Microcalcifications in the breast detected by a color Doppler method using twinkling artifacts: some important discussions based on clinical cases and experiments with a new ultrasound modality called multidetector-ultrasonography (MD-US).

The twinkling artifact is well known as a color Doppler artifact but it is still an unresolved phenomenon [Rahmouni et al., Radiology 1996;199:269-271 ; Atan et al., Astas Urol Esp 2001;35:396-402; Kamaya et al., AJR 2003;80:215-222]. Many factors affect the appearance of the twinkling artifact, such as the surface roughness of stones creating multiple reflections and a form of intrinsic noise known as clock jitter within the Doppler circuitry of the ultrasound equipment. However, no studies have reported on the twinkling artifact of breast microcalcifications. While considering these premises, I detected microcalcifications in the breast using twinkling artifacts that could not be detected on B-mode imaging. The twinkling artifact is a well-defined but not well-understood phenomenon that may assist in the detection of calcified foci. The phenomenon of the twinkling artifact is discussed here with regard to prospectively and retrospectively studied cases including experiments with a new ultrasound modality called multidetector-ultrasonography (MD-US). MD-US using detectability of the twinkling artifact in microcalcifications of the breast may play an important role in breast screening.

Sonographic characterization of 271 hepatic hemangiomas with typical appearance on CT imaging.

PURPOSE: Hepatic hemangioma is the most frequent benign solid tumor that requires differentiation from hepatic malignancy on ultrasonography. Useful ultrasound findings are therefore required for diagnosis. SUBJECTS AND METHODS: The following factors were investigated for 271 masses diagnosed as hepatic hemangioma by contrast-enhanced computed tomography (CT) in 188 patients: hepatic subsegment location, shape, maximum diameter, internal echo level, hyperechoic rim, posterior echoes, marginal hypoechoic band (halo), lateral shadow, blood flow signal in the central portion of the mass, and underlying liver disease. RESULTS: Hepatic masses were classified by internal echo pattern as homogeneous hyperechoic (35.0%), homogeneous hypoechoic (22.9%), isoechoic (5.2%), mixed hyperechoic (22.1%), or mixed hypoechoic (14.8%) masses. Twelve masses were isoechoic, and could be recognized by the hyperechoic rim. Posterior echo enhancement was present in 66 masses. There were no cases of posterior echo attenuation. A halo was present in six masses, with the underlying condition being fatty infiltrated liver in two masses; a hypoechoic region with a small amount of fat deposit was present around the mass, and this resembled a halo. This finding was termed a "pseudohalo." There were no masses in which a lateral shadow was observed. In terms of blood flow signals in the central portion of the mass, pulsatile flow was present in only one mass. CONCLUSIONS: Important ultrasonographic findings of hepatic hemangioma are characterized as the absence of lateral shadow (100%) and no attenuation of posterior echoes (100%), while the presence of a hyperechoic rim is useful for detecting isoechoic hemangioma.

The value of dynamic imaging for standardization of abdominal ultrasonography.

PURPOSE: Digital video recording of dynamic images is a potential way to improve the reproducibility of abdominal ultrasonography (US). Static US and dynamic US were compared using contrast-enhanced computed tomography (CE-CT) as a reference standard, and the value of stored video images was verified. METHODS: The subjects were 120 individuals who had undergone CE-CT ≤1 month before undergoing US. After static US, dynamic US was carried out according to the Scanning Procedure for Abdominal Ultrasonography described in this paper, and records of 30 separate scans were saved on digital video discs (DVD) as individual video files for interpretation. The findings from static US and dynamic US were compared. RESULTS: With respect to the abdominal US signs covered in this evaluation, dynamic US achieved a detection rate equivalent to or better than that of static US. Detection rates were significantly more frequent on dynamic US for: enlarged hepatic hilum lymph nodes (P < 0.001); gallbladder wall thickness (P < 0.01); cystic lesions of the liver, bright liver, and splenomegaly (P < 0.05). CONCLUSION: Dynamic US is a valuable tool because it enables repeated evaluation of target organs with playback speed adjustment.

Relationship between the echogenicity of subcutaneous tissue and the depth of eye corner wrinkles.

BACKGROUND/PURPOSE: A close relationship was found between the internal structure of subcutaneous tissue and wrinkle depth in our previous study of human forehead. The present study examined the relationship in the eye corner. METHODS: One hundred and seventy-three Japanese subjects were divided into four age groups (21-28 years, 35-41 years, 47-59 years and 65-75 years). The maximum wrinkle depth (Rmax) of an eye corner wrinkle was obtained. On an ultrasound image, which was captured by scanning perpendicular to the wrinkle, we set a 12.5-mm-wide region of interest (ROI) by aligning the deepest point of the wrinkle at its center and then obtained the ratio of the area exceeding an echogenicity threshold to the total area as the echogenicity. RESULTS: No correlation was found between the Rmax and echogenicity. The relationship was further analyzed by dividing the ROI into two: one above and the other below the deepest point of the wrinkle. A negative correlation was detected in the lower ROI of the oldest group. The difference in echogenicity between the upper and the lower ROIs of the oldest group showed a positive correlation with the Rmax. CONCLUSION: These results suggest that the subcutaneous tissue structure is related to wrinkle depth.

Relationship between the echogenicity of subcutaneous tissue and the depth of forehead wrinkles.

BACKGROUND/PURPOSE: Subcutaneous tissue is rarely studied in research on wrinkles. We used diagnostic ultrasonography to produce images of subcutaneous tissue of the forehead, one of the areas where age-related wrinkles form. We quantified the resulting echogenicity and investigated its relationship with wrinkle depth. METHODS: One hundred and seventy-three Japanese subjects were divided into four age groups (21-28 years, 35-41 years, 47-59 years, 65-75 years). Maximum wrinkle depth (Rmax) was measured in the forehead. On an ultrasound image, which was captured by scanning perpendicular to the deepest wrinkle, we set a 12.5-mm-wide region of interest by aligning the deepest point of the wrinkle at its center and then obtained the ratio of the area exceeding this threshold to the total area as the echogenicity. RESULTS: R max increased and the echogenicity decreased with age. A negative correlation was found in the oldest group but was not found in other groups, presumably due to individual differences in the echogenicity among younger subjects. CONCLUSION: This study suggests that the internal structure of subcutaneous tissue, as observed by ultrasonography, is related to wrinkle depth. The relationship between wrinkle depth and echogenicity of subcutaneous tissue is particularly pronounced in the elderly.

Evaluation of renal microcirculation by contrast-enhanced ultrasound with Sonazoid as a contrast agent.

Chronic kidney disease (CKD) is a major and serious risk factor for cardiovascular disease (CVD). Continuous hypoxia due to hypoperfusion in peritubular capillaries is one of the factors aggravating CKD, but evaluation of perfusion in this region is difficult using clinically available imaging methods. Since the second-generation ultrasound contrast agent Sonazoid has a stable shell, it enables visualization of the renal vasculature for a long period of time. We therefore evaluated changes in contrast-enhanced ultrasound (CEUS) imaging with Sonazoid in CKD patients.Sonazoid was used in 85 CKD patients and 5 control subjects, and images were recorded for 10 minutes. Time-intensity curves were generated from the images of 62 time points in both cortex and medulla.In control samples, contrast enhancement spread from the hilar portion to the periphery along the direction of arterial flow, and renal cortex and medulla were then enhanced in sequence. Enhancement was maximal soon after, then gradually decreased, but was still visible at 600 seconds. In CKD patients, renal contrast enhancement was attenuated in both cortex and medulla. On time-intensity curves, the attenuation of enhancement was composed of delayed rising, reduction of peak, and acceleration of decay in both cortex and medulla with progression of renal dysfunction. No side effects of the contrast agent were observed in any subjects.The attenuation of renal contrast enhancement observed in CKD patients appears to reflect disturbance of perfusion in peritubular capillaries. CEUS with Sonazoid is a useful and safe means of visualizing the renal microvasculature.

Radiologic-pathological correlation of punctate hyperechoic foci by ultrasound in stereotactic vacuum-assisted breast biopsy samples.

PURPOSE: To correlate punctate hyperechoic foci (PHF) on ultrasound (US) with microcalcifications detected by mammography (MMG) and at histopathology. MATERIALS AND METHODS: Forty-eight subjects who underwent stereotactic vacuum-assisted breast biopsy (SVABB) for evaluation of breast microcalcifications between April and December 2008 were evaluated for 191 lesions obtained after SVABB. The concordance between PHF on US with microcalcifications detected on MMG and histopathology was therefore evaluated for 191 lesions. Values for sensitivity and specificity were determined against histopathology as the reference standard. RESULTS: In 154 of 191 samples (80.6%), the PHF on US corresponded with microcalcifications on MMG and histopathology. The overall sensitivity and specificity were 85.3% and 80.0%, respectively, for US, and 89.7% and 90.7%, respectively, for MMG. There were no significant differences between values for US and MMG. At US, 12 PHF did not correlate with any microcalcifications at MMG or histopathology. Histopathology revealed collagen fibers in fatty tissue in 5 of 12 lesions and collagenization in 2 of 12 lesions. CONCLUSION: There was a general concordance between PHF on US and microcalcifications detected at MMG. However, in addition to microcalcifications, collagen fibers in fatty tissue and collagenization may account for some PHF. This possibility should be considered when interpreting US findings.

Use of ultrasonography as an alternative modality for first-line examination in detecting breast cancer in selected patients.

BACKGROUND: Detecting lesions in dense breast tissue can be difficult when using mammography. If a patient can be identified as having an increased likelihood of having dense breast tissue based on background factors, ultrasonography can be selected as an alternative method to detect lesions efficiently. We focused on age and reproductive history as factors that determine whether mammography or ultrasonography should be used first. PATIENTS AND METHODS: We retrospectively examined 193 breasts in 192 patients (1 case of bilateral breast cancer) who had undergone surgery and received a histopathologic diagnosis of breast cancer. Patients were divided into the 2 following groups based on age: 40-49 years and > or = 50 years. These groups were then subdivided based on reproductive history as follows: no history of pregnancy, < 3 parturitions (excluding no history of pregnancy), and > or = 3 parturitions. Sensitivities were then compared among the 6 groups. RESULTS: Significant differences in sensitivities were found between mammography and ultrasonography in 3 groups: patients aged 40-49 years with no history of pregnancy; patients aged 40-49 years with a history of < 3 parturitions; and patients aged > or = 50 years with no history of pregnancy. Limiting the results to these groups, sensitivities were 51.5% (34 of 66 cases) with mammography and 81.8% (54 of 66 cases) with ultrasonography. CONCLUSION: We suggest that ultrasonography be used as a first-line examination in detecting breast cancer in such patients; however, this must be confirmed in a future upscale study using larger numbers of subdivided groups.

Use of hand-held ultrasonography to confirm the correct placement of a central venous catheter tip.

To avoid severe complications resulting from malpositioning of a central venous catheter, removal and recannulation of the catheter may be necessary, thus wasting medical equipment and increasing stress on the patient. Therefore, central venous catheters should be inserted correctly the first time. We tested whether real-time hand-held ultrasound-guided confirmation of the location of the tip of a central venous catheter inserted from the femoral vein could reduce the rate of malpositioning. Catheters were inserted using conventional methods for 65 patients, and using ultrasound guidance for 29 patients. For the latter group, when a central venous catheter was inserted, the ultrasound examiner first identified its tip located dorsal to the liver in the inferior vena cava and then fixed the catheter in position. We considered a central venous catheter to be malpositioned when its tip appeared in neither the inferior vena cava nor the right atrium-inferior vena cava junction in X-rays. Flexed or inverted catheters were also considered to be malpositioned. We compared the malpositioning rates for the ultrasound and conventional groups. Malpositioning was identified for two (6.9%) patients in the ultrasound group and 19 (29.2%) patients in the conventional group. The relative risk of ultrasound-guided versus conventional catheter insertion was 0.23 (95% confidence interval, 0.09-0.62). Our data suggest that real-time ultrasound monitoring is useful for avoiding malpositioning of central venous catheters inserted from the femoral vein.

Ultrasonographic findings of invasive lobular carcinoma differentiation of invasive lobular carcinoma from invasive ductal carcinoma by ultrasonography.

BACKGROUND: Although controversy exists, invasive lobular carcinoma (ILC) differs in its high frequency of microscopically positive margins after conservative therapy compared to invasive ductal carcinoma (IDC). If ILC could be recognized by imaging modalities, it would provide important information for surgeons. We tried to confirm whether it is possible to distinguish ILC from other invasive carcinomas by ultrasonography (US). METHODS: A total of 81 histologically confirmed cases of IDC, including 26 cases of papillotubular carcinoma, 28 cases of solid-tubular carcinoma and 27 cases of scirrhous carcinoma, as well as 24 cases of ILC were selected and retrospectively studied with regard to the features of mass lesions on US examination. RESULTS: The sensitivities of US for papillotubular carcinoma, solid-tubular carcinoma, scirrhous carcinoma and ILC were 88.5%, 100%, 92.6% and 91.7% respectively. We could divide invasive breast cancer into two groups by US findings. One group had a low frequency of malignant findings and consisted of papillotubular and solid-tubular carcinomas, and the other group had a high frequency of malignant findings and consisted of scirrhous carcinomas and ILC. However, there were no statistical differences between papillotubular carcinoma and solid-tubular carcinoma or between scirrhous carcinoma and ILC with regard to the US findings. CONCLUSIONS: Scirrhous carcinoma, the most common type of IDC, and ILC are difficult to distinguish by US. Therefore it is difficult to separate ILC from IDC by US.