Practical applications of digital tomosynthesis of the chest.

Digital tomosynthesis is a radiographic technique that generates a number of coronal raw images of a patient from a single pass of the x-ray tube. Tomosynthesis provides some of the tomographic benefits of computed tomography (CT), but at a much lower dose of radiation and cost when compared to CT. This review illustrates the range of practical applications of digital tomosynthesis of the chest.

The varied sonographic appearances of focal fatty liver disease: review and diagnostic algorithm.

Focal fat infiltration and focal fat sparing of the liver are less common than diffuse fat infiltration but present a greater diagnostic conundrum. Although typical features of these conditions are well described, there is a wide variety of different appearances. These atypical patterns present significant difficulty in differentiation from other pathological processes and often require additional investigation. We present an innovative diagnostic algorithm and illustrate its effectiveness in diagnosing focal fatty liver disease with typical and atypical examples.

Decontamination of transvaginal ultrasound probes: review of national practice and need for national guidelines.

AIM: To determine the national practice of transvaginal ultrasound (TVUS) probe decontamination in English hospitals and to develop recommendations for guidance. MATERIALS AND METHODS: A literature review was undertaken to clarify best practice and evaluate methods of decontamination of TVUS probes. A questionnaire was developed to ascertain TVUS probe decontamination programmes in current use within English hospitals. This was sent to ultrasound leads of 100 English hospitals; 68 hospitals responded. RESULTS: There is a wide variation in TVUS probe decontamination across English hospitals. Although the majority of respondents (87%, 59/68) reported having clear and practical written guidelines for TVUS decontamination, the frequency, methods, and types of decontamination solutions utilized were widely variable and none meet the standards required to achieve high-level disinfection. CONCLUSION: While the decontamination of other endoluminal medical devices (e.g., flexible endoscopes) is well defined and regulated, the decontamination of TVUS probes has no such guidance. There appears to be incomplete understanding of the level of risk posed by TVUS probes, and in some cases, this has resulted in highly questionable practices regarding TVUS hygiene. There is an urgent need to develop evidence-based national guidance for TVUS probe decontamination.

MRI appearances of acute idiopathic scrotal oedema in an adult.

Acute idiopathic scrotal oedema is an uncommon cause of acute painless scrotal swelling that is usually seen in children. Traditionally, ultrasound has been used to help establish the diagnosis in the appropriate clinical setting. We report the MRI appearances of acute idiopathic scrotal oedema in a 51-year-old male with associated involvement of the penis.

Obstetric ultrasound education for the developing world: A learning partnership with the World Federation for Ultrasound in Medicine and Biology.

The ultrasound techniques in pregnancy e-learning project is an online resource commissioned and supported by the Education Committee of the World Federation for Ultrasound in Medicine and Biology (WFUMB). This currently consists of 10 e-learning sessions aimed at midwives and other health workers in developing countries where WFUMB has Educational Centres of Excellence, and in particular at those based mainly in rural communities at considerable distance from urban training centres. The project covers all of the basics of obstetric ultrasound such as fetal and maternal anatomy, ultrasound techniques, assessment in both early and late pregnancy, prediction of pregnancy complications and identification of common abnormalities that might interfere with delivery. The e-learning project complements a wider training programme which covers operator skills and machine controls, in order to minimise the time that the professional has to leave their rural, often poorly staffed, workplace to attend classroom-based courses in the city. Each session outlines often complex concepts using simple diagrams, interactive exercises and cine clips. Tips, tricks and best practice guidelines are provided in simple terms.

Isolated clinic hypertension is not an innocent phenomenon: effect on the carotid artery structure.

This study examines the common carotid intimal-medial wall thickness (CCA-IMT) in untreated patients with elevated clinic blood pressure (BP) but normal ambulatory BP (isolated clinic hypertension, n = 22), in comparison with a group with elevated clinic and ambulatory BP (hypertensives, n = 41) and a group with normal clinic and ambulatory BP (normotensives, n = 17) readings. The three groups did not differ in age, male/female ratio, lipid profile, glucose tolerance test, or smoking habits. No difference existed in CCA-IMT values between the groups with hypertension (0.67 +/- 0.18 mm) and isolated clinic hypertension (0.68 +/- 0.14 mm), but the values in these two groups were significantly higher (one-way ANOVA; F = 8.09, P < .001) than in the group of normotensives (0.50 +/- 0.09 mm). The CCA-IMT did not correlate with clinic systolic or diastolic BP readings or with BP derivatives of 24-h ambulatory monitoring. Mean 24-h BP in the isolated clinic hypertensives did not differ from that in the normotensives, whereas both were lower than in the hypertensives. We conclude that changes in the CCA-IMT occuring in subjects with isolated clinic hypertension are equal to the changes in sustained hypertension, indicating that isolated clinic hypertension may not be a benign condition.

Ultrasound criteria in the diagnosis of polycystic ovary syndrome (PCOS).

Not all women with the polycystic ovary syndrome (PCOS) on ultrasound (US) will have the syndrome, and clinical and biochemical features of PCOS may be present without US features. The sensitivity of US in detecting PCOS was, therefore, prospectively determined in 72 women (32 PCOS and 40 controls). The most sensitive features were the presence of 10 or more follicles (82% and 69% in the left and right ovary) and a peripheral distribution of follicles (81.8% and 71.9% in the left and right ovary). Although ovarian enlargement and stromal brightness were not as sensitive as the previous criteria, stromal brightness was most specific. Combining all the criteria predicted a diagnosis of PCOS or control correctly in 86.4% of cases. This study shows that established US criteria of polycystic ovaries remain of value in the diagnosis of PCOS; however, the discrepancy between the left and right ovaries is an interesting but unexplained finding.

Renal artery stenosis: duplex Doppler evaluation.

The renal arteries of 40 patients without renal or renovascular disease were examined with duplex real-time Doppler sonography. Special views were employed to obtain adequate images and Doppler recordings from the renal arteries. Time limits were placed on the duration of the examination, the better to reflect common clinical practice. Velocity spectral analysis of the Doppler shift frequency was achieved in 82.5% of the arteries examined and a characteristic "Doppler signature" for the renal artery identified. This was compared with the Doppler signal from the renal arteries of eight patients with renal artery stenosis. Significant differences in spectral pattern were demonstrated in renal artery stenosis. These differences are illustrated and their potential for screening for renovascular disease in systemic hypertension is discussed.

Renal carcinoma: duplex Doppler evaluation.

Doppler ultrasound has a clearly defined role in the assessment of carotid and peripheral vascular disease. In these situations vessel pathology produces alterations in velocity and volume flow and in the flow-velocity spectrum. Flow in the renal arteries is affected not only by disease of the renal vessels but also by the peripheral resistance to flow within the kidney. Alterations in this peripheral resistance resulting from renal disease are reflected in the Doppler flow spectrum analysis. In 14 patients with renal carcinoma, three different blood flow patterns were observed, reflecting the differing vascularity of the renal tumours. These were compared with blood flow in normal kidneys and in kidneys containing renal cysts. Doppler ultrasound adds further information to the study of renal carcinomas, allowing the prediction of tumour vascularity, and may be useful as a preliminary investigation prior to angiography and embolisation.

Renal artery stenosis: the use of duplex ultrasound as a screening technique.

Over an 18-month period, 44 patients with hypertension were referred for evaluation of the renal arteries by duplex Doppler ultrasound. Those patients referred were pre-selected in that they were either young, or suffering from accelerated hypertension. Eleven patients (12 arteries) were considered to have characteristics suggesting renal artery stenosis. Of the 11 patients, nine have submitted themselves for further evaluation by angiography and radionuclide renography. These further investigations have identified seven true positive and three false positive results. Criteria for duplex diagnosis of renal artery stenosis are presented and a possible role for duplex Doppler ultrasound as a screening tool for renal vascular hypertension is discussed.

Ultrasound in hepatoma-can specific diagnosis be made?

The ultrasound appearances of primary hepatocellular carcinoma in 32 patients are described. Attempts to correlate the appearances with serological, histological, and arteriographic findings revealed no consistent pattern. There appears to be no great difference in the range of ultrasound appearances in primary hepatocellular carcinoma when compared with that reported for metastatic disease. The findings suggest that in patients with cirrhosis, ultrasound is a sensitive method for the detection and accurate location of hepatocellular carcinoma, but that in these patients the echo pattern provides little help in the differentiation of primary from secondary carcinoma. Our study has revealed four different echo patterns in patients with hepatocellular carcinoma: echofree (47%), echogenic (23%), mixed (175) and diffuse infiltration 13%).

Duplex sonography in splenomegaly.

The aetiology of splenomegaly is seldom clear from either clinical or imaging assessment of the spleen. In the majority of cases sonographic assessment of the spleen produces a homogeneous enlargement of variable echodensity, but with very poor correlation with pathology. A study has been undertaken to assess the Doppler characteristics of the splenic artery in splenomegaly, excluding cases of portal hypertension in an attempt to provide further diagnostic information. Duplex assessment of 18 normal subjects and 10 patients with splenomegaly due to five different causes was undertaken. Analysis of waveform, peak frequency and pulsatility index were compared and failed to demonstrate any significant change. In the normal subject there is a broad systolic spectrum related to the tortuosity of the splenic artery, with persistence of forward flow throughout diastole, a reflection of the low peripheral resistance of the spleen. In splenomegaly the broad systolic spectrum is unchanged, since vessel tortuosity persists. Pathological and physiological assessment of the spleen in splenomegaly shows that a low resistance circulation persists, explaining maintenance of the diastolic flow pattern in splenomegaly. Increased blood flow to the spleen in splenomegaly occurs either as a result of an increase in vessel diameter or an increase in flow velocity, or a variable combination of the two which does not seem to be governed by specific pathology. An increase in peak frequency in some cases reflected some increase in flow velocity but provided no useful correlation. Analysis of the pulsatility index supported the above findings without adding further information.

Screening for chromosomal abnormality.

Screening for fetal abnormalities has become one of the most high profile health care issues of modern times. This issue is predicated on major advances in health care technology that permit wider detection of fetal anomalies, including the development of more advanced biochemical markers and improvements in ultrasound imaging. The effectiveness of these screening methods and their rational application is a point of great controversy, and is the cause of considerable unease in clinical obstetrical practice. This article reviews the general concepts of fetal screening for fetal chromosome abnormalities and then focuses on certain aspects of ultrasound screening that are particularly controversial. The scientific basis for each ultrasound finding (e.g., nuchal translucency) is reviewed, as well as the frequently divergent clinical experience with the finding. Finally, a plea is made for the development of a more scientific database for fetal ultrasound screening, and the setting of fetal screening guidelines for practicing physicians based on diagnostic accuracy and cost-effectiveness.

Screening for gynecological malignancy.

Treatment for gynecological malignancy depends for its efficacy at least in part on the stage at presentation. Earlier diagnosis would allow the opportunity for more effective and potentially curative treatment. As a consequence, and in common with initiatives for many other cancers, a search for effective methods of screening is a high priority for the detection of early gynecological cancer. Such methods already exist for cervical cancer, and in many countries screening programs are in place to provide such early diagnosis. Patients with endometrial cancer often present symptomatically at stage I and as a consequence the value of screening of asymptomatic patients may be of lesser importance than for other cancers. Ovarian cancer, however, characteristically presents late and is insidious in onset and progress. Transvaginal ultrasound, together with serum tumor markers, may offer the possibility of early diagnosis and modification of therapy with the potential for improved outcome. However, the evidence from the literature is at present confusing, and it is worthwhile to review the current status of research data to evaluate the place of screening procedures for ovarian and other gynecological malignancies.