Fumio Tsujimoto

Natural Course of Autoimmune Pancreatitis Without Steroid Therapy Showing Hypoechoic Masses in the Uncinate Process and Tail of the Pancreas on Ultrasonography

Autoimmune pancreatitis, a unique form of chronic pancreatitis, is characterized by irregular narrowing of the pancreatic duct, swelling of the parenchyma, lymphoplasmacyte infiltration and fibrosis, hyperglobulinemia, positive autoantibody test results, and effectiveness of steroid therapy. 1-4 Although autoimmune pancreatitis has become widely recognized as a new clinical entity of the pancreatic diseases, and several authors have reported patients with autoimmune pancreatitis, particularly in Japan, 5-9 to our knowledge, the imaging findings of the natural course of autoimmune pancreatitis without steroid therapy have not been described previously. In addition, few cases of autoimmune pancreatitis show separated plural pancreatic lesions. 8,10 We describe a case of autoimmune pancreatitis found incidentally that showed separated plural pancreatic lesions and that was followed without steroid therapy.

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

PurposeHepatic 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 methodsThe 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.ResultsHepatic 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.ConclusionsImportant 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.

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.

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

PurposeTo correlate punctate hyperechoic foci (PHF) on ultrasound (US) with microcalcifications detected by mammography (MMG) and at histopathology.Materials and methodsForty-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.ResultsIn 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.ConclusionThere 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.

Relationship between the echogenicity of subcutaneous tissue and the depth of forehead wrinkles: Forehead wrinkle profile by ultrasonography

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.

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.