Features of time-intensity curve parameters of colorectal adenocarcinomas evaluated by double-contrast enhanced ultrasonography: initial observation

Dynamic contrast enhanced ultrasound in gastrointestinal diseases: A current trend or an indispensable tool?

Contrast enhanced ultrasound (CEUS) has been widely implemented in clinical practice because of the enormous quantity of information it provides, along with its low cost, reproducibility, minimal invasiveness, and safety of the second-generation ultrasound contrast agents. To overcome the limitation of CEUS given by the subjective evaluation of the contrast enhancement behaviour, quantitative analysis of contrast kinetics with generation of time-intensity curves has been introduced in recent years. The quantification of perfusion parameters [named as dynamic-CEUS (D-CEUS)] has several applications in gastrointestinal neoplastic and inflammatory disorders. However, the limited availability of large studies and the heterogeneity of the technologies employed have precluded the standardisation of D-CEUS, which potentially represents a valuable tool for clinical practice in management of gastrointestinal diseases. In this article, we reviewed the evidence exploring the application of D-CEUS in gastrointestinal diseases, with a special focus on liver, pancreas, and inflammatory bowel diseases.

Quantitative analysis of renal blood flow during thoracic endovascular aortic repair in type B aortic dissection using syngo iFlow

Background

Currently, the thoracic endovascular aortic repair is the recommended clinical treatment for type B aortic dissections. Unfortunately, malperfusion or ischemia of the kidneys is a major complication of type B aortic dissections. Despite this, few studies have focused on the effects of thoracic endovascular aortic repair on blood flow in renal arteries and parenchyma. This current investigation used novel real-time imaging software to quantitatively analyze the hemodynamic changes in renal artery blood flow and perfusion before and after stent graft placement.

Methods

A total of 51 patients with type B aortic dissection undergoing thoracic endovascular aortic repair between April 2017 and September 2019 were retrospectively recruited. The pre-and post-procedural digital subtraction angiography images were converted into color-coded maps using syngo iFlow for quantitative comparison. Time-intensity curves and related parameters, including the average peak ratio (avg.Pr), average delayed time to peak (avg.dTTP), and average area under the curve ratio (avg.AUCr) of the renal arteries and renal cortex were obtained and analyzed. Wilcoxon signed-rank test was used to compare iFlow parameters before and after endovascular repair. Spearman correlation analyses were performed to study iFlow parameters and renal function parameters and the estimated glomerular filtration rate (eGFR) and blood urea nitrogen (BUN).

Results

A total of 102 images including 51 pre-operative and 51 post-operative image datasets were successfully post-processed. Following endovascular repair, syngo iFlow showed a significant 33.0% increase in avg.Pr (P<0.001) and a significant 35.1% increase in avg.AUCr (P<0.001) in the renal artery. Additionally, there was a significant 12.2% decrease in the avg.dTTP (P=0.001), a significant 24.5% increase in avg.Pr (P=0.004), and a significant 38.3% increase in avg.AUCr (P=0.009) in the renal cortex. Spearman correlation analysis showed that after endovascular repair there was a significant correlation between the avg.Pr of the renal artery and eGFR (r=0.30; P=0.0349), the avg.Pr of the renal cortex and eGFR (r=0.30; P=0.0300), and the avg. AUCr of the renal cortex and BUN (r=0.31; P=0.0289).

Conclusions

syngo iFlow provided a novel quantitative method for evaluating renal hemodynamic changes in patients with type B aortic dissection undergoing endovascular treatment. Time-intensity curve parameters may facilitate the intraprocedural evaluation of renal blood flow and perfusion to complement the color-coded map.

Biplane transrectal ultrasonography plus ultrasonic elastosonography and contrast-enhanced ultrasonography in T staging of rectal cancer

Background

The aim of this study is to assess biplane transrectal ultrasonography (TRUS) plus ultrasonic elastosonography (UE) and contrast-enhanced ultrasonography (CEUS) in T staging of rectal cancer.

Methods

Between March 2016 and January 2019, 66 rectal cancer patients who completed biplane TRUS plus UE and CEUS for preoperative workup and were treated by primary total mesorectal excision (TME) were retrospectively analyzed.

Results

The accuracy of TRUS plus UE and CEUS in all T staging of rectal cancer was 69.7%. The highest accuracy was achieved in the T3 stage (87.5%), while it was 71.4 and 50.0% in the T1 and T2 stage, respectively. The mean sizes of uT1-T2 lesions and uT3-T4 lesions were 30.0 ± 10.6 mm (range, 10.0–55.0) and 40.2 ± 11.2 mm (range, 14.0–57.0), respectively (p < 0.001). According to the receiver operating characteristic (ROC) curve to predict pT stages (pT1,2 vs. pT3), the optimal cut-off value of lesions in greatest dimension was 28.5 mm by TRUS with areas under the curve (AUC) of 0.769, and the optimal cut-off values of peak systolic velocity (PSV) and resistive index (RI) were 18.8 cm/sec and 0.645, respectively. The AUCs of PSV and RI were 0.588 and 0.555, respectively.

Conclusions

Diagnostic accuracy of TRUS plus UE and CEUS in T staging of rectal cancer does not reach the excellent published study results, especially for patients with early rectal cancer. Tumor sizes, PSV and RI are useful additions for TRUS in T staging of rectal cancer.

Double contrast-enhanced ultrasonography of a small intestinal neuroendocrine tumor: a case report of a recommendable imaging modality

A 57-year-old male presenting with spontaneously relieved abdominal cramp and distension was admitted to the West China Hospital. The diagnosis remained unclear after colonoscopy and computed tomography. Double contrast-enhanced ultrasonography was then performed and a neoplasm in the small intestine was suspected, supported by a thin-section computed tomography and positron emission tomography/computed tomography. This was confirmed pathologically after surgery to be a small intestinal G1 neuroendocrine tumor. Surgery was performed to remove approximately 25 cm of small bowel and a 3-cm solid mass located in the mesentery. The patient had a complete recovery and was tumor-free at the final follow-up. Small intestinal tumors including neuroendocrine tumors have always posed a diagnostic challenge. This case indicated that double contrast-enhanced ultrasonography is feasible in detection of small intestinal neuroendocrine tumors, and it may be an advisable approach assisting diagnosis of small intestinal tumors.

Double contrast-enhanced ultrasound improves the detection and localization of occult lesions in the pancreatic tail: a initial experience report

PURPOSE

The aim of this study is to review our initial experience of Double contrast-enhanced ultrasonography (DCEUS) in the preoperative detection of pancreatic tail occult tumors.

METHODS

Thirty-five patients were recruited to undergo DCEUS of the pancreas suspected by occult lesions of pancreatic with MRI or clinical evidence. The radiologists assessed the images (conventional US, DCEUS, and MRI) for enhancement phases, tumor presence, location, enhancement characteristics, and tumor conspicuity. The differences in the onset times of the phases between DCEUS and MRI were noted. Tumor conspicuity was graded on a four-point scale for conspicuity comparison among three imaging modalities.

RESULTS

Pancreatic tail tumors were missed on conventional transabdominal US in 11 of 35 patients. DCEUS revealed 12 lesions of 35 patients. Pancreatic tail tumors were identified on MRI in 10 of 35 patients. The sensitivity and specificity of DCEUS for depicting occult lesions of ≤ 2.2 cm were 92% and 95%, respectively. In contrast, the sensitivity and specificity of conventional US were 67% and 66%, respectively. The sensitivity and specificity of MRI were 91% and 88%, respectively. The conspicuity ratings of the three phases did not significantly differ between the DCEUS and MRI groups (P > 0.05). The DCEUS phases started much earlier than the corresponding MRI phases.

CONCLUSION

DCEUS is a promising technique in the detection of occult pancreatic tail tumors and is possibly superior to dynamic enhanced MRI in the case of some peripheral lesions.

Assessing tumor angiogenesis in colorectal cancer by quantitative contrast-enhanced endoscopic ultrasound and molecular and immunohistochemical analysis

Background and Objectives

Data on contrast-enhanced endoscopic ultrasound (CE-EUS) for colorectal cancer (CRC) evaluation are scarce. Therefore, we aimed to assess the vascular perfusion pattern in CRC by quantitative CE-EUS and compare it to immunohistochemical and genetic markers of angiogenesis.

Patients and Methods

We performed a retrospective analysis of CE-EUS examinations of 42 CRC patients, before any therapy. CE-EUS movies were processed using a dedicated software. Ten parameters were automatically generated from the time-intensity curve (TIC) analysis: peak enhancement (PE), rise time (RT), mean transit time, time to peak (TTP), wash-in area under the curve (WiAUC), wash-in rate (WiR), wash-in perfusion index (WiPI), wash-out AUC (WoAUC), and wash-in and wash-out AUC (WiWoAUC). The expression levels of the vascular endothelial growth factor receptor 1 (VEGFR1) and VEGFR2 genes were assessed from biopsy samples harvested during colonoscopy. Microvascular density and vascular area were calculated after CD31 and CD105 immunostaining.

Results

Forty-two CE-EUS video sequences were analyzed. We found positive correlations between the parameters PE, WiAUC, WiR, WiPI, WoAUC, WiWoAUC, and N staging (Spearman r = 0.437, r = 0.336, r = 0.462, r = 0.437, r = 0.358, and r = 0.378, respectively, P < 0.05), and also between RT and TTP and CD31 vascular area (r = 0.415, and r = 0.421, respectively, P < 0.05). VEGFR1 and VEGFR2 expression did not correlate with any of the TIC parameters.

Conclusions

CE-EUS with TIC analysis enables minimally invasive assessment of CRC angiogenesis and may provide information regarding the lymph nodes invasion. However, further studies are needed for defining its role in the evaluation of CRC patients.

Advances in endoscopic ultrasound imaging of colorectal diseases

The development of endoscopic ultrasound (EUS) has had a significant impact for patients with digestive diseases, enabling enhanced diagnostic and therapeutic procedures, with most of the available evidence focusing on upper gastrointestinal (GI) and pancreatico-biliary diseases. For the lower GI tract the main application of EUS has been in staging rectal cancer, as a complementary technique to other cross-sectional imaging methods. EUS can provide highly accurate in-depth assessments of tumour infiltration, performing best in the diagnosis of early rectal tumours. In the light of recent developments other EUS applications for colorectal diseases have been also envisaged and are currently under investigation, including beyond-rectum tumour staging by means of the newly developed forward-viewing radial array echoendoscope. Due to its high resolution, EUS might be also regarded as an ideal method for the evaluation of subepithelial lesions. Their differential diagnosis is possible by imaging the originating wall layer and the associated echostructure, and cytological and histological confirmation can be obtained through EUS-guided fine needle aspiration or trucut biopsy. However, reports on the use of EUS in colorectal subepithelial lesions are currently limited. EUS allows detailed examination of perirectal and perianal complications in Crohn’s disease and, as a safe and less expensive investigation, can be used to monitor therapeutic response of fistulae, which seems to improve outcomes and reduce the need for additional surgery. Furthermore, EUS image enhancement techniques, such as the use of contrast agents or elastography, have recently been evaluated for colorectal indications as well. Possible applications of contrast enhancement include the assessment of tumour angiogenesis in colorectal cancer, the monitoring of disease activity in inflammatory bowel disease based on quantification of bowel wall vascularization, and differentiating between benign and malignant subepithelial tumours. Recent reports suggest that EUS elastography enables highly accurate discrimination of colorectal adenocarcinomas from adenomas, while inflammatory bowel disease phenotypes can be distinguished based on the strain ratio calculation. Among EUS-guided therapies, the drainage of abdominal and pelvic collections has been regarded as a safe and effective procedure to be used as an alternative for the transcutaneous route, while the placing of fiducial markers under EUS guidance for targeted radiotherapy in rectal cancer or the use of contrast microbubbles as drug-delivery vehicles represent experimental therapeutic applications that could greatly impact the forthcoming management of patients with colorectal diseases, pending on further investigations.

Contrast-enhanced ultrasound defines vascularization pattern of hamartomatous colonic polyps in Peutz-Jeghers syndrome

The hamartomatous polyps in Peutz-Jeghers syndrome may have malignant potential. To differentiate between hamartomatous and adenomas polyps, vascular characterization can be assessed using noninvasive procedures, such as contrast-enhanced ultrasound (CEUS). The neo-angiogenic characteristics of colorectal adenomas and carcinomas are expressed as an anarchic vascular pattern observed on CEUS. Using CEUS in a patient with Peutz-Jeghers syndrome, we describe for the first time the vascularization of a hamartomatous colonic polyp that exhibits a hierarchy branching pattern.

Double-contrast-enhanced sonography for diagnosis of rectal lesions with pathologic correlation

OBJECTIVES

Transabdominal sonography with a gastrointestinal contrast agent has been widely used in China for investigation of digestive disorders. Double-contrast-enhanced sonography combines a gastrointestinal luminal contrast agent with an intravenous contrast agent for imaging of lesions. The purpose of this pilot study was to assess the value of double-contrast-enhanced sonography for preoperative diagnosis of rectal lesions.

METHODS

We conducted a prospective single-center study using double-contrast-enhanced sonography of rectal lesions. Patients were administered both rectal and intravenous contrast agents, and imaging was performed transabdominally, transanally, and transrectally. Morphologic characteristics and perfusion parameters were compared between histologically proven adenocarcinomas, adenomas, and inflammatory masses. Perfusion parameters were analyzed with time-intensity curves, measuring the contrast arrival time, time to peak, peak intensity, and area under the curve of the lesions and normal rectal tissue.

RESULTS

From January 2009 to September 2012, 420 patients were recruited, with 227 patients meeting inclusion/exclusion criteria and having 232 rectal lesions analyzed (172 rectal adenocarcinomas, 45 adenomas, and 15 inflammatory masses). Adenocarcinomas had variable enhancement patterns. Adenomas were all hypoenhanced in a homogeneous pattern. Inflammatory masses had a hyperenhanced rim with no central enhancement. Time-intensity curve perfusion parameters (arrival time, time to peak, peak intensity, and area under the curve) of rectal adenocarcinomas, adenomas, and inflammatory masses were significantly different compared to normal rectal tissue (P < .05). The differences in the arrival time, peak intensity, and time to peak among the different lesions were also significant (P < .05).

CONCLUSIONS

Double-contrast-enhanced sonographic assessment of morphologic enhancement patterns combined with vascularity parameters may help differentiate benign and malignant rectal lesions.

GX1 targeting delivery of rmhTNFα evaluated using multimodality imaging

GX1 is a tumor targeting peptide. In this study, we evaluated the antitumor efficacy of a GX1-derived fusion toxin, GX1-rmhTNFα, and investigated its targeting efficiency and pharmacokinetics in vivo using multimodality imaging. Flow cytometry revealed a greater level of cell apoptosis induced by GX1-rmhTNFα (27.1%) compared with rmhTNFα or a saline control (13.7% and 4.7%, respectively). SPECT (single-photon emission computed tomography) demonstrated high accumulation of GX1-rmhTNFα in tumor site. Biodistribution studies indicated GX1-rmhTNFα was cleared by the liver and kidney, and the drug may not cross the blood-brain barrier. In addition, bioluminescence imaging (BLI) showed that GX1-rmhTNFα caused a satisfactory delay in tumor growth in both subcutaneous and orthotopic cancer models. Contrast-enhanced ultrasound (CEUS) and CD31 staining revealed a loss in blood perfusion and vasculature. TUNEL and Ki67 staining validated the in vivo results. Biochemical analyses revealed limited renal and hepatic toxicity of GX1-rmhTNFα. This study demonstrated that GX1-rmhTNFα is a safe and potent anticancer agent that may have great potential for the targeted therapy of gastric cancer.