Contrast-enhanced computed tomography in carcinoma of the urinary bladder. The use of different injection methods

Computed tomography (CT) scans of the urinary bladder were taken before and in combination with intravenous contrast medium injection in 30 patients with invasive bladder carcinoma. Three different ways of injecting the same amount of intravenous contrast material were used in three groups, each consisting of ten patients. In the first group the contrast medium was given during 90 seconds, in the second group during 40 seconds and in the third one, the first half during 20 seconds and the second half during 90 seconds. The attenuation in the tumors and in the bladder wall was measured in Hounsfield units. Independent of injection method, all tumors showed significantly higher contrast enhancement than the bladder wall when the injection was terminated. The difference in contrast enhancement was greatest in the group where the shortest injection time was used and greatest immediately after the conclusion of the injection. The difference in contrast enhancement between tumor and bladder wall was visible on the monitor in all cases.     

Contrast-enhanced cadaver-specific computed tomography in gross anatomy teaching

Objectives

To establish contrast-enhanced (CE) cadaver-specific post-mortem computed tomography (PMCT) in first-year gross anatomy teaching and quantitatively evaluate its learning benefit.

Methods

132 first-year medical students were included in this IRB-approved study and randomly assigned to an intervention group (n=59) provided with continuous access to CE and non-enhanced (NE) cadaver-specific PMCT-scans during the first-semester gross anatomy course, and a control group (n=73) that had only NE cadaver-specific PMCT data available. Four multiple-choice tests were carried out (15 questions each) subsequent to completion of the corresponding anatomy module: Head and neck anatomy, extremities, thorax, and abdomen. Median test results were compared in each module between the groups using the Wilcoxon rank-sum test. Additionally, participants of the intervention group answered a 15-item feedback-questionnaire.

Results

The intervention group achieved significantly higher test scores in head and neck anatomy (median=12.0, IQR=10.0–13.0) versus the control group (median=10.5, IQR=9.0–12.0) (p<0.01). There were no significant differences in the comparison of other modules. CEPMCT was highly appreciated by undergraduate medical students.

Conclusions

The incorporation of contrast-enhanced cadaver-specific PMCT-scans in gross anatomy teaching was proven to be feasible in the framework of the medical curriculum and significantly improved the students’ learning performance in head and neck anatomy.

Key Points

? Cadaver-specific contrast-enhanced post-mortem CT (CEPMCT) is feasible in the medical curriculum. ? CEPMCT yields significantly improved learning performance in head and neck anatomy (p<0.01). ? CEPMCT is highly appreciated by medical students and used in tutor- or self-guided modes.

     

Contrast-enhanced computed tomography of the normal and abnormal gallbladder

One hundred and fourteen upper abdominal computed tomography examinations performed before and after intravenous contrast were reviewed. In 48 patients who had no evidence of biliary or pancreatic disease, the mean gallbladder wall attenuation before contrast was 25 +/- 13 HU and after contrast 42 +/- 18 HU, with a wall thickness of 1.9 +/- 0.43 mm. In 14 patients with chronic pancreatitis these values were 24 +/- 10.5 HU, 44 +/- 25 HU and 2.0 +/- 0.54 mm, respectively. In a further group of 15 patients with chronic biliary disease, the values were 34 +/- 15 HU, 53 +/- 18 HU and 2.3 +/- 0.9 mm. The degree of wall enhancement was statistically significant in each group. There was no statistical difference in the attenuation characteristics or wall enhancement between normal patients and those with chronic pancreatitis. Patients with chronic biliary disease had a thicker gallbladder wall with higher attenuation before contrast but a similar degree of enhancement.     

Small cell lung carcinoma: Eight types of extension and spread on computed tomography

OBJECTIVE: The aim of this study was to classify the types of tumor extension and spread of small cell lung carcinoma (SCLC) and to recognize the unusual types of spread pattern of SCLC on computed tomography (CT) including multidetector row CT (MDCT) using contrast-enhanced material. MATERIALS AND METHODS: Sixty-eight cases (53 men and 15 women aged 54-83 years old) of pathologically proven SCLC were examined mainly by contrast-enhanced CT scan. In surgically treated 7 cases, CT-pathologic correlations were performed. RESULTS: Eight types of extension and spread were recognized by the examinations of chest CT. The type of central mass + mediastinal extension (n = 20 [29.4%]) was the most common manifestation. The types of central perihilar mass (n = 12 [17.6%]), peripheral mass + mediastinal extension (n = 14 [20.6%]), and peripheral mass (n = 7 [10.3%]) were frequently observed. The primary site of SCLC was in peripheral lung tissue in 21 of 68 cases (30.9%) in this study. Unusual CT manifestations, such as the types of lymphangitic spread (n = 6 [8.8%]), pleural dissemination (n = 4 [5.9%]), lobar replacement (n = 3 [4.4%]), pneumonialike air-space infiltrative spread (n = 2 [2.9%]) were recognized in our study. Stenosis of trachea and main bronchus caused by peribronchial extension were commonly noted. In the advanced cases with mediastinal extension, we observed the extension of SCLC to superior vena cava (n = 22), main pulmonary artery (n = 18), pulmonary vein (n = 11), and thoracic aortic wall (n = 7). Peri-and intracardial invasions were also observed in 9 cases. CONCLUSIONS: Computed tomography including MDCT analysis revealed 8 types of extension and spread of SCLC including unusual forms in 68 SCLC cases. Peribronchial extension and great vessel wall involvement, such as superior vena cava, main pulmonary artery, and peri-/intra-cardial extension, were commonly observed in advanced stage.     

Pelvic adenopathy from bladder and prostate carcinoma: detection by rapid-sequence computed tomography

Diagnostic pelvic lymphadenectomies are used in both bladder and prostate carcinoma. Enhanced rapid-sequence computed tomographic (CT) scanning of the retroperitoneum and pelvis was done prospectively in patients scheduled for lymphadenectomies. The CT results were then compared to the histopathological findings in 32 patients to analyze the ability of dynamic CT to indicate whether a lymphadenectomy is needed. The comparison showed eight true positive, four false negative, 18 true negative, and two false positive. The sensitivity was 66%, specificity 90% and accuracy 81%. The diagnostic considerations of the role of CT based on these findings are illustrated and discussed.     

Contrast-enhanced ultrasonography and spiral computed tomography in the detection and characterization of portal vein thrombosis complicating hepatocellular carcinoma

The aim was to compare the performances of contrast-enhanced (CE) ultrasonography (US) and spiral computed tomography (CT) in the detection and characterization of portal vein thrombosis complicating hepatocellular carcinoma (HCC). We studied 50 patients with HCC who had biopsy-proven portal vein thrombi that had been detected with US and color Doppler US. Thirteen of the thrombi involved the main portal trunk and 37 the segmental branches. CEUS and CT were performed within a week of thrombus biopsies. For each imaging technique, diagnoses of thrombosis (present/absent) and thrombus nature (malignancy/benignancy) were made by experienced readers under blinded conditions and compared with pathological findings to determine accuracy rates for thrombus detection and characterization. Forty-four of the 50 thrombi were pathologically diagnosed as malignant and the remaining six were benign. CEUS detected 50/50 (100%) thrombi and correctly characterized 49/50 (98%). CT detected 34/50 (68%) thrombi and correctly characterized 23 of these 34 (68%). CEUS outperformed CT in terms of both thrombus detection (P < 0.0001) and characterization (P = 0.0001). CEUS appears to be significantly superior to CT for detection and characterization of portal vein thrombosis complicating HCC, and it should be considered in the staging of these tumors.     

Perfusion computed tomography in renal cell carcinoma

Various imaging modalities are available for the diagnosis, staging and response evaluation of patients with renal cell carcinoma (RCC). While contrast enhanced computed tomography (CT) is used as the standard of imaging for size, morphological evaluation and response assessment in RCC, a new functional imaging technique like perfusion CT (pCT), goes down to the molecular level and provides new perspectives in imaging of RCC. pCT depicts regional tumor perfusion and vascular permeability which are indirect parameters of tumor angiogenesis and thereby provides vital information regarding tumor microenvironment. Also response evaluation using pCT may predate the size criteria used in Response Evaluation Criteria in Solid Tumors, as changes in the perfusion occurs earlier following tissue kinase inhibitors before any actual change in size. This may potentially help in predicting prognosis, better selection of therapy and more accurate and better response evaluation in patients with RCC. This article describes the techniques and role of pCT in staging and response assessment in patients with RCCs.     

Dynamic computed tomography of hepatocellular carcinoma

Nineteen patients with clinically proven hepatocellular carcinoma were studied by dynamic computed tomographic (CT) scanning. Ten consecutive 3 sec scans were performed within 30 sec, providing uninterrupted data collection. Dynamic CT scanning was useful in recognizing tumor vascularity, multiple small tumors, isodense tumors on conventional CT scans, the capsule of an encapsulated hepatocellular carcinoma, arteriovenous shunts, and vascular pools. Time-density curves were useful in evaluating the hemodynamics of the tumors; these could be classified into three types according to differences in their enhancement patterns.     

Role of multidetector computed tomography (MDCT) in diagnosis and staging of gall bladder carcinoma

Background

Carcinoma of the gall bladder is the fifth most common malignancy of the gastrointestinal tract after colorectal, pancreatic, gastric and esophageal carcinomas.

Aim of the work

To study the role of multidetector computed tomography in the diagnosis and staging of gall bladder carcinoma.

Subjects and methods

This study included twenty-five patients presented to us during the period from June 2011 till May 2012 and were diagnosed radiologically by multidetector computed tomography as carcinoma of the gall bladder and the diagnosis was confirmed histopathologically. All the patients were subjected to ultrasonography followed by multidetector computed tomographic imaging using triphasic examination technique.

Results

Among the twenty-five patients included in this study there were fifteen females and ten males. Their ages ranged from 50 to 70 years old (average 60 years). All the patients were radiologically diagnosed as gall bladder carcinoma based on the multidetector computed tomographic findings. Infiltrating masses were detected in fifteen patients (60%), Intraluminal polypoidal masses were detected in nine patients (36%) while one patient (4%) presented with mural thickening of the gall bladder wall.

Conclusion

We conclude that multidetector CT is the diagnostic tool of choice in the detection and staging of gall bladder carcinoma.     

Contrast-enhanced computed tomography and ultrasound for the evaluation of tumor blood flow

OBJECTIVE: We evaluated implanted rat mammary adenocarcinoma tumors during a 5-week period using ultrasound, computed tomography (CT), and histology. MATERIALS AND METHODS: Contrast-enhanced ultrasound with a destruction-replenishment imaging scheme was used to derive estimates of blood volume and flow. These ultrasound-derived measures of microvascular physiology were compared with contrast-enhanced CT-derived measures of perfusion and vascular volume made by the Mullani-Gould formula and Patlak analysis, respectively. RESULTS: The tumor cross-sectional area and necrotic core cross-sectional area determined by the 3 methods were correlated (r>0.8, P<0.001, n=15). The spatial integral of perfusion estimated by CT correlated with the spatial integral of flow from ultrasound (P<0.05). The contrast-enhanced tumor area calculated from the ultrasound analysis was highly correlated with the contrast-enhanced area estimated by CT images (r=0.89, P<0.001, n=15). However, the fraction of the tumor area enhanced by the CT contrast agent was significantly larger than either the fraction enhanced by ultrasound contrast agent or than the viable area as estimated from histology slides. CONCLUSION: Destruction-replenishment ultrasound provides valuable information about the spatial distribution of blood flow and vascular volume in tumors and ultrasound analysis compares favorably with a validated contrast-enhanced CT method.     

Enhancement pattern of hilar cholangiocarcinoma: Contrast-enhanced ultrasound versus contrast-enhanced computed tomography

Objective

To compare the enhancement pattern of hilar cholangiocarcinoma on contrast-enhanced ultrasound (CEUS) with that on contrast-enhanced computed tomography (CECT).

Methods

Thirty-two consecutive patients with pathologically proven hilar cholangiocarcinomas were evaluated by both low mechanical index CEUS and CECT. The enhancement feature of the tumor, portal vein infiltration, and lesion conspicuity on them was investigated.

Results

In the arterial phase, the numbers of the lesions showing hyperenhancement, isoenhancement, and hypoenhancement, were 14 (43.8%), 14 (43.8%), and 4 (12.6%), on CEUS, and 12 (37.5%), 9 (28.1%), and 11 (34.4%), on CECT (P = 0.162). In portal phase, the numbers of the lesions showing hypoenhancement, isoenhancement, and hyperenhancement were 30 (93.8%), 1 (3.1%), and 1 (3.1%), on CEUS, and 23 (71.9%), 8 (25.0%), and 1 (3.1%), on CECT (P = 0.046). The detection rates for portal vein infiltration were 84.2% (16/19) for baseline ultrasound, 89.5% (17/19) for CEUS, and 78.9% (15/19) for CECT (all P > 0.05 between every two groups). CEUS significantly improved the lesion conspicuity in comparison with CECT. CEUS and CECT made correct diagnoses in 30 (93.8%) and 25 (78.1%) lesions prior to pathological examination (P = 0.125).

Conclusion

The enhancement pattern of hilar cholangiocarcinoma on CEUS was similar with that on CECT in arterial phase, whereas in portal phase hilar cholangiocarcinoma shows hypoenhancement more likely on CEUS. CEUS and CECT lead to similar results in evaluating portal vein infiltration and diagnosis of this entity.     

Preoperative computed tomography staging of rectal carcinoma

Pelvic computed tomography (CT) was analyzed in 48 patients with rectal carcinoma. Air was insufflated into the rectum before CT scanning. The areas of tumor (T) and rectosigmoid lumen (L) were determined for T/L ratio. Changes of the perirectal fatty tissues on CT were classified into five patterns: shaggy, granular, linear, clubbed, and wavy appearances. The T/L ratio and changes of the perirectal fatty tissue were correlated with transmural tumor extension. When the T/L ratio was above 1, tumors were frequently classified as Dukes' staging B and C, whereas a T/L ratio above 2 suggested Dukes' C classification. Clubbed or wavy appearance in the perirectal fatty tissues suggested that the tumor extended beyond the submucosa involving the muscularis propria. These findings were very useful for surgery.     

Urachal carcinoma: evaluation with computed tomography

The computed tomographic (CT) findings in 7 patients with urachal carcinoma were reviewed. Computed tomography was useful in establishing an initial diagnosis, determining the tumor extent, and visualizing tumor recurrence. The embryology, histology, and clinical course of urachal carcinoma are reviewed.     

Urachal carcinoma: Evaluation with computed tomography

The computed tomographic (CT) findings in 7 patients with urachal carcinoma were reviewed. Computed tomography was useful in establishing an initial diagnosis, determining the tumor extent, and visualizing tumor recurrence. The embryology, histology, and clinical course of urachal carcinoma are reviewed.     

The value of computed tomography in delineating suprasellar extension of pituitary adenomas

Summary Pituitary tumors commonly produce suprasellar extension. We have found that in assessing lateral suprasellar extent, the pneumoencephalogram and arteriogram are least accurate. CT scanning significantly increases the occuracy, and it is recommended that all patients with pituitary tumors have an initial CT scan.