CAROTID PI and CV DISEASE

Discussion

In this population of aging Australian women, the ICA PI is demonstrated to be associated with cardiovascular disease. It was significantly correlated to aortic PWV and the Framingham 10-year cardiovascular risk. The ICA PI was significantly predicted by cardiovascular risk factors including age, systolic blood pressure, MAP, BMI, smoking and diabetes. The CCA PI was also significantly related to the Framingham risk score and femPWV, though this relationship was not as strong as for the ICA. Neither CCA nor ICA PI was a significant predictor of ischaemic heart disease over age and systolic blood pressure. Reasons for the stronger relationship of the ICA PI to cardiovascular risk over the CCA may include the following: 1 The normal cerebral circulation is maintained in a constant flow due to a well-developed system of autoregulation, where acute falls in perfusion pressure can have potentially disastrous consequences to cerebral function.16 It can be expected that arteriosclerotic changes will increase flow impedance and should be readily detectable in the ICA.17 2 Readings taken in the common carotid will be influenced by the external carotid artery, which supplies the high resistance vascular beds of the muscles and skin of the face and scalp. Assessment of the PI of the internal carotid is noninvasive and relatively easy to acquire. Only one patient (0.6%) could not be assessed due to high positioning of the carotid bifurcation. The intra- and inter-operator repeatability of this potential cardiovascular health measure is still to be established at this site. Reports are varied for the reliability of PI measures in other applications including trans-cranial Doppler assessment of the cerebral vessels19 and intrauterine assessment of foetal vessels,20,21 with both intra-operator repeatability and technician experience having a significant impact on results.

 The main limitations of this study include the following: 1 This is a cross-sectional analysis, and it therefore does not imply causality. 2 The delay between evaluation of PWV and PIs approached 2 years in some participants. 3 The rate of ischaemic heart disease was low relative to the population sample size, making estimates of the true effect size and odds ratio or risk measures more unreliable.22 4 We were unable to assess the relationship of PI to the prevalence of stroke as no participants had experienced either an ischaemic or haemorrhagic event.

In summary, the PI, as measured by carotid Doppler ultrasound, was significantly related to the Framingham 10-year cardiovascular risk and aortic stiffening as measured by carotid–femoral PWV. Of the two PIs measured, the ICA had the strongest relationship to cardiovascular risk factors and may relate more closely to cardiovascular disease progression. Neither index significantly contributed to prediction of ischaemic heart disease in this analysis.

RENAL SONOGRAPHY and C K D

PRP for ROTATOR CUFF TENDINOPATHY: US-Guided INJECTIONS

 PRP has been increasingly used in recent years to treat musculoskeletal injuries such as tendinopathy. While a number of studies have assessed the effectiveness of the therapy, researchers have primarily evaluated the clinical symptoms and functions of the treated patient. Furthermore, the studies have produced ambiguous and sometimes conflicting results, Arrigoni said.

As a result, the Italian team sought to evaluate the effectiveness of ultrasound-guided PRP injection of the supraspinatus tendon and compare it with medical and physical therapy alone. Patients were included in the study if they had a diagnosis of tendinosis or a focal tear of the supraspinatus tendon with a diameter of 1 cm or less. The researchers evaluated the success of each method based on morphological changes as seen on MRI and four years of follow-up.

Half of the 240 patients in the study were treated with ultrasound-guided PRP injection, while the other half received only medical and physical therapy. The hospital's blood transfusion department prepared the PRP. After being given local anesthesia with mepivacaine hydrochloride in the subacromial bursa, patients received one of two PRP injections under ultrasound guidance in the supraspinatus tendon. The second injection was provided 21 days later. Patients were immobilized with a soft brace for three days after injection.

Patients with a history of trauma or surgery during the four-year follow-up period were excluded, Arrigoni noted. MRI exams were performed on each patient before and four years after PRP injection, as well as on the group of patients who received medical and physical therapy.

Based on the MRI results, patients were classified as showing improvement, having stationary findings, or worsening. In addition, all patients were given a clinical and functional evaluation before therapy and after the four-year follow-up period. Pain was assessed using scores based on a visual analogue scale (VAS), while shoulder joint function was evaluated with Constant function scores.

"PRP injection in fact delays the degenerative changes of the tendons, and this is documented by the pain relief and functional improvement," Arrigoni said.

PRIMARY THYROID LYMPHOMA: US FINDINGS

MCA and TCS

FIBROSCAN in United States Practice

HEPATIC HEMODYNAMICS DURING VALSALVA MANEUVER

The Valsalva maneuver is a widely used physiologic technique for the non-invasive evaluation of heart murmurs and ventricular function [1-3]. The Valsalva maneuver consists of forceful expiration against a closed glottis, resulting in an increase in both intra-thoracic and intra-abdominal pressure, and activation of autonomic nervous function [4-6]. Although the hemodynamic changes during Valsalva maneuver have been well documented, these have been focused on cardiac chambers, aorta and systemic large veins [4,7-10]. Anatomically, venous return consists of systemic and hepatic venous return, and systemic venous return decreased markedly during the Valsalva maneuver [8,11]. However, it was not well defined that hemodynamic changes focused on the liver during Valsalva maneuver.
Clinically, the Valsalva maneuver is considered as main cause of defecation syncope and surgery Hepatic hemodynamics during Valsalva maneuver performed in a patient with functional suprahepatic inferior vana cava (IVC) obstruction during the Valsalva maneuver [12]. Collapsed IVC showed during the maneuver in normal healthy subjects using ultrasonography study, but IVC howed angular appearance and not collapsed during the maneuver in the venography study [10,11]. The change of IVC during the maneuver is ambiguous and hemodynamic contribution of hepatic vein and portal vein during the maneuver has not been studied in normal healthy subjects. Duplex Doppler ultrasonography of the liver provides important information about liver condition [11,13]. Hepatic vein flow depends on hepatic parenchymal compliance, thoracoabdominal pressure, and right atrial pressure. It is known that hepatic vein Doppler waveform is triphasic pattern which is composed of two anterograde flow peaks toward the heart and one retrograde flow peak toward the liver in healthy subjects [14]. Recently, volume flow measurement has been used for quantification of blood flow and it showed good correlation with magnetic resonance in quantification of cerebral blood flow [15-17]. Therefore, analysis of flow pattern and quantification of liver flow can be helpful to understand liver
condition under the Valsalva maneuver. Even the liver hemodynamic changes during the Valsalva maneuver in healthy volunteers have been studied in previous reports, its contribution to venous return is not focused enough [18,19]. We hypothesized that the hepatic circulation might be an important role to maintain venous return to the heart during Valsalva maneuver.

The aim of our study was to assess the hemodynamic change of liver including hepatic vein and portal vein during the Valsalva maneuver.

B-mode ultrasound spots subclinical atherosclerosis

B-mode ultrasound spots subclinical atherosclerosis

By Erik L. Ridley, AuntMinnie staff writer

January 13, 2015 -- Thanks to advances in automation and improved imaging capabilities, B-mode ultrasound can be used to assess subclinical atherosclerotic disease and better identify those patients who would benefit from medical intervention prior to symptom onset, according to research published in Global Heart.

For the study, a multi-institutional, multinational research team examined two cohorts from India with automated B-mode ultrasound and compared the results with those of two cohorts from North America. Automated ultrasound of the carotid and iliofemoral arteries could feasibly provide rapid screening for subclinical atherosclerotic disease in a range of settings, the researchers found.

They also concluded that adding B-mode examination of the iliofemoral arterial beds to carotid ultrasound screening identifies additional subjects who would benefit from prophylactic medical intervention for atherosclerotic cardiovascular disease (ASCVD)-related events.

"Surely, such a simple approach merits adoption on a wide scale as a modern approach to a modern scourge of rapidly rising ASCVD-related events worldwide," wrote the authors, led by Ram Bedi, PhD, of the University of Washington's department of bioengineering, and senior author Dr. Jagat Narula, PhD, from Icahn School of Medicine.

Asymptomatic subjects

Doppler-based ultrasound systems are commonly used to assess carotid stenosis in symptomatic patients to identify those who would benefit from surgical intervention. The researchers believed that recent image quality improvements and advances in automation could enable B-mode systems to be similarly used for assessing subclinical atherosclerosis in the asymptomatic population to determine subjects who would benefit from prophylactic medical intervention (Global Heart, December 2014, Vol. 9:4, pp. 367-378).

To test their theory, the researchers used B-mode ultrasound to calculate the prevalence of atherosclerotic disease in 941 asymptomatic volunteers (mean age, 44.27 ± 13.76 years) from two underserved communities in India where ASCVD risk factor information was unknown. While one community was from an urban city (Jaipur), the other community -- from the semiurban town of Sirsa -- consisted of devout followers of a local spiritual leader, and the subjects had undergone aggressive lifestyle changes.

The results were compared with reference data gathered from two primary care clinics in North America: one was in Toronto, and the other was in Richmond, TX. The 481 subjects in this part of the study had a mean age of 59.68 ± 11.95 years; most were office workers in mid- to high-income brackets and few engaged in regular physical activity, according to the researchers.

Automated bilateral B-mode ultrasound studies of the carotid and iliofemoral arteries were performed at two health camps in India, using a CardioHealth Station (Panasonic Healthcare) ultrasound system, by one of eight radiology residents. The residents did not have prior experience in vascular ultrasound but received two hours of training. Ultrasound exams were performed by trained vascular sonographers at the two North American clinics in the study.

While conventional 2D imaging was considered satisfactory for identifying focal lesions, 3D imaging data for the arterial segment of interest were acquired to automate the process of plaque identification and quantification. To present the clinical findings in an easy-to-understand manner, the researchers developed an index called the Fuster-Narula (FUN) score, which summarizes the intima-media volume for the scanned peripheral arteries.

The researchers found that 224 (24%) of the participants from India had plaque in at least one of the four arterial sites. Furthermore, 107 (11%) had plaque only in the carotid arteries, 70 (7%) had plaque in both the carotid and iliofemoral arteries, and 47 (5%) had plaque only in the iliofemoral arteries. The presence of plaque was associated with older age and the male gender, but not with systolic blood pressure, the group noted.

ULTRASOUND IMPLEMENTATION on LEARNING and TEACHING for the 1st Year of Medical Education

Discussion

We found that the introduction of a pilot ultrasound curriculum integrated with the physical diagnosis course at our institution did not worsen year 1 medical student physical examination skills and may be potentially beneficial when compared to historic controls. Students who had the ultrasound curriculum had better overall associated OSCE scores compared to students in the historic control group.

Students and faculty predominantly had positive responses to the course, and most agreed or strongly agreed that ultrasound has a valuable role in medical education. Faculty gave constructive feedback on how to improve ultrasound implementation. Other studies have shown that point-of-care ultrasound training can enhance ultrasound skills and specific physical examination skills such as abdominal and cardiac examinations.18,26 We believe that no previous study has shown that implementation of a point-of-care ultrasound curriculum in the year 1 medical student curriculum may have substantial benefits to the overall traditional physical examination.

Previous work has shown that ultrasound curricula for medical students and residents, during their respective training, can improve their ultrasound skills20,26–31 when compared to control groups without ultrasound training.6,32,33 It inherently makes sense that learners who are taught any skill should outperform learners who are naive to that skill. Specific physical examination skills have also been shown to improve with introduction of ultrasound training.

One study found that ultrasound improves year 1 medical students’ abdominal examination.17 However, only the abdominal examination was assessed in that study. Other studies have shown that medical students could more accurately diagnose cardiac diseases using ultrasound even when compared to a trained cardiologist using auscultation alone.32–34 Most of these studies used ultrasound defined end points; hence, the effect of ultrasound on traditional physical examination skills remained unknown.

By not using any ultrasound end points, our study was unique in demonstrating that year 1 medical students with point-of-care ultrasound training had improved overall traditional OSCE scores and a trend toward improved physical examination skills in almost all organ systems when compared to students with no point-of-care ultrasound training. This finding suggests that point-of-care ultrasound does not worsen the overall physical examination skills of year 1 medical students but may actually improve their physical examination skills. The concern that technology may impede critical thinking and tactile skills is a valid point.21–24,35 The purpose of point-of-care ultrasound must be differentiated from the use of CT, MRI, and comprehensive

ultrasound scans. In point-of-care ultrasound,the clinical sonographer is the actual practitioner with a focused question regarding the patient being treated. The goal of point-of-care ultrasound would be to confirm or refute a diagnosis as a result of the practitioner’s physical examination.36 Point-of-care ultrasound may actually promote critical thinking because the sonographer knows what condition is of concern before performing the ultrasound examination rather than haphazardly performing an ultrasound examination looking for incidental findings, as may occur with CT, MRI, and comprehensive ultrasound examinations.

Ultrasound curriculum implementation into medical schools has been shown to be feasible.1–7,37 However,many of these institutions have ample point-of-care ultrasound faculty experts and considerable industry support for numerous ultrasound machines. We piloted a curriculum with minimal resources, using only 4 ultrasound machines, 1 point-of-care ultrasound expert, and 8 ultrasound-naïve faculty to train a group of 163 year 1 medical students. We found that it was feasible to implement this curriculum through faculty development and student peer teaching. Another concern is the addition of time for ultrasound training into medical students’ already demanding schedules.

Incorporating ultrasound directly into the required physical diagnosis course obviated the need to add more time to the overall students’ curriculum. Furthermore, having open ultrasound lab sessions allowed students to practice their physical examination and ultrasound skills on their own. Given the limited availability of point-of-care ultrasound experts an institution may have, we believe that most schools will need to use ultrasound-naive faculty members for ultrasound curriculum implementation. The feedback from the faculty members in this study raises many important points when implementing an ultrasound curriculum.

Dedicated faculty development must be performed on a longitudinal basis, so faculty will feel comfortable with the basic ultrasound skills. Some faculty members may have years of clinical experience but might not see the direct benefits of point-of-care ultrasound if they do not use it in their own clinical practice. However, with more residencies requiring ultrasound competency for residency completion,8–11 medical students with comprehensive ultrasound training may have a considerable advantage when they enter residency training. Previous studies have shown that medical students and residents already have a strong interest in ultrasound and believe it is important to their medical training.4,38,39 The importance of this emerging technology should also be emphasized to all faculty involved with ultrasound teaching.40,41

We realize that integration of ultrasound is difficult because each school has a unique curriculum that has been in place for many years. An additional problem with ultrasound is that it can be a substantial financial burden to administrators and requires added student time and faculty commitment. Another concern may be that most schools may not have an ultrasound expert to adequately implement a curriculum.We found that a curriculum can be feasibly developed with minimal resources. Students in our study strongly agreed that peer teaching was useful for learning point-of-care ultrasound. Peer teaching has also been used successfully at other institutions.42-44 Further research needs to be done on the barriers to ultrasound implementation in medical schools and how implementation can be facilitated with limited resources.

There were several limitations to our study. The control group was a historic control, and the students from both groups may have been inherently different, which could have caused the difference in OSCE scores. There were no notable curriculum or faculty changes between the 2 years, except for the point-of-care ultrasound implementation.

Twenty-five student data points were missing from the historic controls, which may have affected the mean pre-ultrasound group scores. This study could have been improved if the groups were randomized, but we thought that all students would benefit from the ultrasound curriculum. There is no current recommended standardized curriculum, and the ultrasound curriculum we implemented may have had different results if we had more intense ultrasound training for students and faculty. The effect of ultrasound training on medical student proficiency in the clinical setting needs further investigation.

We conclude that implementing an ultrasound curriculum into a physical diagnosis course is feasible with limited resources and may increase the physical examination skills of year 1 medical students. Overall, students and faculty had a positive response to the ultrasound curriculum. Despite the controversy that introducing ultrasound may decrease time for learning traditional physical examination skills and may cause reliance on such technology, our study found that by using ultrasound synergistically to learn the physical examination, there seems to be an overall benefit to the introduction of ultrasound into medical education.

Dinh et al—Ultrasound Effects on Physical Examination in Medical Education, J UltrasoundMed 2015; 34:43–50.

LYMPHOCYTIC THYROIDITIS and PAPILLARY THYROID CARCINOMA

ULTRAFAST DOPPLER US for HEPATIC VESSELS

C A P based on TRANSIENT ELASTOGRAPHY for HEPATIC STEATOSIS

Discussion

Hepatic steatosis, particularly because of NAFLD, is common and increasing in prevalence. In some patients, steatosis may progress to NASH, cirrhosis and end-stage liver disease.^{[1, 4]} In light of the growing burden of NAFLD and anticipated development of specific therapies, reliable noninvasive methods for grading steatosis are needed.^[9] We have demonstrated that the CAP is correlated with steatosis independent of inflammation and fibrosis, and can be used to noninvasively identify steatosis with good performance. Specifically, for significant steatosis (≥10% of affected hepatocytes), the AUROC of the CAP was 0.81; a CAP threshold of 283 dB/m was 76% sensitive and 79% specific for this outcome. Similar findings were reported in a study of 615 patients with HCV in whom the CAP had an AUROC of 0.80.^[27]A threshold of 222 dB/m was 76% sensitive and 71% specific in this cohort. However, our data are somewhat less optimistic than described by Sasso et al. in a study of 115 patients with various liver disorders.^[15] In this study, the AUROC for significant steatosis was 0.91; a CAP cut-off of 238 dB/m was 91% sensitive and 81% specific. These discrepancies may relate to differences in the study populations including disease aetiologies, the prevalence of obesity and extent of subcutaneous adiposity, and the severity of steatosis, which may influence CAP performance because of spectrum bias.^[10]For example, the mean BMI in our cohort was 32 kg/m² and 65% of patients had significant steatosis. In the other studies, mean BMI was 24–25 kg/m² and 31–58% had significant steatosis.^{[15, 27]} Future studies in larger cohorts, including ideally an individual patient data meta-analysis, will be useful for refining the operating characteristics of the CAP, including the optimal cut-offs in different disorders. Our data suggests that the performance of the CAP did not differ substantially between conditions.

We also examined the diagnostic performance of the CAP for quantifying steatosis according to the NAS classification.^[4] CAP performed well for identifying S1–S3 (≥5%) and S2–S3 (>33%) steatosis with AUROCs of 0.79 and 0.76 respectively. However, because the CAP was not significantly different between patients with S2 and S3 steatosis (Fig. 2), severe (>66%) steatosis was sub-optimally identified (AUROC 0.70). These findings were corroborated in our analysis evaluating the CAP's ability to discriminate individual steatosis grades, which overall, revealed reasonable performance (Obuchowski measure = 0.89). However, a problem with the CAP is that the optimal cut-offs identified for each outcome – based on the maximal sum of sensitivity and specificity – were similar (Table 2), which makes grading steatosis with this technology difficult. Similarly, although the CAP reliably differentiated steatosis at least 2 grades apart, the identification of single-grade differences was poor (Table 3). This limitation, which also applies to other surrogate markers of liver histology (e.g. serum fibrosis markers and FibroScan®) is in part because of the imprecision of the CAP, but also the limitations of liver biopsy. Indeed, in a study that evaluated sampling error of biopsy among 51 NAFLD patients who underwent dual pass biopsies, discordance in steatosis grading was observed in 22% of cases.^[7] In 18% of patients, the difference in steatosis severity exceeded 20%. It is conceivable that the CAP actually provides a more accurate assessment of steatosis within the entire liver as it samples a volume ~100-times larger than biopsy.^[15] Furthermore, the reliability and variability in the pathologic grading of steatosis, even by experts, is poor.^[28–30] Steatosis evaluation can also be influenced by tissue fixation and staining methods.^{[31, 32]} Therefore, although we included only high-quality biopsies and centralized histological grading by experts, we cannot exclude an 'imperfect gold standard bias'. Future CAP studies including more objective assessments of steatosis (e.g. computerized morphometry)[28] would be useful to investigate these issues.

Previous reports have shown higher rates of discordance in fibrosis staging using the FibroScan® in patients with highly variable LSMs.^{[22, 23]} Therefore, we examined the impact of CAP variability – as assessed by IQR/MCAP – on the diagnostic performance of this tool. Although we did not observe significant differences in the AUROCs of the CAP for significant (≥10%) steatosis between patients with high and low IQR/M, highly variable measurements (IQR/MCAP ≥15) were less accurate for ≥5% steatosis in a post hoc analysis. These findings require confirmation. The AUROC for significant steatosis was higher among patients with no to minimal fibrosis (AUROC 0.89 vs. 0.72 with moderate to severe fibrosis), suggesting a potential role for the CAP as a screening tool in the general population. The reason for this novel finding [15, 27] remains unclear because the prevalence of significant steatosis was similar between groups (60–70%). Moreover, the CAP was not associated with fibrosis after adjustment for steatosis and inflammation. Additional studies in larger cohorts are necessary for confirmation and to examine other predictors of CAP performance.

Our study suggests that the CAP may be a worthwhile adjunct in the evaluation of patients with chronic liver disease. As LSM by FibroScan® is routine in many regions, an appealing aspect of the CAP is that it is provided automatically and immediately by the FibroScan® VCTE™ software in the same region of interest as LSM. Moreover, CAP measurement is operator-independent and requires no specific training. Another potential application of CAP is the exclusion of steatosis in donors for living-related liver transplantation, in whom steatosis increases the risk of primary graft non-function.^[33] Evaluation of CAP in other clinical settings will be the focus of future investigation.

Other serum and imaging-based methods have been examined for the noninvasive assessment of steatosis. Although liver biochemistry is widely available and inexpensive, the sensitivity of these tests is sub-optimal. In our study, the AUROCs (95% CI) of ALT and GGT for significant steatosis were only 0.50 (0.40–0.60) and 0.56 (0.46–0.66) respectively (both P < 0.00005 vs. CAP). Several serum marker panels have also been proposed for quantifying steatosis. For example, the SteatoTest includes age, gender, BMI, cholesterol, triglycerides, glucose, ALT, GGT, bilirubin, haptoglobin, alpha-2-macroglobulin and apolipoprotein A1.^[34] For steatosis ≥5%, its AUROC was 0.80 in a cohort of 811 patients with various liver disorders. The proprietary nature of this algorithm and delayed results are important limitations. A recently described nonproprietary panel, the FLI, includes triglycerides, GGT, BMI and waist circumference.^[17] The FLI is associated with steatosis detected songraphically^[17] and is an independent predictor of mortality.^[18] Similarly, the HSI, which includes the ALT/AST ratio, BMI, gender and diabetes, is associated with the presence and severity of steatosis on ultrasound.^[19] In our study, the CAP outperformed these indices for the primary outcome and most secondary outcomes although the small sample size may have rendered some analyses underpowered. Ultrasound is the most common imaging method for detecting steatosis, which is recognized by a diffuse increase in hepatic echogenicity.^{[12, 13]} 

Limitations of ultrasound include its markedly reduced sensitivity for mild steatosis (under 30%),^{[35, 36]} operator and machine-dependence, the inability to reliably quantify hepatic fat content,^{[12, 13, 35]} and the potential for extensive fibrosis to increase liver echogenicity.^[13] Although promising, other abdominal imaging techniques (e.g. CT, MRI and proton magnetic resonance spectroscopy), are not widely available, expensive, lack standardization, have controversial diagnostic performance, and in the case of CT, exposure to ionizing radiation.^{[12, 13]}

Our study has several limitations. Most importantly, our study population was highly selected in that it included only patients with a BMI ≥28 kg/m²; moreover, a significant number of patients were excluded predominantly because of missing data. Therefore, the generalizability of our findings to other patient populations (e.g. a 'screening cohort' seen in primary care) requires confirmation. Second, our sample size was limited in part because of the difficulty of obtaining valid CAP measurements in obese patients using the FibroScan® M probe. Future studies are necessary to develop a CAP algorithm for the novel FibroScan® XL probe, which was designed for use in this population.^[16] Second, because of a median delay of approximately 1 month between CAP measurement and biopsy, we cannot exclude changes in steatosis that may have influenced our findings. Third, we assessed only the diagnostic accuracy of CAP although additional properties including agreement, precision, and responsiveness deserve mention. Finally, our cohort included patients with numerous liver diseases in whom inflammation and fibrosis may be staged using different scoring systems. As these classifications are not interchangeable, this issue may have influenced our multivariate analyses.

In conclusion, the CAP is a promising tool for the noninvasive detection of hepatic steatosis. Advantages of the CAP include its simplicity, operator-independence and sensitivity to lesser degrees of steatosis than are detectable using other widely available imaging modalities. Moreover, the CAP provides an immediate assessment of steatosis simultaneously with LSM used to stage hepatic fibrosis. Future studies are necessary to validate our findings in larger cohorts to define optimal CAP thresholds and to develop a CAP algorithm for the FibroScan® XL probe that will facilitate measurement in a greater proportion of obese patients.

UNCOMPLICATED ACUTE DIVERCULITIS: BENEFITS of ULTRASOUND DIAGNOSIS