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Intra-abdominal fat. Part II: Non-cancerous lesions of the adipose tissue localized beyond organs.

Smereczyński A, Kołaczyk K, Bernatowicz E - J Ultrason (2016)

Bottom Line: The value of ultrasonography in the diagnosis of this pathology is underestimated, and a number of US scan reports do not reflect its presence in any way.This section focuses on infarction of the greater and lesser omentum, epiploic appendagitis, mesenteric volvulus and focal fat necrosis resulting from pancreatitis.Abstract available from the publisher.

View Article: PubMed Central - PubMed

Affiliation: Self-Education Ultrasound Study Group, Department of Genetics and Pathomorphology of the Pomeranian Medical University in Szczecin, Poland.

ABSTRACT
Adipose tissue does not belong to the most favorite structures to be visualized by ultrasound. It is not, however, free from various pathologies. The aim of this paper is to make abdominal cavity examiners more familiar with non-cancerous lesions found in intra-abdominal fat. The main focus is lesions that are rarely discussed in the literature. Visceral adiposity is one of important pathogenetic factors contributing to cardiovascular events, metabolic syndrome and even certain neoplasms. That is why this article exposes sonographic features that are the most characteristic of these lesions. The value of ultrasonography in the diagnosis of this pathology is underestimated, and a number of US scan reports do not reflect its presence in any way. Moreover, the article discusses more and more common mesenteritis, the lack of knowledge of which could pose difficulties in explaining the nature of symptoms reported by patients. Furthermore, this review presents lesions referred to in the literature as focal infarction of intra-abdominal fat. This section focuses on infarction of the greater and lesser omentum, epiploic appendagitis, mesenteric volvulus and focal fat necrosis resulting from pancreatitis. These lesions should be assessed with respect to the clinical context, and appropriate techniques of ultrasonography should be employed to allow careful determination of the size, shape, acoustic nature and location of lesions in relation to the integuments and large bowel, as well as their reaction to compression with an ultrasound transducer and behavior during deep inspiration. Moreover, each lesion must be obligatorily assessed in terms of blood flow. Doppler evaluation enables the differentiation between primary and secondary inflammation of intra-abdominal fat. The paper also draws attention to a frequent indirect sign of a pathological process, i.e. thickening and hyperechogenicity of fat, which sometimes indicates an ongoing pathology at a deeper site. This structure may completely conceal the primary lesion rendering it inaccessible for ultrasound. In such cases and in the event of other doubts, computed tomography should be the next diagnostic step.

No MeSH data available.


Related in: MedlinePlus

A. The transverse view of the right lumbar region presents infarction of the greater omentum (arrows). B. The same axis as in Fig. 4 A. Color Doppler set to detect slow flows does not show any vascularity
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Figure 0004: A. The transverse view of the right lumbar region presents infarction of the greater omentum (arrows). B. The same axis as in Fig. 4 A. Color Doppler set to detect slow flows does not show any vascularity

Mentions: In approximately 90% of cases, the site of primary infarction (torsion) of the greater omentum is the right side. It can result from the following predisposing factors: structural anomalies in the omentum and its veins (particularly of the right side), thrombophilia, circulatory insufficiency and vasculitis as well as obesity, cough, excessive physical exertion and an abrupt change of the position of the torso. The secondary nature of this pathology is a consequence of an abdominal surgery, trauma, inflammation, presence of a cyst and abdominal hernia. In these cases, lesions can be located at various sites in the abdominal cavity(24, 25). A typical ultrasound image of omental infarction is characterized by: a slightly or moderately hyperechoic plaque-like mass greater than 5 cm (in adults) located under the abdominal integuments to the right of the navel. The mass is sensitive to compression but with no visible compressibility (Fig. 4 A). It shows no blood flow in an examination with colored blood flow mapping (Fig. 4 B). However, vessels on the periphery of a central hypoechoic necrotic area have been observed in children with this pathology. Sometimes, the lesion is surrounded with a hypoechoic rim, or slight amounts of fluid are found in the vicinity. Moreover, the medial aspect of the affected omentum adheres to the ascending colon which does not usually show wall thickening. The situation, particularly as far as vessels are concerned, is presented in a better way in a contrast-enhanced CT scan(24–28). Because infarction of the greater omentum clinically resembles appendicitis, its assessment is very important from the point of view of adequate patient management since the thickened omentum can at times conceal an underlying pathology. In the considerable majority of cases, omental infarction resolves spontaneously without specific treatment. The lesion undergoes involution, mainly with fibrosis, sometimes with calcifications or adhesions between adjacent tissues. At times, a necrotic fragment detaches to the peritoneal cavity and behaves as a loose body. Occasionally, an abscess forms in consequence of omental infarction(29).


Intra-abdominal fat. Part II: Non-cancerous lesions of the adipose tissue localized beyond organs.

Smereczyński A, Kołaczyk K, Bernatowicz E - J Ultrason (2016)

A. The transverse view of the right lumbar region presents infarction of the greater omentum (arrows). B. The same axis as in Fig. 4 A. Color Doppler set to detect slow flows does not show any vascularity
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4834369&req=5

Figure 0004: A. The transverse view of the right lumbar region presents infarction of the greater omentum (arrows). B. The same axis as in Fig. 4 A. Color Doppler set to detect slow flows does not show any vascularity
Mentions: In approximately 90% of cases, the site of primary infarction (torsion) of the greater omentum is the right side. It can result from the following predisposing factors: structural anomalies in the omentum and its veins (particularly of the right side), thrombophilia, circulatory insufficiency and vasculitis as well as obesity, cough, excessive physical exertion and an abrupt change of the position of the torso. The secondary nature of this pathology is a consequence of an abdominal surgery, trauma, inflammation, presence of a cyst and abdominal hernia. In these cases, lesions can be located at various sites in the abdominal cavity(24, 25). A typical ultrasound image of omental infarction is characterized by: a slightly or moderately hyperechoic plaque-like mass greater than 5 cm (in adults) located under the abdominal integuments to the right of the navel. The mass is sensitive to compression but with no visible compressibility (Fig. 4 A). It shows no blood flow in an examination with colored blood flow mapping (Fig. 4 B). However, vessels on the periphery of a central hypoechoic necrotic area have been observed in children with this pathology. Sometimes, the lesion is surrounded with a hypoechoic rim, or slight amounts of fluid are found in the vicinity. Moreover, the medial aspect of the affected omentum adheres to the ascending colon which does not usually show wall thickening. The situation, particularly as far as vessels are concerned, is presented in a better way in a contrast-enhanced CT scan(24–28). Because infarction of the greater omentum clinically resembles appendicitis, its assessment is very important from the point of view of adequate patient management since the thickened omentum can at times conceal an underlying pathology. In the considerable majority of cases, omental infarction resolves spontaneously without specific treatment. The lesion undergoes involution, mainly with fibrosis, sometimes with calcifications or adhesions between adjacent tissues. At times, a necrotic fragment detaches to the peritoneal cavity and behaves as a loose body. Occasionally, an abscess forms in consequence of omental infarction(29).

Bottom Line: The value of ultrasonography in the diagnosis of this pathology is underestimated, and a number of US scan reports do not reflect its presence in any way.This section focuses on infarction of the greater and lesser omentum, epiploic appendagitis, mesenteric volvulus and focal fat necrosis resulting from pancreatitis.Abstract available from the publisher.

View Article: PubMed Central - PubMed

Affiliation: Self-Education Ultrasound Study Group, Department of Genetics and Pathomorphology of the Pomeranian Medical University in Szczecin, Poland.

ABSTRACT
Adipose tissue does not belong to the most favorite structures to be visualized by ultrasound. It is not, however, free from various pathologies. The aim of this paper is to make abdominal cavity examiners more familiar with non-cancerous lesions found in intra-abdominal fat. The main focus is lesions that are rarely discussed in the literature. Visceral adiposity is one of important pathogenetic factors contributing to cardiovascular events, metabolic syndrome and even certain neoplasms. That is why this article exposes sonographic features that are the most characteristic of these lesions. The value of ultrasonography in the diagnosis of this pathology is underestimated, and a number of US scan reports do not reflect its presence in any way. Moreover, the article discusses more and more common mesenteritis, the lack of knowledge of which could pose difficulties in explaining the nature of symptoms reported by patients. Furthermore, this review presents lesions referred to in the literature as focal infarction of intra-abdominal fat. This section focuses on infarction of the greater and lesser omentum, epiploic appendagitis, mesenteric volvulus and focal fat necrosis resulting from pancreatitis. These lesions should be assessed with respect to the clinical context, and appropriate techniques of ultrasonography should be employed to allow careful determination of the size, shape, acoustic nature and location of lesions in relation to the integuments and large bowel, as well as their reaction to compression with an ultrasound transducer and behavior during deep inspiration. Moreover, each lesion must be obligatorily assessed in terms of blood flow. Doppler evaluation enables the differentiation between primary and secondary inflammation of intra-abdominal fat. The paper also draws attention to a frequent indirect sign of a pathological process, i.e. thickening and hyperechogenicity of fat, which sometimes indicates an ongoing pathology at a deeper site. This structure may completely conceal the primary lesion rendering it inaccessible for ultrasound. In such cases and in the event of other doubts, computed tomography should be the next diagnostic step.

No MeSH data available.


Related in: MedlinePlus