Abdominal ultrasonography in the diagnosis of colonic cancer

Retrospective Analysis of Right Iliac Fossa Mass: A Single-Center Study

Background

Right iliac fossa mass is one of the most common clinical scenarios a surgeon encounters during their surgical practice. It poses a critical diagnostic dilemma for surgeons and requires considerable diagnostic skills. Its clinical diagnosis becomes difficult in the presence of comorbidities, such as severe obesity and guarding, as in these cases, the mass becomes palpable only upon the administration of a relaxant.

Methods

A total of 108 patients admitted to Bhima Bhoi Medical College & Hospital, exhibiting signs and symptoms of mass in the right iliac fossa upon cross-examination, were included in the study. We recorded their detailed clinical history and performed physical examinations, including erect abdomen, chest (post-anterior view), and contrast x-rays, ultrasonogram; and CT scans.

Results

In this study, patients with appendicular masses, appendicular abscesses, ileocecal tuberculosis, cecum carcinoma, ovarian tumors, and parietal lipoma accounted for 45.3%, 17.5%, 12.9%, 7.4%, 6.4%, and 4.6% of the total cases, respectively, whereas patients with retroperitoneal tumors, parietal abscesses, and ileocecal lymphadenopathy accounted for 1.8% each.

Diagnostic point-of-care ultrasound (POCUS) for gastrointestinal pathology: state of the art from basics to advanced

The use of point-of-care ultrasound (POCUS) by non-radiologists has dramatically increased. POCUS is completely different from the routine radiological studies. POCUS is a Physiological, On spot, extension of the Clinical examination, that is Unique, and Safe. This review aims to lay the basic principles of using POCUS in diagnosing intestinal pathologies so as to encourage acute care physicians to learn and master this important tool. It will be a useful primer for clinicians who want to introduce POCUS into their clinical practice. It will cover the basic physics, technical aspects, and simple applications including detection of free fluid, free intraperitoneal air, and bowel obstruction followed by specific POCUS findings of the most common intestinal pathologies encountered by acute care physicians including acute appendicitis, epiploic appendagitis, acute diverticulitis, pseudomembranous colitis, intestinal tuberculosis, Crohn’s disease, and colonic tumours. Deep understanding of the basic physics of ultrasound and its artefacts is the first step in mastering POCUS. This helps reaching an accurate POCUS diagnosis and avoiding its pitfalls. With increased skills, detailed and accurate POCUS findings of specific intestinal pathologies can be achieved and properly correlated with the clinical picture. We have personally experienced and enjoyed this approach to a stage that an ultrasound machine is always accompanying us in our clinical on calls and rounds.

Sonographic Findings of Malignant Appendix Tumors in Seven Cases

We report the sonographic features of confirmed malignant appendiceal tumors in seven cases. The histologic diagnoses of these tumors were mucinous cystadenocarcinoma (n = 2), colonic type adenocarcinoma (n = 4), and signet-ring cell carcinoma (n = 1). The 2 mucinous cystadenocarcinomas showed mucocele type, which had markedly enlarged inner luminal diameters (mean, 23 mm; range, 15–31 mm) and thick, irregular walls (mean wall thickness, 5.5 mm; range, 5–6 mm). In contrast, the 5 nonmucinous carcinomas (4 adenocarcinomas and 1 signet-ring cell carcinoma) showed nonmucocele type, which had relatively small inner luminal diameters (mean ± standard deviation [SD], 6.6 ± 4.5 mm; range, 2–15 mm) and prominent wall thickening (mean wall thickness ± SD, 6.2 ± 2.3 mm; range, 3–10 mm). Of the 5 nonmucinous tumors, only one had a discernible mass, three had thick irregular walls, two had loss of the wall layer pattern, and four had submucosal hypoechogenicity. Regardless of the histologic type, five of the seven malignant appendiceal tumors showed a severe periappendiceal fat infiltration or periappendiceal abscess, suggestive of perforation. Although the sonographic findings of the malignant appendiceal tumors were nonspecific, some of the sonographic features seen in these seven cases may help radiologists consider the possibility of underlying malignant appendiceal tumors.

Ultrasound virtual endoscopy: Polyp detection and reliability of measurement in an in vitro study with pig intestine specimens

AIM: To present our initial experience regarding the feasibility of ultrasound virtual endoscopy (USVE) and its measurement reliability for polyp detection in an in vitro study using pig intestine specimens.

METHODS: Six porcine intestine specimens containing 30 synthetic polyps underwent USVE, computed tomography colonography (CTC) and optical colonoscopy (OC) for polyp detection. The polyp measurement defined as the maximum polyp diameter on two-dimensional (2D) multiplanar reformatted (MPR) planes was obtained by USVE, and the absolute measurement error was analyzed using the direct measurement as the reference standard.

RESULTS: USVE detected 29 (96.7%) of 30 polyps, remaining a 7-mm one missed. There was one false-positive finding. Twenty-six (89.7%) of 29 reconstructed images were clearly depicted, while 29 (96.7%) of 30 polyps were displayed on CTC with one false-negative finding. In OC, all the polyps were detected. The intraclass correlation coefficient was 0.876 (95%CI: 0.745-0.940) for measurements obtained with USVE. The pooled absolute measurement errors ± the standard deviations of the depicted polyps with actual sizes ≤ 5 mm, 6-9 mm, and ≥ 10 mm were 1.9 ± 0.8 mm, 0.9 ± 1.2 mm, and 1.0 ± 1.4 mm, respectively.

CONCLUSION: USVE is reliable for polyp detection and measurement in in vitro study.

Advances in molecular imaging for diagnosis of digestive tract cancers

Digestive tract cancers are common cancer types and have high incidence and mortality. Currently available diagnostic methods have some limitations that make an early and accurate diagnosis and prompt treatment difficult. Molecular imaging, which has been formally defined as visualization, characterization and measurement at the molecular level instead of the anatomic level, significantly increases the sensitivity and specificity of cancer detection. Several modalities have been utilized for molecular imaging in digestive tract cancers, such as endoscopy, scintigraphy (PET/SPECT), magnetic resonance imaging (MRI), and ultrasound (US). Antibodies, peptides, and aptamers are classes of molecular probes that have been extensively used as affinity ligands. After being conjugated with various labels such as radioisotopes, fluorophore, supermagnetic or paramagnetic metals and microbubbles, the probes can specifically target tumor cells and stroma and are used with imaging modalities to detect cancers. Molecular imaging is a methodology for not only the early detection of cancer, but also the judgment of tumor staging and the guidance of therapy. With the development of new instrument and probes, as well as multi-modal platforms, molecular imaging has been gradually perfected and taken from bench to bedside, bringing opportunities for early, accurate and comprehensive diagnosis of digestive tract cancers.

The role of ultrasound in the management of intestinal obstruction

Intestinal obstruction (IO) is a common cause of acute abdominal pain. The recent increased use of sonography in the initial evaluation of abdominal pain has made point-of-care ultrasound a valuable tool for the diagnosis of IO. Sonography is as sensitive, but more specific, than plain abdominal X-ray in the diagnosis of IO. Point-of-care ultrasound can answer specific questions related to IO that assist the acute care physician in critical decision making. Sonography can also help in the resuscitation of patients by serial measurement of the IVC diameter. We review the sonographic findings of IO and the role of point-of-care ultrasound in the management of patients having IO.

Microvascular structure and perfusion imaging of colon cancer by means of contrast-enhanced ultrasonography

OBJECTIVE

To determine whether contrast-enhanced ultrasonography (CEUS) can be used to discriminate between colon cancer and acute inflammation, and between mucinous and non-mucinous carcinoma.

MATERIALS AND METHODS

CEUS (with perflubutane microbubbles) was performed in two study groups: colon cancer (n = 34) and acute inflammation (n = 14). For evaluation, the microvascular structure was classified as irregular or regular, and vessel diameter was classified as ≥2 mm or <2 mm. Tumor enhancement was classified as homogeneous, heterogeneous (obvious defect), or hypoenhancement. Moreover, the defect area was classified according to the presence or absence of vessels. Differences in imaging features between the two groups or between types of tumors were examined statistically.

RESULTS

The vascular structure was irregular in 76.5% of colon cancers but only 28.6% of acute inflammations (P < 0.01). A significantly greater number of cancers contained vessels ≥2 mm (70.6% vs. 7.1%) (P < 0.001). Both abnormalities were found in 58.8% of colon cancers but in none of the acute inflammations. Enhancement patterns differed between tumor types, with mucin pools being readily identifiable.

CONCLUSION

Differentiation between colon cancer and acute inflammation is possible with CEUS. Furthermore, prediction of mucinous vs. non-mucinous adenocarcinoma is possible.

Is the routine abdominal ultrasound a sufficiently sensitive method for the detection of colonic malignancy?

OBJECTIVE

This study examined the sensitivity of routine abdominal ultrasound scanning in the detection of colonic malignancy.

PATIENTS AND METHODS

A case control prospective study included 101 patients hospitalized at the Department of Gastroenterology and Liver Diseases of Zemun Clinical Hospital over a four-year period. Since the complaints pointed to colonic malignancy, the patients underwent routine golden standard diagnostic procedures. These patients were referred to an experienced abdominal ultrasound operator who searched for some characteristic signs of colonic malignancy. All of the participants were surgically treated after the completion of relevant procedures for diagnosing colonic malignancy. SPSS for Windows 10.0 was used for data analysis.

RESULTS

The sensitivity of an abdominal ultrasound scan in the detection and location of pathological changes pointed to colonic malignancy was different- 76% and 84% respectively. This method was very reliable in detecting right-sided colonic carcinoma (100%). Some specific ultrasonographic signs of colonic carcinoma were observed at the advanced stages of disease.

CONCLUSIONS

The routine abdominal ultrasonography can be used for the screening of colonic malignancy owing to its high sensitivity, particularly in advanced disease, but solely in conjunction with other methods. Finally, abdominal ultrasonography cannot be a definitive diagnostic tool for colonic carcinoma.

Colonic diseases: the value of US examination

The colon is affected by a number of diseases, mainly inflammatory, ischemic, and neoplastic conditions. Depending upon clinical indications endoscopy, US, CT, or other radiological methods are used for evaluation. The fact that US is frequently used as the initial imaging method in patients with non-specific clinical symptoms allows for greater influence in further diagnostic evaluation and with treatment, provided the investigator is familiar with the features of different intestinal diseases. This article will describe the anatomical characteristics of the colon, the US technique for examination of the colon, and the typical US features of the more common diagnoses of the colon.

Utility of abdominal sonography in patients with idiopathic deep vein thrombosis

PURPOSE

Studies have confirmed an association between idiopathic deep vein thrombosis (DVT) and malignant tumors. We assessed the usefulness of routine abdominal sonography in patients with idiopathic DVT to detect malignant tumors and other relevant findings.

METHODS

We retrospectively analyzed abdominal sonograms and records from 135 consecutive patients with confirmed idiopathic DVT and interviewed patients and their physicians during the follow-up period (mean, 30 months). Malignancy and other clinically relevant findings determined by sonography were tabulated, and the cost of each malignancy detected by abdominal sonography in this study was calculated.

RESULTS

Malignant tumors were found in 14 patients (10%), 7 by routine abdominal sonography, 3 by other means during hospitalization, and 4 during the follow-up period. Other clinically relevant findings detected by routine abdominal sonography were found in 33 patients (24%). The estimated cost of discovering malignancy by using screening abdominal sonography was approximately US$3,000/malignancy.

CONCLUSIONS

Abdominal sonography was useful in detecting a variety of clinically relevant findings in addition to half of the malignant tumors found in our study.

Ultrasonographically-guided fine-needle aspiration cytology in the diagnosis of colonic lesions

BACKGROUND

The use of fine-needle aspiration cytology (FNAC) in the diagnosis of colonic lesions was investigated.

METHODS

Some 22 patients (median age 71 years) with a colonic lesion identified on abdominal ultrasonography underwent ultrasonographically-guided FNAC using a 21-G needle. The sample was checked immediately by a cytopathologist for adequacy.

RESULTS

Eighteen patients had colonic carcinoma; aspiration cytology detected malignant epithelial cells consistent with colonic carcinoma in 17 patients and severely dysplastic cells in one patient. The sensitivity and specificity of ultrasonographically-guided FNAC in the diagnosis of colonic carcinoma was 94 and 100 per cent respectively. The remaining four patients had a diagnosis of ileocaecal tuberculosis, ileocaecal Crohn's disease, and metastatic adenocarcinoma in the liver with no identifiable primary (two patients). One demonstrated granulomata, grew acid-fast bacilli and the patient was treated for tuberculosis. One had inflammatory cells and the patient was found to have Crohn's disease on histology. The remaining two patients had confirmed metastatic adenocarcinoma in the liver on aspiration cytology but suspected colonic lesions were found to be benign on cytological examination and no primary lesion was subsequently demonstrated. There were no complications of FNAC and patients complained of minimal discomfort. There has been no evidence of tumour recurrence with a median follow-up of 12 (range 1-25) months.

CONCLUSION

Ultrasonographically-guided FNAC is a valid method for the diagnosis of colonic tumours.