The food-service industry, dietary guidelines and change

This study was aimed at assessing the clinical usefulness of measuring the contrast enhancement (CE) of solitary pulmonary nodules (SPN) in distinguishing benign from malignant lesions. We used spiral CT to study prospectively 35 pulmonary lesions presenting as SPNs < 30 mm phi; we evaluated the CE of the nodules 120 minutes after the administration of 100 mL of nonionic contrast material (= 30 grams of iodine), at 2 mL/s. The final diagnosis of the 35 SPNs was made at surgery (27 cases); positive sputum cytology (2 cases), 12 months' follow-up (5 cases) or fine-needle aspiration biopsy and 6 months' follow-up (1 case). Thus, 25 of 35 SPNs proved malignant (11 adenocarcinomas, 5 squamous cell carcinoma, 2 large cell carcinomas, 2 carcinoids, 1 small cell carcinoma, 2 cases with positive sputum cytology, 2 metastases) and the extant 10 of 35 proved benign. Malignant nodules enhanced markedly more (mean value: 36.8 HU) more than benign lesions (mean value: 18.6 HU). CE exceeded 20 HU in 23/25 malignant nodules and did not in 2/25; it did not exceed 20 HU in 6/10 benign nodules and did in 4/10. With 20 HU as the threshold value for a positive test (malignancy), sensitivity was 92%, specificity 60% and accuracy 83%; positive and negative predictive values were 85% and 75%, respectively. In conclusion, CE evaluation is a sensitive, although not very specific, indicator of malignancy in SPNs.     

Sodium butyrate induces NIH3T3 cells to senescence-like state and enhances promoter activity of p21WAF/CIP1 in p53-independent manner

PURPOSE: To evaluate the diagnostic efficacy of computed tomography (CT) after hepatic intraarterial injection of iodized oil in patients with hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Forty patients who underwent CT with iodized oil before orthotopic liver transplantation (OLT) were evaluated prospectively. All patients underwent digital subtraction angiography and injection of iodized oil during chemoembolization. CT during arterial portography (CTAP) was performed in 34 patients. The number of neoplastic nodules was assessed in explanted livers and compared with the radiologic results. RESULTS: Sixty-six HCC nodules were present in the explanted livers. CT with iodized oil enabled correct diagnosis in 38 of 66 lesions (58%), and the results were false-positive in two lesions (3%). Digital subtraction angiography had a sensitivity of 67% (44 of 66 nodules) and CTAP had a sensitivity of 85% (45 of 53 nodules). Four (6%) false-positive diagnoses were made at digital subtraction angiography and three (6%) at CTAP. The diagnostic efficacy of CT with iodized oil was significantly related to lesion diameter greater than 2 cm (P < .0001) and hypervascularity (P < .0001). CONCLUSION: CT with iodized oil failed to provide any substantial information in the pre-OLT staging of HCC: It was inaccurate for small HCC nodules (<2 cm) and intrahepatic metastases. Its sensitivity matched that of digital subtraction angiography and was statistically significantly inferior to that of CTAP.     

Depot medroxyprogesterone acetate or oral contraception in postpartum adolescents

The purpose of the study was the evaluation of low-dose spiral CT in the detection and assessment of contours of pulmonary nodules. In a prospective investigation 71 consecutive chest CT examinations were acquired both at 30 and 200 mA. Films were interpreted independently by two radiologists. According to the size, nodules were divided into four categories: 10 mm; nodule shape was registered. With both protocols, 240 nodules were detected. The correlation coefficient for both methods was 0.89. Discrepancies were found most frequently in nodules near to pulmonary vessels. Nodule size estimation did not differ more than one size category. Eight spiculated nodules were identified by both techniques. Low-dose spiral CT of the chest has a high sensitivity in the detection of pulmonary nodules. If clinical circumstances require dose minimization, low-dose spiral CT may be advocated as an alternative screening method to conventional dose spiral CT.     

Ghosting of pulmonary nodules with respiratory motion: comparison of helical and conventional CT using an in vitro pediatric model

OBJECTIVE: The study was designed to compare helical CT with varying pitch and reconstruction intervals and conventional CT for revealing pulmonary nodules in a model that simulates respiratory motion in children. MATERIALS AND METHODS: CT scans were obtained in an experimental model with one nodule (3 or 10 mm) in each scan. One-second scans were obtained at rates of 10, 20, and 30 respirations per minute using conventional CT with 4-mm collimation and table incrementation and helical CT with 4-mm collimation and either 4-mm/sec (pitch, 1:1) or 8-mm/sec (pitch, 2:1) table speed. Reconstructions were at 1-, 2-, and 4-mm intervals for scans obtained using 4-mm/sec table speed and at 1- and 4-mm intervals for scans obtained using 8-mm/sec table speed. Images were independently reviewed by three radiologists who estimated the number of nodules on each image. RESULTS: Ghosting (depiction of more than one nodule in a study) was seen in 79%, 80%, and 75% of helical CT scans obtained with a 1:1 pitch using 1-, 2-, and 4-mm reconstruction intervals, respectively. By comparison, ghosting was seen in only 54% and 58% of helical CT scans with a 2:1 pitch using 1-mm reconstruction intervals and 4-mm reconstruction intervals, respectively, and in 56% of conventional CT scans (p < .0001). A single nodule was detected on all other scans, and at least one nodule was seen on all scans. CONCLUSION: Ghosting of nodules is common in this model. Ghosting was seen less often on conventional scans and helical scans with 2:1 pitch than it was on helical scans with 1:1 pitch. Nonetheless, ghosting was seen on more than 50% of all scans with each technique.     

Unicornuate uterus: imaging appearance, associated anomalies, and clinical implications

OBJECTIVE: The study is a prospective comparison of helical CT with nonhelical CT arterial portography (CTAP) in the detection of liver metastases from colorectal carcinoma, using surgical and histologic findings as the gold standard. SUBJECTS AND METHODS: Thirty-five patients with colorectal carcinoma and suspected liver metastases were prospectively examined with helical CT and CTAP before surgery. In nine cases, surgery was not performed. In the remaining 26 patients, imaging results were correlated with surgical and pathologic findings. Three radiologists prospectively assessed metastatic involvement with both techniques. The results were compared with pathologic and surgical findings on a lesion-by-lesion basis. In a second phase, three radiologists not directly concerned in the design of the study independently assessed metastatic involvement of the liver as revealed on helical CT and CTAP on a segment-by-segment basis with a five-level scale of confidence. Results were analyzed by receiver operating characteristic methods. RESULTS: The results of the histologic study disclosed 50 metastatic lesions. Helical CT had a sensitivity of 76% (38/50) and a positive predictive value of 90%. CTAP had a sensitivity of 74% (37/50) and positive predictive value of 69%. Receiver operating characteristic analysis revealed a greater area under the curve (Az index), 0.96, for helical CT than for CTAP (0.86). Differences were statistically significant (p < .001). CONCLUSION: Helical CT is superior to nonhelical CTAP in the detection of hepatic metastases from colorectal carcinoma.     

Pulmonary nodules: effect of increased data sampling on detection with spiral CT and confidence in diagnosis

PURPOSE: To compare spiral computed tomography (CT) with interscan spacing of 4-5 mm versus 8-10 mm for detection rate and level of confidence in diagnosis of pulmonary nodules. MATERIALS AND METHODS: Four radiologists (two junior and two senior faculty members) retrospectively reviewed 67 spiral CT studies with one to six nodules per study. Every second image was masked, which resulted in 8-mm sections every 8 or 10 mm; then all images reconstructed every 4 or 5 mm were reviewed. Lesions were classified as definite, probable, or possible. RESULTS: Narrow interscan spacing yielded more lesions overall (583 vs 566, P < .025) and more definite lesions and fewer equivocal lesions (482 vs 431 and 101 vs 135, respectively; P < .055). The greatest effects were in the reduction of possible lesions (50 vs 88, P < .001) and in the reduction of false-positive diagnoses made by less experienced radiologists. CONCLUSION: Increased reconstruction frequency of spiral CT volume data sets improves detection of pulmonary nodules and enhances confidence in the diagnosis.     

Transfectable and transplantable postmitotic human neurons: a potential "platform" for gene therapy of nervous system diseases

OBJECTIVE: To evaluate F-18 fluorodeoxyglucose positron emission tomography (PET) in terms of its sensitivity and specificity in diagnosing malignant pulmonary nodules and staging bronchogenic carcinoma. METHODS: A retrospective review of any patient that presented to the VA Palo Alto Health Care System with a pulmonary nodule between 9/94 and 3/96 revealed 49 patients (four female, 45 male) age 37-85 (mean 63) with 54 pulmonary nodules who had: chest CT scan, PET scan; and tissue characterization of the nodule. Characterization of each nodule was achieved by histopathologic (N = 44) or cytopathologic (N = 10) analysis. Of the 49 patients, 18 had bronchogenic carcinoma which was adequately staged. Mediastinal PET and CT findings in these 18 patients were compared with the surgical pathology results. N2 disease was defined as mediastinal lymph node involvement by the American Thoracic Society's classification system. Mediastinal lymph nodes were interpreted as positive by CT if they were larger that 1.0 cm in the short-axis diameter. RESULTS: Sensitivity and specificity for the diagnosis of malignant pulmonary nodules using PET was 93 and 70%, respectively. All nodules (N = 3) that were falsely positive by PET scan were infectious in origin. All nodules (N = 4) that were falsely negative by PET were technically limited studies (outdated scanner, no attenuation correction, hyperglycemia) except for one case of metastatic adenocarcinoma. The sensitivity and specificity of PET in diagnosing N2 disease was 67 and 100%, compared with 56% and 100% for CT scan (not statistically significant). However, one more patient with N2 disease was correctly diagnosed by PET than by CT scan. CONCLUSION: PET is a valuable tool in the diagnosis and management of pulmonary nodules and may more accurately stage patients with bronchogenic carcinoma than CT scanning alone.     

Oxylipin formation in fungi: biotransformation of arachidonic acid to 3-hydroxy-5,8-tetradecadienoic acid by Mucor genevensis

STUDY OBJECTIVE: The objectives of the present study were to evaluate the importance of intrapulmonary lymph nodes (IPLNs) in the differential diagnosis of small pulmonary nodules and to review the CT findings of IPLNs. DESIGN: Retrospective analysis of patient records. SETTING: Chest Disease Research Institute Hospital, Kyoto University. PATIENTS: Between January 1991 and May 1996, we examined 26 patients with pulmonary nodular shadows smaller than 1 cm in diameter that could not be diagnosed before surgery. All patients (19 men, 7 women) underwent chest CT (28 to 72 years old; mean, 52.3 years). RESULTS: The pathologic diagnoses were IPLNs in 46.2% (12/26), pulmonary hamartoma in 23.1% (6/26), lung cancer in 11.5% (3/26), pulmonary tuberculoma in 11.5% (3/26), and metastatic lung tumor in 7.7% (2/26). IPLNs were located in the lower lobe in 72%. The characteristic CT findings of IPLNs were a clear border and location close to the pleura. Two of them resembled lung cancer. The CT features in these two IPLNs and in three small lung cancers overlapped. CONCLUSIONS: In the present study, we investigated small nodular shadows <1 cm in diameter and found that IPLNs located underneath the pleura are important to consider in the differential diagnosis of lung cancer. The CT scan findings of IPLNs were not necessarily specific and sometimes resembled those of lung cancer. Because of their location, video-assisted thoracic surgery is useful in making a definite diagnosis.     

Endogenous benzodiazepine-like compounds and diazepam binding inhibitor in serum of patients with liver cirrhosis with and without overt encephalopathy

PURPOSE: The purpose of our work was to determine the usefulness of double-phase helical CT during arterial portography (CTAP) for the detection of hypervascular hepatocellular carcinoma (HCC). METHOD: Eighty-four patients with 176 hypervascular HCC nodules underwent double-phase CTAP. Hypervascular HCCs were diagnosed by iodized oil CT after transcatheter arterial chemoembolization (TACE). The first-phase images were obtained 30 s after the initiation of injection of a nonionic iodinated contrast medium into the superior mesenteric artery or splenic artery, and the second-phase images were obtained after 70 s. These images were interpreted separately for detection of HCC. RESULTS: The double-phase CTAP detected two nodules and six nodules that were missed by the first- and second-phase images, respectively. The sensitivity for hypervascular HCC nodules was 89% for the first phase, 91% for the second phase, and 93% for the first phase and second phase combined. The double-phase CTAP showed significantly superior sensitivity to the first-phase CTAP for detecting HCC nodules (p < 0.05). However, there was no statistically significant difference between the sensitivities of the double-phase CTAP and the second-phase CTAP. The positive predictive values of the double-phase images were inferior to those of either the first-phase or the second-phase images alone. CONCLUSION: Double-phase helical CTAP was found to be no better than second-phase CTAP alone for the detection of hypervascular HCC nodules.     

The hepatopulmonary syndrome: radiologic findings in 10 patients

OBJECTIVE: The purpose of this study was to review the radiologic manifestations of the hepatopulmonary syndrome. MATERIALS AND METHODS: We retrospectively reviewed clinical records, chest radiographs, 99m Tc-macroaggregated albumin (MAA) perfusion lung scans, chest CT scans, and pulmonary angiograms of 10 patients with proven hepatopulmonary syndrome. RESULTS: Chest radiographs showed basilar, medium-sized (1.5-3.0 mm) nodular or reticulonodular opacities in all cases. CT was done in eight cases and showed basilar dilatation of lung vessels with a larger than normal number of visible branches. The vascular basis for these opacities was best appreciated on conventional CT scans of 10-mm sections. No individual arteriovenous malformations were seen on CT scans. High-resolution CT scans showed no evidence of interstitial fibrosis. 99mTc-MAA perfusion lung imaging, done in seven patients, showed pulmonary arteriovenous shunting in five. Contrast echocardiography confirmed intrapulmonary shunting in these five patients. Pulmonary angiography, done in four cases, showed subtle distal vascular dilatation in two and moderate dilatation with early venous filling in two but did not reveal any individual arteriovenous malformations. CONCLUSION: Chest radiographs in hepatopulmonary syndrome usually show bibasilar nodular or reticulonodular opacities. Conventional CT shows that these opacities represent dilated lung vessels. High-resolution CT is useful in excluding pulmonary fibrosis or emphysema as the cause of these opacities. 99mTc-MMA perfusion imaging or contrast echocardiography can be used to confirm intrapulmonary arteriovenous shunting.     

CT colonography with three-dimensional problem solving for detection of colonic polyps

OBJECTIVE: We performed CT colonography in patients referred for conventional colonoscopy, interpreted the axial images, and used commercially available software to reconstruct endoluminal perspective views to differentiate polyps from folds. SUBJECTS AND METHODS: We prospectively examined 44 patients (27 men and 17 women; mean age, 58 years old) with CT colonography by interpreting the axial images and using three-dimensional rendering for problem solving only. The CT scans were interpreted by two radiologists who were unaware of patients' histories as revealed by colonoscopic findings. The findings on colonography were compared with those of conventional colonoscopy to determine sensitivity, specificity, time spent on interpretation, and confidence of interpretation. RESULTS: Colonoscopy showed normal findings in 28 patients and 22 polyps in the remaining 16 patients. Six polyps were 8 mm or larger, three were 5-7 mm, and 13 were 5 mm or smaller. The findings of the two observers revealed an overall sensitivity of 50% and 38%, respectively, and a specificity of 93% and 86%, respectively. Sensitivity for polyps larger than 8 mm was 83% and specificity was 100% for both observers. The average amount of time spent on interpretation was 28 min 30 sec (range, 14-65 min). Both observers used the endoluminal view for differentiating folds from polyps in 23 (52%) of 44 patients, which had only minimal impact on interpretation time. CONCLUSION: CT colonography can be performed and the images interpreted using currently available hardware and software by initially using the axial images to search for polyps of significant size. Endoluminal views should be used only when necessary to help distinguish normal folds from fixed raised lesions that are suggestive of polyps.     

CT-image analysis of resected peripheral adenocarcinomas of the lung less than 1 cm in diameter

Conventional CT (10-mm thick) and helical thin-section CT (2-mm thick) high-resolution images were obtained to study the relationship between the appearance of small peripheral adenocarcinomas of the lung and pathological findings. Eleven cases in which adenocarcinomas less than 1.0 cm in diameter were resected were retrospectively reviewed. Conventional CT images revealed air spaces within pulmonary nodules in 82% of tumors, an ill-defined margin in 91%, and involvement of vessels in 91%. When these findings are observed in pulmonary nodules, thin-section CT should be used for further examination. Helical thin-section CT images showed inhomogeneous internal attenuation (91%), irregularly undulating margins (91%), and vascular involvement (100%).     

The mammalian homologue of mago nashi encodes a serum-inducible protein

OBJECTIVE: We prospectively compared the ability of two techniques--bone scintigraphy with single-photon emission computed tomography (SPECT) of the chest and CT of the chest--to reveal potential osteosarcoma metastases of the lung. SUBJECTS AND METHODS: Our study included 27 patients with osteosarcoma who prospectively underwent both bone scintigraphy with SPECT of the chest and CT of the chest. The imaging results were compared with outcome or pathologic analysis of any lung lesions found. RESULTS: Eight (30%) of the 27 patients had pulmonary metastases. Four of these eight patients had positive results on both CT studies and bone SPECT studies, with additional lesions detected with bone SPECT in two of these four patients. The other four patients with pulmonary metastases had positive results on CT studies, whereas the results of bone SPECT studies remained negative. The results of bone SPECT studies were negative in the 19 patients without pulmonary metastases. CT, however, showed abnormalities in seven (37%) of the 19 patients, which were eventually attributed to benign conditions. CONCLUSION: Negative results on a bone SPECT study of the chest should not be used to exclude the possibility of lung metastases. However, if the results are positive, a bone SPECT study can be used to confirm abnormalities seen on CT scans and may also reveal subtle lesions missed on CT scans.     

Cardiorespiratory responses to acute hypoxemia in the chronically catheterized fetal llama at 0.7-0.9 of gestation

PURPOSE: To compare hard-copy digital chest radiographs obtained with a selenium-based system with wide-latitude asymmetric screen-film radiographs for detection of pulmonary nodules. MATERIALS AND METHODS: Fifty patients undergoing thoracic computed tomography (CT) for suspected pulmonary nodules were recruited to undergo both digital and screen-film posteroanterior (PA) and lateral chest radiography. Three chest radiologists blinded to the CT results independently reviewed each digital and screen-film radiograph, identified each nodule, and graded their confidence for its presence. RESULTS: Seventy-eight pulmonary nodules (mean diameter, 1.5 cm; range, 0.5-3.5 cm; 62 soft tissue, 16 calcified) were identified with CT in 34 patients, while 16 patients had clear lungs. The mean sensitivity for the detection of all nodules by all readers (PA and lateral) was 66% (95% Cl, 54%, 76%) for digital radiographs and 64% (95% Cl, 52%, 74%) for screen-film radiographs. Differences between the two techniques were not statistically significant (P > .05, Student t test). There was no difference in mean false-positive-true-positive ratios (PA, 0.35; lateral, 0.53) or positive predictive values (PA, 74%; lateral, 65%), and no significant difference (P > .05) was seen in mean reader confidence rating. CONCLUSION: In detecting pulmonary nodules, radiologists perform comparably with selenium-based digital and wide-latitude asymmetric screen-film radiographs.     

Influence of diagnostic and treatment factors in the population pharmacokinetics of gentamicin

STUDY OBJECTIVES: To determine the feasibility of macroscopic visualization of small ovarian cancer metastases in vivo by fluorescence after intravenous administration of 5-aminolevulinic acid (ALA); to assess the time after drug injection when fluorescence of small metastases is maximum; and to correlate macroscopic in vivo fluorescence with both microscopic ex vivo fluorescence and histologic findings. DESIGN: Controlled animal study (Canadian Task Force classification I). SETTING: University-based facility. SUBJECTS: Twenty-four healthy, female Fischer rats. INTERVENTION: Diffuse peritoneal metastatic cancer was induced in Fischer 344 rats by intraperitoneal injection of 1 million syngeneic ovarian cancer cells (NuTu-19). Four weeks after induction ALA100 mg/kg was injected intravenously, and diagnostic laparotomy was performed 1, 3, 6, or 9 hours thereafter. MEASUREMENTS and MAIN RESULTS: The peritoneal cavity was illuminated with the Wood's lamp (ultraviolet light). Fluorescence was determined by direct visualization and compared with a calibrated fluorescent disk. Tissues were collected, sectioned, and examined by fluorescence and conventional light microscopy. Within 1 to 3 hours after intravenous injection of ALA, in vivo fluorescence of tumor nodules (diameter 0.4-5.0 mm) was macroscopically visible. Tumor-free peritoneum did not show fluorescence and was significantly distinguishable from cancer nodules. Fluorescence from intestinal tissues was comparable with tumor nodules. Microscopic fluorescence analysis showed similar values for tumor nodules and peritoneum. Stained histologic specimens of peritoneal surface revealed a superficial layer of cancer cells responsible for fluorescence. The time course of the fluorescence curve in the intestine peaked twice, at 1 and 6 hours after ALA injection. Macroscopically fluorescing nodules were histology confirmed as malignant. CONCLUSIONS: Fluorescence detection of small cancer nodules after intravenous injection of ALA is feasible for nodules smaller than 0.5 mm on the peritoneum. One to 3 hours after drug injection is optimal for diagnosis of metastases.     

Significance of circulating hepatocyte growth factor level as a prognostic indicator in primary breast cancer

OBJECTIVE: The purpose of the study was to develop quantitative and qualitative criteria for diagnosing fatty liver on contrast-enhanced helical CT. SUBJECTS AND METHODS: Differential liver-spleen attenuation was evaluated between 80 and 120 sec after injection in 76 patients who underwent contrast-enhanced helical CT. Unenhanced CT images had earlier established fatty liver when the liver minus spleen attenuation difference was less than or equal to -10 H (n = 18). Four observers who had not seen the unenhanced images used contrast-enhanced CT images to assess the presence of fatty liver on a five-point Likert scale, the presence of geographic areas spared from fatty infiltration, and the relative liver-spleen attenuation. The diagnostic accuracies of various imaging criteria were compared using McNemar's chi-square test (for sensitivity and specificity) and analysis of receiver operating characteristic curves. RESULTS: Sensitivity, specificity, and receiver operating characteristic curve areas for observers' qualitative judgments were 54%, 95%, and .91, respectively; for quantitative differential liver-spleen attenuation (80-100 sec; -20.5 H discriminatory value), the values were 86%, 87%, and .94, respectively; and for quantitative differential liver-spleen attenuation (101-120 sec; -18.5 H discriminatory value), the values were 93%, 93%, and .98, respectively. Differential liver-spleen attenuation was time-dependent; overlap was noted between healthy subjects and patients with fatty liver. Qualitatively, geographic sparing was highly specific (94%) for fatty liver, whereas liver attenuation greater than or equal to spleen attenuation excluded fatty liver in all but one case. CONCLUSION: Although quantitative and qualitative criteria for diagnosing fatty liver on helical CT can be determined, they are protocol-specific. Limited unenhanced hepatic CT remains the optimal technique for detection of fatty infiltration of the liver.     

Evaluation of a pharmaceutical care model on diabetes management

PURPOSE: To determine the value of spiral CT during arterial portography (SCTAP) in detecting and localising focal liver lesions we compared the SCTAP findings to those gained by conventional CT during arterial portography (CTAP). MATERIAL AND METHODS: We evaluated a total of CT scans of 128 patients with 162 malignant lesions of the liver. 45 patients underwent SCTAP and 83 patients CTAP. Results of radiological studies were compared with surgical and pathological findings. RESULTS: The overall sensitivity of SCTAP was 93% with a sensitivity of 80% for lesions of less than 1 cm diameter. For CTAP the overall sensitivity was 88%, but the sensitivity for lesions smaller than 1 cm was only 53%. Although with SCTAP examination of hepatic vasculature and liver parenchyma was continuous, we found no advantage in the localisation of lesions to the liver segments compared to CTAP, and the sensitivity of localisation did not correlate with the size of lesions. CONCLUSION: In our study SCTAP turned out to be a reliable radiological method in the preoperative detection of focal liver lesions, with a high overall sensitivity. SCTAP showed improved sensitivity in the detection of small malignant lesions (< 1 cm) in comparison to CTAP.     

Dual-phase helical CT of the liver: value of an early-phase acquisition in the differential diagnosis of noncystic focal lesions

OBJECTIVE: Contrast-enhanced helical CT images of the liver are usually obtained during the portal vein phase (PVP), during which the parenchyma achieves peak enhancement. The purpose of this study was to determine whether the addition of arterial-phase (AP) scans would lead to improved characterization of focal lesions. MATERIALS AND METHODS: We reviewed the CT appearance of 102 focal lesions with a proven diagnosis. In the first part of the study, we assessed whether the addition of AP scans influenced the diagnostic performance of the three observers. In the second part of the study, we analyzed the morphologic appearance revealed on CT scans of the different types of lesions in the AP and PVP. RESULTS: The addition of AP scans led to a significant increase in the number of correct diagnoses: 71 lesions (70%) were correctly diagnosed with CT scans in both the AP and the PVP, compared with 54 lesions (53%) correctly diagnosed with CT scans in the PVP alone (p < .01). The largest difference was observed in the diagnosis of focal nodular hyperplasia (FNH) and adenoma (16/24 correct diagnoses instead of 6/24) (p < .005). Conversely, AP images did not significantly contribute to the diagnosis of hemangiomas and metastases. The following morphologic features were seen much more often on AP scans than on PVP scans and had a high positive predictive value (PPV): spoke-wheel pattern (FNH; PPV, 100%), central feeding vessel (FNH; PPV, 100%), and heterogeneous appearance with hyperdense components (hepatocellular carcinoma; PPV, 75%). CONCLUSION: Our data show that the radiologists' evaluation of CT scans in both the AP and the PVP improves the differentiation of hepatocellular carcinoma and FNH from other types of hepatic neoplasms.     

Detection of recurrent and metastatic colorectal cancer: comparison of positron emission tomography and computed tomography

BACKGROUND: This study evaluates the clinical value of positron emission tomography (PET) with 2-[F-18] fluoro-2-deoxy-D-glucose (FDG) as compared to computed tomography (CT) in patients with suspected recurrent or metastatic colorectal cancer (CRC). METHODS: A retrospective review of the records of 58 patients who had FDG-PET for evaluation of recurrent or advanced primary CRC was performed. FDG-PET results were compared with those of CT and correlated with operative and histopathologic findings, or with clinical course and autopsy reports. RESULTS: Recurrent or advanced primary CRC was diagnosed in 40 and 11 patients, respectively. The sensitivity and specificity of FDG-PET were 91% and 100% for detecting local pelvic recurrence, and 95% and 100% for hepatic metastases. These values were superior to CT, which had sensitivity and specificity of 52% and 80% for detecting pelvic recurrence, and 74% and 85% for hepatic metastases. FDG-PET correctly identified pelvic recurrence in 19 of 21 patients; CT was negative in 6 of these patients and equivocal in 4. FDG-PET was superior to CT in detecting multiple hepatic lesions and influenced clinical management in 10 of 23 (43%) patients. CONCLUSION: FDG-PET is more sensitive than CT in the clinical assessment of patients with recurrent or metastatic CRC, and provides an accurate means of selecting appropriate treatment for these patients.     

Spiral computed tomography and operative staging of gastric carcinoma: a comparison with histopathological staging

BACKGROUND: Much controversy exists as to the value of computed tomography (CT) in the preoperative staging of gastric cancer, because of its limited ability to identify correctly lymph node (LN) metastases, invasion of adjacent organs, or hepatic and peritoneal metastases. Spiral CT scanners have a number of potential advantages over conventional scanners, including the absence of respiratory misregistration, image reconstruction smaller than scan collimation permitting overlapping slices and optimisation of intravenous contrast enhancement. AIM: To compare the performance of spiral CT and operative assessment against formal (TNM) pathological staging. PATIENTS AND METHODS: A study of 105 consecutive patients who underwent both spiral CT and operative staging was performed. All CT scans were reviewed by a radiologist who commented on tumour location and size, evidence of adjacent organ invasion, lymph node metastases to both N1 and N2 nodes, and evidence of hepatic and peritoneal metastases. All patients underwent careful operative assessment at the time of surgery, along the lines suggested by Rohde and colleagues. RESULTS: Spiral CT remained poor at identifying LN metastases to both N1 and N2 lymph nodes, with sensitivity ranging from 24 to 43%; specificity, however, was 100%. Operative staging was superior, with sensitivities between 84 and 94%, but specificity was much lower (63-74%). Spiral CT correctly detected 13 of 17 cases of invasion of either the colon or the mesocolon (sensitivity 76%) compared with 16 of 17 cases at operative staging (sensitivity 94%). Spiral CT correctly identified three of six cases with invasion of the pancreas (sensitivity 50%) compared with six of six cases on operative staging (sensitivity 100%). Spiral CT correctly identified 12 of 17 cases of peritoneal metastases (sensitivity 71%) and four of seven cases of hepatic metastases (sensitivity 57%). CONCLUSION: Whilst spiral CT remains poor at identifying lymph node metastases, it correctly identified most cases with invasion of either the colon or the mesocolon and half the cases of pancreatic invasion. It was of value in detecting peritoneal metastases and some cases with hepatic metastases. At present, at Leeds General Infirmary spiral CT is performed routinely on all patients with gastric cancer and a selective staging laparoscopy policy is adopted in those patients in whom the status of the peritoneal cavity and liver is in doubt.