Yoong Ki Jeong

Two-phase helical CT for detection of early gastric carcinoma: importance of the mucosal phase for analysis of the abnormal mucosal layer.

Purpose To evaluate the efficacy of two-phase dynamic helical computed tomography (CT), including the gastric mucosal phase, for detection of early gastric carcinoma with typical hyperattenuating and atypical nonhyperattenuating enhancement patterns. Method Two-phase helical CT scanning was performed using the water-filling method as negative oral contrast material for 212 patients with proven adenocarcinoma on endoscopic biopsy. Two gastrointestinal radiologists prospectively analyzed the focal alterations of the inner hyperattenuating mucosal layer and the outer hypoattenuating layer before the information obtained at barium study and pathologic examination was available. The first, so-called mucosal phase was obtained at 38–45 seconds after the start of intravenous injection of contrast material for a total of 150 ml/sec at a rate of 4 ml/sec to obtain maximum enhancement of the inner mucosal layer. The second delayed phase was obtained at 3 minutes. Results Fifty-four cases of early gastric cancer were suspected on two-phase helical CT preoperatively. Postoperatively, 49 cases of early gastric cancer were pathologically confirmed. The detection rate for the typical hyperattenuating early gastric cancer, that is the type 1 enhancement pattern defined as the localized thickening of the inner hyperattenuating layer, using two-phase helical CT was 18% (9/49 patients). The type 2 enhancement pattern, defined as the focal interruption of the inner hyperattenuating mucosal layer without abnormal enhancement of the outer hypoattenuating layer on the mucosal phase, was seen in 15 cases. These were pathologically confirmed as early gastric cancer IIb + IIc (three patients), IIc (four patients), IIc + IIa (one patient), IIc + III (three patients), IIb + IIc (one patient), and advanced cancer (T2) lesions (three patients). The type 3 enhancement pattern was defined as the focal polypoid protrusion of the inner hyperattenuating layer without abnormal enhancement of the outer thickened hypoattenuating layer on the mucosal phase, and was seen in seven patients who were pathologically confirmed with early gastric cancer IIb + IIc (three patients), IIc + IIa (one patient), and IIc + IIb (three patients). The lesions became less distinct on the delayed phase. Five T2 advanced gastric cancers were falsely interpreted as early gastric cancer. The detection rate for early gastric cancer after considering type 2 and 3 atypical enhancement patterns was increased to 57% (28/49 patients). Conclusion Helical CT with two-phase scan including the mucosal phase was efficient for identifying the enhancement patterns of early gastric cancer.

Imaging features of benign solid testicular and paratesticular lesions.

ObjectiveThe presence of an intratesticular solid lesion is usually highly suspicious for malignancy. Conversely, most extratesticular solid lesions including paratesticular lesions are benign. The characteristic imaging features of malignant solid testicular lesions are well known, but various unusual causes and imaging features of benign solid testicular lesions can be particularly misleading. Therefore, a careful assessment of solid testicular and paratesticular lesions is warranted. The purpose of this article is to present the clinical and imaging features of the spectrum of benign solid testicular and paratesticular lesions.MethodsWe demonstrate a variety of benign solid testicular and paratesticular lesions and correlate them with pathologic results.ResultsSpecific the clinical and imaging features of the spectrum of benign solid testicular and paratesticular lesions have been described.ConclusionsFamiliarity with the clinical setting and imaging features of benign solid testicular and paratesticular lesions should facilitate prompt, accurate diagnosis and treatment.

Doppler sonographic resistive index in obstructed kidneys.

Doppler sonographic findings were correlated with symptoms and intravenous urographic findings in 31 patients with unilateral renal obstruction and in 30 control subjects. No significant correlation was found between resistive index and symptom duration or between resistive index and pelvicalyceal opacification time on intravenous urography. With a cutoff resistive index of 0.7, the sensitivity was 19.3% in diagnosing unilateral obstruction; however, it was 80% in the subgroup with acute symptoms and severely delayed pelvicalyceal opacification time. Doppler sonography has very low sensitivity in diagnosing unilateral renal obstruction, but it may be useful when the obstruction is acute and severe.

Intermittent Sonographic Guidance in Air Enemas for Reduction of Childhood Intussusception

Objective. The purpose of this study was to prospectively assess the value of intermittent sonographic guidance in nonsurgical air reduction of childhood intussusception. Methods. The study group included 86 consecutive childhood intussusceptions confirmed on sonography for which we designed an air enema. With intermittent sonographic guidance of our own method, air was gradually injected to the initial intracolonic pressure of 60 mm Hg, which we attempted for 30 seconds on the initial attempt. If the air enema reduction attempts were not successful at a given pressure setting, we repeated the technique at each pressure setting upgraded by increments of 20 mm Hg up to 120 mm Hg. Surgery was performed when even repeated reduction attempts at the maximum intracolonic pressure of 120 mm Hg were unsuccessful. We calculated the successful reduction rate for the intussusceptions at each pressure setting. Results. The overall success rate of sonographically guided air enema reductions was 95% (82/86). The success rates of air enema reductions at 60, 80, 100, and 120 mm Hg showed progressive increases of 53% (42/86), 67% (58/86), 78% (67/86), and 95% (82/86), respectively, with no immediate recurrence and no gross perforation. Conclusions. The use of intermittent sonographic guidance in air enemas is thought to help safely increase successful reductions of childhood intussusception even with sufficient air enema attempts.

A Case of Chronic Pancreatitis Associated with Liver Infarction and Acrodermatitis Enteropathica

Liver infarction and acrodermatitis enteropathica are rare complications of chronic pancreatitis. This report shows the case of a 56-year-old man who developed liver infarction due to portal vein thrombosis from chronic pancreatitis and acrodermatitis enteropathica during the course of his treatment. The rare combination of these complications in a patient with chronic pancreatitis has never previously been reported in the literature.

Vasculature in Hepatocellular Carcinoma After Transcatheter Arterial Chemoembolization: Comparison of Power and Color Doppler Sonography

The purpose of this study was to compare power Doppler sonography with conventional color Doppler sonography for the detection of the vascularity of hepatocellular carcinomas after transcatheter arterial chemoembolization. Of the 93 embolized hepatocellular carcinomas, hypervascularity was demonstrated in 36 on angiography; power Doppler sonography correctly identified pulsatile flow signals in 33 (92%) of these 36, whereas color Doppler sonography identified flow signals in 24 (67%). A statistically significant difference was noted when the sizes of the nodules were 30 mm or less. Despite technical difficulties, such as flash artifact, power Doppler sonography is superior to color Doppler sonography for detection of hypervascularity, especially in small embolized nodules of hepatocellular carcinoma (30 mm or less in diameter).

Comparison of Knowledge-based Iterative Model Reconstruction and Hybrid Reconstruction Techniques for Liver CT Evaluation of Hypervascular Hepatocellular Carcinoma.

Objective The purpose of this work was to evaluate the image quality, lesion conspicuity, and dose reduction provided by knowledge-based iterative model reconstruction (IMR) in computed tomography (CT) of the liver compared with hybrid iterative reconstruction (IR) and filtered back projection (FBP) in patients with hepatocellular carcinoma (HCC). Methods Fifty-six patients with 61 HCCs who underwent multiphasic reduced-dose CT (RDCT; n = 33) or standard-dose CT (SDCT; n = 28) were retrospectively evaluated. Reconstructed images with FBP, hybrid IR (iDose4), IMR were evaluated for image quality using CT attenuation and image noise. Objective and subjective image quality of RDCT and SDCT sets were independently assessed by 2 observers in a blinded manner. Results Image quality and lesion conspicuity were better with IMR for both RDCT and SDCT than either FBP or IR (P < 0.001). Contrast-to-noise ratio of HCCs in IMR-RDCT was significantly higher on delayed phase (DP) (P < 0.001), and comparable on arterial phase, than with IR-SDCT (P = 0.501). Iterative model reconstruction RDCT was significantly superior to FBP-SDCT (P < 0.001). Compared with IR-SDCT, IMR-RDCT was comparable in image sharpness and tumor conspicuity on arterial phase, and superior in image quality, noise, and lesion conspicuity on DP. With the use of IMR, a 27% reduction of effective dose was achieved with RDCT (12.7 ± 0.6 mSv) compared with SDCT (17.4 ± 1.1 mSv) without loss of image quality (P < 0.001). Conclusions Iterative model reconstruction provides better image quality and tumor conspicuity than FBP and IR with considerable noise reduction. In addition, more than comparable results were achieved with IMR-RDCT to IR-SDCT for the evaluation of HCCs.

Simultaneous occurrence of malignant fibrous histiocytoma and hepatocellular carcinoma in cirrhotic liver: A case report

Primary hepatic malignant fibrous histiocytoma (MFH) is rarely encountered. There have been no reports to date of hepatic MFH associated with liver cirrhosis. The presence of liver cirrhosis is considered an adjunctive feature favoring sarcomatoid hepatocellular carcinoma (HCC) in the diagnosis of spindle cell tumors in liver. We describe here a 59-year-old man with liver cirrhosis due to hepatitis B virus infection 20 years ago. On abdominal computed tomography scanning, two distinct hepatic masses were identified in the background of cirrhosis, which had different radiological features from conventional HCC. He underwent segmentectomy for removal of the tumors. The pathological examination of surgically resected specimen revealed the large malignant spindle cell tumor and small conventional HCC. Additional tissue sampling and immunohistochemical stainings demonstrated that the spindle cell tumor was consistent with MFH. On the post-operative follow-up for 21 mo, a round mass showing similar radiological findings for the previous MFH was appeared on the surface of resection margin, suggesting the recurrence. Despite its rarity, hepatic MFH should be considered during differential diagnosis, even in cirrhotic patients, and extensive tissue sampling and immunohistochemical analyses are necessary in the diagnosis of hepatic spindle cell tumors.

Optimal Phase of Dynamic Computed Tomography for Reliable Size Measurement of Metastatic Neuroendocrine Tumors of the Liver: Comparison between Pre- and Post-Contrast Phases

Objective The reliability of size measurements of liver metastases from neuroendocrine tumors (NETs) on contrast-enhanced computed tomography (CT) phases made by different readers may be hampered due to transient, variable rim enhancement in arterial phase (AP) or portal venous phase (PVP) images. We aimed to assess the reliability of tumor size measurements in pre- and post-contrast scans. Materials and Methods The study coordinator selected target lesions according to Response Evaluation Criteria in Solid Tumors 1.1 guidelines in 44 consecutive patients with pathologically confirmed NET liver metastases. Two blinded readers measured the longest diameters of target lesions on pre-contrast, AP, and PVP images twice with a 4-week interval. Inter- and intra-observer agreements were evaluated using Bland-Altman plots and 95% limit of agreement (LOA) calculations. Results Of the 79 target lesions (approximate mean size of 3 cm), 45 showed rim enhancement. Inter-observer agreement assessed based on LOA was highest in pre-contrast CT images (−6.1–5.7 mm), followed by PVP (−7.9–7.1 mm) and AP (−8.5–7.4 mm) images. Intra-observer agreement showed the same trend: −2.8–2.9 mm and −2.9–2.9 mm for readers 1 and 2, respectively, on pre-contrast CT, −2.8–2.9 mm and −3.0–3.2 mm, respectively, on PVP, and −3.2–4.2 mm and −3.4–3.2 mm, respectively, on AP images. Mean tumor diameters differed significantly among the phases in the following increasing order: pre-contrast CT, PVP, and AP images. Conclusion There was better inter- and intra-observer agreement in size measurements of NET liver metastases on precontrast scans than on AP and PVP scans. Pre-contrast CT may be the optimal for measuring NET liver metastases if its accuracy is proven.

Gastrosplenic fistula occurring in lymphoma patients: Systematic review with a new case of extranodal NK/T-cell lymphoma

AIM To provide the overall spectrum of gastrosplenic fistula (GSF) occurring in lymphomas through a systematic review including a patient at our hospital. METHODS A comprehensive literature search was performed in the MEDLINE database to identify studies of GSF occurring in lymphomas. A computerized search of our institutional database was also performed. In all cases, we analyzed the clinicopathologic/radiologic features, treatment and outcome of GSF occurring in lymphomas. RESULTS A literature search identified 25 relevant studies with 26 patients. Our institutional data search added 1 patient. Systematic review of the total 27 cases revealed that GSF occurred mainly in diffuse, large B-cell lymphoma (n = 23), but also in diffuse, histiocytic lymphoma (n = 1), Hodgkin’s lymphoma (n = 2), and NK/T-cell lymphoma (n = 1, our patient). The common clinical presentations are constitutional symptoms (n = 20) and abdominal pain (n = 17), although acute gastrointestinal bleeding (n = 6) and infection symptoms due to splenic abscess (n = 3) are also noted. In all patients, computed tomography scanning was very helpful for diagnosing GSF and for evaluating the lymphoma extent. GSF could occur either post-chemotherapy (n = 10) or spontaneously (n = 17). Surgical resection has been the most common treatment. Once patients have recovered from the acute illness status after undergoing surgery, their long-term outcome has been favorable. CONCLUSION This systematic review provides an overview of GSF occurring in lymphomas, and will be helpful in making physicians aware of this rare disease entity.