Helical Computed Tomography (helical + computed_tomography)

Distribution by Scientific Domains


Selected Abstracts


Impact of Helical Computed Tomography on the Outcomes of Emergency Department Patients with Suspected Appendicitis

ACADEMIC EMERGENCY MEDICINE, Issue 8 2003
Sam S. Torbati MD
Abstract Objectives: To assess the impact of an emergency department (ED) guideline employing selective use of helical computed tomography (CT) on clinical outcomes of female patients with suspected appendicitis. Methods: All patients presenting with suspected appendicitis were prospectively enrolled and managed in accordance with a guideline incorporating selective use of helical CT. Although not the objective of this investigation, male patients were included for purposes of comparison. Patients with clinically evident appendicitis were referred to the surgical service, and patients with equivocal presentations were studied with helical CT. Patients were followed to final surgical or clinical outcomes. Outcome measures included time from ED presentation to laparotomy and rate of appendiceal perforation. These measures were compared with those of a historical cohort of patients preceding the use of helical CT. Results: A total of 310 consecutive patients with suspected appendicitis were enrolled; 92 had appendicitis. Sixty patients were referred to the surgical service without helical CT, and 41 had appendicitis (68%). Helical CT was performed on 250 patients; 51 had appendicitis (20%). For males, the mean interval from ED presentation to laparotomy was 559 minutes (95% CI = 444 to 674 minutes) during guideline use and 480 minutes (95% CI = 405 to 555 minutes) before. This interval for females was 433 minutes (95% CI = 326 to 540 minutes) during guideline use and 710 minutes (95% CI = 558 to 862 minutes) before. Appendiceal perforation rate for males was 0.25 (95% CI = 0.14 to 0.36) during guideline use and 0.38 (95% CI = 0.29 to 0.47) before; perforation rate for females was 0.06 (95% CI =,0.05 to 0.17) during guideline use and 0.23 (95% CI = 0.14 to 0.32) before. Helical CT had 92% sensitivity, 97% specificity, and 96% accuracy in diagnosing appendicitis. Conclusions: Helical CT is highly accurate in detecting appendicitis in patients with equivocal ED presentations. The use of a guideline employing selective helical CT was associated with a decline in the time from ED presentation to operative intervention in females. [source]


Diagnosis of pancreatic cancer

HPB, Issue 5 2006
Fumihiko Miura
Abstract The ability to diagnose pancreatic carcinoma has been rapidly improving with the recent advances in diagnostic techniques such as contrast-enhanced Doppler ultrasound (US), helical computed tomography (CT), enhanced magnetic resonance imaging (MRI), and endoscopic US (EUS). Each technique has advantages and limitations, making the selection of the proper diagnostic technique, in terms of purpose and characteristics, especially important. Abdominal US is the modality often used first to identify a cause of abdominal pain or jaundice, while the accuracy of conventional US for diagnosing pancreatic tumors is only 50,70%. CT is the most widely used imaging examination for the detection and staging of pancreatic carcinoma. Pancreatic adenocarcinoma is generally depicted as a hypoattenuating area on contrast-enhanced CT. The reported sensitivity of helical CT in revealing pancreatic carcinoma is high, ranging between 89% and 97%. Multi-detector-row (MD) CT may offer an improvement in the early detection and accurate staging of pancreatic carcinoma. It should be taken into consideration that some pancreatic adenocarcinomas are depicted as isoattenuating and that pancreatitis accompanied by pancreatic adenocarcinoma might occasionally result in the overestimation of staging. T1-weighted spin-echo images with fat suppression and dynamic gradient-echo MR images enhanced with gadolinium have been reported to be superior to helical CT for detecting small lesions. However, chronic pancreatitis and pancreatic carcinoma are not distinguished on the basis of degree and time of enhancement on dynamic gadolinium-enhanced MRI. EUS is superior to spiral CT and MRI in the detection of small tumors, and can also localize lymph node metastases or vascular tumor infiltration with high sensitivity. EUS-guided fine-needle aspiration biopsy is a safe and highly accurate method for tissue diagnosis of patients with suspected pancreatic carcinoma. 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) has been suggested as a promising modality for noninvasive differentiation between benign and malignant lesions. Previous studies reported the sensitivity and specificity of FDG-PET for detecting malignant pancreatic tumors as being 71,100% and 64,90%, respectively. FDG-PET does not replace, but is complementary to morphologic imaging, and therefore, in doubtful cases, the method must be combined with other imaging modalities. [source]


Unenhanced helical computed tomography in the evaluation of acute flank pain

INTERNATIONAL JOURNAL OF UROLOGY, Issue 6 2003
NAZIM ALI AHMAD
Abstract Objectives: The purpose of this study was to determine the value of unenhanced helical computed tomography (UHCT) in the diagnosis of acute flank pain at our institution. Methods: Two hundred and thirty-three consecutive UHCT examinations, performed for suspected renal/ureteral colic between July 2000 and August 2001 were reviewed, along with pertinent medical records. Results: Ureteral calculi were identified in 148 (64%) examinations, evidence of recent passage of calculi was found in 10 (4%) and no calculi were found in 75 (32%). Thirty-two of the conservatively managed patients were excluded for inadequate follow-up. In the remaining 201 patients, sensitivity of UHCT in diagnosing calculi was 99% and specificity was 98%, while the positive predictive value was 99% and negative positive predictive value was 98%. Overall, an alternative or additional diagnosis was established in 28 (12%) patients. Upon diagnosis of ureterolithiasis on UHCT, none of the patients required additional imaging studies for confirmation. Conclusion: UHCT is a highly sensitive imaging modality for the detection of urinary tract calculi and obstruction. [source]


Western Australian cigarette smokers have fewer small lung nodules than North Americans on CT screening for lung cancer

JOURNAL OF MEDICAL IMAGING AND RADIATION ONCOLOGY, Issue 4 2009
CP Murray
Summary To determine the prevalence of small lung nodules on low-dose helical computed tomography (CT) in a Western Australian cohort of asymptomatic long-term cigarette smokers and to compare this with a large, similarly derived cohort of North Americans from the Mayo Clinic Lung Cancer Screening Trial. Forty-nine asymptomatic long-term cigarette smokers of minimum age 50 years underwent a low-dose 64-slice helical CT of the lungs. Images were viewed on a soft copy reporting station with thin section axial and coronal images, maximum intensity projection images, and advanced image manipulation tools. The prevalence of all nodules was 39%, significantly lower than the Mayo Clinic cohort prevalence of 51% (P < 0.01, Fisher's exact test), despite the use of more advanced imaging technology and image manipulation designed to increase the sensitivity for nodules. The prevalence of small nodules in asymptomatic long-term cigarette smokers in Western Australia is high, though significantly less than that found in a large study in North America. The authors postulate this is due to the relatively low rates of mycobacterium tuberculosis and soil-derived fungal pulmonary infections in Western Australia, as well as a lower degree of urban air pollution. [source]


Observation of three cases of temporomandibular joint osteoarthritis and mandibular morphology during adolescence using helical CT

JOURNAL OF ORAL REHABILITATION, Issue 4 2004
K. Yamada
summary, Temporomandibular joint (TMJ) osteoarthritis (OA) is a potential cause of craniofacial deformity. If TMJ OA appears during orthodontic treatment, the mandible usually rotates posteriorly, resulting in an unsatisfactory profile, especially in patients with pre-treatment mandibular retrusion. Although it is important to confirm the kind of TMJ pathosis at the start of orthodontic treatment, the relationship between TMJ OA, condylar remodelling and changes in craniofacial morphology remains unclear because of a lack of longitudinal studies. Elucidating this relationship might allow better prediction of post-treatment craniofacial morphology. In the present case reports, helical computed tomography and cephalometry were used to analyse relationships between the pattern and location of condylar remodelling and the changes in craniofacial morphology in three patients with TMJ OA. [source]


Computed Tomography (CT) of the Lungs of the Dog Using a Helical CT Scanner, Intravenous Iodine Contrast Medium and Different CT Windows

ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 5 2007
L. Cardoso
Summary The aim of this study was to determine the accuracy of helical computed tomography (CT) for visualizing pulmonary parenchyma and associated formations in normal dogs. CT scan was performed by using intravenous contrast medium and by applying different types of CT windows: soft tissue and lung windows, and high-resolution computed tomography of the lung. This technique allowed, especially with lung window types, a good view of the parenchyma, bronchial tree, vascular structures and pleural cavity. The selected images, with high anatomical quality and tissue contrast, may be a reference for future clinical studies of this organ. Thus, helical CT is a promising non-invasive method of diagnosing a wide variety of pulmonary diseases in dogs. [source]


Surgical validation of unenhanced helical computed tomography in acute appendicitis,

BRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 12 2004
K. H. in't Hof
Background: Surgery for pain in the right lower quadrant of the abdomen remains a clinical dilemma. This prospective study assessed the accuracy of preoperative unenhanced helical computed tomography (CT) in the evaluation of patients with suspected acute appendicitis. Methods: One hundred and three adult patients with suspected acute appendicitis underwent unenhanced helical CT of the abdomen. Subsequently, all patients underwent laparoscopic inspection of the abdominal cavity by a surgeon who was blinded to the diagnosis suggested by CT. Patients underwent appropriate surgical therapy accordingly. Follow-up was at least 6 weeks. Results: Appendicitis was diagnosed by CT in 83 patients (80·6 per cent). Acute appendicitis was identified during laparoscopy in 87 patients (84·5 per cent). Prospective interpretation of CT images yielded a sensitivity of 95·4 per cent and a specificity of 100 per cent for the diagnosis of acute appendicitis. There were four false-negative scans. In 12 of 20 patients without signs of appendicitis on CT, the scan established the presence of other pathology. At operation no additional pathology was observed in this group and all other diagnoses proved to be correct. Conclusion: Plain helical CT in patients with suspected acute appendicitis provides an accurate diagnosis without the disadvantages of contrast enhancement. Copyright © 2004 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. [source]


Evaluation of tumor response after locoregional therapies in hepatocellular carcinoma,

CANCER, Issue 3 2009
Are response evaluation criteria in solid tumors reliable?
Abstract BACKGROUND: Evaluation of response to treatment is a key aspect in cancer therapy. Response Evaluation Criteria in Solid Tumors (RECIST) are used in most oncology trials, but those criteria evaluate only unidimensional tumor measurements and disregard the extent of necrosis, which is the target of all effective locoregional therapies. Therefore, the European Association for the Study of the Liver (EASL) guidelines recommended that assessment of tumor response should incorporate the reduction in viable tumor burden. The current report provides an assessment of the agreement/concordance between both RECIST and the EASL guidelines for the evaluation of response to therapy. METHODS: The authors evaluated a cohort of 55 patients within prospective studies, including 24 patients with hepatocellular carcinoma who underwent transarterial chemoembolization (TACE) with drug eluting beads (DEB-TACE) and 31 patients who underwent percutaneous ablation (percutaneous ethanol injection [PEI]/radiofrequency [RF]). Triphasic helical computed tomography scans were performed at baseline, at 1 month, and at 3 months after procedure, and 2 independent radiologists evaluated tumor response. RESULTS: Evaluating response according to RECIST criteria, no patients achieved a complete response (CR), 21.8% of patients achieved a partial response (PR) (none in the PEI/RF group), 47.3% of patients had stable disease (SD), and 30.9% of patients had progressive disease (PD). When response was evaluated according to the EASL guidelines, 54.5% of patients achieved a CR, 27.3% of patients achieved a PR, 3.6% of patients had SD, and 14.5% had PD. The , coefficient was 0.193 (95% confidence interval, 0.0893-0.2967; P < .0001). CONCLUSIONS: RECIST missed all CRs and underestimated the extent of partial tumor response because of tissue necrosis, wrongly assessing the therapeutic efficacy of locoregional therapies. This evaluation should incorporate the reduction in viable tumor burden as recognized by nonenhanced areas on dynamic imaging studies. Cancer, 2009. © 2008 American Cancer Society. [source]


Angiographic subsegmentectomy for the treatment of patients with small hepatocellular carcinoma

CANCER, Issue 4 2003
Shozo Iwamoto M.D.
Abstract BACKGROUND The therapeutic results of nonsurgical treatment for patients with hepatocellular carcinoma (HCC) have been poor, and improved treatments are needed. The authors recently developed a new technique called angiographic subsegmentectomy for the treatment of patients with small HCC. METHODS The technique includes confirming the diagnosis of small HCC using a helical computed tomography (CT) scan combined with an angiography system for identifying the tumor-feeding subsegmental hepatic artery, injecting lipiodol containing farmorubicin until it enters the portal vein in sufficient amounts, and injecting sponge particles into the hepatic artery for embolization. Occlusion of the hepatic artery with gel particles and occlusion of the portal vein by lipiodol induce infarction necrosis, which encompasses the entire tumor and the surrounding liver parenchyma. RESULTS The treatment was given to 23 patients with 30 HCC tumors that measured < 20 mm in greatest dimension. It was successful in all 23 patients. Serum alanine aminotransferase levels were elevated to a significant level in the majority of patients after treatment, mild ascites developed in three patients, and the patients complained of pain and fever posttreatment that were controlled readily. No patients developed hepatic failure. Only one patient developed recurrent disease posttreatment at 1.5 years, for a recurrence rate of 5% at 1 year and 6.6% at 1.5 years, a rate that has never been achieved with other treatment modalities. CONCLUSIONS Angiographic subsegmentectomy is a novel treatment for patients with small HCC. The results indicated that it is equivalent to undergoing small resection and is superior to conventional arterial chemoembolization. Cancer 2003;97:1051,6. © 2003 American Cancer Society. DOI 10.1002/cncr.11106 [source]