US elastography of breast and prostate lesions.

Elastography is a technique that maps relative tissue stiffness. Ultrasonographic (US) elastography (sonoelastography) is a novel modality that is the subject of active research for clinical applications, primarily breast and prostate lesion imaging. Breast and prostate tumors generally have biomechanical properties different from those of normal tissues: Tumors are usually stiffer. This phenomenon is responsible for tissue contrast on elastograms. For the prostate gland and breast, the main image acquisition techniques are vibration sonoelastography and compression sonoelastography. The sonoelastographic appearances of several common breast lesions, including fibroadenomas, simple and complex cysts, ductal carcinomas, malignant lymph nodes, and hematomas, are reviewed. In addition, the US elastographic appearances of the normal prostate gland, prostate carcinomas, and benign prostate hyperplasia are illustrated. Potential pitfalls in the interpretation of elastograms, including false-positive and false-negative images, are illustrated. These imaging findings are derived from ongoing research because sonoelastography is not yet accepted for routine clinical use.

Pulmonary metastases from uterine neoplasms after long tumour-free interval: four cases and review of the literature.

AIMS: Uncommon cases of lung metastasis from different types of uterine neoplasms with a long tumour-free interval after hysterectomy are reported. METHODS AND RESULTS: Four cases were retrieved from our surgical pathology archives. Case 1 was a 68-year-old woman who had three pulmonary nodules 23 years after hysterectomy for low-grade endometrial stromal sarcoma (LGESS). The nodules obtained with video-assisted thoracic surgeries were consistent with metastatic LGESS. Case 2 was a 36-year-old woman who had numerous bilateral pulmonary nodules 6 years after hysterectomy for leiomyoma. A transthoracic biopsy revealed benign metastasising leiomyoma. Case 3 was a 77-year-old woman who had a large lung mass with satellite nodules 17 years after hysterectomy with bilateral salpingo-oophorectomy and subsequent radiotherapy for endometrial endometrioid adenocarcinoma (EEA). The biopsied and resected lung tumour was consistent with metastatic EEA. Case 4 was a 51-year-old woman who underwent total hysterectomy and subsequent radiotherapy for endocervical adenocarcinoma 12 years ago and lung lobectomy for metastatic disease 8 years ago. She then developed two pulmonary lesions 14 months ago, and these resected after radiotherapy were metastatic endocervical adenocarcinoma. CONCLUSIONS: A review of the literature revealed that late pulmonary metastasis from uterine neoplasms is rare but not negligible. Immunohistochemical studies and molecular tests, together with detailed clinical information and imaging findings, are important for rendering a diagnosis.

TC de cuerpo: secretos

Contenido: Principios básicos de la tomografía computarizada. Dosis de radiación tomográfica. Reacciones adversas a los medios de contraste. Planifición de la radioterapia mediante tomografía computarizada. Combinación de tomografía por emisión de positrones y tomografía computarizada en oncologia. Tórax. Abdomen y pelvis

Real-time sonoelastography of hepatic thermal lesions in a swine model.

Sonoelastography has been developed as an ultrasound-based elasticity imaging technique. In this technique, external vibration is induced into the target tissue. In general, tissue stiffness is inversely proportional to the amplitude of tissue vibration. Imaging tissue vibration will provide the elasticity distribution in the target region. This study investigated the feasibility of using real-time sonoelastography to detect and estimate the volume of thermal lesions in porcine livers in vivo. A total of 32 thermal lesions with volumes ranging from 0.2 to 5.3 cm3 were created using radiofrequency ablation (RFA) or high-intensity focused ultrasound (HIFU) technique. Lesions were imaged using sonoelastography and coregistered B-mode ultrasound. Volumes were reconstructed from a sequence of two-dimensional scans. The comparison of sonoelastographic measurements and pathology findings showed good correlation with respect to the area of the lesions (r2 = 0.8823 for RFA lesions, r2 = 0.9543 for HIFU lesions). In addition, good correspondence was found between three-dimensional sonoelastography and gross pathology (3.6% underestimate), demonstrating the feasibility of sonoelastography for volume estimation of thermal lesions. These results support that sonoelastography outperforms conventional B-mode ultrasound and could potentially be used for assessment of thermal therapies.

Quantitative characterization of viscoelastic properties of human prostate correlated with histology.

Quantification of mechanical properties of human prostate tissue is important for developing sonoelastography for prostate cancer detection. In this study, we characterized the frequency-dependent complex Young's modulus of normal and cancerous prostate tissues in vitro by using stress relaxation testing and viscoelastic tissue modeling methods. After radical prostatectomy, small cylindrical tissue samples were acquired in the posterior region of each prostate. A total of 17 samples from eight human prostates were obtained and tested. Stress relaxation tests on prostate samples produced repeatable results that fit a viscoelastic Kelvin-Voigt fractional derivative (KVFD) model (r(2)>0.97). For normal (n = 8) and cancerous (n = 9) prostate samples, the average magnitudes of the complex Young's moduli (|E*|) were 15.9 +/- 5.9 kPa and 40.4 +/- 15.7 kPa at 150 Hz, respectively, giving an elastic contrast of 2.6:1. Nine two-sample t-tests indicated that there are significant differences between stiffness of normal and cancerous prostate tissues in the same gland (p < 0.01). This study contributes to the current limited knowledge on the viscoelastic properties of the human prostate, and the inherent elastic contrast produced by cancer.

Image-guided brachytherapy for prostate cancer.

Prostate brachytherapy offers and effective treatment for organ-confined prostate carcinoma. It is rapidly delivered compared with external beam radiation therapy or surgery and well tolerated by patients. Volumetric imaging and image guidance play critical roles in patient selection, treatment planning, treatment delivery, and postimplant assessment. Costs, availability and ease of use often dictate the local and regional differences in imaging approach, whether ultrasound, CT, or MR. Future volumetric image developments may permit multimodality image fusion to integrate tumor-specific imaging such as MR spectroscopy or positron emission tomography/CT into real-time ultrasound, CT, or MR.

Randomized prospective study comparing routine versus selective use of sonography of the complete calf in patients with suspected deep venous thrombosis.

OBJECTIVE: We compared patient outcomes using two protocols: one routinely and the other selectively evaluating the calves completely during sonographic assessment of the lower extremities in patients with suspected deep venous thrombosis. SUBJECTS AND METHODS: In this randomized prospective study, patients were assigned to two groups. In one group, the deep calf veins were routinely evaluated in their entirety, and in the other group the calf was not evaluated unless the patient had symptoms or physical signs in the calf, in which case only the areas of symptoms or physical signs were evaluated. Patients were followed up for 3 months by medical record review, physician surveys, and telephone calls. An adverse outcome was a propagated deep venous thrombosis into the thigh or a pulmonary embolus. Examination times were recorded when possible. RESULTS: Of the 235 patients in the group in which the deep calf veins were routinely evaluated, we saw no adverse outcomes (0.0%; 97.5% one-sided confidence interval [CI], 0.6-1.6%). Of the 261 patients in the group in which the calf was only evaluated if there were signs or symptoms, we saw two adverse outcomes (0.8%; 95% CI, 0.1-2.7%). CONCLUSION: We found no significant difference in adverse outcomes in patients undergoing a protocol in which the deep calf veins were routinely evaluated or a protocol in which the calf was evaluated only if physical signs or symptoms were present.

Detection and diagnosis of nonpalpable supraclavicular lymph nodes in lung cancer at CT and US.

PURPOSE: To assess frequency and significance of enlarged nonpalpable supraclavicular lymph nodes by using chest computed tomography (CT) and supraclavicular ultrasonography (US) in patients at initial diagnosis of lung cancer. MATERIALS AND METHODS: Fifty-five patients with no prior malignancy who presented with suspected and subsequently proven lung cancer of any stage or a proven but potentially resectable lung cancer were prospectively selected after chest CT. Chest CT and other radiologic findings were reviewed and tabulated. Standardized US technique was used to identify and guide needle biopsy of enlarged supraclavicular lymph nodes (> or =0.5 cm short axis). RESULTS: Twenty-two (40%) of 55 patients had supraclavicular abnormalities detected at CT and/or US. In 18 (82%) of the 22 patients, supraclavicular abnormalities were recognizable at CT. Seventeen of 22 patients had malignant nodes, and five patients had benign nodes (n = 3), a cyst (n = 1), or an indeterminate lesion (n = 1) at US-guided supraclavicular needle sampling. There were no complications. Supraclavicular metastases (31% of patients) were about as common as the combined number of patients with indeterminate (n = 13) and probably or proven malignant (n = 6) adrenal nodules (35% of patients). Supraclavicular metastases were often associated with mediastinal adenopathy or suspected extrapulmonary nonnodal metastases (P <.05). CONCLUSION: In many patients with lung cancer, chest CT that includes the neck base followed by US-guided sampling of enlarged supraclavicular lymph nodes is a simple and safe method for simultaneously establishing a tissue diagnosis and tumor nonresectability.