Combined Use Of Computed Tomography Research Articles

Comparative Analysis of Computed Tomography and Laparoscopy Data in Preoperative Staging of Gastric Cancer

Objective: to compare the data of computed tomography (CT) and diagnostic laparoscopy (DL) in the preoperative estimation of the extension of gastric cancer.Material and methods. Data on 51 patients with a histologically confirmed diagnosis of gastric cancer were analyzed. CT and DL were performed in all the patients at an interval of 1–2 days during their preoperative examinations to determine the stage of a tumor process. Of the 51 patients, 34 (66.7%) were found to have no distant abdominal metastases and underwent radical surgery. CT and DL revealed distant abdominal organ metastases in 17 (33.3%) of the 51 patients. To evaluate the diagnostic efficiency of CT and DL, the investigators calculated the main characteristics (sensitivity, specificity) and auxiliary criteria (accuracy, positive (PPV) and negative (NPV) predictive values.Results. The findings suggested that the diagnostic efficiency of CT in determining the T category was a sensitivity of 86% and a specificity of 92%; and that of DL was 83% and 87%, respectively. CT in diagnosing a regional lymph node metastasis had a higher sensitivity than DL (88% vs. 63%), but a lower specificity than DL (80% vs. 90%). CT diagnosis of peritoneal carcinomatosis exhibited a sensitivity of 46%, a specificity of 97.4%, an accuracy of 84.3%, PPV of 85.7%, and NPV of 84.1%. The symptoms of peritoneal carcinomatosis were ascites, soft tissue nodules along the peritoneum, diffuse induration and thickening of abdominal tissue planes, and increased mesenteric vascularity.Conclusion. The combined use of CT and DL is a current algorithm for examining patients with gastric cancer. It makes it possible to obtain complete information about the extension of the process, to increase the accuracy of preoperative diagnosis and to form a group of patients to undergo radical surgery.

Computed Tomography and Magnetic Resonance Imaging Manifestations of Spinal Monostotic Fibrous Dysplasia.

Aim:The purpose of the study was to analyze and summarize the computed tomography (CT) and magnetic resonance imaging (MRI) findings of spinal monostotic fibrous dysplasia (MFD) as well as evaluate the clinical value of CT and MRI in MFD diagnosis.Materials and Methods:CT (n = 4) and MRI (n = 5) images of six patients with pathologically confirmed spinal MFD were examined. The assessed image features included location, shape, rib involvement, vertebral collapse, margin, attenuation, and sclerotic rim on CT, as well as signal intensity, dark signal rim, and enhancement pattern on MRI.Results:In total, four of six patients underwent CT scanning. The most common findings on CT scanning were expansile lesions (n = 4), sclerotic rims (n = 4), and ground-glass opacity (GGO) (n = 4). In total, five of six patients underwent MRI. The lesions were low-signal intensity (n = 2), low-to-isointense signal intensity (n = 1), and low-signal intensity with several isointense portions (n = 2) on T1-weighted imaging (T1WI). The lesions were low-signal intensity (n = 1), isointense to high intensity (n = 1), and isointense signal intensity with several high portions (n = 3) on T2WI. A dark signal rim was found in most cases on T1WI and T2WI (n = 4). The lesions (n = 2) showed obvious enhancement.Conclusions:The CT and MRI manifestations of spinal MFD have the following characteristics: expansile lesion, GGO, sclerotic rim, and no obvious soft-tissue mass. The combined use of CT and MRI examinations is necessary for patients with suspected spinal MFD.

The role of transcavitary ultrasonography in diagnosis and staging of nonmuscle-ınvasive bladder cancer: a prospective non-randomized clinical study.

To evaluate the efficacy of cystoscopy, computed tomography (CT), transcavitary ultrasound (TCUS) and cytology, separately and in combination, for the diagnosis and evaluation of superficial bladder cancer.Initial cystoscopy and wash-out cytology were performed for 1548 patients. Of these, 206 with proven bladder tumors were included in this prospective study. CT and TCUS were performed for patients with bladder tumors without knowledge of their cystoscopy results. The lesions were classified as low- (pTa) and high- (pT1) risk superficial tumors according to multiplicity and size.Patients were divided into three categories according to their cystoscopically evaluated tumor size: ≤1 cm (88 patients, 42.7%), 1–3 cm (51 patients, 24.8%) and ≥3 cm (67 patients, 32.5%). TCUS identified 46 (22.3%) high-risk patients with/without invasion and 160 (77.7%) low-risk patients with no invasion. Overall, the sensitivity, specificity, positive predictive value and negative predictive value of TCUS for tumor detection were 77.4%, 60%, 94.7% and 22.2%, respectively.Cystoscopy remains the most widely used technique for the diagnosis of bladder cancer. The combined use of CT, TCUS and cytology detected 72% of cystoscopically proven tumors. Among the three, TCUS findings exhibited the strongest correlation with cystoscopy findings.

Hepatocellular carcinoma after ablation: The imaging follow-up scheme

Percutaneous ablation using thermal or chemical methods has been widely used in the treatment of hepatocellular carcinoma (HCC). Nowadays, contrast-enhanced imaging modalities such as computed tomography (CT), magnetic resonance imaging (MRI), and contrast-enhanced ultrasound (CEUS) are widely used to evaluate local treatment response after ablation therapies. CEUS is gaining increasing attention due to its characteristics including real-time scanning, easy performance, lack of radiation, wide availability, and lack of allergy reactions. Several studies have documented that CEUS is comparable to CT or MRI in evaluating local treatment efficacy within 1 mo of treatment. However, little information is available regarding the role of CEUS in the follow-up assessment after first successful ablation treatment. Zheng et al found that in comparison with contrast-enhanced computed tomography (CECT), the sensitivity, specificity, positive predictive value, negative predictive value and overall accuracy of CEUS in detecting local tumor progression (LTP) were 67.5%, 97.4%, 81.8%, 94.4% and 92.3%, respectively, and were 77.7%, 92.0%, 92.4%, 76.7% and 84.0%, respectively for the detection of new intrahepatic recurrence. They concluded that the sensitivity of CEUS in detecting LTP and new intrahepatic recurrence after ablation is relatively low in comparison with CECT, and CEUS cannot replace CECT in the follow-up assessment after percutaneous ablation for HCC. These results are meaningful and instructive, and indicated that in the follow-up period, the use of CEUS alone is not sufficient. In this commentary, we discuss the discordance between CT and CEUS, as well as the underlying mechanisms involved. We propose the combined use of CT and CEUS which will reduce false positive and negative results in both modalities. We also discuss future issues, such as an evidence-based ideal imaging follow-up scheme, and a cost-effectiveness analysis of this imaging follow-up scheme.

Scenes from the Past: CT-guided Endoscopic Recovery of a Foreign Object from the Cranial Cavity of an Ancient Egyptian Mummy

The aim of this study was to test the value of computed tomography (CT)-guided endoscopy in the scientific study of mummified remains and the recovery of unidentified objects from ancient mummified remains. CT-guided endoscopy was performed on an Egyptian mummy from the Late Period to help retrieve an unidentified object from its skull. The combined use of CT and endoscopy facilitated the recovery of the object, minimizing further damage to the remains and to the object itself. The successful recovery of the brittle object allowed detailed analysis of the item to be performed in an attempt to determine the nature of its presence in the cranial cavity. It was confirmed that the object was a monocotyledon stem fragment. Relying on the existing literature on mummification and excerebration methods in ancient Egypt, we concluded that the stick was probably used for transnasal removal of the brain. The results of this study demonstrate the great potential of CT-guided endoscopy for minimally invasive recovery of small unidentified items from mummies that could yield important information about mummification procedures and the materials used to preserve bodies.

CT and PET in Stomach Cancer: Preoperative Staging and Monitoring of Response to Therapy

Stomach cancer is one of the leading causes of cancer mortality worldwide. Complete resection of a gastric tumor and adjacent lymph nodes represents the only potentially curative intervention. Computed tomography (CT) has remained the modality of choice for the preoperative staging of gastric cancer and for follow-up. A recently developed advanced CT technique that makes use of thin sections, optimal contrast material enhancement, and multiplanar reformation allows more accurate staging. However, CT may be limited in the identification of nonenlarged lymph node metastasis, peritoneal dissemination, and small hematogenous metastasis. Positron emission tomography (PET) with 2-[fluorine-18]fluoro-2-deoxy-d-glucose (FDG) has been recognized as a useful diagnostic technique in clinical oncology. FDG PET allows scanning of a larger volume than is possible with CT. Although FDG PET is not an appropriate first-line diagnostic procedure in the detection of stomach cancer and is not helpful in tumor staging, it may play a valuable role in the detection of distant metastases, such as those of the liver, lungs, adrenal glands, ovaries, and skeleton. FDG PET may also be helpful in the follow-up of patients undergoing chemotherapy, as it allows the identification of early response to treatment. Further studies are needed to determine the efficacy of FDG PET in the detection of local nodal metastases and peritoneal dissemination. Nevertheless, the combined use of CT and PET can be helpful in the preoperative staging of stomach cancer and in the therapeutic monitoring of affected patients.

Adenocarcinoma of the esophagus and the esophagogastric junction: positron emission tomography improves staging and prediction of survival in distant but not in locoregional disease.

In adenocarcinoma of the esophagus and esophagogastric junction for prognostication and treatment allocation, one prerequisite is accurate pretreatment staging. This staging, we hypothesized, would be improved by the use of positron emission tomography (PET). After 55 patients suitable for radical esophageal resection were staged with PET, spiral computed tomography (CT), and endoscopic ultrasonography (EUS), results were compared with histopathology and with survival. Accuracy in detecting locoregional lymph node metastasis did not differ significantly between EUS (72%), PET (60%), and CT (58%). Adding PET to standard staging failed to improve the accuracy of N staging (P=0.250). In M staging, accuracy between CT (75%) and PET (76%) did not differ. The accuracy of combined studies of CT and PET and of EUS, CT, and PET were 87% (P=0.016 versus CT) and 91% (P=0.031 versus EUS and CT), respectively. Of the 55 patients, 19 (35%) had metastatic lesions. By combined use of CT and EUS and by combined use of CT, EUS, and PET, 8 and 14 (P=0.031), respectively, could be detected. In nodal disease without distant metastases, PET did not improve the prediction of survival. However, positive PET for distant metastasis by either positive EUS or CT predicts well the poor survival of these patients. The staging value of PET by itself in adenocarcinoma of the esophagus is limited because of low accuracy for nodal and the lack of specificity for distant disease prognosis. Adding PET to standard staging does, however, improve detection of stage IV disease and its associated poor survival.

Oral PresentationsImag Techr

An accurate pretreatment staging is prerequisite for prognostication and treatment allocation of adenocarcinoma of the esophagus. We hypothesized that this staging would be improved by positron emission tomography (PET). Fifty-five patients suitable for radical esophageal resection were staged with PET, spiral computed tomography (CT), and endoscopic ultrasonography (EUS) and the results were compared with histopathology and with survival. The accuracy for detecting locoregional lymph node metastasis did not differ significantly between EUS (72%), PET (60%), and CT (58%). By adding PET to standard staging the accuracy of N-staging did not improve (P = 0.250). By adding PET to CT (P = 0.016) or to combined use of EUS and CT (P = 0.031) improved the accuracy of M-staging. Nineteen (35%) of the 55 patients had metastatic lesions. By combined use of CT and EUS, eight and by combined use of CT, EUS and PET 14 (P = 0.031) could be detected. In nodal disease without distant metastases, PET did not improve the prediction of survival. However, positive PET for distant metastasis by either positive EUS or CT predicts well the poor survival of these patients. The staging value of PET by itself in adenocarcinoma of the esophagus is limited because of low accuracy in nodal and the lack of specificity in distant disease. By adding PET to standard staging does, however, improve the detection of stage IV disease and the related poor survival.

Far lateral lumbar disc herniations: 3- to 14-year results

A retrospective review of 38 patients who underwent surgical treatment for far lateral lumbar disc herniation (FLLDH) using two different techniques is reported. Between October 1986 and October 1997, we operated on 38 patients with FLLDH: 12 had extraforaminal disc herniation and 26 had foraminal disc herniation. Plain roentgenograms, computed tomography (CT) scans and magnetic resonance (MR) images were obtained before surgery. Postoperative outcomes showed a relief of clinical symptoms with recovery of neurological signs. There was no difference among the results encountered in the two surgical groups. A diagnosis of level based on physical examination alone is difficult. The combined use of CT and MR imaging helps to confirm the exact localization of disc herniation.

Three-dimensional computerized selection of hip prostheses in patients with congenital dislocated hips.

This study assessed the effectiveness of the combined use of computed tomography (CT) and computer-aided design (CAD) in the preoperative evaluation and implant selection in 20 patients (20 hips) with congenital dislocation of the hip who were scheduled to undergo total hip arthroplasty. Computerized selection of the femoral implant with optimum fit and fill was made after a three-dimensional reconstruction of the femoral canal using CT data and CAD. Implantation of all sizes of 5 noncemented and 2 cemented femoral implants was simulated using CATIA software (IBM, Kingstone, NY). When patients underwent surgery, 18 of 20 preselected prostheses agreed by type and size with the prostheses implanted. The remaining 2 preselected implants agreed by type only. In patients with dislocated and dysplastic hips, combined use of CT and CAD allows effective preoperative planning by providing the surgeon with vital information about the proximal femoral canal geometry and the possible femoral implant with optimum fit and fill to be used.

Vascular Invasion of Klatskin Tumor: Computed Tomography vs Digital Subtraction Angiography in Determining Resectability

Purpose : To compare the accuracy of computed tomography (CT) with that of digital subtraction angiography (DSA) in predicting the resectability of Klatskin tumor on the basis of vascular invasion. Materials and Methods : Twenty-five patients with Klatskin tumor who had undergone laparotomy were in-cluded in this study. In order to assess the surgical resectability of their tumors, the preoperative CT scans and DSA of these patients were retrospectively assessed in terms of vascular invasion. The criteria of unresectability were tumoral invasion of the proper hepatic artery or main portal vein, or simultaneous invasion of the hepatic artery on one side and the other side portal vein. Results : Tumors were unresectable in 13 cases, and resectable in 12. CT and DSA predicted nine and three tumors as unresectable ones, respectively. The sensitivity, specificity, positive predictive value, negative predic-tive value and accuracy of CT in determining whether a tumor was unresectable were 61.5%, 91.7%, 88.9%, 68.8% and 76.0%, respectively. For DSA, the respective figures were 23.1%, 100%, 100%, 54.5% and 60.0%. For the detection of vascular invasion without diameter change, CT was superior to DSA; for the evaluation of vascular anatomy, it was, however, less effective. CT failed to detect small hepatic metastasis (n=2), lymph node metastasis (n=1), variation of the bile duct (n=1), and the distal extent of tumor in the bile duct (n=1), factors which precluded surgical resection. Conclusion : CT is a reliable method for the detection of vascular invasion and tumor unresectability. For the detection of vascular anatomic variation, the combined use of CT and DSA would be helpful.

Computed tomography of soft-tissue lesions of the extremities, pelvic and shoulder girdles: Sonographic and pathological correlations

Sixty-five patients with various soft-tissue tumours were examined by computed tomography (CT) and ultrasonography. Results were correlated with pathological findings. Although an accurate histological prediction could not be made in most cases, certain patterns appeared to be characteristic of specific types of tumours. A lipoma of uniformly low density may be differentiated from the heterogeneously denser liposarcoma. Multiple irregular linear densities with calcification are characteristic of haemangioma. An echo-free mass on the sonogram with soft-tissue density on CT suggests lymphoma or certain sarcomas. Small isodense subcutaneous lipomas or intramuscular lymphomatous masses may be clearly delineated on sonogram but not seen on CT. Our study indicates that the combined use of CT and ultrasound gives a very detailed basis for planning the surgical approach to the tumour.