Effect of visceral fat area on outcomes of laparoscopyassisted distal gastrectomy for gastric cancer: subgroup analysis by gender and parameters of obesity

PURPOSE: The aim of this study was to investigate the impact of the visceral fat area (VFA) of patients with gastric cancer undergoing laparoscopic surgery on operative outcomes such as number of retrieved lymph nodes (LNs) and operative time. METHODS: We retrospectively reviewed the medical records and the CT scans of 597 patients with gastric cancer who underwent laparoscopy assisted distal gastrectomy (LADG) with partial omentectomy and LN dissection (>D1 plus beta). Patients were stratified by gender, VFA, and body mass index (BMI), and the clinicopathologic characteristics and operative outcomes were evaluated. Multiple linear regression analysis was used to assess the effects of VFA and BMI on the number of retrieved LNs and operative time in male and female patients. RESULTS: The mean number of retrieved LNs was significantly decreased for both male and female patients with high VFA. The operative time was significantly longer for both male and female patients with high VFA. The number of retrieved LNs had a statistically significant negative correlation with VFA in both men and women, but not with BMI. The operative time had a statistically significant positive correlation with VFA in men, whereas the operative time had a statistically significant positive correlation with BMI in women. CONCLUSION: The preoperative VFA of male patients with gastric cancer who undergo LADG may affect the number of retrieved LNs and operative time. VFA was more useful than BMI for predicting outcomes of LADG.

Usefulness of acoustic radiation force impulse elastography in the differential diagnosis of benign and malignant solid pancreatic lesions

PURPOSE: The aim of this study was to evaluate the tissue stiffness of solid pancreatic lesions by using acoustic radiation force impulse (ARFI) elastography to differentiate benign from malignant pancreatic lesions. METHODS: ARFI elastography was performed in 26 patients who had 27 focal solid pancreatic lesions, including 8 benign lesions (mass-forming pancreatitis, 5; autoimmune pancreatitis, 3) and 19 malignant lesions (pancreatic adenocarcinoma, 16; metastasis from colorectal cancer, 2; malignant neuroendocrine tumor, 1). On the elastographic images of virtual touch tissue imaging (VTI), the echogenicity of the mass was categorized on a 5-grade scale. On the elastographic image of virtual touch tissue quantification (VTQ), the shear wave velocities (SWVs) of the lesion and surrounding parenchyma were measured. RESULTS: On the VTI images, the mean echogenicity score of the malignant lesions (3.7+/-1.0) was higher than that of the benign lesions (3.1+/-0.4; P=0.023). On the VTQ images, there were no statistical differences in the mean SWV between the benign (2.4+/-1.1 m/sec) and malignant (3.3+/-1.0 m/sec) lesions (P=0.101). However, the mean SWV difference values between the lesion and background parenchyma of the malignant lesions (1.5+/-0.8 m/sec) were higher than those of the benign lesions (0.4+/-0.3 m/sec; P=0.011). CONCLUSION: ARFI elastography can determine the relative stiffness between a lesion and the background pancreatic parenchyma using VTI and VTQ, which is helpful in the differentiation between benign and malignant solid pancreatic lesions.

Focal Thickening at the Fundus of the Gallbladder: Computed Tomography Differentiation of Fundal Type Adenomyomatosis and Localized Chronic Cholecystitis

BACKGROUND/AIMS: The objective of our study was to identify useful computed tomography (CT) findings for differentiating fundal type adenomyomatosis from localized chronic cholecystitis involving the fundus of the gallbladder. METHODS: We retrospectively identified cases of 41 patients with pathologically proven adenomyomatosis (n=21) or chronic cholecystitis (n=20) who had fundal thickening of the gallbladder on preoperative abdominal CT. Analysis of the CT findings included evaluation of the thickness, contour, border, intralesional cystic area, adjacent gallbladder wall thickening, presence of inner layer enhancement, enhancement grade, enhancement pattern, and presence of stones. Statistical analyses were performed using the Mann-Whitney U test and Fisher exact test. RESULTS: Oval contour, inner layer enhancement and intralesional cystic area were more frequently noted in adenomyomatosis than in chronic cholecystitis (p<0.05 for each finding). Flat contour and adjacent gallbladder wall thickening were more frequently observed in chronic cholecystitis than in adenomyomatosis. No differences between adenomyomatosis and chronic cholecystitis in terms of the thickness, enhancement grade, enhancement pattern and presence of stones were apparent. CONCLUSIONS: CT may help to differentiate fundal type adenomyomatosis from localized chronic cholecystitis involving the fundus of the gallbladder.

Application of 31P MR Spectroscopy to the Brain Tumors

OBJECTIVE: To evaluate the clinical feasibility and obtain useful parameters of 31P magnetic resonance spectroscopy (MRS) study for making the differential diagnosis of brain tumors. MATERIALS AND METHODS: Twenty-eight patients with brain tumorous lesions (22 cases of brain tumor and 6 cases of abscess) and 11 normal volunteers were included. The patients were classified into the astrocytoma group, lymphoma group, metastasis group and the abscess group. We obtained the intracellular pH and the metabolite ratios of phosphomonoesters/phosophodiesters (PME/PDE), PME/inorganic phosphate (Pi), PDE/Pi, PME/adenosine triphosphate (ATP), PDE/ATP, PME/phosphocreatine (PCr), PDE/PCr, PCr/ATP, PCr/Pi, and ATP/Pi, and evaluated the statistical significances. RESULTS: The brain tumors had a tendency of alkalization (pH = 7.28 +/- 0.27, p = 0.090), especially the pH of the lymphoma was significantly increased (pH = 7.45 +/- 0.32, p = 0.013). The brain tumor group showed increased PME/PDE ratio compared with that in the normal control group (p = 0.012). The ratios of PME/PDE, PDE/Pi, PME/PCr and PDE/PCr showed statistically significant differences between each brain lesion groups (p < 0.05). The astrocytoma showed an increased PME/PDE and PME/PCr ratio. The ratios of PDE/Pi, PME/PCr, and PDE/PCr in lymphoma group were lower than those in the control group and astrocytoma group. The metastasis group showed an increased PME/PDE ratio, compared with that in the normal control group. CONCLUSION: We have obtained the clinically applicable 31P MRS, and the pH, PME/PDE, PDE/Pi, PME/PCr, and PDE/PCr ratios are helpful for differentiating among the different types of brain tumors.

Omental Infarction Following Laparoscopy-assisted Gastrectomy (LAG) for Gastric Cancer

PURPOSE: Omental infarction (OI) following laparoscopy-assisted gastrectomy (LAG) for gastric cancer could become more common in the future because the indications for LAG are expected to expand. The aim of this study was to determine the clinical characteristics of OI following LAG. MATERIALS AND METHODS: Three hundred ninety patients who underwent LAG for T1 or T2 gastric cancer from April 2003 to November 2007 were enrolled. OI was diagnosed by two radiologists using the patients' abdominal 16 row-detector CT scans. The clinicopathologic characteristics were retrospectively evaluated in the omental infarction (OI) group and the non-omental infarction (non-OI) group using the gastric cancer database of Dong-A University Medical Center and the medical records. RESULTS: Nine omental infarctions (2.3%) of 390 LAGs were diagnosed. All the OIs could be discriminated from omental metastasis on the initial or follow up CT images. The location of the omental infarctions was on the epigastrium in 3 patients and in the left upper quadrant in 3 patients. The mean size of the OIs was 4.1 cm. Most patients with OI had no signs or symptoms. The body mass index of the OI group was higher than that of the non-OI group (P=0230), and OI was more common in patients who underwent total gastrectomy than in the patients who underwent subtotal gastrectomy (P=0.0011). CONCLUSION: Laparoscopy-assisted gastrectomy (LAG) with partial omentectomy for gastric cancer can be a cause of secondary OI. Omental infarction after LAG has different clinical characteristics and CT findings that those of other omental infarctions or postoperative omental metastases. Further multicenter study will be needed to evaluate in detail the clinical features of omental infarction after LAG.

Real-Time fMRI-Guided Functional MR Spectroscopy: The Lactate Peaks at the Motor Cortex during Hand-Grasping Tasks

PURPOSE: There is debate concerning the observation of metabolite changes on MRS at the designated cortex during some tasks. The purpose of this study is to assess the change of the lactate content at the motor cortex during hand-grasping tasks with performing real-time fMRI-guided fMRS. MATERIALS AND METHODS: Seven healthy volunteers (23-28 years old) underwent realtime fMRI during right hand grasping tasks with using a 1.5 T system. After confirming the activating area, single voxel MRS was preformed at 1) the baseline, 2) during the task and 3) after the task on the activating cortex. The three consecutive spectra were compared for observing the changes of the lactate content by the tasks. The Cho/Cr, NAA/Cr and Lac/Cr ratios were calculated manually from those spectra. RESULTS: MRS during the tasks revealed the lactate peaks at the 1.33 ppm resonance frequency with great conspicuity at the activated area, which was identified on the real-time fMRI. After the task scan, the lactate peaks completely disappeared and the spectra recovered to the values of the baseline scan in all volunteers. At baseline, during the task and after the task, the Cho/Cr ratios were 0.81, 0.76 and 0.77, respectively, and the NAA/Cr ratios were 1.68, 1.65 and 1.72, respectively, and the Lac/Cr ratios were 0.28, 0.41 and 0.30, respectively. During the task, Lac was significantly increased by 46%. CONCLUSION: We observed prominent lactate peaks on MRS during hand-grasping tasks at the activated area, as was shown on the real-time fMRI. We suggest that fMRS can be used as a sensitive tool for observing the metabolite changes of the functioning brain.

Radiofrequency Ablation Treatment for Renal Cell Carcinoma: Early Clinical Experience

OBJECTIVE: To evaluate the early clinical experience associated with radiofrequency (RF) ablation in patients with renal cell carcinoma (RCC). MATERIALS AND METHODS: The RF ablation treatment was performed on 17 tumors from 16 patients (mean age, 60.5 years; range, 43-73 years) with RCC. The treatment indications were localized, solid renal mass, comorbidities, high operation risk, and refusal to perform surgery. All tumors were treated by a percutaneous CT (n = 10), followed by an US-guided (n = 2), laparoscopy-assisted US (n = 2), and an open (n = 2) RF ablation. Furthermore, patients underwent a follow-up CT at one day, one week, one month, three and six months, and then every six months from the onset of treatment. We evaluated the technical success, technical effectiveness, ablation zone, benign periablation enhancement, irregular peripheral enhancement, and complications. RESULTS: All 17 exophytic tumors (mean size, 2.2 cm; range, 1.1-5.0 cm) were completely ablated. Technical success and effectiveness was achieved in all cases and the mean follow-up period was 23.8 months (range, 17-33 months). A local recurrence was not detected in any of the cases; however, five patients developed complications as a result of treatment, including hematuria (n = 2), mild thermal injury of the psoas muscle (n = 1), mild hydronephrosis (n = 1), and fistula formation (n = 1). CONCLUSION: The RF ablation is an alternative treatment for exophytic RCCs and represents a promising treatment for some patients with small RCCs.

Prognostic Factors for Survival in Patients with Hepatocellular Carcinoma after Radiofrequency Ablation / 대한소화기학회지

BACKGROUND/AIMS: Currently there is no consensus on which staging system is the best in predicting the survival of patients with hepatocellular carcinoma (HCC). The aim of this study was to identify independent factors to predict survival and to compare 4 available prognostic staging systems in patients with early HCC after radiofrequency ablation. METHODS: We retrospectively studied 100 Korean patients with early HCC. Prognostic factors for survival were analysed by univariate and multivariate analysis using the Kaplan-Meier method and Cox proportional hazard regression models. Okuda, Cancer of the Liver Italian Program (CLIP), TNM and Japanese integrated staging score (JIS score) were evaluated before the treatments. RESULTS: Overall survival rates of 12, 24 and 36 months were 89%, 76%, and 64% respectively and the mean survival duration was 45 months. Multivariable analysis showed that albumin, total bilirubin and size of tumor were independent prognostic factors. Multivariate analysis showed that TNM and JIS score staging systems were significant staging systems for the prediction of prognosis. CONCLUSIONS: Both TNM and JIS score are more effective than the Okuda and CLIP staging systems in stratifying patients into different risk groups with early HCC. However, JIS score gives better prediction of prognosis in patients with HCC after radiofrequency ablation.

Utility of Vascular Enhancement Technique (ClarifyTM) in Ultrasonographic Evaluation of Abdominal Vessels

PURPOSE: Vascular enhancement (VE) technology(ClarifyTM) is a new technique in vascular, B-mode imaging. The purpose of this study was to evaluate the value of VE technology in ultrasonographic diagnosis of abdominal vasculature. MATERIALS and METHODS: Seventy-one adult patients (39 men and 32 women; age range, 25-89 years; mean age, 56 years) who had undergone abdominal ultrasonography were included in this study. The imaging was performed with a 1.8-4.0 MHz convex array transducer (SONOLINE, Antares, Siemens Medical Solutions, WA) by an abdominal radiologist. The radiologist obtained images of the same vascular area with each of conventional ultrasonography imaging (CUS), tissue harmonic imaging (THI), CUS plus VE technique and THI plus VE technique. Images were divided into normal (56) and abnormal (15) groups. The vessel visibility, conspicuity of the vascular wall and contrast resolution with adjacent structures were evaluated in the normal group, and the lesion conspicuity and border sharpness were evaluated in the abnormal group. On the PACS monitor, the images were graded into four grades by two radiologists in consensus. Statistical analysis was performed using Wilcoxon signed rank test. RESULTS: In the normal group, all parameters of the ultrasonographic imaging which applied the VE technique were superior to those of the imaging without VE technique (p < 0.05). In the abnormal group, combined use of VE technique with CUS or THI provided better results than CUS or THI alone in terms of lesion conspicuity and border sharpness (p < 0.05). THI combined with VE technique provided the best image quality among the 4 ultrasonographic methods examined in this study for the evaluation of both normal and abnormal abdominal vessels (p < 0.05). CONCLUSION: VE technology was a helpful technique to evaluate the abdominal vasculature. Furthermore, VE technique combined with THI provided better image quality than other ultrasonographic methods in the evaluation of abdominal vessels.

Anti-tumoral Effect of Recombinant Vaccinia Virus through US Guided Injection in a Rabbit Model of Hepatic VX2 Carcinoma

PURPOSE: The purpose of this study was to evaluate the anti-tumoral effect of recombinant vaccinia virus (rVV) (Thymidine kinase (-)/GM-CSF (+)) that was administered as a US guided intratumoral injection in a rabbit model of hepatic VX2 carcinoma. MATERIALS AND METHODS: VX2 carcinoma was implanted in the livers of 12 rabbits. US was performed at every week interval to detect hepatic mass after the implantation of VX2 carcinoma. The accurate tumor size and volume was evaluated with CT when the tumor was detected on US. US guided injection of rVV (109 pfu/ml) was preformed in three rabbits, intravenous injection of the same dose of rVV was done in two rabbits and another seven rabbits that were without any treatment were selected as a control group. We evaluated the change of the hepatic tumor size and extrahepatic metastasis on serial CT. Tumor specimens were harvested from rabbits that were killed at 8 weeks after VX2 implantation. These tissues were histoimmuopathologically compared to each other (the virus injection group and the control group). The differences between these groups were statistically assessed with student t-tests. RESULTS: Tumor growth was significantly suppressed in the US guided injection group compared with the intravenous injection group or the control group (p< 0.01). The intravenous injection group showed statistically significant tumor suppression compared to the control group (p< 0.01) until 2 weeks after virus injection. Quantification of the pulmonary metastatic nodules was performed in view of both the number and volume. The average number or volume of the pulmonary metastatic nodules in the US injection group was much smaller than these in the control group. Histopathologically, the tumors of the US guided injection group showed less extensive necrosis than those of the control group. Immunohistochemically, the tumor of the US guided injection group showed more prominent infiltration of CD4 (+) and CD8 (+) lymphocytes than did the tumors of the other group. CONCLUSION: rVV was markedly effective in suppressing hepatic tumor growth and extrahepatic metastasis in a rabbit model of hepatic VX2 carcinoma. US guided intra-tumoral injection was more effective than systemic intravenous injection.

Comparison of Colonoscopy and Virtual Colonoscopy for the Detection of Colorectal Polyps / 대한소화기내시경학회지

BACKGROUND/AIMS: Virtual colonoscopy using abdominal spiral computed tomography scanning allows total colonic evaluation with minimal invasiveness. We compared the performance of virtual colonoscopy and colonoscopy for the detection of colorectal polyps. METHODS: We performed colonoscopy before the virtual colonoscopy. Virtual colonoscopy was performed immediately before the colonoscopic polypectomy in 24 adults (16 men and 8 women: mean age, 59 years). RESULTS: A total of 48 polyps were found by colonoscopy. Virtual colonoscopy identified 20 of 28 polyps that were 10 mm or more in diameter (71%), 3 of 4 that were 6 to 9 mm (75%), and 9 of 16 that were 5 mm or smaller (56%). Overall sensitivity of virtual colonoscopy for colorectal polyps was 67%. CONCLUSIONS: Our result of virtual colonoscopy showed lower sensitivity for detection of significant colorectal lesions than previously reported studies. Further large group study may be needed to determine the usefulness of virtual colonoscopy.

Categorization of Vascular Lesions and Selection of Treatment Modalities Using Color Doppler Ultrasound / 대한피부과학회지

BACKGROUND: Vascular lesions can be diagnosed by biopsy, simple x-ray, ultrasound, CT, MRI, venography and MR angiography. These diagnostic tools can identify the detailed structure and abnormalities in the peri-lesional area of vascular lesions. Color Doppler ultrasound (CDU) can demonstrate the hemodynamic features, distribution of veins and arteries, shunts and structures of vascular lesions. Authors have tried to categorize vascular lesions with CDU and also applied this to the selection of treatment methods. MATERIALS AND METHODS: Forty-seven vascular lesions were evaluated by means of CDU. All patients underwent a complete clinical evaluation as well as peak systolic velocity (PSV), peak diastolic velocity (PDV), resistive index (RI) of feeding arteries. In particular, we evaluated the hemodynamic features and structures of vascular lesions. We categorized the vascular lesions and then treated them with systemic steroid, compression, SPTL1 Dye laser, steroid intralesional injection and sclerotherapy. We evaluated the clinical improvement and objective effects of treatments by CDU. RESULTS: There were 37 hemangiomas and 10 vascular malformations. Vascular lesions were classified by the hemodynamic features and structures: category Ia (infantile hemangioma, regressed infantile hemangioma), Ib (RICH), Ic (deep hemangioma, mixed hemangioma), II (arteriovenous malformation), III (venous malformation, verrucous hemangioma). The clinical improvement after treatment was associated with the decrease of PSV and RI values. The clinical improvement above 50% resolution of the lesion showed 70.9% in category Ia, 50% in Ib, 66.6% in Ic, 83.3% in II and 50% in III. CONCLUSIONS: The analysis of hemodynamic feature and structures by CDU can be helpful in the study of vascular lesions. These processes suggest CDU be a useful modality in differential diagnosis of vascular lesions and a more advantageous tool in the decision of treatment policy than the conventional modalities. And it is also useful for the evaluation of treatment effects.

Congenital Hepatoportal Arteriovenous Fistula associated with Intrahepatic Portal Vein Aneurysm and Portohepatic Venous Shunt: Case Report

A congenital hepatoportal arteriovenous fistula associated with an intrahepatic portal vein aneurysm is a rare type of arteriovenous malformation. Only 14 pediatric cases have been reported to the best of the authors' knowledge. An intrahepatic shunt between the portal and systemic veins is also relatively rare. We report a case of a congenital hepatoportal arteriovenous fistula associated with an intrahepatic portal vein aneurysm and a portohepatic venous shunt in a neonate who presented with tachypnea and melena.

Perfusion Imaging of the Brain Using Z-Score and Dynamic Images Obtained by Subtracting Images from before and after Contrast Injection

OBJECTIVE: The aim of this study was to examine the feasibility of perfusion imaging of the brain using the Z-score and subtraction dynamic images obtained from susceptibility contrast MR images. MATERIALS AND METHODS: Five patients, each with a normal MRI, Moya-moya, a middle cerebral artery occlusion, post-trauma syndrome, and a metastatic brain tumor, were selected for a presentation. A susceptibility-contrast echo-planar image after a routine MRI was taken as the source image with a rapid manual injection of 0.1 mmol/kg of Gd-DTPA. The inflow and washout patterns were observed from the time-signal intensity curve of the serial scans using the standard program of an MRI machine. The repeated Z-score images of the peak and late phases were made using the threshold Z-score values between 1.4 and 2.0 in four to five studies of the pre-contrast, peak, and late phases. Dynamic subtraction images were produced by subtracting sequential post-contrast images from a pre-contrast image and coloring these images using a pseudocolor mapping method. RESULTS: In the diseases with perfusion abnormalities, the Z-score images revealed information about the degree of perfusion during the peak and late phases. However, the quality varied with the Z-score threshold and the studies selected in a group. The dynamic subtraction images were of sufficient quality with no background noise and more clearly illustrated the temporal changes in perfusion and delayed perfusion. CONCLUSION: The Z-scores and dynamic subtraction images illustrated the degree of perfusion and sequential changes in the pattern of perfusion, respectively. These images can be used as a new complimentary method for observing the perfusion patterns in brain diseases.

Primary Abscess of the Falciform Ligament

Surgical lesions of the falciform ligament are rare, but most often present clinically as a cystic abdominal mass, and less often an abscess. A falciform ligament lesion can present as an acute abdomen, when a cyst undergoes torsion or becomes abscessed. Secondary inflammation of the falciform ligament may seed from an infection in the gallbladder, liver or umbilicus. Here, a case of primary abscess of the falciform ligament is reported, with a review of the literature.

Transarterial Embolotherapy in Patients with Duodenal Hemorrhage Using Microcoils and Gelfoam Particles

PURPOSE: To assess the efficacy and safety of arterial embolotherapy in patients with massive duodenal hemorrhage. MATERIALS AND METHODS: Between January 1999 and June 2002, 25 patients (age: 34-81, mean 58, male: 19, female: 6) underwent arterial embolization for duodenal hemorrhage after failed endoscopic therapy. The hemorrhage originated from duodenal ulcer in sixteen patients, from cancer with duodenal invasion in five patients, from endoscopic sphincterectomy in two patients, and from pseudoaneurysm complicating acute pancreatitis in two patients. Hemorrhage was detected at endoscopy and an attempt was made to treat it endoscopically in all patients, but failed in each case. At angiography, direct bleeding signs such as contrast extravasation or pseudoaneurysm were demonstrated in nineteen patients. In the six patients without angiographic evidence of bleeding, blind embolization of the gastroduodenal artery was performed based on the endoscopic examination. Microcoil and gelfoam particles were used as embolic agents. RESULTS:Hemostasis was achieved immediately after embolotherapy in 21 patients (84%). Bleeding recurred in 4 patients (16%), and of these cases, one was successfully treated purely by endoscopic means, a second was reembolized three times due to bleeding from the collateral vessels of the tumor and the two others were treated by surgery. After the procedure, six patients died (24%). The causes of death were disseminated intravascular coagulopathy, multiorgan failure, sepsis and acute renal failure. The underlying diseases of the deceased patients were cancers with duodenal invasion (n=4) and abdominal aortic aneurysm with ischemic colitis (n=1). CONCLUSION: Transarterial embolotherapy in the case of massive duodenal hemorrhage is a safe and effective procedure. Even in the absence of angiographic evidence of bleeding, blind embolization of the gastroduodenal artery is effective for patients in the surgically high risk group.

Hemoptysis and Hemoperitoneum due to Metastatic Gestational Choriocarcinma: Bronchial Artery Embolization and Superselective Splenic Artery Embolization: A Case Report

Gestational choriocarcinoma is easily disseminated hematogenously and its hypervascular nature places the patient at risk of significant hemorrhage both at the sites of metastatic lesions and in the uterus. In addition, its tends to give rise to pseudoaneurysm formation. Treatment of the condition by percutaneous embolization has been reported in several published articles, and hemoperitoneum secondary to rupture of splenic metastasis of gestational choriocarcinoma has also been reported, as has angiographic embolization. Hemoptysis resulting from pulmonary metastasis and treatment by means of embolization of the bronchial artery have not been reported, however. In this article, we describe a case of hemoptysis and hemoperitoneum due to pulmonary and splenic metastasis of gestational choriocarcinoma. Treatment of the condition involved embolization of the bronchial artery and superselective embolization of the splenic artery.

Angiomyolipoma of the Perinephric Space: Case Report

Angiomyolipomas commonly originate from renal parenchyma but extremely rarely from perinephric space. We report a case of angiomyolipoma of the perinephric space confirmed by radical nephrectomy. A 13-year-old boy presented with left flank pain and abdominal distension, first experienced five months earlier. Ultrasonography and CT indicated that in the space surrounding the left kidney, a huge fat-containing mass with linear strands was present.

Shrinkage Rate of Necrotic Lesion after Radiofrequency (RF) Ablation of Hepatocellular Carcinoma: Correlation with Marginal Recurrence and Influencing Factors

PURPOSE: To compare the CT findings of hepatocellular carcinomas (HCCs) immediately after radiofrequency (RF) ablation with those obtained at six months' follow-up, to analyse the relationship between degree of shrinkage of a necrotic lesion and marginal recurrence, and to evaluate the factors influencing shrinkage. MATERIALS AND METHODS: We retrospectively evaluated 54 patients with 62 HCCs who underwent only RF ablation between May 1999 and July 2000. For six months after ablation, all had been free from marginal recurrence ad new-growth tumors. The findings of six-month follow-up CT were compared with those obtained immediately after RF ablation, and the volume of each necrotic lesion was calculated and compared. In terms of degree of shrinkage, tumors were classified as belonging to either group I (below 50%), group II (50-80%) or group III (above 80%). Each tumor was analysed in terms of its Child-Pugh classification, vascularity at CT, size, treatment details, the post-ablation appearance of its margins, and the presence, during necrosis, of peritumoral vessles and air bubbles. For statistical evaluation, Fisher's exact test was used. Shrinkage after ablationwas correlated to marginal recurrence during a period of more than one year. RESULTS: The Follow-up CT at six months showed that since immediately after ablation, necrotic lesions had shrunk by an average of 72%. Peritumoral vessels were seen in 12 of 14 cases in group I (86%), three of 13 in cases of group II (23%), and 11 of 35 in group III (31%)(p=0.001). Immediate CT revealed the presence of air bubbles in two cases in group I (14%), five in group II (38%), and 24 in group III (69%)(p<0.05). At follow-up CT performed during a period of more than one year, marginal recurrence was noted in four cases in group I, two in group II and two in group III (p<0.05). CONCLUSION: When a necrotic lesion contains no peritumoral vessels but does contain air bubbles, the degree of post-RFablation shrinkage increases. The greater the shrinkage, the less the marginal recurrence rate.

Spontaneous Rupture of Choledochal Cyst: Case Report

Spontaneous rupture of a choledochal cyst leading to biliary peritonitis is a rare complication which can be fatal if not promptly diagnosed. The authors report the ultrasound and CT findings of two cases of spontaneous choledochal cystic rupture and the biliary peritonitis which ensued.