Rafal Z. Slapa

Shear Wave Elastography May Add a New Dimension to Ultrasound Evaluation of Thyroid Nodules: Case Series with Comparative Evaluation

Although elastography can enhance the differential diagnosis of thyroid nodules, its diagnostic performance is not ideal at present. Further improvements in the technique and creation of robust diagnostic criteria are necessary. The purpose of this study was to compare the usefulness of strain elastography and a new generation of elasticity imaging called supersonic shear wave elastography (SSWE) in differential evaluation of thyroid nodules. Six thyroid nodules in 4 patients were studied. SSWE yielded 1 true-positive and 5 true-negative results. Strain elastography yielded 5 false-positive results and 1 false-negative result. A novel finding appreciated with SSWE, were punctate foci of increased stiffness corresponding to microcalcifications in 4 nodules, some not visible on B-mode ultrasound, as opposed to soft, colloid-inspissated areas visible on B-mode ultrasound in 2 nodules. This preliminary paper indicates that SSWE may outperform strain elastography in differentiation of thyroid nodules with regard to their stiffness. SSWE showed the possibility of differentiation of high echogenic foci into microcalcifications and inspissated colloid, adding a new dimension to thyroid elastography. Further multicenter large-scale studies of thyroid nodules evaluating different elastographic methods are warranted.

Advantages and disadvantages of 3D ultrasound of thyroid nodules including thin slice volume rendering

BackgroundThe purpose of this study was to assess the advantages and disadvantages of 3D gray-scale and power Doppler ultrasound, including thin slice volume rendering (TSVR), applied for evaluation of thyroid nodules.MethodsThe retrospective evaluation by two observers of volumes of 71 thyroid nodules (55 benign, 16 cancers) was performed using a new TSVR technique. Dedicated 4D ultrasound scanner with an automatic 6-12 MHz 4D probe was used. Statistical analysis was performed with Stata v. 8.2.ResultsMultiple logistic regression analysis demonstrated that independent risk factors of thyroid cancers identified by 3D ultrasound include: (a) ill-defined borders of the nodule on MPR presentation, (b) a lobulated shape of the nodule in the c-plane and (c) a density of central vessels in the nodule within the minimal or maximal ranges. Combination of features provided sensitivity 100% and specificity 60-69% for thyroid cancer.Calcification/microcalcification-like echogenic foci on 3D ultrasound proved not to be a risk factor of thyroid cancer.Storage of the 3D data of the whole nodules enabled subsequent evaluation of new parameters and with new rendering algorithms.ConclusionsOur results indicate that 3D ultrasound is a practical and reproducible method for the evaluation of thyroid nodules. 3D ultrasound stores volumes comprising the whole lesion or organ. Future detailed evaluations of the data are possible, looking for features that were not fully appreciated at the time of collection or applying new algorithms for volume rendering in order to gain important information. Three-dimensional ultrasound data could be included in thyroid cancer databases. Further multicenter large scale studies are warranted.

Gray-scale three-dimensional sonography of thyroid nodules: feasibility of the method and preliminary studies

The aim of the study was differential evaluation of new and classical sonographic features of benign thyroid nodules and thyroid cancer with three-dimensional gray-scale sonography and evaluation of the effectiveness of the thin-slice surface rendered images in comparison with multiplanar reformation (MPR) presentation. Fifty-four thyroid nodules were interactively evaluated with thin-slice smooth surface rendering: shape in the c-plane (parallel to the probe) and evaluation of echogenicity, margins and calcification/microcalcification-like echogenic foci in the a-plane (plane of the probe). Evaluation of the level of agreement in readers’ interpretation and between sonographic techniques was performed using the κ statistic. Surface rendering permitted visualization of the shape of the nodule in the c-plane in all cases, in contrast to only up to 48% of cases in MPR evaluation. Lobulated nodule shape in the c-plane was 82–100% sensitive and 47–53% specific in diagnosis of carcinoma. Surface rendered images showed more calcification/microcalcification-like echogenic foci than MPR ones. The level of agreement between the observers in the evaluation of features of thyroid nodules and the agreement between features of thyroid nodules on MPR and surface-rendered images showed at least moderate reproducibility (κ≥0.41). Three-dimensional thin-slice surface rendering sonography appears to be a feasible and effective method for thyroid nodule evaluation.

Tissue harmonic imaging of thyroid nodules: Initial experience

Objective. To determine the impact of tissue harmonic imaging on visualization of the thyroid and gray scale contrast between thyroid nodules and adjacent thyroid parenchyma. Methods. A prospective study was performed on 144 patients (148 lesions) undergoing sonographically guided fineneedle biopsy. The fundamental frequency and tissue harmonic images were obtained on a scanner with a wideband 7.5‐MHz linear probe. One hundred forty‐two benign nodules, 2 papillary carcinomas, 1 anaplastic carcinoma, and 1 metastatic lesion were found. In 1 case a suggestion of a follicular carcinoma was raised, and in 1 case no diagnostic material was obtained. The gray scale intensity of the lesions and adjacent thyroid tissue was measured with graphics software, and the gray scale contrast between lesions and adjacent thyroid tissue was calculated. Additionally, the overall conspicuity and border definition were evaluated by 2 independent observers. Results. Tissue harmonic imaging improved the gray scale contrast between thyroid nodules and adjacent thyroid parenchyma in 116 lesions (78.4%). The overall conspicuity and border definition were improved or equal in the harmonic mode for most lesions. Conclusions. The tissue harmonic imaging technique used as an adjunct to conventional thyroid sonography may improve lesion detectability and characterization.

Adrenal ganglioneuroblastoma in pregnant woman: Diagnosis with three-dimensional ultrasound

Abstract. The diagnostic approach for evaluation of adrenal tumour in pregnant women is a problem. This article presents the multifactorial diagnosis of rare, incidentally detected massive adrenal tumour with 2D and 3D US. Grey-scale 2D and 3D US with tissue harmonic imaging showed inhomogeneous, encapsulated, solid tumour of the right adrenal region. Three-dimensional colour Doppler and power Doppler studies showed ample neovascularization in the tumour and the adrenal vein draining to the inferior vena cava similarly to angiographic studies performed in the past.

Application of parametric ultrasound contrast agent perfusion studies for differentiation of hyperplastic adrenal nodules from adenomas—Initial study

OBJECTIVES To evaluate the possibilities of differentiation of non-malignant adrenal masses with the application of the new technique for the evaluation of enhancement after administration of an ultrasound contrast agent: parametric imaging. PATIENTS AND METHODS 34 non-malignant adrenal masses in 29 patients were evaluated in a dynamic examination after the administration of ultrasound contrast agent with parametric imaging. Patterns on parametric imaging of arrival time were evaluated. The final diagnosis was based on CT, MRI, biochemical studies, follow up and/or histopathology examination. RESULTS The study included: 12 adenomas, 10 hyperplastic nodules, 7 myelolipomas, 3 pheochromocytomas, hemangioma with hemorrhage and cyst. The pattern of peripheral laminar inflow of Sonovue on parametric images of arrival time of was 100% sensitive for hyperplastic nodules and 83% specific in regard to adenomas. CONCLUSIONS Parametric contrast enhanced ultrasound may accurately differentiate hyperplastic adrenal nodules from adenomas and could be complementary to CT or MRI. Incorporation of perfusion studies to CT or MRI could possibly enable one-shop complete characterization of adrenal masses. This could deliver additional information in diagnostics of patients with Conn Syndrome and warrants further studies in this cohort of patients.

Usefulness of 3D transperineal ultrasound in severe stenosis of the anal canal: preliminary experience in four cases

BackgroundOrganic or functional anal canal stenoses are uncommon conditions that occur in the majority of cases as a consequence of anal diseases. A proper assessment is fundamental for decision making; however, proctological examination and endoanal ultrasound are often unfeasible or very difficult to perform even under local or general anesthesia. We therefore began to use 3D transperineal ultrasound to assess patients. The aim of this study was to compare the results of evacuation proctography and 3D transperineal ultrasound in patients with severe anal canal stenosis.MethodsFour consecutive patients with high-grade anal canal stenosis were evaluated using both proctography and 3D transperineal ultrasound with a micro-convex transducer between March and June 2011.ResultsIn all cases, 3D transperineal ultrasound provided detailed information on the length and level of stenosis and on the integrity of the anal sphincters.ConclusionsOur preliminary experience suggests that 3D transperineal ultrasound makes it possible to plan optimal surgical treatment.

Shear wave elastography of adrenal masses is feasible and may help to differentiate between solid and cystic lesions - an initial report.

INTRODUCTION The aim of this study was to evaluate the feasibility and usefulness of supersonic shear wave elastography (SSWE) in the diagnosis of nonmalignant adrenal masses. MATERIAL AND METHODS 13 patients with a total number of 16 adrenal masses were enrolled in the study. In each case, both conventional ultrasound imaging and SSWE for stiffness assessment were performed. The final diagnosis was based on CT, MRI, biochemical studies, surgery or more than one year of follow up. RESULTS The final diagnosis: nodular hyperplasia in six masses, six adenomas, three cysts, and one myelolipoma. All solid adrenal masses presented the elastography signal in contrast to cystic lesions that were devoid of it, as shear waves do not propagate through fluids. CONCLUSIONS SSWE is a feasible technique that can be applied during ultrasound of the abdomen and retroperitoneum. SSWE presents potential for the differentiation of solid and cystic adrenal lesions. Further large scale studies evaluating the possibility of differentiation of adrenal and other retroperitoneal masses with SSWE are warranted.

Standards of ultrasound imaging of the adrenal glands

Adrenal glands are paired endocrine glands located over the upper renal poles. Adrenal pathologies have various clinical presentations. They can coexist with the hyperfunction of individual cortical zones or the medulla, insufficiency of the adrenal cortex or retained normal hormonal function. The most common adrenal masses are tumors incidentally detected in imaging examinations (ultrasound, tomography, magnetic resonance imaging), referred to as incidentalomas. They include a range of histopathological entities but cortical adenomas without hormonal hyperfunction are the most common. Each abdominal ultrasound scan of a child or adult should include the assessment of the suprarenal areas. If a previously non-reported, incidental solid focal lesion exceeding 1 cm (incidentaloma) is detected in the suprarenal area, computed tomography or magnetic resonance imaging should be conducted to confirm its presence and for differentiation and the tumor functional status should be determined. Ultrasound imaging is also used to monitor adrenal incidentaloma that is not eligible for a surgery. The paper presents recommendations concerning the performance and assessment of ultrasound examinations of the adrenal glands and their pathological lesions. The article includes new ultrasound techniques, such as tissue harmonic imaging, spatial compound imaging, three-dimensional ultrasound, elastography, contrast-enhanced ultrasound and parametric imaging. The guidelines presented above are consistent with the recommendations of the Polish Ultrasound Society.

Three-Dimensional Sonography in Diagnosis of Retroperitoneal Hemorrhage From Adrenocortical Carcinoma

onography has limited value in visualization and differentiation of adrenal masses, although sonography of the abdomen can usually show adrenal tumors with a maximal diameter of greater than 1 cm on the right side and 1.5 to 2 cm on the left side.1 Small tumors often have a homogeneous echo texture that becomes heterogeneous as the tumor grows.2 Central necrosis or hemorrhage within the tumor may result in a hypoechoic area.3 Sonography is useful for follow-up of nonhyperfunctioning adrenal masses diagnosed on the basis of computed tomography (CT) or magnetic resonance imaging as adenomas.4 Sonography is the method of choice for the visualization of adrenal masses in small children.5,6 Diagnosis of adrenal masses in pregnant women can be established only with noninvasive methods such as sonography or magnetic resonance imaging.7 Three-dimensional sonography has been recognized and studied for 20 years.8 However, only recently, because of developments in computer techniques and in the construction of scanners, has the acquisition of volumes with automatic 3-dimensional (3D) probes become more simple and the quality of the images acquired in 3D sonography improved to compare with conventional sonographic images. With the matrix or automatic 3D probes and fast computers now available, even real-time 3D sonography (4-dimensional sonography) has become possible. In 3D sonography, the volume of tissues can be analyzed interactively in 3 perpendicular planes in the multiplanar reformation (MPR) mode or as a rendered image of the 3D object on a plane through the application of various algorithms. From 2001 through 2003, we investigated the application of 3D sonography for the evaluation of adrenal masses. The purpose of the procedure was explained to the patients, and their informed consent was obtained. Here we report the diagnosis of retroperitoneal hemorrhage from adrenal carcinoma on the basis of 3D sonography. Received May 10, 2004, from the Department of Diagnostic Imaging (R.Z.S., M.S.-K., W.J.) and Second Department of Surgery (J.A.P.), Medical Faculty II, Medical University of Warsaw, Warsaw, Poland; Department of Endocrinology, Center for Postgraduate Medical Education, Warsaw, Poland (A.A.K.-Z.); and Department of Pathomorphology, Czerniakowski Hospital, Warsaw, Poland (K.B.). Revision requested May 18, 2004. Revised manuscript accepted for publication June 14, 2004. This study was supported by State Committee for Scientific Research (Komitet Badan Naukowych) grant 6 P05B 072 20. Address correspondence and reprint requests to Rafal Z. Slapa, MD, Department of Diagnostic Imaging, Medical Faculty II, Medical University of Warsaw, ulica Kondratowicza 8, 03-242 Warsaw, Poland. E-mail: r.slapa@acn.waw.pl. Abbreviations CT, computed tomography; MPR, multiplanar reformation; 3D, 3-dimensional; 2D, 2-dimensional