tubes that detect scattered light from tissue.

All patients also underwent ultrasound-guided core needle biopsy or surgery. One of a team of six radiologists reviewed the conventional ultrasound features of each lesion, assessed its BI-RADS category, and reviewed optical diffusion imaging results.
Of the 217 lesions, 108 were malignant and 109 were benign. Malignant lesions included the following:

• 86 invasive ductal carcinomas
• 15 ductal carcinomas in situ
• 1 invasive lobular cancer
• 2 mucinous cancers
• 2 tubular cancers
• 1 metaplastic cancer
• 1 microinvasive ductal carcinoma

Using conventional ultrasound results, the study's interpreting radiologists categorized 30 lesions as BI-RADS 3 (probably benign), 79 as BI-RADS 4A (indeterminate), 25 as BI-RADS 4B (intermediate suspicion of malignancy), 11 as BI-RADS 4C (moderate concern for malignancy), and 72 as BI-RADS 5 (highly likely to be malignant).

Moon's team found that using optical diffusion breast imaging contributed to ultrasound's performance, particularly in its specificity and accuracy.

When the researchers compared the total hemoglobin concentration level and oxygen saturation level of benign and malignant lesions, they found that the mean hemoglobin value was 0.144 mmol/L in benign lesions and 0.262 mmol/L in malignant lesions, a statistically significant difference (p < 0.0001). The mean oxygen saturation value was 0.971 mmol/L in benign lesions and 0.975 mmol/L in malignant lesions, which was not statistically significant (p = 0.953).

"These results show that the total hemoglobin concentration level is a more useful measure than oxygen saturation level for the differentiation of benign from malignant disease," Moon and colleagues wrote.

Compared with mammography or MRI, ultrasound has proved to be the best match for optical diffusion imaging, due to the modality's good resolution and high performance-cost ratio, according to the authors.

"Our results show that optical diffusion imaging may be helpful to radiologists for differentiating a lesion detected on conventional ultrasound," they wrote.

View the article online.

Article written by staff at auntminnie.com. and adapted for the purposes of this newsletter.

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