Various congenital anomalies and anatomical variations of the spleen: a multimodality pictorial review.

There are various congenital anomalies and anatomical variations of the spleen (CAAVS). CAAVS are common and are often associated with systemic anomalies. Widespread use of computed tomography and magnetic resonance imaging in a variety of clinical situations has increased the detection of CAAVS. However, CAAVS are frequently overlooked and are occasionally misdiagnosed as pathologic disease entities. This article aimed to review the various manifestations of CAAVS with radiologic findings.

Gadoxetate disodium-enhanced MRI for diagnosis of hepatocellular carcinoma in patients with chronic liver disease: late portal venous phase may improve identification of enhancing capsule.

PURPOSE: To investigate added value of late portal venous phase (LPVP) for identification of enhancing capsule (EC) on gadoxetate disodium-enhanced MRI (GD-MRI) for diagnosing hepatocellular carcinoma (HCC) in patients with chronic liver disease (CLD). METHODS: This retrospective study comprised 116 high-risk patients with 128 pathologically proven HCCs who underwent GD-MRI including arterial phase, conventional portal venous phase (CPVP, 60 s), LPVP (mean, 104.4 ± 6.7 s; range, 90-119 s), and transitional phase (TP, 3 min). Two independent radiologists assessed the presence of major HCC features, including EC on CPVP and/or TP (CPVP/TP) and EC on LPVP. The frequency of EC was compared on GD-MRI between with and without inclusion of LPVP. The radiologists assigned Liver Imaging Reporting and Data System (LI-RADS) v2018 categories before and after identifying EC on LPVP. RESULTS: Of the total 128 HCCs, 74 and 73 revealed EC on CPVP/TP for reviewer 1 and 2, respectively. After inclusion of LPVP, each reviewer identified seven more EC [Reviewer 1, 57.8% (74/128) vs. 63.3% (81/128); Reviewer 2, 57.0% (73/128) vs. 62.5% (80/128); P = 0.016, respectively]. Sensitivities of LR-5 assignment for diagnosing HCCs were not significantly different in GD-MRI with or without LPVP for EC identification [Reviewer 1, 71.9% (92/128) vs. 72.7% (93/128); Reviewer 2, 75.0% (96/128) vs. 75.8% (97/128); P = 1.000, respectively]. CONCLUSION: Including the LPVP in GD-MRI may improve identification of EC of HCC in patients with CLD. However, LI-RADS v2018 using GD-MRI showed comparable sensitivity for diagnosing HCC regardless of applying LPVP for EC.

Preoperative CT image-based assessment for estimating risk of ovarian torsion in women with ovarian lesions and pelvic pain.

PURPOSE: To define and weight the preoperative CT findings for ovarian torsion and to develop an integrated nomogram for estimating the probability of ovarian torsion in women with ovarian lesion and pelvic pain. METHODS: This retrospective study included 218 women with surgically resected ovarian lesions who underwent preoperative contrast-enhanced CT for pelvic pain from January 2014 to February 2019. Significant imaging findings for torsion were extracted using regression analyses and a regression coefficient-based nomogram was constructed. The diagnostic performance with sensitivity, specificity, and accuracy of the significant imaging findings and the nomogram were assessed. RESULTS: A total of 255 ovarian lesions (123 lesions with torsion and 132 lesions without torsion) were evaluated. Multivariable regression analysis showed that whirl sign (odds ratio [OR] 11.000; p < 0.001), tubal thickening (OR 4.621; p = 0.001), unusual location of ovarian lesion (OR 2.712; p = 0.020), and hemorrhagic component within adnexal lesion (OR 2.537; p = 0.028) were independent significant parameters predicting ovarian torsion. Tubal thickening showed the highest sensitivity (91.1%) and whirl sign showed the highest specificity (94.7%). When probabilities of ovarian torsion of 0.5 or more in the nomogram were diagnosed as ovarian torsion, sensitivity, specificity, and accuracy of the nomogram were 78.1%, 91.7%, and 85.1%, respectively. CONCLUSION: The whirl sign, tubal thickening, unusual location of ovarian lesion, and hemorrhagic component within adnexal lesion, and an integrated nomogram derived from these significant findings can be useful for predicting ovarian torsion.

Gadoxetic acid-enhanced MRI for diagnosis of hepatocellular carcinoma in patients with chronic liver disease: can hypointensity on the late portal venous phase be used as an alternative to washout?

PURPOSE: To investigate the added value of considering hypointensity on late portal venous phase (LPVP) images as washout for diagnosis of hepatocellular carcinoma (HCC) using gadoxetic acid-enhanced MRI (Gd-EOB-MRI) in patients with chronic liver disease (CLD). METHODS: This retrospective study comprised 97 patients at high risk for HCC who underwent Gd-EOB-MRI including unenhanced, multi-arterial phase, conventional portal venous phase (CPVP, 60 s), and LPVP (mean, 99.9 ± 9.1 s; range, 90-119 s) images. A total of 115 hepatic lesions were identified by histopathological or clinical diagnosis. Three independent radiologists assessed the MRI images by consensus. Diagnosis of HCC was made using criteria of arterial hyperenhancement and hypointensity relative to the surrounding liver parenchyma (1) on CPVP or (2) on CPVP and/or LPVP images. The generalized estimating equation was used to compare diagnostic performance for HCC between Criterion 1 and 2. RESULTS: In 82 HCCs, the frequency of hypointensity differed significantly between the CPVP and LPVP images (64.6% [53/82] vs. 84.1% [69/82], P < 0.001). Among 33 non-HCCs, two cHCC-CCs showed additional hypointensity on LPVP than CPVP images (33.3% [11/33] vs. 39.4% [13/33], P = 0.500). Criterion 2 provided significantly greater sensitivity for diagnosing HCC than Criterion 1 (54.9% [45/82] vs. 74.4% [61/82], P < 0.001), with relatively little reduction in specificity (90.9% [30/33] vs. 84.8% [28/33], P = 0.145). CONCLUSION: Additional use of LPVP hypointensity as washout could significantly improve sensitivity for HCC diagnosis when utilizing Gd-EOB-MRI in patients with CLD, without a significant decrease in specificity.

Liver Abscess Caused by Klebsiella oxytoca with Hepatic Artery Pseudoaneurysm: A Case Report.

Hepatic artery pseudoaneurysm is a rare but potentially life-threatening condition that usually occurs after trauma. Early recognition and prompt management are essential for preventing catastrophic consequences, such as hemoperitoneum. We report a rare case of liver abscess caused by Klebsiella oxytoca resulting in hepatic artery pseudoaneurysm without iatrogenic injury. The unique feature of the present case is that the abscess cavity itself became a pseudoaneurysm as a result of fistula formation with the hepatic artery. Vascular complications should be considered in patients with unfavorable clinical course even in the absence of iatrogenic injury. Endovascular treatment is safe and effective.

Various Congenital Abnormalities and Anatomic Variants of the Pancreas: A Pictorial Review.

Numerous and various congenital abnormalities and anatomic variants of the pancreas (CAAVPs) have been reported. Some of them are not so uncommon. Recent advances and accessibility of various multiplanar imaging modalities today offer the increased capabilities of detection and full diagnosis of these CAAVPs. With a precise diagnosis, the symptomatic CAAVPs can not only be more specifically treated but even more their detection and exact description can modify the surgical or interventional strategy to avoid unexpected post-operative complications. This article aimed to review the embryogenesis of the pancreas and describe imaging findings of CAAVPs.

LI-RADS v2017 categorisation of HCC using CT: Does moderate to severe fatty liver affect accuracy?

OBJECTIVES: To compare the sensitivity of Liver Imaging Reporting and Data System (LI-RADS) v2017 for diagnosis of hepatocellular carcinoma (HCC) using multiphasic computed tomography (CT) between patients with and without moderate to severe fatty liver (MSFL). METHODS: This retrospective study included a total of 106 high-risk patients with 112 pathologically proven HCCs who underwent multiphasic CT. Patients were classified as MSFL (24 men, 2 women; mean age, 59.5 years [range, 38-79 years]) and non-MSFL (64 men, 16 women; mean age, 62.9 years [range, 40-89 years]) groups according to unenhanced CT liver and spleen parenchymal attenuation. Two independent radiologists assigned LI-RADS categories and accessed HCC features on CT. Sensitivities for LR-5 assignment and frequencies of HCC features were compared between the two groups. RESULTS: Sensitivities of LR-5 assignment for diagnosing HCCs were not significantly different between MSFL and non-MSFL groups (65.4% [17/26] vs. 76.7% [66/86] for reviewer 1, p = 0.247; 73.1% [19/26] vs. 76.74% [66/86] for reviewer 2, p = 0.702). No significant differences in the frequencies of arterial hyperenhancement, washout, and capsule were observed between the two groups (96.2% [25/26] vs. 98.8% [85/86], p = 0.412; 80.8% [21/26] vs. 89.5% [77/86], p = 0.308; and 53.8% [14/26] vs. 57% [49/86], p = 0.778, respectively). CONCLUSIONS: LI-RADS v2017 using CT showed comparable sensitivity for diagnosing HCC regardless of MSFL. KEY POINTS: • Using LI-RADS v2017 with CT, diagnosis of HCC in patients with MSFL showed similar sensitivity to that in patients without MSFL. • Frequencies of major HCC features (arterial hyperenhancement, washout, and capsule) on CT between the MSFL and non-MSFL groups were not significantly different. • LI-RADS using CT may be feasible for diagnosing HCC in patients with fatty liver.

Adult Langerhans' cell histiocytosis with multisystem involvement: A case report.

RATIONALE: Langerhans' cell histiocytosis (LCH), also called histiocytosis X, is an uncommon disorder manifesting in a variety of ways. Although LCH can involve various organs including bone, skin, and lymph nodes, multisystem involvement of LCH is rare in adults. PATIENT CONCERNS: A 31-year-old woman first presented to our hospital with left leg pain. She had a history of a 20-kg weight gain over three months. DIAGNOSES: X-ray, magnetic resonance imaging (MRI), computed tomography (CT), and bone scan images revealed enhancing lesions in the left femur and right temporal bone, multiple cystic lesions in the lung, enhancing mass in the pituitary stalk, and fat density lesions in the liver. The patient underwent excisional biopsy for the femoral lesion and histologic examination confirmed the diagnosis of LCH. INTERVENTIONS: Excisional biopsy was performed for the bony lesion in the left femur. She received chemotherapy with vinblastine and prednisolone. OUTCOMES: The patient expired after 21 months from initial admission following recurrent episodes of pneumothorax, pneumonia, and sepsis. LESSONS: Our case showed LCH involvement in bone, lung, central nervous system (CNS), and liver. Although it is occasionally difficult to discriminate LCH from other disorders, systemic evaluation might be helpful for differential diagnosis. Familiarity with the various multisystemic involvements of LCH on imaging is vital for diagnosing and managing patients in daily practice.

Various congenital anomalies of the inferior vena cava: review of cross-sectional imaging findings and report of a new variant.

The inferior vena cava (IVC) is an important structure receiving a large amount of venous return and is associated with various congenital disorders. Advances in diagnostic imaging and its increasing accessibility have led to an increase in the incidental detection of IVC anomalies. Congenital anomalies of the IVC are not uncommon and are occasionally critical to treatment planning. However, they are frequently overlooked in abdominal imaging. The IVC is composed of four segments (intrahepatic, suprarenal, renal, and infrarenal), and each segment arises from different embryonic structures in a complex process. Anomalies of the IVC can be classified according to the involved segment. Familiarity with the variety of IVC anomalies seen on imaging is vital for correctly diagnosing and managing patients in daily practice.

The many faces of Meckel's diverticulum and its complications.

Meckel's diverticulum is the most frequent congenital malformation of the gastrointestinal tract, occurring in 2% of the general population. Meckel's diverticulum is usually asymptomatic and found incidentally. However, the lifetime risk of complications is 4-40%. In this essay, we describe the clinical and imaging findings in 12 cases of Meckel's diverticula with complications over a 5-year period, which were confirmed pathologically. The major complications of Meckel's diverticulum include gastrointestinal bleeding, bowel obstruction, perforation and inflammation. Small bowel follow-through (SBFT), computed tomography (CT) including CT enterography and RI scintigraphy can be used to show typical imaging features of Meckel's diverticulum and its complications. Knowledge of the clinical and radiologic findings of Meckel's diverticulum can aid in the early and accurate diagnosis of this anomaly and its complications.

Role of ¹8F-FDG PET/CT in the prediction of gastric cancer recurrence after curative surgical resection.

PURPOSE: The study evaluated the role of preoperative (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT in the prediction of recurrent gastric cancer after curative surgical resection. METHODS: A total of 271 patients with gastric cancer who underwent (18)F-FDG PET/CT and subsequent curative surgical resection were enrolled. All patients underwent follow-up for cancer recurrence with a mean duration of 24 ± 12 months. (18)F-FDG PET/CT images were visually assessed and, in patients with positive (18)F-FDG cancer uptake, the maximum standardized uptake value (SUV(max)) of cancer lesions was measured. (18)F-FDG PET/CT findings were tested as prognostic factors for cancer recurrence and compared with conventional prognostic factors. Furthermore, (18)F-FDG PET/CT findings were assessed as prognostic factors according to histopathological subtypes. RESULTS: Of 271 patients, 47 (17 %) had a recurrent event. Positive (18)F-FDG cancer uptake was shown in 149 patients (55 %). Tumour size, depth of invasion, presence of lymph node metastasis, positive (18)F-FDG uptake and SUV(max) were significantly associated with tumour recurrence in univariate analysis, while only depth of invasion, positive (18)F-FDG uptake and SUV(max) had significance in multivariate analysis. The 24-month recurrence-free survival rate was significantly higher in patients with negative (18)F-FDG uptake (95 %) than in those with positive (18)F-FDG uptake (74 %; p < 0.0001). In subgroup analysis, (18)F-FDG uptake was a significant prognostic factor in patients with tubular adenocarcinoma (p = 0.003) or poorly differentiated adenocarcinoma (p = 0.0001). However, only marginal significance was shown in patients with signet-ring cell carcinoma and mucinous carcinoma (p = 0.05). CONCLUSION: (18)F-FDG uptake of gastric cancer is an independent and significant prognostic factor for tumour recurrence. (18)F-FDG PET/CT could provide effective information on the prognosis after surgical resection of gastric cancer, especially in tubular adenocarcinoma and poorly differentiated adenocarcinoma.

Epstein-Barr virus-associated lymphoepithelioma-like gastric carcinoma presenting as a submucosal mass: CT findings with pathologic correlation.

A lymphoepithelioma-like carcinoma, characterized by a carcinoma with heavy lymphocyte infiltration, is one of the histological patterns observed in patients with Epstein-Barr virus (EBV)-associated gastric carcinoma. Less than half of invasive carcinomas with lymphoepithelioma-like histology can grow to make a submucosal mass. These tumors generally have a better prognosis than conventional adenocarcinomas. We report a case of an EBV-associated lymphoepithelioma-like gastric carcinoma that presented as a submucosal mass on multi-detector (MD) CT and correlate them with the pathology.

Diffuse pattern of transient hepatic attenuation differences in viral hepatitis: a sign of acute hepatic injury in patients without cirrhosis.

OBJECTIVES: Our objective was to describe the transient hepatic attenuation differences (THADs) on dynamic computed tomography in patients with viral hepatitis who had no evidence of cirrhosis. METHODS: After excluding patients who had known causative factors for the development of THAD, a retrospective review of dynamic CT scans in 67 patients with viral hepatitis was performed to determine whether THAD was present. The patients were assigned to 3 groups according to the magnitude of alanine aminotransferase (ALT) level alteration (normal to mild, moderate, and marked) or hepatitis type (acute hepatitis, acute exacerbation of chronic hepatitis, and chronic infection), and differences in the presence of various CT features including THAD among these groups were evaluated. RESULTS: Five THADs observed had a focal pattern, and 18 THADs had a diffuse pattern. All of the diffuse THADs were observed in patients with marked ALT level alteration (ALT level > 400 IU/L) and in patients with a clinical diagnosis of acute hepatitis or acute exacerbation of chronic hepatitis. In addition, there were significant differences of the presence of other CT findings including hepatomegaly, periportal tracking, gallbladder wall thickening, perihepatic lymphadenopathy, and splenomegaly among these groups (each P < 0.05). CONCLUSIONS: A diffuse THAD of the liver and other CT features indicates acute hepatic injury in patients with viral hepatitis who have no clinical evidence of cirrhosis.

Color Doppler twinkling artifacts in various conditions during abdominal and pelvic sonography.

OBJECTIVE: The aims of this study were to describe the mechanisms likely to be responsible for color Doppler twinkling artifacts and their associated machine factors and to illustrate the various conditions that cause twinkling artifacts and those pitfalls. METHODS: We evaluated various sonographic machine-associated factors that influence artifact appearance and identified various conditions that display twinkling artifacts during abdominal and pelvic sonography. RESULTS: The presence of twinkling artifacts was found to be dependent on focal zones, gray scale gains, color write priorities, and pulse repetition frequencies. Twinkling artifacts were found to be associated with calcified lesions in the liver, gallbladder adenomyomatosis, hepatic bile duct hamartoma, gallstones and choledocholithiasis, chronic pancreatitis, urinary stones, encrusted indwelling urinary stents, bowel gas, and metallic foreign bodies. However, some of the twinkling artifacts were found to be associated with false-negative and -positive results. CONCLUSIONS: Color Doppler twinkling artifacts are additional useful sonographic signs in the diagnosis of calcified lesions, urinary and biliary stones, gallbladder adenomyomatosis, and some miscellaneous conditions.

CT findings of colonic complications associated with colon cancer.

A broad spectrum of colonic complications can occur in patients with colon cancer. Clinically, some of these complications can obscure the presence of underlying malignancies in the colon and these complications may require emergency surgical management. The complications of the colon that can be associated with colon cancer include obstruction, perforation, abscess formation, acute appendicitis, ischemic colitis and intussusception. Although the majority of these complications only rarely occur, familiarity with the various manifestations of colon cancer complications will facilitate making an accurate diagnosis and administering prompt management in these situations. The purpose of this pictorial essay is to review the CT appearance of the colonic complications associated with colon cancer.

MRI of gastric carcinoma: results of T and N-staging in an in vitro study.

AIM: To determine the accuracy of 1.5-T magnetic resonance imaging (MRI) in the evaluation of gastric wall invasion and perigastric lymph node metastasis in gastric adenocarcinoma. METHODS: Twenty resected gastric specimens containing 20 tumors were studied with a 1.5-T MR system using a commercial head surface coil. MR scanning was performed with a T1 weighted image (TR/TE = 500/20), and a T2 weighted image (TR/TE = 2500/90). MR findings were compared with pathologic findings. RESULTS: A T1-weighted image demonstrated three layers in the normal gastric wall. All of the gastric tumors were well demonstrated by lesions and location. In a MRI findings of gastric wall invasion, there was 1 case of T1, 7 of T2, 11 of T3. Pathologic results of resected specimens included 3 cases of pT1, 4 of pT2, and 12 of pT3. The accuracy of T staging with MRI was 74% (14 of 19). MRI findings of lymph node metastasis included 6 cases of N0, 13 cases of N1. The accuracy of the N staging with MRI was 47% (9 of 19). CONCLUSION: MRI has a high diagnostic accuracy in the evaluation of the T staging of gastric cancer in vitro and thus potentially enables preoperative histopathologic staging.

Transient arterial enhancement of the hepatic parenchyma in patients with acute cholangitis.

OBJECTIVES: Our objectives were to determine the clinical significance of transient arterial enhancement (TAE) of the hepatic parenchyma in patients with suspected biliary disease and to investigate the relationship between the pattern and extent of TAE and acute cholangitis. METHODS: A retrospective review of dynamic computed tomographic scans in 76 patients with suspected biliary disease was performed. Patterns of TAE were classified as polymorphous, sectorial, peribiliary, diffuse, and a combination of features. The extent of TAE was evaluated by counting the involved liver segments. The extent of TAE was correlated with laboratory and clinical findings. Patients were also divided into 2 groups: cholangitis group (n = 40) and noncholangitis group (n = 36). The pattern and extent of TAE were compared between these 2 groups. RESULTS: Among the laboratory findings that showed significant correlation with the extent of TAE, the white blood cell count and C-reactive protein concentration were found to have a relatively high correlation (r = 0.540 and 0.514, respectively). The presence of abdominal pain, fever, and cholangitis showed a statistically significant difference with the extent of TAE (P < 0.01). Statistically significant differences in the pattern and extent of TAE between the 2 groups were found (P < 0.001). Diffuse or diffuse heterogeneous TAE patterns that involve more than 5 liver segments, such as a polymorphous combined with a peribiliary pattern and a diffuse pattern, had a high association with acute cholangitis. CONCLUSIONS: Transient arterial enhancement in patients with suspected biliary disease is well correlated with clinical parameters suggestive of inflammation. Transient arterial enhancement provides useful complementary information for biliary infection in the computed tomographic diagnosis of acute cholangitis.

Foreign body granulomas simulating recurrent tumors in patients following colorectal surgery for carcinoma: a report of two cases.

We report here two cases of foreign body granulomas that arose from the pelvic wall and liver, respectively, and simulated recurrent colorectal carcinomas in patients with a history of surgery. On contrast-enhanced CT and MR images, a pelvic wall mass appeared as a well-enhancing mass that had invaded the distal ureter, resulting in the development of hydronephrosis. In addition, a liver mass had a hypointense rim that corresponded to the fibrous wall on a T2-weighted MR image, and showed persistent peripheral enhancement that corresponded to the granulation tissues and fibrous wall on dynamic MR images. These lesions also displayed very intense homogeneous FDG uptake on PET/CT.

Duplication of the extrahepatic bile duct in association with choledocholithiasis as depicted by MDCT.

We report here on an extremely rare case of duplicated extrahepatic bile ducts that was associated with choledocholithiasis, and this malady was visualized by employing the minimum intensity projection images with using multi-detector row CT. The presence of duplicated extrahepatic bile ducts with a proximal communication, and the ducts were joined distally and they subsequently formed a single common bile duct, has not been previously reported.

Multiplanar reformations and minimum intensity projections using multi-detector row CT for assessing anomalies and disorders of the pancreaticobiliary tree.

CT scan is regarded as the imaging modality of choice in patients with pancreaticobiliary ductal abnormalities. However, the axial orientation of the CT images provides only limited anatomical view of pancreaticobiliary ductal abnormalities. The technological advances of multi-detector row CT and three-dimensional image processing in workstations allows rapid image acquisition and a short postprocessing time. In particular, multiplanar reformations (MPR) and minimum intensity projections (MinIP) offer rapid and accurate images of the anatomy and abnormalities of the pancreaticobiliary tree. Moreover, MPR and MinIP help determine the relationship between the pancreaticobiliary ductal anatomy and the surrounding structures. This pictorial review illustrates the wide spectrum of images obtained by the MPR and MinIP of the anomalies and disorders of the pancreaticobiliary tree.