H.K. Lim

Needle-tract implantation in hepatocellular carcinoma: frequency and CT findings after biopsy with a 19.5-gauge automated biopsy gun

AbstractBackground: Needle-tract implantation is an important complication of cutting biopsy of hepatocellular carcinoma (HCC). This study was performed to evaluate the frequency of needle-tract implantation after ultrasound (US)-guided percutaneous biopsy of HCC and to describe triple-phase helical computed tomographic (CT) findings of implanted nodules. Methods: Between April 1994 and December 1997, 205 patients underwent US-guided percutaneous biopsy for HCC. Review of medical records and the pathology database disclosed seven patients who were found to have needle-tract implantation of HCC. Among these patients, five underwent triple-phase helical CT examination. We analyzed the frequency of needle-tract implantation and triple-phase helical CT findings of implanted nodules, with particular attention to the morphology and enhancement pattern. Results: Seven of 205 patients (3.4%) had tumor implantation along the needle tract at histologic examination after surgical resection. Eight implanted nodules in five patients were found on triple-phase helical CT images (one nodule in three patients, two nodules in one patient, and three nodules in one patient). All implanted nodules has well-circumscribed margins and were ovoid or lobulated in contour. On triple-phase helical CT, six (75%) implanted nodules were isodense compared with abdominal wall muscle on all triple-phase CTs, and two (25%) nodules were hyperdense on hepatic arterial and portal venous phases and isodense on equilibrium phase. Conclusions: The frequency of needle-tract implantation of HCC after percutaneous needle biopsy was higher than reported previously, and careful attention should be paid during interpretation of CT images in patients with a history of previous percutaneous biopsy.

Mucocele of the appendix: ultrasonographic and CT findings

Abstract.Background: Mucocele of the appendix is a rare disease entity, but preoperative diagnosis is very important. With the advent of ultrasonography (US) and computed tomography (CT), it has been possible to preoperatively diagnose mucocele of the appendix. We describe the spectrum of US and CT findings of mucocele of the appendix and the differential points from mimicking diseases. Methods: We evaluated 17 patients with pathologically proven mucocele of the appendix by using US and CT. Pathologic diagnoses of 17 patients were mucinous cystadenoma in 11 patients, mucinous cystadenocarcinoma in two, and mucosal hyperplasia in four. We analyzed morphologic characteristics of mucocele of the appendix at US and CT. Results: The typical US finding were a cystic mass with variable internal echogenicity, layered wall, and calcification in the wall. The CT finding was a well-encapsulated cystic mass with a wall of variable thickness. Both cases with focal nodular solid enhancing portion in the wall on CT were pathologically proven as mucinous cystadenocarcinoma. Conclusion: US and CT were useful methods in diagnosing mucocele of the appendix and differentiating this condition from mimicking diseases. Nodular enhancing lesion in the wall of the mucocele may be a finding suggestive of malignant cause of mucocele.

Hepatocellular carcinoma: evaluation of therapeutic response to interventional procedures.

Surgical resection remains the principal curative treatment for hepatocellular carcinoma (HCC) [1]. However, most patients with HCC are not eligible for surgical resection at the time of diagnosis owing to the status of the patients or tumors [2, 3]. In the past decade, a variety of interventional procedures have been employed for the local control of HCC. These include transcatheter arterial chemoembolization (TACE) [4], local ablation techniques using a direct intratumoral injection of compounds such as absolute ethanol [5] or hot saline [6], and thermal ablation techniques such as microwave ablation [7] and radiofrequency (RF) ablation [8]. Precise evaluation with imaging modalities is important to determine whether the tumor is completely treated or needs additional treatment. The information provided by imaging studies is used to estimate prognosis and can modify the treatment plan. Color or power Doppler sonography (US), computed tomography (CT), magnetic resonance imaging (MRI), and angiography have been used for that purpose [9–15]. After successful treatment, the treated lesion is devoid of vascularity on color or power Doppler US and it no longer enhances with contrast material on CT and MRI. When the tumor is not completely treated, residual viable tissue can be detected on Doppler US, CT, and MRI as focal hypervascular foci within the treated lesion [9–11, 14, 15]. For the definite assessment of therapeutic efficacy of interventional procedures, histologic examination using percutaneous needle biopsy may be needed. The procedure, however, is invasive and the specimen retrieved does not always represent the entire lesion owing to sampling errors [15]. Therefore, follow-up imaging studies have been used mostly for that purpose. In this article, we review the imaging findings of HCC treated with interventional procedures and discuss the values and pitfalls of each imaging modality in evaluating therapeutic response.

Completely isolated enteric duplication cyst: case report

AbstractWe present a case of a completely isolated enteric duplication cyst in a 28-year-old man. Computed tomography showed a large complex cystic mass with curvilinear and nodular calcifications near the anterior aspect of the left kidney. It had no connection to the pancreas, stomach, small bowel, or large bowel. We found no report describing computed tomographic findings of completely isolated enteric duplication cyst in the English-language literature.

Necrotic granuloma of the liver by human fascioliasis: imaging findings

We report a case of necrotic granuloma of the liver by human fascioliasis. The lesion showed unusual findings at sonography, computed tomography, and magnetic resonance imaging that have not been reported previously.

First-line radiofrequency ablation with or without artificial ascites for hepatocellular carcinomas in a subcapsular location: Local control rate and risk of peritoneal seeding at long-term follow-up

AIM To compare the long-term local control of hepatocellular carcinoma (HCC) and risk of peritoneal seeding via percutaneous radiofrequency ablation (RFA) using artificial ascites with those of RFA without artificial ascites. MATERIALS AND METHODS The Institutional Review Board approved this retrospective study. From April 2005 to February 2008, 160 patients (121 men, 39 women; age range 36-79 years) with a single subcapsular HCC (mean size 2.19 cm) were treated with ultrasonography-guided percutaneous RFA as a first-line therapy. Forty-four patients were treated with RFA using artificial ascites, whereas the other 116 patients were treated without artificial ascites. The cumulative local tumour progression (LTP) and peritoneal seeding were compared in both groups using follow-up computed tomography (CT). Cumulative LTP rates were analysed using the Kaplan-Meier method and the log-rank test. Risk of peritoneal seeding was investigated by means of multivariate analysis. RESULTS The overall median follow-up period was 52.5 months (range 13-76 months). The 1, 2, 4, and 6 year cumulative LTP rates were 17.1, 27.6, 35.2, and 35.2%, respectively, in the group with artificial ascites, and 8, 15.2, 26.6, and 34.4% in the group without artificial ascites, without significant difference (p = 0.332). The rates of peritoneal seeding were 6.8% (3/44) in the group with artificial ascites and 2.6% (3/116) in the group without artificial ascites, a non-significant difference (p = 0.347). The biopsy prior to RFA was the independent risk factor of peritoneal seeding regardless of the use of artificial ascites. CONCLUSION Long-term local tumour control and risk of peritoneal seeding were comparable for RFA with or without artificial ascites when used as a first-line therapy for subcapsular HCC.

Imaging of extrahepatic cholangiocarcinoma.

Preoperative staging of extrahepatic cholangiocarcinoma is important in determining the best treatment plan. Several classification systems have been suggested to determine the operability and extent of surgery. Longitudinal tumor extent is especially important in extrahepatic cholangiocarcinoma because operative methods differ depending on the tumor extent. The Bismuth-Corlette classification system provides useful information when planning for surgery. However, this classification system is not adequate for selecting surgical candidates. Anatomic variation of the bile duct and gross morphology of the tumor must be considered simultaneously. Lateral spread of the tumor can be evaluated based on the TNM staging provided by American Joint Committee on Cancer (AJCC). However, there is a potential for ambiguity in the distinction of T1 and T2 cancer from one another. In addition, T stage does not necessarily mean invasiveness. Blumgart T staging is helpful for the assessment of resectability with the consideration of nodal status and distant metastasis as suggested by the AJCC cancer staging system. Computed tomography (CT) and magnetic resonance imaging (MRI) are the primary tools used in the assessment of longitudinal and lateral spread of a tumor when determining respectability. Diagnostic laparoscopy and positron emission tomography (PET) may play additional roles in this regard.

CT findings of isolated small bowel angioedema due to iodinated radiographic contrast medium reaction

We report three cases of small bowel angioedema that showed circumferential wall thickening of the small bowel loops during infusion of iodinated contrast media. Follow-up small bowel series or computed tomography confirmed the normalized small bowel loops. When significant wall thickening of the long segment of the small bowel during infusion of contrast media is seen, radiologists should consider the possibility of isolated small bowel angioedema in spite of its rarity.

Multiple infarcted regenerative nodules in liver cirrhosis after systemic hypotension due to septic shock: radiologic findings.

We describe a case of multiple infarcted regenerative nodules in a patient with advanced liver cirrhosis who had experienced an episode of septic shock. Sonography showed multiple hypoechoic or isoechoic nodules; contrast-enhanced computed tomography showed multiple, low-attenuating nodules with rim enhancement; and magnetic resonance imaging showed multiple nodules of low, iso-, or high signal intensity. Explanted liver showed coagulation necrosis of multiple regenerative nodules. Peribiliary cysts in chronic liver diseases, liver abscesses, spontaneous necrosis of hepatocellular carcinomas, and metastasis should be differentiated.

Iodized oil retention due to postbiopsy arterioportal shunt : a false positive lesion in the investigation of hepatocellular carcinoma

Abstract.Background: Iodized-oil computed tomography (CT) is useful for the diagnosis of hepatocellular carcinoma, but there may be false-positive results in patients who have undergone some percutaneous transhepatic interventional procedures. The purpose of the present study was to verify the correlation between subsegmental hepatic parenchymal retention of iodized oil on CT and the arterioportal shunt caused by liver biopsy. Methods: Iodized-oil CT scans were reviewed in 24 patients with hepatic tumors who had liver biopsy and subsequent iodized oil chemoembolization. Iodized oil chemoembolization was performed shortly after biopsy (1–10 days; mean = 2.6 days). The results were correlated with hepatic arteriography, with a special emphasis on the presence of hepatic arterioportal shunt. Results: Wedge-shaped subsegmental retention of iodized oil along or adjacent to the biopsy needle path was observed in iodized-oil CT in 17 of the 24 patients. In three patients, there was subsegmental enhancement on prebiopsy helical dynamic liver CT at the same area of iodized oil retention, and therefore iodized oil retention was considered to be due to hepatocellular carcinoma. In the remaining 13 (54%) patients, the peripheral iodized oil retention was considered to be due to biopsy-induced arterioportal shunt. In all these patients, arterioportal shunt was confirmed by hepatic arteriography. Conclusion: Wedge-shaped hepatic parenchymal retention of iodized oil is commonly observed in iodized-oil CT due to biopsy-induced arterioportal shunt, and this appearance should not be confused with a hepatocellular carcinoma.