CT of radiation-induced injury of the gastrointestinal tract: spectrum of findings with barium studies correlation.

Because of improvement in survival rate of patients with abdominal cancer, gastrointestinal complications following external radiation therapy are becoming more frequent. Thus, an increased number of patients are commonly investigated with imaging because of suspected radiation-induced injury of the gastrointestinal tract. This pictorial review highlights the spectrum of CT and barium study manifestations of radiation-induced injury of the gastrointestinal tract. The major role of CT in the evaluation and management of patients with radiation injury of the gastrointestinal tract is highlighted. Emphasis is placed on CT imaging signs that may help in distinguishing between radiation-induced injury and recurrent disease.

[Rectal malignant stromal tumor (leiomyosarcoma): echoendoscopic, computed tomographic aspects and anatomopathologic correlations]. / Tumeur stromale maligne rectale (léiomyosarcome): aspects échoendoscopique, tomodensitométrique et corrélation anatomopathologique.

We report the CT and endorectal us features of a malignant stromal tumor of the rectum (leiomyosarcoma). On CT scan, rectal leiomyosarcoma appeared as a large soft tissue mass, arising from the anterior rectal wall with exorectal extension. On endorectal US, the rectal leiomyosarcoma presented as a well-defined hypoechogenic and heterogeneous mass arising from the rectal muscularis propria. The uncommon location of leiomyosarcoma to the rectum may simulate other rectal tumors such as adenocarcinoma on CT. As suggested by this report, endorectal us demonstrated the muscular origin of the tumor.

Carcinoid tumors of the abdomen: CT features.

Carcinoid tumors are rare neuroendocrine neoplasms that belong to a more general category of tumor called the APUDomas. Ninety percent of carcinoid tumors are located in the gastrointestinal tract. Abdominal carcinoid tumors are categorized according to the division of the primitive gut from which they arise. Carcinoid tumors originating from the foregut develop in the gastric wall, duodenum, and pancreas; those originating from the midgut develop from the small bowel, appendix, and right colon; and those originating from the hindgut develop from the transverse or left colon or from the rectum. This report illustrates the computed tomographic appearance of primary and metastatic carcinoid tumors of the abdomen. Among the different organs that may be involved by metastases from carcinoid tumor, special emphasis is placed on the liver.

Cystic fibrosis in adolescents and adults: fatty replacement of the pancreas--CT evaluation and functional correlation.

PURPOSE: To compare the computed tomographic (CT) features of pancreatic fatty replacement in adolescents and adults with cystic fibrosis (CF) with those in control subjects and to correlate the degree of fatty replacement with the functional status of the pancreas. MATERIALS AND METHODS: CT scans in 15 patients with CF (group 1) and in 15 control subjects without CF (group 2) were evaluated for thickness and degree of pancreatic fatty replacement. Thickness was measured at four anatomic levels. The pattern of pancreatic fatty replacement was visually evaluated in four pancreatic regions. Images were semiquantitatively analyzed by two readers. The degree of fatty replacement was correlated with the functional status of the pancreas. RESULTS: In group 1, pancreatic glandular tissue was significantly thinner (P < .001) and the degree of fatty replacement was significantly greater in the four regions (P < .001) than those in group 2. In Group 1, no relationship was found between the degree of pancreatic fatty replacement and that of pancreatic endocrine dysfunction. A significant relationship was found between the degree of fatty replacement and that of pancreatic exocrine dysfunction (P < .001). CONCLUSION: In patients with CF, pancreatic glandular tissue is significantly reduced in size. Pancreatic fatty replacement is the most frequent pattern in older patients with CF and correlates with pancreatic exocrine dysfunction.

CT of abdominal wall implantation metastases after abdominal percutaneous procedures.

PURPOSE: Our goal was to report the CT manifestations of abdominal wall implantation metastases occurring after abdominal percutaneous procedure. METHOD: CT scans and clinical data of six patients with abdominal wall implantation metastases at the puncture site following abdominal percutaneous procedure were reviewed. The abdominal percutaneous procedures included drainage of intraperitoneal abscess in patients with colon or gastric cancer (n = 2), transhepatic biliary drainage in a patient with hilar cholangiocarcinoma (n = 1), biopsy of intrahepatic hepatocellular carcinoma (n = 1), biopsy of a metastatic left adrenal gland (n = 1), and laparoscopic cholecystectomy in a patient with unsuspected gallbladder cancer (n = 1). RESULTS: CT enabled the diagnosis of abdominal wall implantation metastasis in all six patients and showed coexisting intraabdominal tumor sites in five patients. All abdominal wall implantation metastases were homogeneous before intravenous administration of iodinated contrast material and became moderately heterogeneous on contrast-enhanced CT scan with marked enhancement relative to adjacent tissues. CONCLUSION: Abdominal wall implantation metastases are moderately heterogeneous on contrast-enhanced CT scan with marked enhancement relative to adjacent tissues. In most cases of abdominal wall implantation metastasis following abdominal percutaneous procedure, CT shows additional intraabdominal tumor sites. This complication may occur following a variety of abdominal percutaneous procedures (either radiological or surgical).

[Percutaneous vertebroplasty of the cervico-thoracic junction using an anterior route. Technique and results. Report of nine cases]. / Vertébroplastie percutanée de la charnière cervico-dorsale par voie antérieure. Technique et résultats. A propos de neuf cas.

Percutaneous vertebroplasty using fluoroscopy is a well known technique. Visualization of the posterior wall of the vertebra is mandatory. Good assessment of this part of the vertebra is usually difficult at the cervico-thoracic junction. We propose an original method to obtain adequate visualization of the posterior wall, avoiding the shoulders superposition. Using this technique, we performed twelve vertebroplasties in nine patients (one angioma and eleven metastatic lesions). Clinical outcome was good for all patients, even a total filling of the vertebra body by the cement was obtained in only eight cases on twelve. No clinical complication was observed.

Differentiation between hepatic cavernous hemangioma and malignant tumor with T2-weighted MRI: comparison of fast spin-echo and breathhold fast spin-echo pulse sequences.

PURPOSE: The goal of our study was to compare a T2-weighted breathhold fast spin-echo (BHFSE) technique with T2-weighted nonbreathhold fast spin-echo (FSE) technique for characterizing cavernous hemangioma of the liver and differentiating this entity from malignant tumor. MATERIALS AND METHODS: Eighteen patients with cavernous hemangiomas and 18 patients with malignant hepatic tumors were studied with T2-weighted MRI with a nonbreathhold FSE technique with and without fat suppression and with a BHFSE technique without fat suppression. Hepatic lesions were analyzed quantitatively using signal intensity (SI) and contrast-to-noise (C/N) ratio. In addition, images were qualitatively compared for accuracy in characterizing hepatic lesion. RESULTS: Quantitatively, hemangioma had significantly higher SI and C/N ratios than did the malignant tumor on every pulse sequence (P < 0.01). Qualitatively, all malignant tumors were correctly categorized; differentiation between cavernous hemangioma and malignant tumor was impossible in three cases of cavernous hemangioma with the three pulse sequences (92% accuracy, 100% sensitivity, and 83% specificity). CONCLUSION: T2-weighted FSE and BHFSE MRI shows comparable levels of accuracy for differentiating between hepatic cavernous hemangioma and malignant tumor. Because overlap may exist using quantitative measurement, morphologic patterns must be carefully analyzed, supporting that quantitative analysis and morphologic evaluation are complementary.

Hepatic cavernous hemangioma: appearance on T2-weighted fast spin-echo MR imaging with and without fat suppression.

OBJECTIVE: The goals of our study were to define the morphologic appearance of cavernous hemangioma of the liver on T2-weighted fast spin-echo MR imaging and to determine if the use of fat suppression may quantitatively and qualitatively modify the MR imaging appearance of cavernous hemangioma. SUBJECTS AND METHODS: Twenty-six patients with cavernous hemangiomas of the liver were prospectively studied with T2-weighted MR imaging with a fast spin-echo technique with and without fat suppression. Thirteen patients had known hemangiomas for more than 2 years, with no change in size or morphology during this period. The remaining 13 patients had diagnoses based on dynamic CT and sonography and an absence of change in the morphology and size of their lesions during follow-up of more than 6 months (range, 6-12 months) after the MR imaging studies. Values for signal intensity and contrast-to-noise (C/N) ratios in cavernous hemangiomas that were obtained with and without fat suppression were compared. Images were qualitatively analyzed separately at identical level and window settings by two interpreters for morphologic features of cavernous hemangiomas. RESULTS: No significant difference was found between signal intensity values obtained using the fat-suppressed fast spin-echo MR imaging technique (5.62 +/- 1.14 [SD]) and those obtained without fat suppression (5.51 +/- 1.23). Values for C/N ratios obtained with the fat-suppressed fast spin-echo MR imaging technique (20.13 +/- 7.63) were significantly superior to those obtained without fat suppression (16.59 +/- 5.31) (p < .001). On T2-weighted fast spin-echo MR imaging without fat suppression, 100% of cavernous hemangiomas were hyperintense relative to the spleen, 90% had well-defined and sharp margins, 55% were isointense to CSF, and 76% were homogeneous. Without fat suppression, 34% of cavernous hemangiomas showed the combination of isointensity to CSF, well-defined margins, and homogeneity. On T2-weighted fast spin-echo MR imaging with fat suppression, all cavernous hemangiomas showed this same combination of features. CONCLUSION: Seventy-six percent of hepatic cavernous hemangiomas were homogeneous on T2-weighted fast spin-echo MR imaging, and 55% were isointense to CSF. However, only 34% of hepatic cavernous hemangiomas showed typical features. Although fat suppression significantly increased the C/N ratio of cavernous hemangiomas of the liver, fat suppression did not affect their morphologic appearance on T2-weighted fast spin-echo MR imaging.

MR imaging of the liver: effect of portal hypertension on hepatic parenchymal enhancement using a gadolinium chelate.

The purpose of this study was to prospectively investigate the extent to which reduced portal blood flow in patients with hepatic cirrhosis and portal hypertension affects hepatic parenchymal enhancement during gadolinium-chelate-enhanced dynamic MR imaging. Breath-hold three-dimensional (3D) spoiled gradient-recalled echo (GRE) MR imaging technique obtained after intravenous administration of a gadolinium chelate was used to measure hepatic parenchymal enhancement and time to peak enhancement in 20 patients with hepatic cirrhosis and clinical evidence of portal hypertension (group 1) and in 20 control subjects without portal hypertension (group 2) who were matched for age, sex, and body weight. Mean peak hepatic enhancement values +/- SD and times to peak enhancement +/- SD were determined for both groups of patients. Mean peak enhancement value (+/-SD) was 78.7% +/- 36.2 in group 1 and 91.6% +/- 46.2 in group 2 (not significant). However, in the nine patients in group 1 with splenomegaly, mean peak enhancement value was 61.3% +/- 14.4, whereas it was 93.0% +/- 42.7 in the 11 patients without splenomegaly (P < .05). Mean time to peak enhancement was 84 seconds +/- 23 in group 1 and 54.0 sec +/- 25.0 in group 2 (P < .01). Our results show that mean peak enhancement value of hepatic parenchyma after intravenous administration of a gadolinium chelate is significantly altered for patients with portal hypertension and splenomegaly. In addition, the time to peak enhancement is delayed significantly when portal hypertension is present. Thus, it is possible that the optimal time for imaging the liver during the portal phase must be tailored to the status of the portal system of the patient.

Focal nodular hyperplasia of the liver: assessment of hemodynamic and angioarchitectural patterns with gadolinium chelate-enhanced 3D spoiled gradient-recalled MRI and maximum intensity projection reformatted images.

PURPOSE: Our goal was to determine the relative merits of gadolinium chelate-enhanced 3D spoiled gradient-recalled (GRE) MRI versus maximum intensity projection (MIP) reformatted images in assessing the morphologic, hemodynamic, and angioarchitectural patterns of focal nodular hyperplasia (FNH) of the liver. METHOD: Ten consecutive patients with 10 FNHs had prospectively gadolinium chelate-enhanced 3D spoiled GRE MRI (TR/TE/FA = 10.1/1.9/30) of the liver at 1.5 T. Gadolinium chelate-enhanced 3D spoiled GRE source images and MIP reformatted images were separately analyzed with respect to morphologic and hemodynamic features and angioarchitectural patterns by two independent readers. RESULTS: Gadolinium chelate-enhanced 3D spoiled GRE source images and MIP reformatted images showed the most intense degrees of enhancement of FNH during the arterial phase of hepatic parenchymal enhancement in all cases. Gadolinium chelate-enhanced 3D spoiled GRE source images were superior to MIP reformatted images for the assessment of morphologic features of FNH (p < 0.02). MIP reformatted images were superior to the corresponding source images for showing the main branches of the hepatic artery, an arterial branch going to the FNH, and a small artery within the FNH radiating to peripheral areas (p < 0.05). There was excellent agreement between the two observers for analysis of the MIP reformatted images (p < 0.05). CONCLUSION: The combination of gadolinium chelate-enhanced 3D spoiled GRE source images and MIP reformatted images allows the analysis of morphologic, hemodynamic, and angioarchitectural patterns of FNH of the liver. Further study and comparison with currently applied strategies will determine the value of these two techniques for diagnosing FNH of the liver.