A possible new ancillary sign for diagnosing midgut volvulus: the truncated superior mesenteric artery

MRI of the bowel - beyond inflammatory bowel disease

MR enterography is traditionally used to evaluate inflammatory bowel disease (IBD) both at initial presentation and at follow-up. MR enterography can also be used to evaluate non-IBD conditions such as polyps or other masses of the gastrointestinal tract. In this article, we emphasize how to recognize bowel conditions beyond IBD on conventional abdominal MRI without a specific enterographic technique. In this overview we discuss common and uncommon pediatric bowel conditions beyond IBD seen on MRI including infectious and inflammatory conditions, congenital diseases and tumor and tumor-like conditions. Radiologists should become familiar with the salient imaging features of these bowel conditions to help guide management.

Ultrasound assessment of the bowel: inflammatory bowel disease and conditions beyond

Ultrasound (US) is a versatile imaging study for the evaluation of the bowel in children. US imaging of the bowel can be used as the initial examination or in follow-up for many common pediatric diseases. In this article, we highlight our bowel US technique and describe how US can depict the features of a select group of bowel pathologies relevant to pediatric practice.

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.

Assessment of retromesenteric position of the third portion of the duodenum: an US feasibility study in 33 newborns

BACKGROUND

US can be used to assess bowel and does not require ionizing radiation or the administration of contrast material. Prior studies of the duodenum with US are limited.

OBJECTIVE

This study assesses the success rate of US demonstration of the third portion of the duodenum (D3) between the superior mesenteric artery (SMA) and the aorta in newborns to exclude malrotation based on embryologic and anatomic principles.

MATERIAL AND METHODS

Thirty-three newborns underwent US studies. The structures between the SMA and the aorta, including D3, were evaluated in axial and longitudinal planes. The length of time to acquire diagnostic images was recorded.

RESULTS

In both the axial and longitudinal planes, D3 was seen between the SMA and the aorta in all 33 infants, including some with abundant bowel gas. The mean length of time to acquire diagnostic images was 34 s.

CONCLUSION

Bedside US successfully illustrated the retromesenteric position of D3 in all 33 infants. Overlying gas-filled bowel was effectively effaced by graded compression. The short study duration indicates the practicality of the method. Further studies in broader patient populations and in correlation with other imaging and/or surgical findings is required to validate our technique.

The position of the duodenojejunal junction: the wrong horse to bet on in diagnosing or excluding malrotation

PURPOSE

The purpose of this communication is to highlight the shortcomings of all currently used imaging criteria in diagnosing or excluding malrotation and offer ultrasound demonstration of the 3(rd) portion of the duodenum (D3) between the AO and the SMA in transverse and sagittal plains as the most reliable diagnostic method.

BACKGROUND

Although UGI is currently considered to be the imaging modality of choice in diagnosis of malrotations, numerous publications indicate that in certain patients, false positives and negatives can be encountered.

MATERIALS AND METHODS

The material consists of more than 10 years experience in university settings, during which the author has used US as the definitive imaging modality for the work-up of malrotation. High resolution linear transducers (5-17 MHz) are the transducers of choice. Imaging plains: A. Transverse. With gradual grading compression, the following landmarks are illustrated in cehaplocaudad directions in the following order. The junction of splenic vein with the SMV portal vein. The cross sections of SMA and SMV that may either be situated in midline, or to the right or the left of the midline. Left renal vein crossing the spine from left to right between the AO and the SMA. The jejunal vein, often coming from left, transversing between the AO and the SMA. The transverse portion of the duodenum, D3, between the AO & the SMA. B. Sagittal. D3 between vertically oriented SMA-SMV and the AO. If SMA is not aligned with the AO by slight compression on the right or the left side of the abdomen, it will be aligned (depending on leftward or rightward position of SMA-SMV in axial plain). Vertical orientation of SMA and SMV if they have an anteroposterior orientation. C. Coronal. Side by side orientation of SMA and SMV if they don't have an anteroposterior orientation.

RESULTS

In overwhelming majority of cases, by illustrating a retromesenteric D3 malrotation and, therefore, midgut volvulus were excluded.

DISCUSSION

None of the current imaging criteria addresses the following most fundamental anatomic and embryologic facts regarding the gut rotation and fixation. In first trimester, the D3 is secured in retroperitoneal space after the embryologic journey comes to an end, making the duodenum immune of midgut volvulus. The surgical pathology of malrotation-midgut volvulus indicates that D3 is always Intraperitoneal and has not reached its final embryologic destination in retroperitoneal space. Demonstrating a retromesenteric D3, therefore, indicates that the embryologic journey is completed and the patient does not have malrotation. Excluding malrotation excludes the likelihood of midgut volvus.

CONCLUSION

The position of the DJJ, the configuration of the duodenal sweep, the orientation of the mesenteric vessels are all wrong horses to bet on because none of them addresses the fundamental anatomic and embryologic facts. Only the cross-sectional imaging, US, CT and MRI can prove that the D3 is retromesenteric, therefore, excluding malrotation and volvulus. Therefore, demonstrating a retromesenteric duodenum is the reference standard of imaging in the work-up of malrotation, not any other previously published criteria. The US imaging is the most acceptable imaging method for malrotation work-up, in the spirit of ALARA principle and "Image Gently" campaign.

Unusual presentations of midgut volvulus with the whirlpool sign

OBJECTIVE

The purpose of this series was to emphasize the varied presentations of midgut volvulus from neonatal life to well into adulthood and to evaluate the role of the whirlpool sign on sonography in diagnosing this condition.

METHODS

A retrospective search of all midgut volvulus cases diagnosed in the radiology department of a 1500-bed general hospital between February 2002 and July 2005 was done. Eight patients with surgically confirmed midgut volvulus were found, all of whom had undergone sonography as the initial screening investigation.

RESULTS

Eight patients, with ages ranging from 9 days to 32 years (mean age, 11.8 years), had undergone sonography for varied conditions, including bilious and nonbilious vomiting, vague abdominal pain, epigastric lumps, weight loss, features mimicking appendicitis, and pancreatitis. In all patients, the diagnosis of midgut volvulus was made on the basis of the clockwise whirlpool sign on sonography. Subsequently, 4 patients underwent upper gastrointestinal series, and contrast-enhanced computed tomography was done in 6 cases. Surgical confirmation of the diagnosis was obtained in all cases. Two patients were taken for surgery on the basis of only sonographic findings.

CONCLUSIONS

Midgut volvulus can also appear much beyond the neonatal age group with a variety of clinical presentations, making the clinical diagnosis in such patients very difficult, if not impossible. Identification of the clockwise whirlpool sign on sonography is an accurate way of diagnosing this condition, which can preclude the need for further investigations and can allow prompt surgical intervention.

Disorders of intestinal rotation and fixation ("malrotation")

Malrotation with volvulus is one of the true surgical emergencies of childhood. Prompt radiological diagnosis is often paramount to achieving a good outcome. An understanding of the normal and anomalous development of the midgut provides a basis for understanding the pathophysiology and the clinical presentation of malrotation and malrotation complicated by volvulus. In this essay, the radiologic findings of malrotation and volvulus are reviewed and illustrated with particular attention to the child with equivocal imaging findings.