Compare Computed Tomography Scans Research Articles

FDG-PET/CT in the evaluation of anal carcinoma

Surgical staging and treatment of anal carcinoma has been replaced by noninvasive staging studies and combined modality therapy. In this study, we compare computed tomography (CT) and physical examination to [(18)F]-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography (FDG-PET/CT) in the staging of carcinoma of the anal canal, with special emphasis on determination of spread to inguinal lymph nodes. Between July 2003 and July 2005, 41 consecutive patients with biopsy-proved anal carcinoma underwent a complete staging evaluation including physical examination, CT, and 2-FDG-PET/CT. Patients ranged in age from 30 to 89 years. Nine men were HIV-positive. Treatment was with standard Nigro regimen. [(18)F]-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography (FDG-PET/CT) detected 91% of nonexcised primary tumors, whereas CT visualized 59%. FDG-PET/CT detected abnormal uptake in pelvic nodes of 5 patients with normal pelvic CT scans. FDG-PET/CT detected abnormal nodes in 20% of groins that were normal by CT, and in 23% without abnormality on physical examination. Furthermore, 17% of groins negative by both CT and physical examination showed abnormal uptake on FDG-PET/CT. HIV-positive patients had an increased frequency of PET-positive lymph nodes. [(18)F]-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography detects the primary tumor more often than CT. FDG-PET/CT detects substantially more abnormal inguinal lymph nodes than are identified by standard clinical staging with CT and physical examination.

Comparison of Magnetic Resonance Imaging Sequences With Computed Tomography to Detect Low-Grade Subarachnoid Hemorrhage

To compare computed tomography (CT) with magnetic resonance imaging (MRI) for the presumptive diagnosis and localization of acute and subacute low-grade subarachnoid hemorrhage (SAH). We consecutively enrolled 45 patients clinically suspected of low-grade SAH, comparing them with a control group. We obtained axial nonenhanced CT scans as well as fluid-attenuated inversion recovery (FLAIR) and T2-weighted gradient echo (T2*) MRI sequences at 1.0 T. Two neuroradiologists scrutinized the presence of blood at 26 different regions in the intracranial subarachnoid space (SAS). Three of 45 patients had normal CT and MRI scans, and SAH was excluded by lumbar puncture. We demonstrated SAH on CT scans in 28 of 42 (66.6%) patients, T2* sequences in 15 of 42 (35.7%) patients, and FLAIR sequences in 42 of 42 (100%) patients. Fluid-attenuated inversion recovery sequences were superior to CT in 16 of the 26 evaluated regions. The FLAIR sequence was superior for presumptive diagnosis and localization of acute and subacute low-grade SAH, representing a potential tool in this setting.

Comparison of Sagittal Computed Tomography and Plain Film Radiography in a Scaphoid Fracture Model

To compare computed tomography (CT) in the sagittal plane and plain film radiography in the diagnosis of scaphoid fracture and displacement. Three groups of scaphoids (no fracture, undisplaced fractures, fractures with displacement > 1 mm) from 11 cadaver wrists were prepared. Each wrist then was imaged by using sagittal plane CT scans in the long axis of the scaphoid and plain film imaging using 6 standard scaphoid views. Eight readers from 3 specialties read each group of images. The sensitivity and specificity for the presence of fracture and fracture displacement were calculated in addition to interobserver and intraobserver reliabilities for each. Both x-ray and CT scans showed a high sensitivity and specificity in detecting the presence of a fracture with no interspecialty differences. The sensitivity for displacement greater than 1 mm was lower for both modalities with no inter-specialty differences. The specificities for x-ray and CT for detecting displacement greater than 1 mm were 84% and 89%, respectively. The poor sensitivity for detecting displacement was explained by the low sensitivity of CT in the diagnosis of radial/ulnar displacement compared with x-ray and the low sensitivity of x-ray in the diagnosis of volar/dorsal displacement compared with CT scans. When fellowship-trained hand surgeons reviewed CT scans and plain films together the sensitivity and specificity for fracture displacement increased significantly. Intraobserver and interobserver reliability for both x-ray and CT scans was excellent except for the reading of CT scans among emergency physicians and for the reading of plain x-rays among senior house staff, representing moderate agreement. Based on these results both CT scans in the sagittal plane and plain films accurately detect fractures with a high degree of interobserver and intraobserver reliability, but they fall short in detecting displacement greater than 1 mm.

Myocysticercosis: Experience with imaging and therapy

Objective To compare computed tomography (CT) and B-scan ultrasonography (USG) in the diagnosis and to study the efficacy of a combination of oral albendazole and prednisolone in the management of myocysticercosis. Design Retrospective, noncomparative case series. Participants Twenty-six consecutive patients with myocysticercosis. Intervention Diagnostic imaging was performed by CT scan and USG in 24 and 22 patients, respectively; serial USG was obtained in 7 patients receiving treatment. All patients received oral albendazole (15 mg/kg body weight per day) and prednisolone (1.5 mg/kg body weight per day) for 4 weeks. Main outcome measures Presence of scolex on CT scan compared to USG and clinical response to medical therapy were the main outcome measures. Recovery was defined as complete resolution of the scolex or of the main presenting clinical feature. Results Presence of scolex on CT scan (11 of 24) and USG (11 of 22) was not different ( P = 1.0; chi-square test). Recovery was seen in 24 (92%) of 26 patients receiving medical treatment. On serial USG of patients receiving treatment (n = 7), cysts with scolex were seen to progress to a cyst without scolex before final resolution. Time to recovery on treatment (0.5–35 months) correlated with the duration of symptoms at presentation (correlation coefficient r = 0.56, P = 0.003, linear regression analysis), but not with positive serum enzyme-linked immunosorbent assay for anticysticercal antibodies ( P = 0.57, log-rank test) or the presence of scolex ( P = 0.52, log-rank test). Conclusions Treatment with a combination of oral albendazole and prednisolone is effective in the management of myocysticercosis. Imaging methods CT and USG are equally effective in identifying the cyst and the scolex; serial USG is useful in studying the temporal sequence of therapeutic response. The longer recovery time correlating with the duration of symptoms may indicate the chronicity of the inflammatory changes requiring longer time for recovery.

Evaluation of Prevertebral Muscle Invasion by Squamous Cell Carcinoma: Can Computed Tomography Replace Open Neck Exploration?

To compare computed tomography (CT) with open neck exploration in determining prevertebral invasion by squamous cell carcinoma of the oropharynx or hypopharynx. Retrospective analysis using the findings at open neck exploration and results of histopathologic studies as the criterion standards. Tertiary care referral center. Twenty-nine of 40 patients with advanced squamous cell carcinoma of the oropharynx or hypopharynx treated between January 1, 1986, and December 31, 1994, were selected for analysis based on CT findings of posterolateral extension of the primary tumor placing the prevertebral muscle (PVM) at risk. All study patients had no previous therapy and underwent neck exploration to determine resectability. Overall accuracy of CT in predicting PVM status was 55.2%. The sensitivity of preoperative CT for PVM invasion was 50%; the specificity was 61%. Using an estimate of 21% for the prevalence of PVM invasion, the predictive value of a positive CT scan was 0.254 and the predictive value of a negative CT scan was 0.821. Open neck exploration correctly predicted PVM status in all cases. Open neck exploration is superior to CT to evaluate possible PVM invasion by squamous cell carcinoma of the oropharynx or hypopharynx. The predictive value of a negative CT scan for PVM invasion is high, so it may be useful in treatment planning. Patients with advanced squamous cell carcinoma of the oropharynx or hypopharynx at risk for PVM invasion who are otherwise surgical candidates should be considered for open neck exploration to determine resectability most accurately.

Assessment of asbestos-induced pleural disease by computed tomography — correlation with chest radiograph and lung function

We compared computed tomography (CT) scanning with chest radiography in the assessment of asbestos-induced pleural disease (AIPD) in 20 patients (17 men and 3 women, mean age 55 years, range 43-74 years). Involved pleura was scored on plain chest radiographs according to the International Labour Office (ILO) method of evaluating AIPD. A CT score was calculated from the measurement, using a digital length probe, of the circumference of the chest wall involved by pleural disease in each slice. The maximum width of pleural disease was taken into account in a way analogous to the ILO method for the chest radiograph. The CT score correlated with the chest radiograph score (r = +0.82, P less than 0.0006). CT demonstrated discrete plaques in 95% of patients but these were identified only in 59% patients on the radiograph. Diffuse pleural thickening was evident on the CT scan in all patients and in 70% on the radiograph. There was more inter-reader agreement about the type of pleural disease on the CT scans than on the chest radiographs. CT and chest radiograph scores inversely correlated with all lung function measurements except KCO. We conclude that increasingly extensive pleural disease is associated with increasingly severe impairment of lung function. CT scanning demonstrates the type of AIPD better than plain chest radiography.

THE VALUE OF RADIOGRAPHIC AND COMPUTED TOMOGRAPHY IN THE STAGING OF LUNG CARCINOMA

Abstract A prospective double-blind study was undertaken to compare computed tomography (CT) and conventional radiographic tomography (RT) in the staging of lung carcinoma. Seventy-five patients had CT and RT of the mediastinum and hilum prior to operation. The presence or absence of metastasis to lymph nodes documented at the time of operation was the standard applied to the studies. CT correctly predicted the presence or absence of mediastinal lymphadenopathy in most cases (sensitivity 91%, specificity 94%), while RT was less helpful (sensitivity 61%, specificity 86%). Metastatic mediastinal lymph nodes in those patients with false negative CT and RT studies averaged only 0.8 cm in diameter, probably accounting for the negative radiographic findings. Both CT and RT had poor predictive values in detecting hilar lymphadenopathy (sensitivity 73% and 47%, specificity 87% and 72%, respectively). The predictive value of CT in the evaluation of mediastinal lymphadenopathy equaled that of mediastinoscopy or mediastinotomy. When CT of the mediastinum demonstrates no lymphadenopathy, invasive staging can be deferred for definitive thoracotomy. Since false positive values were seen with both CT and RT scans of the mediastinum (4% and 8%, respectively), invasive staging will still be necessary in those patients with positive studies.

The Value of Radiographic and Computed Tomography in the Staging of Lung Carcinoma

A prospective double-blind study was undertaken to compare computed tomography (CT) and conventional radiographic tomography (RT) in the staging of lung carcinoma. Seventy-five patients had CT and RT of the mediastinum and hilum prior to operation. The presence or absence of metastasis to lymph nodes documented at the time of operation was the standard applied to the studies. CT correctly predicted the presence or absence of mediastinal lymphadenopathy in most cases (sensitivity 91%, specificity 94%), while RT was less helpful (sensitivity 61%, specificity 86%). Metastatic mediastinal lymph nodes in those patients with false negative CT and RT studies averaged only 0.8 cm in diameter, probably accounting for the negative radiographic findings. Both CT and RT had poor predictive values in detecting hilar lymphadenopathy (sensitivity 73% and 47%, specificity 87% and 72%, respectively). The predictive value of CT in the evaluation of mediastinal lymphadenopathy equaled that of mediastinoscopy or mediastinotomy. When CT of the mediastinum demonstrates no lymphadenopathy, invasive staging can be deferred for definitive thoracotomy. Since false positive values were seen with both CT and RT scans of the mediastinum (4% and 8%, respectively), invasive staging will still be necessary in those patients with positive studies.