CT-maximum intensity projection is a clinically useful modality for the detection of gastric varices

Efficacy of interventional radiology in the management of portal hypertension: A narrative review

Portal hypertension is associated with numerous adverse effects, including the formation of gastroesophageal varices and a portal vein general circulation shunt. Portal hypertension can lead to portal blood flow into the liver and a subsequent reduction in liver function. Clinical interventions can be hampered by a concurrent reduction in circulating platelets associated with increased splenic activity. Pharmaceutical interventions for the treatment of complications associated with portal hypertension have achieved various degrees of success. However, an effective therapeutic strategy for portal hypertension has not yet been established. A literature search was performed using "PubMed." Database between 1966 and January 2021 using the following keywords: portal hypertension, interventional radiology, balloon-occluded retrograde transvenous obliteration, transjugular retrograde obliteration of gastric varices, percutaneous transhepatic obliteration, partial splenic embolization, and transjugular intrahepatic portosystemic shunting. In this narrative review, we summarize the application of interventional radiology in patients with portal hypertension, including techniques for embolization of collateral veins and portal pressure reduction. These up-to-date interventional radiology techniques can be used to treat portal hypertension. The data that support the findings of this study are available from the corresponding author, upon reasonable request.

Computed Tomography Images of Spontaneous Portosystemic Shunt in Liver Cirrhosis

Spontaneous portosystemic shunt (SPSS) refers to collateral vessels that communicate between the portal vein system and systemic circulation. SPSS mainly includes esophageal varices, gastric varices, left gastric vein, recanalized paraumbilical vein, abdominal wall varices, and spontaneous splenorenal shunt. SPSS contributes to the development of hepatic encephalopathy caused by portal vein inflow bypassing and carries a higher risk of death in liver cirrhosis. Abdominal contrast-enhanced computed tomography is a major imaging approach to establish a diagnosis of SPSS and evaluate its location and feature. This review primarily describes the main contrast-enhanced CT features of SPSS in liver cirrhosis.

Multidetector computed tomography three-dimensional and multiplanar reconstruction diagnosis of a rare cause of gastrointestinal bleeding: A case report

BACKGROUND

Anastomosis of the testicular vein with the superior mesenteric vein rarely causes severe gastrointestinal bleeding. To date, there have been few studies describing its appearance on medical imaging. Here, we present multidetector computed tomography three-dimensional and multiplanar reconstruction (MPR) images of a typical digital subtraction angiography showing proven ectopic bleeding and provide the first review of the image performance.

CASE SUMMARY

A 68-year-old man who had been rushed to the hospital with a four-day history of melena and fainting underwent multiple esophagogastroduodenoscopy procedures that failed to identify the source of bleeding. We used MPR combined with three-dimensional reconstruction images, and found that the testicular vein had anastomosed with the superior mesenteric vein, and they clustered together in the jejunal vessel wall, which caused severe gastrointestinal bleeding. Digital subtraction angiography confirmed the location of bleeding. After transfusion and embolization therapy, the patient’s condition improved.

CONCLUSION

Computed tomography-MPR combined with three-dimensional images offers significant value in the localization and qualitative assessment of rare gastrointestinal hemorrhage. The features of multiphase spiral scanning can improve the accuracy of the diagnosis.

Evaluation of Treatment Response after Endoscopic Variceal Obturation with Abdominal Computed Tomography

Backgrounds/Aims

Rebleeding of gastric varices (GVs) after endoscopic variceal obturation (EVO) can be fatal. This study was performed to evaluate the usefulness of computed tomography (CT) for the prediction of rebleeding after EVO GV bleeding.

Methods

Patients who were treated with EVO for GV bleeding and underwent CT before and after EVO were included. CT images of the portal phase showing pretreatment GVs and feeding vessels, and nonenhanced images showing posttreatment cyanoacrylate impaction were reviewed.

Results

Fifty-three patients were included. Their mean age was 60.6±11.6 years, and 40 patients (75.5%) were men. Alcoholic liver disease was the most frequent underlying liver disease (45.3%). Complete impaction of cyanoacrylate in GVs and feeding vessels were achieved in 40 (75.5%) and 24 (45.3%) of patients, respectively. During the follow-up, GV rebleeding occurred in nine patients, and the cumulative incidences of GV rebleeding at 3, 6, and 12 months were 11.8%, 18.9%, and 18.9%, respectively. The GV rebleeding rate did not differ significantly according to the complete cyanoacrylate impaction in the GV, while it differed significantly according to complete cyanoacrylate impaction in the feeding vessels. The cumulative incidences of GV rebleeding at 3, 6, and 12 months were 22.3%, 35.2%, and 35.2%, respectively, in patients with incomplete impaction in feeding vessels, and there was no rebleeding during the follow-up period in patients with complete impaction in the feeding vessels (p=0.002).

Conclusions

Abdominal CT is useful in the evaluation of the treatment response after EVO for GV bleeding. Incomplete cyanoacrylate impaction in feeding vessels is a risk factor for GV rebleeding.

Combined application of single-energy metal artifact reduction and reconstruction techniques in patients with Cochlear implants

Background

The purpose of this study was to develop an effective method of reducing metal artifacts in cochlear implant (CI) electrodes.

Methods

The temporal bones of 30 patients (34 ears) after CI were examined with 320-detector row computed tomography, which was evaluated by two senior radiologists using a double-blind method. Noise, artifact index, signal-to-noise ratio, and the subjective image quality score were compared before versus after using single-energy metal artifact reduction (SEMAR). The electrode position, single electrode visibility, and electrode count were evaluated using SEMAR combined with either multi-planar reconstruction (MPR) or maximum intensity projection.

Results

The two radiologists’ measurements had good consistency. SEMAR significantly reduced the image noise and artifacts index and significantly improved the signal-to-noise ratio and subjective image quality score (P < 0.01). The combination of SEMAR with MPR was conducive to accurate assessment of electrode position and single-electrode visibility. The combination of SEMAR with MIP facilitated accurate and intuitive matching of the assessed electrode count with the number of electrodes implanted during the operation (P = 0.062).

Conclusion

SEMAR significantly reduces metal artifacts generated by CI electrodes and improves the quality of computed tomography images. The combination of SEMAR with MPR and maximum intensity projection is beneficial for evaluating the position and number of CI electrodes.

Efficacy of CTPV for Diagnostic and Therapeutic Assessment: Comparison with Endoscopy in Cirrhotic Patients with Gastroesophageal Varices

Background and Aims

Computed tomography portal venography (CTPV) shows potential in detecting varices that need treatment and their drainage pathways. However, its agreement with endoscopy requires further study. We investigated the feasibility of CTPV as an alternative tool to endoscopy in screening gastroesophageal varices (GEVs) and developed a CTPV-based model to provide a less invasive assessment of endotherapy for cirrhotic patients with GEVs.

Methods

The study included 33 cirrhotic patients with a recent history of variceal hemorrhage. The presence, grade, and classification of GEVs on endoscopy and CTPV were compared (kappa test). Twenty-four patients were treated endoscopically, including 12 for esophageal varices (EVs), 8 for gastric varices (GVs), and 4 for GEVs. Treatment efficacies were assessed with the newly developed CTPV-based method at 1 week and 1 month after treatment. Efficiency evaluated by CTPV and endoscopy was compared by Fisher's exact test to determine whether CTPV is efficient in the assessment of endotherapy efficacy.

Results

For the screening and grading/classification of EVs and GVs, substantial agreement (EV kappa: 0.63 and 0.68; GV kappa: 0.62 and 0.75, respectively) was noted between endoscopy and CTPV. The therapeutic efficacy of EVs was higher when assessed by CTPV than when evaluated by endoscopy (37.50% vs. 12.50% at 1 week postoperation, P = 0.22; 62.50% vs. 25.00% at 1 month postoperation, P = 0.07), but without statistical significance. The same trend was also found in the assessment of therapeutic efficacy for GVs (25.00% vs. 16.67% at 1 week postoperation, P = 1; 58.33% vs. 41.67% at 1 month postoperation, P = 0.68).

Conclusion

CTPV is comparable to endoscopy in the detection of GEVs and in the evaluation of endotherapy efficacy, which suggests that it could be a less invasive alternative for endoscopy in cirrhotic patients with GEVs needing treatment.

4D-CT angiography with arterial- and venous-phase anatomical pre-surgical approaches in cases with head and neck neoplasms

PURPOSE

The relationship between neoplasm and its surrounding vascular structure is essential to the following clinical treatment plan. In this study, 4D computed tomography angiography (4D-CTA) with a wide scan range and dynamic phases of arteriography and venography was used to describe detailed anatomical information for pre-surgical approaches.

MATERIALS AND METHODS

From January 2011 to February 2012, we subjected 13 patients with head and neck neoplasms to 4D-CTA. 4D-CTA was performed by a multidetector computed tomography (MDCT) scanner of 320 detectors. The parameters were set to a 0.5 mm section thickness, at 0.5 second per rotation, 80 kV and 150 mA. The scan range was set depending on the tumor size, with a maximal setting of 16 cm. A 30 mL contrast medium with 60 mL saline was injected at the rate of 5-7 mL per second based on the vascular patency, scanning every 2 seconds from the 16th to the 28th second after contrast injection.

RESULTS

The vasculature surrounding the tumors was successfully illustrated in all cases. The 4D-CTA provided detailed vascular information that was compatible with the surgical and angiographic findings.

CONCLUSION

4D-CTA with a wide scan range and precise injection timing methods facilitated an anatomical approach to tumor-related vascular structures, providing detailed vascular information. This non-invasive technique may be useful for evaluating neoplasms and developing treatment plans, as an alternative to conventional angiography.

Evaluation of left gastric vein in Chinese healthy adults with multi-detector computed tomography

OBJECTIVES

To evaluate the classification and diameter of left gastric vein (LGV) in healthy Chinese adults with multi-detector computed tomography (MDCT).

METHODS

MDCT angiography was performed in 234 healthy adults for the portal venous system. CT cross-sectional thin-layer reconstruction combined with maximum intensity projection, volume rendering and multiplanar reconstruction were applied. The diameter of LGV was measured at the point within 2 cm from LGV origination.

RESULTS

Of 234 subjects, 11 subjects (4.70%) who did not have clear images were excluded, and 223 subjects (95.30%) with excellent images were included. The LGV was originated from the portal vein in 46.15%, splenic vein in 30.77%, portal splenic angle in 14.53%, and the left branch of the portal vein in 3.85%. The maximal diameter of LGV was 4.74 ± 0.84 mm with a 95% confidence interval of 4.63-4.85 mm, and the LGV diameter was positively correlated with the weight of patients (R = 0.26, P = 0.006). No significant difference existed in the maximal diameter of LGV at different origination sites (P = 0.35). The diameter of LGV was significantly greater in males than in females (4.90 ± 0.85 vs. 4.56 ± 0.80 mm, P = 0.002), and the maximal diameter of LGV was significantly (P = 0.02) greater in the age range of 30-39 and 40-49 years than in the range of >70 years. No statistical significance (P = 0.36) was detected in the other groups.

CONCLUSION

MDCT can clearly display the detailed anatomy and variation of LGV in healthy adults, providing a normal range of LGV diameter for clinical reference for diagnosing possible portal hypertension and for possible intervention.

Sixty-four-slice computed tomography angiography of perigastric veins with image fusion

OBJECTIVE

The objective of this study was to assess the efficacy and clinical value of 64-slice computed tomography angiography (CTA) with image fusion for demonstrating the perigastric venous anatomy.

METHODS

Twenty-six patients with gastric cancer underwent abdominal CTA examinations. Computed tomography angiography of stomach and perigastric veins and arteries were reconstructed and fused using volume-rendering technique. The inflow and courses of perigastric veins as well as the spatial relationship among the perigastric veins, arteries, and stomach were compared with surgery.

RESULTS

Compared with surgical findings, the visualization rate of the 7 perigastric veins on CTA was 90.9% to 100%. There was a statistically significant decrease in number of short gastric veins identified on CTA compared with surgery (P = 0.004). There was no statistically significant difference between the 2 modalities in detecting other perigastric veins including the left gastric vein, right gastric vein, right gastroepiploic vein, left gastroepiploic vein, posterior gastric vein, and gastrocolic trunk (P = 0.317, P = 0.157, P = 1, P = 1, P = 0.317, P = 1, respectively).

CONCLUSIONS

Sixty-four-slice CTA with image fusion clearly depicts most of perigastric veins and their relationship with the stomach and perigastric arteries. It can facilitate gastrectomy.

Value of multidetector computed tomography image segmentation for preoperative planning in general surgery

BACKGROUND

Using practical examples, this report aims to highlight the clinical value of patient-specific three-dimensional (3D) models, obtained segmenting multidetector computed tomography (MDCT) images, for preoperative planning in general surgery.

METHODS

In this study, segmentation and 3D model generation were performed using a semiautomatic tool developed in the authors' laboratory. Their segmentation procedure is based on the neighborhood connected region-growing algorithm that, appropriately parameterized for the anatomy of interest and combined with the optimal segmentation sequence, generates good-quality 3D images coupled with facility of use. Using a touch screen monitor, manual refining can be added to segment structures unsuitable for automatic reconstruction. Three-dimensional models of 10 candidates for major general surgery procedures were presented to the operating surgeons for evaluation. A questionnaire then was administered after surgery to assess the perceived added value of the new technology.

RESULTS

The questionnaire results were very positive. The authors recorded the diffuse opinion that planning the procedure using a segmented data set allows the surgeon to plan critical interventions with better awareness of the specific patient anatomy and consequently facilitates choosing the best surgical approach.

CONCLUSIONS

The benefit shown in this report supports a wider use of segmentation software in clinical practice, even taking into account the extra time and effort required to learn and use these systems.

Usefulness of multi-detector helical CT with multiplanar reconstruction for depicting the duodenal varices with multiple collateral shunt vessels

Duodenal varices are a rare complication in patients with portal hypertension. Bleeding from duodenal varices often results in a severe prognosis. Diagnosis of the disease is usually based on findings obtained by endoscopy or angiography. However, it occasionally fails to detect the lesion and demonstrate its porto-systemic shunt vessels which are necessary information to decide an appropriate treatment. Recent advances in CT may make it possible for us to reveal duodenal varices with complicated porto-systemic shunt vessels. We report the case of a 58-year-old man with liver cirrhosis with repeated bleeding from duodenal varices. Esophagogastroduodenoscopy (EGD) revealed multinodular varices in the third portion of the duodenum. Then we conducted a capsule endoscopy (CE) and found fresh blood in the duodenum, suggesting duodenal variceal hemorrhage. Angiography depicted the varices with one afferent and two efferent vessels. Abdominal CT examination was conducted using a four-channel multi-detector row CT scanner. The multiplanar reconstructed images revealed not only the varices, but also three afferent and two efferent vessels. The patient was treated by surgical ligation and sclerotherapy, because of its complicated porto-systemic shunt and reserved liver function. No gastrointestinal bleeding has been seen after the surgery. Our case suggests the usefulness of multi-detector CT with multiplanar reconstruction (MPR) for the diagnosis and therapeutic decision of duodenal varices.

Evaluation of gastric fundic and oesophageal varices by 64-row multidetector computed tomography before and after transjugular intrahepatic portosystemic shunt with concurrent left gastric vein embolization

OBJECTIVE

To determine the utility of 64-row multidetector computed tomography (MDCT) in assessing the changes of gastric fundic and oesophageal varices before and after transjugular intrahepatic portosystemic shunt (TIPS) with concurrent left gastric vein embolization.

METHODS

Twenty-eight consecutive patients with gastric fundic and oesophageal varices resulted from posthepatitic cirrhosis, clinically confirmed with endoscopy, were enrolled into our study. All the patients underwent thoracicoabdominal triphasic enhancement scans with 64-row MDCT 2 weeks before TIPS along with embolizing left gastric vein, and 6 months after the therapy. Before and after the therapy, the varices shown on multiplanar reconstruction (MPR) were compared by Fisher's exact test to evaluate the changes.

RESULTS

Gastric fundic and oesophageal varices were shown in 26 patients (92.9%) and 25 (89.3%) on MPR before the therapy, respectively. After the therapy, these varices diminished markedly, and were illustrated in six (21.4%) and 10 patients (35.7%), respectively (all P<0.05). As for the main inflowing vessel of the varices (left gastric vein), it was illustrated in 28 patients (100.0%) on preoperative CT-MPR. After the embolization, the left gastric vein had been completely occluded on postoperative CT-MPR.

CONCLUSION

Significant eradication of gastric fundic and oesophageal varices on follow-up CT-MPR portography can be considered to assess the changes of gastric fundic and oesophageal varices before and after TIPS with concurrent left gastric vein embolization, and 64-row MDCT can be an effective modality to evaluate the changes.

64-row multidetector computed tomography portal venography of gastric variceal collateral circulation

AIM: To study characteristics of collateral circulation of gastric varices (GVs) with 64-row multidetector computer tomography portal venography (MDCTPV).

METHODS: 64-row MDCTPV with a slice thickness of 0.625 mm and a scanning field from 2 cm above the tracheal bifurcation to the lower edge of the kidney was performed in 86 patients with GVS diagnosed by endoscopy. The computed tomography protocol included unenhanced, arterial and portal vein phases. The MDCTPV was performed on an AW4.3 workstation. GVs were classified into three types according to Sarin’s Classification. The afferent and efferent veins of each type of GV were observed.

RESULTS: The afferent venous drainage originated mostly from the left gastric vein alone (LGV) (28/86, 32.59%), or the LGV more than the posterior gastric vein/short gastric vein [LGV > posterior gastric vein/short gastric vein (PGV/SGV)] (22/86, 25.58%), as seen by MDCTPV. The most common efferent venous drainage was via the azygos vein to the superior vena cava (53/86, 61.63%), or via the gastric/splenorenal shunt (37/86, 43.02%) or inferior phrenic vein (8/86, 9.30%) to the inferior vena cava. In patients with gastroesophageal varices type 1, the afferent venous drainage of GV mainly originated from the LGV or LGV > PGV/SGV (43/48, 89.58%), and the efferent venous drainage was mainly via the azygos vein to the super vena cava (43/48, 89.58%), as well as via the gastric/splenorenal shunt (8/48, 16.67%) or inferior phrenic vein (3/48, 6.25%) to the inferior vena cava. In patients with gastroesophageal varices type 2, the afferent venous drainage of the GV mostly came from the PGV/SGV more than the LGV (PGV/SGV > LGV) (8/16, 50%), and the efferent venous drainage was via the azygos vein (10/16, 62.50%) and gastric/splenorenal shunt (9/16, 56.25%). In patients with isolated gastric varices, the main afferent venous drainage was via the PGV/SGV alone (16/22, 72.73%), and the efferent venous drainage was mainly via the gastric/splenorenal shunt (20/22, 90.91%), as well as the inferior phrenic vein (3/23) to the inferior vena cava.

CONCLUSION: MDCTPV can clearly display the afferent and efferent veins of all types of GV, and it could provide useful reference information for the clinical management of GV bleeding.

Evaluation of entire gastric fundic and esophageal varices secondary to posthepatitic cirrhosis: portal venography using 64-row MDCT

BACKGROUND

There are no reports regarding entire gastric fundic and esophageal varices evaluated with 64-row multidetector CT (MDCT). We attempt to clarify the feasibility of portal venography with this scanner in evaluation of these varices.

METHODS

A total of 33 patients, with clinically confirmed gastric fundic and esophageal varices secondary to posthepatitic cirrhosis, underwent thoracicoabdominal triphasic enhancement scans using 64-row MDCT along with conventional angiographic portography. CT portography and conventional portography were compared by statistical agreement to determine whether CT maximum intensity projection (CT-MIP) portography is useful in evaluation of entire gastric fundic and esophageal varices.

RESULTS

CT-MIP portography demonstrated gastric fundic and esophageal varices, and the inflowing and outflowing vessels of the varices. Gastric fundic varices were shown in 32 cases (97.0%), and esophageal varices were in 27 (81.8%). The inflowing vessels including the left gastric vein and posterior gastric vein/short gastric vein were illustrated in 31 (94.0%) and 17 (51.5%) cases, respectively. The outflowing vessels including the azygos vein, hemiazygos vein, and gastro-renal shunts were seen in 30 (90.9%), 8 (24.2%), and 12 (36.4%) cases, respectively. Findings of CT-MIP portography and conventional angiographic portography were in close agreement (Kappa value ranged from 0.621 to 1.000).

CONCLUSION

CT-MIP venography with 64-row MDCT could be considered as a method for detecting entire gastric fundic and esophageal varices developed from posthepatitic cirrhosis.

Long-term follow up of esophageal varices after balloon-occluded retrograde transvenous obliteration for gastric varices

AIM

Because the procedure of balloon-occluded retrograde transvenous obliteration (B-RTO) causes extensive thrombosis of the major shunt that connects the spleen and gastric/renal venous systems, an increase in portal pressure is unavoidable. The aim of the present study was to assess the long-term outcome of B-RTO, including changes in esophageal varices.

METHODS

B-RTO was conducted in 22 patients with gastric varices, who were divided according to the severity of esophageal varices at baseline; there were no esophageal varices (n = 7), F(1) varices (n = 11), and F(2) varices (n = 4). The outcome measures included the development/worsening of esophageal varices after B-RTO and survival rates.

RESULTS

The cumulative bleeding-free probability for all 22 patients at 3 years after B-RTO was 100%. The overall 3-year survival was 94.4%. Seven patients who had no esophageal varices prior to B-RTO did not develop any after the procedure. Seven (63.6%) of the 11 patients with stage F(1) esophageal varices prior to B-RTO showed no changes in the varices after B-RTO, while two patients progressed to F(2) varices and two developed F(3) varices. The cumulative treatment-free probability of the esophageal varices at 24 months after B-RTO was 100% for patients without esophageal varices at baseline, 80.8% for patients with pre-existing F(1) varices, and 75% for those with pre-existing F(2) varices.

CONCLUSION

Although the B-RTO procedure is considered useful for the treatment of gastric varices, changes in hemodynamics due to obliteration of this major shunt must be taken into account and observed closely.