Spread of gallbladder carcinoma: CT evaluation with pathologic correlation

Background: To assess the accuracy of computed tomographic (CT) imaging in the detection of spread and staging of gallbladder carcinoma. Methods: CT findings of spread of gallbladder carcinoma in 59 Japanese patients who underwent radical surgery were correlated retrospectively with pathologic findings. Results: The incidence of histologically proven nodal involvement was 54% (32 patients) and the most common spread of gallbladder carcinoma. The sensitivities in CT detection of N1 and N2 nodal involvement were 36% and 47%, respectively; positive predictive values were 94% and 92%, respectively. Direct extension to the liver, extrahepatic bile duct, and gastrointestinal tract or pancreas were histologically confirmed in 24, 18, and five patients. The sensitivities in the CT detection of direct spread to the liver of less than 2 cm, more than 2 cm, the extrahepatic bile duct, and the gastrointestinal tract or pancreas were 65%, 100%, 50%, and 57%, respectively; positive predictive values were 77%, 100%, 90%, and 100%, respectively. The incidence of liver metastases and involvement of interaortocaval nodes were 7% and 16%, respectively. The sensitivities in CT detection of liver metastases and involvement of interaortocaval nodes were 75% and 21%, respectively; positive predictive values were 100% and 86%, respectively. CT could not detect direct spread to omentum and peritoneal seedings. Conclusion: For detecting the spread of gallbladder carcinoma, CT imaging has low to moderate sensitivity; however, CT imaging can help in determining resectability and in planning the treatment, especially in advanced-stage gallbladder carcinoma, because of a high positive predictive value. Received: 5 July 1995/Accepted: 8 August 1995     

Correlation of perfusion abnormalities on CTAP and immediate postintravenous gadolinium-enhanced gradient echo MRI

Background: The purpose of this study was to evaluate patients with wedge-shaped perfusion defects seen on spiral CT arterial portography for the presence of transient increased wedge-shaped enhancement on dynamic gadolinium-enhanced gradient echo MR images. Methods: Nineteen patients underwent CTAP and MRI within a 2-week interval. All patients with wedge-shaped perfusion defects on CT arterial portography were evaluated in a separate review session for the presence of transient increased segmental hepatic enhancement on dynamic gadolinium-enhanced spoiled gradient echo (SGE) MR images. Results: Eight patients were identified to have subsegmental, segmental, or lobar wedge-shaped perfusion defects by CT arterial portography. In 8/8 patients, there was transient wedge-shaped increased hepatic enhancement on MR images which corresponded to the perfusion defects identified on CT arterial portography. Transient increased enhancement on MR images was observed on immediate postgadolinium images as high-signal intensity of the involved subsegment, segment, or lobe. This relatively high-signal area faded to near isointensity in all cases on images obtained at 45 s. Conclusion: Wedge-shaped perfusion defects demonstrated by CT arterial portography corresponded to wedge-shaped increased hepatic enhancement following gadolinium administration on SGE MR images. Received: 29 December 1994/Accepted: 7 February 1995     

Focal hepatic nodules after transcatheter oily chemoembolization; detection with spiral CT versus conventional CT

Background: The objective of this study was to determine if spiral computed tomography (CT) results in increased rate of detection of focal hepatic nodules containing iodized oil after transcatheter oily chemoembolization when compared with conventional CT. Methods: Spiral CT with single 24-s breath-hold technique was compared with conventional sequential CT in 42 patients with suspected hepatocellular carcinomas. Two sets of CT scans obtained after transcatheter oily chemoembolization were independently reviewed by two radiologists. The slice thickness was 10 mm for both data sets. The number and sizes of focal hepatic nodules containing iodized oil were documented. All 42 patients had at least one hepatic nodule. The lesion size varied from 2 mm to 12 cm. Results: In six of the 42 patients, more hepatic nodules could be identified on spiral CT compared with conventional CT. When scans with spiral CT were used, 107 nodules were detected, whereas 98 nodules were detected with conventional CT. Overall, nine (9%) more nodules were detected with spiral CT (<+>p= .002). If lesions larger than 2 cm are excluded, nine (15%) more lesions were detected with spiral CT (<+>p= .002). Conclusion: Spiral CT results in increased rate of detection of focal hepatic nodules after transcatheter oily chemoembolization, particularly in lesions smaller than 2 cm. Received: 11 October 1994/Accepted: 6 November 1994     

The frequency,appearance, and significance of splenic perfusion defects on CT arterial portography

Background: The purpose of this study was to determine the frequency, appearance, and significance of splenic perfusion defects on computed tomographic arterial portography (CTAP). Methods: CTAP was performed with dynamic scanning at 1-cm increments on 46 consecutive patients prior to laparotomy. Two readers retrospectively reviewed these studies in consensus and recorded the number, size, and shape of focal splenic perfusion defects. These defects were later correlated with surgical findings and at least one of the following imaging modalities: delayed CT 4<+>–<+>6 h after CTAP, intravenously enhanced CT, sonography, or magnetic resonance imaging (MRI). Results: Splenic perfusion defects were present in 14 of 46 CTAP studies (30%), and in seven patients these defects were multiple. Most defects were wedge-shaped and peripherally located, although several round defects simulating metastases were also present. The spleen was normal at surgery in all patients, and comparison imaging revealed only a small splenic infarct in one patient on MRI. Conclusions: Splenic perfusion defects occur in about one-third of patients referred for CTAP, are usually wedge-shaped but may be round, and should not be interpreted as metastases without other evidence of a space-occupying mass. Received: 11 October 1994/Accepted: 6 November 1994     

Restorative proctocolectomy: morphological and functional study with coronal CT

Background: Restorative proctocolectomy with ileal pouch has become the surgical treatment of choice for patients with ulcerative colitis (UC) and familial polyposis of the colon. Defecography is the radiological technique commonly employed to obtain detailed information on function and morphology of the ileal pouch; it allows the direct visualization of the ileal pouch and the anal canal, but it does not provide the visualization of the pelvis. Methods: In all patients, computed tomography (CT) on coronal planes was performed to determine its possibilities as an alternative to defecography; 10 patients with UC submitted to restorative proctocolectomy and were examined. Results: Coronal CT images provided a panoramic vision of the pelvis and demonstrated the morphology of the ileal pouch, the thickness of its walls, and its correlation with the surrounding tissues. Coronal CT also allowed the evaluation of the continence of ileo-anal and ileo-ileal anastomosis and the functional changes of the perineal muscles at rest and during squeezing. Conclusion: CT images acquired on coronal planes allows an easy and clear detection of the major postoperative complications, such as stenosis or dehiscences of the anastomosis, pelvic phlogosis, and fistulae. Received: 29 December 1994/Accepted: 5 February 1995     

Spontaneous rectus sheath hematomas: clinical and radiological features

We reviewed the clinical and radiological features in eight patients with spontaneous rectus sheath hematoma (RSH). The diagnosis was confirmed at surgery in four patients, and spontaneous resolution occurred in the other four. All patients were elderly adults. Acute abdominal pain and a palpable mass after muscular strain, such as coughing or twisting, were features highly suggestive of RSH. Sonographically, these hematomas may be confused with abdominal wall tumors. On CT scans, a hyperdense mass posterior to the rectus abdominis muscle with ipsilateral anterolateral muscular enlargement is considered characteristic of acute RSH, although chronic RSH may be isodense or hypodense relative to the surrounding muscle. MRI is very useful in the diagnosis of RSH, which is demonstrated as a high signal intensity area on both T1- and T2-weighted images, especially when the CT findings are not specific for RSH. Received: 16 August 1994/Accepted: 3 October 1994     

Enhancing ascites: an aid to CT diagnosis

Enhancement of ascitic fluid on delayed contrast-enhanced CT has been described as a potential pitfall in diagnosis. We present a case in which the phenomenon was beneficial to diagnosis. Enhancement of ascites was useful in delineating the entire extent of a cystic pelvic mass. We also discuss probable molecular and histologic mechanisms responsible for this unique type of enhancement. Received: 8 August 1994/Accepted after revision: 17 November 1994     

Radiographic findings of intractable gastric ulcers with H2-receptor antagonists

Background: To clarify the radiographic characteristics of intractable gastric ulcers with H₂-receptor antagonists. Methods: The radiographic findings at the time of starting treatment were compared between 42 patients with gastric ulcers that did not heal within eight weeks of starting treatment with H₂-receptor antagonists (the intractable group) and 58 patients whose ulcers healed within the eight-week period (the tractable group). Results: The following radiographic findings in the intractable group were observed at a significantly higher incidence than those in the tractable group and included: an ulcer located on the angle, linear ulcers, a greater depth, an uneven mound surrounding an ulcer, prominent folds' convergence, an overhanging gastric mucosa, an irregular ulcer base, a shortening of the lesser curvature and a U-shaped deformity of the angle. A multiple logistic regression analysis showed that the following three factors had a significant and independent delaying effect on healing: a U-shaped deformity of the angle, an uneven mound surrounding an ulcer and prominent folds' convergence. The relative risk of these factors were 12.7, 14.4 and 12.5, respectively. Conclusions: Intractable gastric ulcer with H₂-receptor antagonists can be predicted based on the characteristic radiographic findings at the start of treatment. Received: 23 December 1994/Accepted: 25 January 1995     

Duodenojejunal intussusception with biliary obstruction and atrophy of the pancreas

Enteroenteric intussusceptions in adults are rare events caused by tumors in most cases. A case of duodenojejunal intussusception is presented which became manifest because of marked biliary obstruction and extensive pancreatic atrophy. As lead point, a large duodenal polypous hamartoma could be identified. The role of ultrasound and CT as diagnostic imaging of choice in this entity are discussed. Received: 1/16/95Accepted: 2/14/95     

Well-differentiated hepatocellular carcinoma: findings of US, CT, and MR imaging

Background: To elucidate the imaging characteristics of well-differentiated hepatocellular carcinomas (HCCs) on ultrasonography (US), computed tomography (CT), and magnetic resonance (MR) imaging. Methods: Ultrasonograms, CTs, and MR images of 18 histopathologically proven well-differentiated HCCs in 15 patients were reviewed. The findings of these images were correlated with histopathologic findings. Results: On US, seven tumors were depicted as a hyperechoic area and eight as a hypoechoic area. Three tumors were not visualized. On precontrast CT, four tumors were depicted as a low-density area, but 14 were not visualized. On conventional contrast-enhanced CT, 12 tumors were depicted as a low-density area but six were not visualized. On T1-weighted MR images, 10 tumors had high signal intensity and two had low signal intensity. Six tumors were not visualized. On T2-weighted MR images, five tumors had high signal intensity and two had low signal intensity. Eleven tumors were not visualized. Tumors with fatty change and/or clear cell formation were frequently hyperechoic on US and hyperintense on T1-weighted MR images. Conclusions: Well-differentiated HCCs show different findings on US, CT, and MR imaging. Therefore, reliable diagnosis of well-differentiated HCCs by these imaging techniques may be difficult. Received: 29 April 1998/Revision accepted: 15 July 1998     

Rectus sheath hematoma: diagnostic classification by CT

A method of classification for hematomas of the rectus abdominis sheath (RSH) is proposed based on findings observed in CT in the 13 cases of RSH in the present study. Type I hematomas (five cases) are slight and do not require hospitalization. Type II (three cases) and type III (five cases) are moderate and severe hematomas, respectively, and do require hospitalization. The patients with type III hematomas were all undergoing anticoagulant therapy and presented with a picture of acute abdomen, and in all five cases blood transfusion was carried out. Ultrasonography and, in particular, CT permitted a correct diagnosis of RSH. RSH should be considered (anticoagulant therapy induced) in females with sudden abdominal pain to avoid unnecessary surgical intervention. Received: 1 May 1995/Accepted: 12 June 1995     

Vascular involvement in pancreatic adenocarcinoma:reassessment by thin-section CT

We defined computed tomographic (CT) criteria of vascular involvement by pancreatic carcinoma and used these criteria to assess vascular involvement in 56 patients with pancreatic adenocarcinoma. CT of the pancreas was performed at 1.5-mm section thickness and 5-mm section intervals during a bolus phase of intravenous contrast enhancement. The type of vascular involvement was correlated with surgical and pathologic findings. When there was fat-plane (type A) or normal pancreatic parenchyma (type B) separating the tumor from adjacent vessels, the tumor could be resected without venous resection in 21 of 22 patients (95%). When the tumor was inseparable from the vessels but the points of contact formed a convexity against the vessel (type C), CT was not reliable in predicting whether or not the tumor was fixed against the vessel. When the tumor was partially encircling (type D) the vessel, the tumor was fixed against the vessels in most cases. The resectable rate was 47%, but resection would also require venous resection. When the tumor was completely encircling (type E) or occluding (type F<+>) the vessel, all tumors were not resectable with a negative margin. Thin-section CT with bolus intravenous contrast enhancement improved the ability to assess vascular involvement in pancreatic adenocarcinoma. Received: 14 April 1995/Accepted: 12 June 1995     

Subcapsular renal spread of a pancreatic pseudocyst

In pancreatitis, the fluid collection may extend to unusual sites and organs and form a pseudocyst. We present US and CT findings of a pancreatic tail pseudocyst extending into the subcapsular space of the left kidney. Received: 23 December 1994/Accepted: 25 January 1995     

Dynamic MR imaging of hepatolithiasis

Background: To report the dynamic magnetic resonance (MR) imaging findings of hepatolithiasis. Methods: Dynamic MR images (fast spoiled gradient echo sequence with intravenous injection of gadopentate dimeglumine) and computed tomography, cholangiography, or angiography of nine patients with hepatolithiasis are analyzed. Results: All affected hepatic segments showed atrophic changes and contained dilated intrahepatic ducts. These segments showed either iso- or hypointensity on T1-weighted imaging and hyperintensity on T2-weighted imaging. Preferential enhancement was noted throughout all phases of the dynamic study and persisted to delayed T1-weighted imaging in seven patients. In the last two patients, severe atrophic changes made evaluating signal intensity differences and enhancement patterns difficult. Conclusion: In addition to intrahepatic stones and biliary dilatation, segmental atrophy, signal intensity differences, and preferential and persistent enhancement are important MR findings of hepatolithiasis. Received: 18 June 1997/Accepted: 23 July 1997     

Significance of the computed tomography finding of subcapsular hepatic necrosis in liver transplantation

Background: To evaluate the clinical significance of the computed tomographic finding of subcapsular hepatic necrosis following liver transplantation. Methods: 105 computed tomography scans performed in 50 allografts, 6 days to 4 years following transplantation, were retrospectively reviewed and divided into two groups: those with and those without the computed tomographic finding of subcapsular hepatic necrosis. Extrahepatic fluid, biliary dilatation, circumcaval rings, periportal collar, biochemistry, and random biopsies were correlated with the computed tomographic finding of subcapsular hepatic necrosis. Results: Computed tomographic finding of subcapsular hepatic necrosis was demonstrated at some point in 21 (42%) patients and was never demonstrated in 29 (58%) patients. The association of periportal collar with the computed tomographic finding of subcapsular hepatic necrosis was significant; there was no significant association with other computed tomographic findings. There was no significant difference in serum transaminases between the two groups. There was no significant difference in necrosis on biopsy between the two groups; however, the association of acute cellular rejection with the computed tomographic finding of subcapsular hepatic necrosis was significant. Conclusions: Computed tomographic finding of subcapsular hepatic necrosis is a common finding following liver transplantation, which has little clinical prognostic significance. Received: 13 December 1994/Accepted: 5 January 1995     

CT of Hodgkin's lymphoma limited to the gallbladder

A complex mass confined to the gallbladder found on CT is unusual, but nor rare, with causes including benign inflammatory disease, early primary carcinoma and metastases. Non-Hodgkin's lymphoma is rare and Hodgkin's disease, prior to the current case, unheard of involving just the gallbladder. Thus, this should be considered part of the differential diagnosis of a complex gallbladder mass. Received: 9 February 1995/Accepted: 4 March 1995     

Current status of small bowel radiography

Background: In the past, small bowel examinations were usually ordered for the sake of ``completeness.' As a result, small bowel radiography was performed casually and without attention to detail. This review examines pertinent clinical issues and the recent contribution of small bowel radiography to the evaluation and management of the patient with suspected small bowel disease. Recommendations for the clinical utilization of small bowel radiography are discussed. Methods: Analysis of pertinent citations addressing valid indications for, and technique of, small bowel radiography from 1980 to July 1995 through a computerized bibliographic search (Medline and Current Contents). Results: Accepted clinical indications for small bowel radiography include (1) unexplained gastrointestinal bleeding, (2) possible small bowel tumor, (3) small bowel obstruction, (4) Crohn disease, and (5) malabsorption. The current literature reflects the limitations of the conventional small bowel follow-through, various modifications to improve its clinical yield, the important contribution of enteroclysis in the workup, and subsequent management of patients with possible small bowel disease. A controversy in the radiology literature exists as to whether to use the small bowel follow-through or enteroclysis as the primary method of examining the small bowel. Conclusion: The thoughtful selection of patients by clinicians for small bowel radiography is essential to make radiologic evaluation cost effective. The incidence of disease of the small intestine is low and is associated with nonspecific symptoms. Because of the inherent difficulty of visualizing numerous loops of an actively peristalsing bowel, a reliable imaging method is needed that not only detects small or early structural abnormality but also accurately documents normalcy. The yield of information provided by enteroclysis and its high negative predictive value suggests that it should be the primary method for small bowel examination. The ``overhead'-based conventional small bowel follow-through should be abandoned. The ``fluoroscopy'-based small bowel follow-through augmented when necessary by the peroral pneumocolon or the gas-enhanced double-contrast follow-through method is an acceptable alternative when enteroclysis is not possible. Received: 0/0/00Accepted: 0/0/00     

Radiologically identifiable intratumoral portal vein in intrahepatic cholangiomas: a diagnostic pitfall

Background: Although intratumoral patent portal vein (ITPV) is one of the characteristic features of benign hepatic lesions, ITPVs can be demonstrated in malignant tumors. We present the spectrum of MR and CT findings of ITPV identified in intrahepatic cholangiomas with pathological correlations. Methods: The ultrasound, CT and/or MRI findings of pathologically-confirmed intrahepatic cholangiomas were reviewed and correlated with surgical specimen or autopsy findings. Results: Intratumoral patent vessels were radiographically-demonstrated in 5 patients with intrahepatic cholangiomas. All intratumoral vessels were secondary or tertiary order portal vein branches. Some wall thickening was identified on pathological examinations. Conclusion: The radiological demonstration of intratumoral portal vein is not a specific sign of benignity. In the case of a hepatic tumor with a patent portal tract, cholangioma should be considered, as well as benign tumors or lymphoma. Received: 28 February 1995/Accepted: 29 March 1995     

Mucin-hypersecreting papillary cholangiocarcinoma presenting as abdominal wall abscess: CT and spiral CT cholangiography

We describe CT findings of a case of mucin-hypersecreting papillary cholangiocarcinoma (MHPC), with extrahepatic bile leakage to the rectus abdominis muscle via the ligamentum teres hepatis forming an abdominal wall abscess. Endoscopic retrograde cholangiography was unsatisfactory. Spiral three-dimensional CT cholangiography was helpful in assessing the resectability of MHPC by offering anatomic details of the uninvolved biliary tree. Received: 20 February 1995/Accepted: 4 April 1995     

Color Doppler imaging of the gallbladder wall in acute cholecystitis: sonographic<+>–<+>pathologic correlation

Background: The purpose of this study was to evaluate the usefulness of color Doppler imaging (CDI) in suspected cases of acute cholecystitis. Methods: Twenty-two patients suspected of having acute cholecystitis were prospectively evaluated over a 12-month period using gray-scale and color Doppler technique. Gallbladder wall thickness was greater than 2 mm in all patients included in the study. Pathologic correlation was obtained in 17 patients, with clinical or sonographic follow-up in five for a period of 6<+>–/011001/months. CDI was considered positive only if the mid to fundal wall demonstrated flow. Sonographic Murphy's sign and laboratory values were recorded. Results: Eight patients had acute cholecystitis. All had positive color Doppler flow. Wall thickness in these patients ranged between 4 and 10 mm. Three patients with necrotizing acute cholecystitis had no flow within 6<+>–<+>8-mm walls. Six patients with pathologically proven chronic cholecystitis had no evidence of increased flow within thickened walls. Five patients with presumed chronic cholecystitis (thickened wall without increased color flow) were treated medically, and their symptoms resolved. CDI was more sensitive in predicting acute cholecystitis than was the sonographic Murphy's sign and/or laboratory values. Conclusion: CDI demonstrates hyperemic changes in thickened gallbladder walls and is an important adjunct in the diagnosis of acute cholecystitis. Received: 3 February 1995/Accepted: 24 March 1995