Use of twinkling artifact in sonographic detection of intestinal pneumatosis

Sonographic Diagnosis of a Colovesical Fistula Due to Sigmoid Colon Cancer

Based on sonographic findings, colovesical fistula was diagnosed in a 71-year-old man with sigmoid colon cancer. Gray-scale sonography revealed an irregular thickening of the sigmoid colon wall abutting the urinary bladder which also showed thickening in the region of contact. Color Doppler sonography showed a twinkling artifact within the thickened bladder wall. Contrast-enhanced computed tomography scan showed luminal communication between the sigmoid colon and the bladder in the region of thickening.

Point-of-care ultrasound identification of pneumatosis intestinalis in pediatric abdominal pain: a case report

We describe a case report of an infant with intussusception who presented to a pediatric emergency department with diarrhea and increased irritability. Pneumatosis intestinalis (intra-mural air) detected on point-of-care ultrasonography (but not apparent on plain abdominal radiographs) alerted the emergency physicians towards the severity of disease process.

Twinkling artifact on color Doppler ultrasound: an advantage or a pitfall?

The twinkling artifact (TA) or color comet-tail artifact is characterized by a rapidly changing mixture of red and blue color Doppler signals. Even though many diseases and clinical conditions have been shown to produce this artifact, its source is not clearly understood yet. The TA may provide additional information to gray-scale ultrasound findings in several clinical situations. However, there may be pitfalls to keep in mind. We must first be aware of the TA to benefit from the advantages and avoid the pitfalls. In this review, we aim to give practicing radiologists an overview of the mechanisms and clinical applications of the TA by illustrating sample cases we have encountered.

Common and uncommon applications of bowel ultrasound with pathologic correlation in children

OBJECTIVE

The purpose of this article is to describe the indications and techniques for bowel ultrasound for inflammatory bowel disease and other common and uncommon entities and describe and illustrate their imaging appearances, including endoscopic or surgical correlation.

CONCLUSION

Ultrasound is a useful tool for the evaluation of inflammatory bowel disease and many other bowel diseases. Radiologists must become familiar with the full potential of ultrasound in the evaluation of the bowel in children because the need for alternative radiation-free imaging techniques continues to grow.

A novel approach for quantification and analysis of the color Doppler twinkling artifact with application in noninvasive surface roughness characterization: an in vitro phantom study

OBJECTIVES

The twinkling artifact is an undesired phenomenon within color Doppler sonograms that usually appears at the site of internal calcifications. Since the appearance of the twinkling artifact is correlated with the roughness of the calculi, noninvasive roughness estimation of the internal stones may be considered as a potential twinkling artifact application. This article proposes a novel quantitative approach for measurement and analysis of twinkling artifact data for roughness estimation.

METHODS

A phantom was developed with 7 quantified levels of roughness. The Doppler system was initially calibrated by the proposed procedure to facilitate the analysis. A total of 1050 twinkling artifact images were acquired from the phantom, and 32 novel numerical measures were introduced and computed for each image. The measures were then ranked on the basis of roughness quantification ability using different methods. The performance of the proposed twinkling artifact-based surface roughness quantification method was finally investigated for different combinations of features and classifiers.

RESULTS

Eleven features were shown to be the most efficient numerical twinkling artifact measures in roughness characterization. The linear classifier outperformed other methods for twinkling artifact classification. The pixel count measures produced better results among the other categories. The sequential selection method showed higher accuracy than other individual rankings. The best roughness recognition average accuracy of 98.33% was obtained by the first 5 principle components and the linear classifier.

CONCLUSIONS

The proposed twinkling artifact analysis method could recognize the phantom surface roughness with average accuracy of 98.33%. This method may also be applicable for noninvasive calculi characterization in treatment management.

Color Doppler twinkling artifacts in small-bowel bezoars

Small-bowel bezoars usually form in the stomach and may subsequently cause small-bowel obstruction. Bezoars associated with small-bowel obstruction have been accurately diagnosed by computed tomography, although some case reports have described the specific sonographic findings of small-bowel bezoars. Bezoars can be overlooked by sonographic examination if a dilated small-bowel loop contains a large amount of air. Twinkling artifacts on color Doppler images appear as rapidly fluctuating red and blue signals behind certain strongly reflecting structures. In this series, we hypothesize that twinkling artifacts might appear in small-bowel bezoars, and we describe the presence of twinkling artifacts in 3 cases of small-bowel bezoars presenting as small-bowel obstruction.

Portal venous gas and cardiopulmonary arrest during pneumatic reduction of an ileocolic intussusception

We present the case of an 8-month-old infant with a small bowel obstruction secondary to an ileocolic intussusception without a pathologic lead point. During pneumatic reduction, the patient went into cardiopulmonary arrest, at which point portal venous gas (PVG) was visualized on radiography. Here we present-to our knowledge-the first reported case of PVG secondary to pneumatic reduction of an intussusception along with a review of the literature regarding known complications of pneumatic reduction and the etiologies of PVG.

Color Doppler twinkling artifact in fetuses with echogenic intracardiac foci: echocardiographic observation and clinical significance

OBJECTIVE

To evaluate echocardiographic characteristics and clinical relevance of color Doppler twinkling artifacts in fetuses with isolated echogenic intracardiac foci (EIF).

METHODS

This study included 50 fetuses with EIF, at 18-38 weeks of gestation. Echocardiographic examination, which was performed using a 1.0-5.0-MHz phased array probe, included gray-scale, color and spectral Doppler imaging. Twinkling artifacts were assessed using fetal color Doppler echocardiography on isolated EIF situated in the left and/or right ventricles. The prevalence, appearance and clinical relevance of the color Doppler twinkling artifacts were analyzed.

RESULTS

Eight of 50 fetuses with EIF (16%) showed color Doppler twinkling artifacts, which appeared as a rapidly changing color complex seen persistently behind the EIF. The spectra obtained in all eight with color Doppler artifacts were composed of straight vertical bands occurring in mid to late systole and early diastole. After birth, none of 50 fetuses with EIF had structural heart diseases or showed clinical signs of cardiac failure.

CONCLUSIONS

Color Doppler twinkling artifacts from isolated EIF occur in some fetuses and may be considered as an additional echocardiographic feature of EIF. Attention should be paid to the identification and interpretation of these artifacts so that they may be accurately distinguished from true color flow generated by atrioventricular valvular regurgitation jets.

[Twinkling artifact on Doppler US: clinical presentations]

Twinkling artifact characterized by a rapidly fluctuating mixture of Doppler signals occurs behind a strongly reflecting granular interface such as urinary tract stones or gallstones. It may occurs in association with several clinical situations, and may sometimes be helpful for diagnosis while it may sometimes be a pitfall that must be recognized by the sonographer. After reviewing the technical nature of this artifact, several cases will be presented to illustrate the advantages and pitfalls related to this artifact.

Gas in portal circulation and pneumatosis cystoides intestinalis during chemotherapy for advanced rectal cancer

OBJECTIVES

Acute abdominal symptoms with CT scan evidence of intramural gas in bowel walls (pneumatosis cystoides intestinalis, PCI) and of gas in the portal venous blood (PBG) in patients undergoing chemotherapy may represent a worrisome picture, suggestive of bowel necrosis. This picture remains a major clinical clue and the reporting of new cases may help to share awareness and experience on management. We describe a patient with acute abdominal symptoms and evidence of PCI with PBG under cetuximab, oxaliplatin, tegafur-uracil and folinic acid chemotherapy for metastatic adenocarcinoma of the rectosigmoid junction.

METHODS

After admission for mucositis with diarrhea and profound dehydration, and subsequent emergency laparotomy for derotation of an intestinal volvulus, on the tenth postoperative day the patient developed fever and abdominal pain, with CT scan evidence of PCI with PBG. The exam of the abdomen did not suggest major problems requiring emergency surgery, and antibiotic treatment with close monitoring were performed, followed by rapid improvement.

RESULTS

Twelve days later, after resumption of oral diet, the patient unexpectedly suffered a spontaneous jejunal microperforation, requiring emergency laparotomy and bowel resection. Pathology showed that the perforation was within an area of ulceration involving the inner superficial layer of the bowel. Subsequently recovery was normal and at present, after 15 months, the patient is well and continuing chemotherapy.

CONCLUSIONS

This is probably the first report of PCI with PBG related to intestinal toxicity during cetuximab, oxaliplatin, tegafur-uracil and folinic acid chemotherapy in a patient with advanced rectal carcinoma, followed by delayed small bowel perforation. It provides an example of the challenges involved in the management of this type of patient.

Intramural and subserosal echogenic foci on US in large-bowel intussusceptions: prognostic indicator for reducibility?

BACKGROUND

In large-bowel intussusceptions, several US signs are known to indicate a lower likelihood of reducibility by enema. US can demonstrate echogenic dots or lines (foci) in the bowel wall, which might indicate an ischemic bowel.

OBJECTIVE

To determine the presence of echogenic intramural and subserosal foci in large-bowel intussusceptions and to evaluate the degree of correlation with reducibility.

MATERIALS AND METHODS

Between 2001 and 2008, 74 consecutive US examinations were retrospectively evaluated by two pediatric radiologists for intramural and subserosal echogenic foci, or trapped gas, in the intussusception. The degree of correlation between the sonographic findings and reducibility was evaluated.

RESULTS

Of 73 intussusceptions examined by US, 56 (76%) were reducible and 17 (23%) were not reducible. Out of 10 intussusceptions with intramural gas, 11 with subserosal gas, and 14 with intramural and subserosal gas, 8 (80%), 6 (56%), 9 (64%), respectively, were not reducible. The presence of intramural gas or subserosal gas or both predicted a lower chance of reduction, but with regard to the effect of these findings together, intramural gas was the only significant predictor.

CONCLUSION

Having intramural gas in large-bowel intussusception significantly decreases the chance of reduction.

Color Doppler twinkling artifact in intrauterine fetal demise

PURPOSE

To determine whether twinkling artifacts on color and power Doppler sonography could be used as a new sonographic sign of intrauterine fetal demise (IUFD).

METHODS

In this prospective study, 24 consecutive pregnant women with IUFD were included after fetal sonographic examinations. Sonographic examination included gray-scale, color, power, and spectral Doppler imaging. The sonograms were then analyzed for the presence, appearance, and intensity of the twinkling artifacts.

RESULTS

Twinkling artifacts on color Doppler were observed in all of the 24 IUFD as a rapidly changing color Doppler signal complex associated persistently with different parts of the fetal body. The artifacts were localized especially in the neck, back, and iliac regions. Artifact intensity correlated with the time elapsed since death.

CONCLUSION

Twinkling artifact was noted in all dead fetuses on color, power, and spectral Doppler examinations. Thus, the observation of these artifacts may be considered as a new sonographic sign of fetal demise, which may reflect the time elapsed since death.