Multidetector-row Helical CT Research Articles

Bladder Cancer: Analysis of Multi-Detector Row Helical CT Enhancement Pattern and Accuracy in Tumor Detection and Perivesical Staging

Bladder Cancer: Analysis of Multi-Detector Row Helical CT Enhancement Pattern and Accuracy in Tumor Detection and Perivesical Staging

Usefulness of Preoperative Chest Multidetector CT for Evaluation of Breast Cancer: Comparison with Breast MRI

Purpose: To evaluate the efficacy of chest multidetector-row helical computed tomography (MDCT) in detecting breast cancer in preoperative metastasis work-ups and to assess the accuracy of MDCT compared with magnetic resonance imaging (MRI). Materials and Methods: MDCT were performed on 69 consecutive patients with 94 lesions of histologically proven breast cancer. Retrospectively, two radiologists performed a blind review of the MDCT images for margin, shape, mass enhancement pattern and the enhancing distribution of non-mass lesions with consensus. CT attenuation values were measured in the average HU on pre-enhancing and enhanced CT in gland, fat, muscle, and in masses with the largest region of interest (ROI). MDCT findings were analyzed and compared with breast MRI. Results: Of the 91 breast lesions detected on MDCT, 64 were mass lesions and 24 were non-mass lesions on enhancement, 86 lesions were malignant and 5 were benign. Three pathologically proven malignant masses were not detected on MDCT. Positive predictive value, false positive rate and false negative rate were 94.5%, 5.3%, 3.2% respectively. The highly predictive features for malignancy were a spiculated or irregular margin, an irregular or round shape, and a heterogeneously or rim enhanced mass. Another highly predictive feature for malignancy was linear or segmentally distributed enhancing non-mass lesions. The CT values of masses in pre-enhanced scans were 38.67.9 HU; these values increased to 110.926.6 HU after contrast injection (90 sec). The attenuation values from enhancing CT of malignant lesions were significantly higher than those of non-enhancing lesions. The depiction of enhancing masses on MDCT compared with MR imaging were 88.6%. The extension of malignancy were equally well correlated MDCT with MR imaging. Conclusion: The diagnostic value of chest MDCT for preoperative staging is comparable with MR imaging for the detection and extension of lesions. Therefore, chest MDCT of breast cancer can add to the information obtained from mammography or ultrasonography and is a useful method of preoperative assessment for cancer staging and limitational condition of MR imaging.

Detection of hypervascular hepatocellular carcinoma: Comparison of multi-detector CT with digital subtraction angiography and Lipiodol CT

The purpose of this study was to compare the diagnostic accuracy of biphasic multi-detector row helical computed tomography (MDCT), digital subtraction angiography (DSA) and Lipiodol computed tomography (CT) in detection of hypervascular hepatocellular carcinoma (HCC). Twenty-eight patients with nodular HCC underwent biphasic MDCT examination: hepatic arterial phase (HAP) 25 s and portal venous phase (PVP) 70 s after injection of the contrast medium (1.5 mL/kg). They also underwent hepatic angiography and intra-arterial infusion of iodized oil. Lipiodol CT was performed 3-4 wk after infusion. MDCT images were compared with DSA and Lipiodol CT images for detection of hepatic nodules. The three imaging techniques had the same sensitivity in detecting nodules >20 mm in diameter. There was no significant difference in the sensitivity among HAP-MDCT, Lipiodol CT and DSA for nodules of 10-20 mm in diameter. For the nodules <10 mm in diameter, HAP-MDCT identified 47, Lipiodol CT detected 27 (chi2 = 11.3, P = 0.005<0.01, HAP-MDCT vs Lipiodol CT) and DSA detected 16 (chi2 = 9.09, P = 0.005<0.01 vs Lipiodol CT and chi2 = 29.03, P = 0.005<0.01vs HAP-MDCT). However, six nodules <10 mm in diameter were detected only by Lipiodol CT. MDCT and Lipiodol CT are two complementary modalities. At present, MDCT does not obviate the need for DSA and subsequent Lipiodol CT as a preoperative examination for HCC.

Computed tomographic imaging of hepatocellular carcinoma

The ability of x-ray computed tomography (CT) to detect and characterize liver lesions has been one of the most studied issues in radiology during the past 20 years. Technological advances, combined with increased knowledge about the pathophysiological characteristics of these tumors, have dramatically increased the ability to detect and characterize large hepatocellular carcinomas (HCCs). Nonetheless, detection and characterization of early and small HCC lesions remains a difficult task. We review the imaging appearances of HCC on CT and discuss the sensitivity and specificity of computed tomographic imaging in screening patients with cirrhosis for HCC.

Small-bowel diseases: prospective evaluation of multi-detector row helical CT enteroclysis in 107 consecutive patients.

To prospectively evaluate multi-detector row helical computed tomographic (CT) enteroclysis for the depiction of small-bowel diseases. The study group included 107 patients who were suspected of having small-bowel tumor (n = 8), active inflammatory small-bowel disease (n = 18), unexplained gastrointestinal bleeding (n = 36), refractory celiac sprue (n = 14), and low-grade small-bowel obstruction (n = 31). A nasoenteric tube was positioned into the duodenojejunal junction by using fluoroscopic guidance and water was infused with a pressure-controlled pump. After intravenous administration of 120 mL of iodinated contrast material, multi-detector row helical CT enteroclysis images were obtained with 4 x 2.5 mm collimation (four detector rows and 2.5-mm section thickness). Multi-detector row helical CT enteroclysis findings were analyzed by two readers working in consensus. Findings were compared with the results of endoscopy, enteroscopy, videocapsule endoscopy, histopathologic analysis, or clinical follow-up. Multi-detector row helical CT enteroclysis was well tolerated in 106 patients; one patient complained of abdominal pain after the examination. Multi-detector row helical CT enteroclysis allowed the diagnosis of small-bowel masses (n = 21), active Crohn disease (n = 9), small-bowel tuberculosis (n = 2), small-bowel lymphoma complicating celiac disease (n = 4), and confirmed low-grade small-bowel obstruction (n = 12). Multi-detector row helical CT enteroclysis demonstrated normal findings in 60 patients. Sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of multi-detector row helical CT enteroclysis were 100%, 95%, 97%, 94%, and 100%, respectively. Multi-detector row helical CT enteroclysis allows depiction of small-bowel diseases in patients suspected of having small-bowel conditions.

Quand, comment et pourquoi réaliser une imagerie des artères des membres inférieurs ?

Noninvasive screening of lower limb arterial disease has long been performed using color Doppler ultrasonography, whereas surgical or endovascular treatment planning relied on conventional angiography. With continued improvements of noninvasive imaging modalities, it is now possible to image the entire lower limb vasculature without arterial catheterization. Multidetector row helical CT angiography has the advantage of visualizing the arterial lumen and arterial wall calcifications, and nephrotoxicity is reduced by decreasing amounts of contrast medium. Three-dimensional MR angiography is a safe procedure, with high contrast sensitivity, and has recently benefited from step table technology that allows a single injection of contrast medium. The literature shows that both helical CT and MR angiography have high levels of accuracy, but outcome studies of their respective role in the setting of acute and chronic lower limb ischemia are lacking. These noninvasive techniques should play a major role in two main situations: first, in critical ischemia where therapeutic planning should ideally be achieved non invasively; second, in the follow-up of treated patients presenting with recurrent ischemia.

Helical computed tomography accurately reports urinary stone composition using attenuation values: in vitro verification using high-resolution micro-computed tomography calibrated to fourier transform infrared microspectroscopy

Objectives To assess the ability of helical computed tomography (CT) to differentiate regions of known mineral composition in typical, heterogeneous urinary stones. Interest is substantial in the urologic community in using radiologic imaging to determine accurately the composition of urinary calculi. Recent advances in CT make this a viable prospect, but the heterogeneity of most stones is a complicating factor. Methods The ability of micro-CT (a high-resolution laboratory instrument) to identify the mineral composition of stones was confirmed by calibrating micro-CT attenuation values to pure mineral regions of sliced stones using infrared microspectroscopy. Intact human urinary stones were then analyzed by micro-CT, and regions-of-interest of pure mineral were correlated with identical regions-of-interest from quad slice multi-detector row helical CT images. With helical CT, narrow slice widths were used to decrease volume-averaging errors, and bone windows were used so that internal stone structure was visible. Results When stones were imaged using helical CT at narrow slice widths, mineral-specific regions-of-interest yielded nonoverlapping attenuation values for uric acid (566 to 632 Hounsfield units [HU]), struvite (862 to 944 HU), calcium oxalate (1416 to 1938 HU), and hydroxyapatite (2150 to 2461 HU). Conclusions High resolution helical CT yields unique attenuation values for common types of stone mineral, but proper windowing is required to localize regions of homogeneity. The results of this in vitro study suggest that high-resolution helical CT may be able to identify stone composition at patient diagnosis.

Coronary artery calcium quantification at multi-detector row helical CT versus electron-beam CT

Coronary artery calcium quantification at multi-detector row helical CT versus electron-beam CT

Bladder cancer: analysis of multi-detector row helical CT enhancement pattern and accuracy in tumor detection and perivesical staging.

To evaluate the enhancement pattern of bladder cancer and the accuracy of multi-detector row helical computed tomography (CT) in the detection and staging of bladder cancer. In 20 patients, the attenuation value of bladder cancer was measured on dynamic contrast material-enhanced multiphasic CT images obtained with scanning delays of 40, 60, 80, and 100 seconds. In 67 patients, CT data were obtained with a 60-second scanning delay that covered the bladder (section thickness, 2.5 mm; beam pitch, 1.5) and a 180-second scanning delay that covered the abdomen (section thickness, 5 mm; beam pitch, 1.5). We prospectively evaluated CT images and compared findings at CT with findings at histologic examination. We evaluated cancer detection rate, positive predictive value of cancer detection, and sensitivity and specificity in the diagnosis of perivesical invasion. The attenuation value of bladder cancers was significantly higher on 60- (105 HU +/- 16) and 80-second (97 HU +/- 15) delayed CT images than on the other images (P <.05). The cancer detection rate and positive predictive value for cancer detection were 97% and 95%, respectively, in 67 patients and increased to 100% and 100%, respectively, in 44 patients with a time interval of 7 or more days between transurethral resection of the bladder (TURB) and CT examination. Sensitivity and specificity in the diagnosis of perivesical invasion were 89% and 95%, respectively, in 67 patients and increased to 92% and 98%, respectively, in 44 patients with a time interval of 7 or more days between TURB and CT examination. Bladder cancer tends to show peak enhancement with the 60-second scanning delay. Multi-detector row helical CT is useful in the detection and staging of bladder cancer.

Usefulness of Multiplanar Reformatted Images of Multi-detector Row Helical CT in Assessment of Biliary Stent Patency

Purpose: To evaluate the usefulness of multi-detector row helical CT (MDCT), multiplanar reformatted images for the noninvasive assessment of biliary stent patency, and for the planning for management in patients with a self-expandable metallic stent due to malignant biliary obstruction. Materials and Methods: Among 90 consecutive patients, from August 1999 to July 2003, 26 cases in 23 patients with malignant biliary obstruction who underwent self-expandable metallic stent insertion in the biliary system and percutaneous transhepatic biliary drainage within 7 days after CT were enrolled in this study. On CT images, the complete and functional obstruction of the stent and the precise level of obstruction were evaluated. The presence of an enhancing intraluminal mass or wall thickening around stent was determined, and the causes of obstruction were evaluated. These findings were then compared with percutaneous transhepatic cholangiography. Results: Multi-detector row helical CT correctly demonstrated the patency of a stent in 24 cases (92.3%). It was adequate in helping to depict the precise level of stent occlusion in 23 cases (88.5%). Multi-detector row helical CT also revealed the extent of tumor that represented as an enhancing intraluminal mass or wall thickening around the stent in 23 cases, and this was represented as complete obstruction on percutaneous transhepatic cholangiography. In the case of functional obstruction, MDCT predicted the possible cause of the obstruction. Conclusion: Multiplanar reformatted images of multi-detector row helical CT is a useful imaging modality for the noninvasive assessement of stent patency and the precise level of obstruction when stent obstrution is suspected in the patients with self-expandable metallic stent due to malignant biliary obstruction. It can also predict the possible cause of the obstruction and allows adequate planning for the medical management of such cases.

A Case of Coronary Arteriovenous Fistula Associated with Pulmonary Artery Aneurysm Confirmed by Multi Detector-Row Helical CT

A congenital coronary arteriovenous fistula is a rare condition, which is an abnormal communication of the coronary artery with the right or left ventricle, the right or left atrium or the pulmonary artery. A coronary arteriovenous fistula, complicated with a pulmonary aneurysm, is quite uncommon. A case of 68-year-old woman, complaining of resting chest pain for 1 week, is reported. The coronary arteriovenous fistula associated, with a pulmonary aneurysm, was confirmed by coronary angiography and multidetector-row helical CT

Hiroshima General Hospital and Its Involvement in Community Health Care-Especially with Respect to Prevention and Control of Cardiovascular Disorders

Hiroshima General Hospital dates back to 1947. Initially it was known as the Saiki Hospital affiliated with the Agricultural Association of Hiroshima Prefecture. It had 60 sickbeds and four departments-internal medicine, surgery, otolaryngology and dentistry. In those days, there were a large number of atomic bomb survivors in this medically underserved province of Saiki, so that the hospital was extremely busy treating these hibakushas. With the increase in the number of patients, the hospital kept expanding. It was not until 1979 when the number of beds increased to 270 that the hospital was reorganized and assumed the present name. Since then, it has continued to expand and its medical facilities improved. Having been accredited with the type B general hospital by Japan Council for Quality Health Care, it has now become the nucleus of the health care system in the western part of Hiroshima Prefecture, with 570 beds.By way of illustrating how our hospital has been involved in community health care, we will take a look at the trend of the number of emergency cases admitted at night or on holidays. Up until 1998, the annual number of such cases had stood at somewhere around 4,000 but in 2003 the figure exceeded 10,000. For routine physical checkups, electrocardiograms are used. In 1975, 1,800 patients underwent ECG tests and in 2000 the number leapt to 27,000. This author has taken it upon himself to interpret all these ECG records.The Department of Cardiology in our hospital had made it a rule to conduct noninvasive testing in diagnosis. In 1984, the x-ray examination system to make a diagnosis of circulatory troubles was introduced. In 1988 when the Department of Cardiovascular Surgery was set up, it started employing percutancous transluminal coronary angioplasty (PTCA) procedures and other interventional techniques. At first, coronary artery imaging was preformed on not more than 40 cases annually, but now the number of such cases surpasses 500. Interventional treatment is given to well over 130 cases, 85% of which have stents implanted. The initial success rate of intervention is 90.3% and the rate of restenosis was 35.8%. The cases of A-C bypass grafting performed at the department of cardiovascular surgery are increasing in number. Now the use of skeletonized artery bypass graft surgery with extracorporeal circulation at normal temperature has become standard procedure. By the use of the multi-detector row helical CT (MDCT), we are now studying coronary bypass patency and imaging quality. Except for some cases, it has become possible to obtain three-dimensional reconstruction images comparable to angiocardiographic images in terms of quality. We expect that MDCT will replace catheterization and become a standard noninvasive diagnostic procedure in the foreseeable future.We will adopt new thechniques and new therapeutic methods positively but not blindly placing too much confidence in state-of-the-art technology. Based on the fundamental principles of our hospital, we will devote ourselves to medical care, putting the needs of patients before everything else.

Assessment of coronary arteries with multi detector row helical computed tomography (MDCT)

Assessment of coronary arteries with multi detector row helical computed tomography (MDCT)

CT angiography with multidetector-row helical CT in spinal arteriovenous malformation

We performed intravenous CT angiography using multidetector-row helical computed tomography (MDCT) in a 63-year-old man with spinal arteriovenous malformation (AVM). The CT angiography demonstrated feeding arteries, varix-like structure, draining veins and their relationship to the spinal cord. Although selective angiography is essential in planning treatment for spinal AVMs as well as in establishing the diagnosis of the disease, CT angiography can be a good supplementary technique for visualizing precise location of abnormal vessels in a certain case of spinal AVM.

Non-invasive detection and assessment of coronary artery disease with multidetector-row computed tomography.

The fast volume coverage of retrospective ECG-gated multidetector-row helical CT(MDCT)arrows for acquisition of the entire heart volume with nearly isotropic spatial resolution(0.5×0.5×0.6 mm)within a single breath-hold. The sub-millimeter spatial resolution enables depiction of the major and also of peripheral coronary artery segments with lumen diameter down to 1 mm. The results of studies of stenosis detection have shown that coronary CT angiography can reliably detect and exclude high-grade stenosis>50%. In addition, preliminary data indicate that MDCT angiography might arrow detection and evaluation of atherosclerotic plaques in different stages. The differentiation of lipid-rich, fibrous and calcified plaques using coronary CT angiography correlates well with the intracoronary ultrasound results based on measurement of the mean HU-value in the lesion. Non-invasive follow-up after

Breast sentinel lymph node mapping at CT lymphography with iopamidol: preliminary experience.

To evaluate sentinel lymph node (SLN) mapping with interstitial computed tomographic (CT) lymphography with small volumes of iopamidol for direction of SLN biopsy in breast cancer. Thin-section transverse and three-dimensional CT images that included the breast and axilla were acquired at multi-detector row helical CT in 17 patients with operable breast cancer before subcutaneous injection of 2 mL of undiluted iopamidol into peritumoral and periareolar areas and 1-5 minutes after massage of injection sites. Location and size of SLNs were assessed at CT lymphography and were compared with SLNs at standard axillary lymph node dissection with blue dye staining. CT lymphography allowed localization of SLNs in all patients by means of visualization of a direct connection between an SLN and its afferent lymphatic vessels draining from the injection sites. Afferent vessels were joined and drained into a single axillary SLN, except in four patients with two or three SLNs, including a parasternal one. SLNs did not enhance because of rerouting of lymph flow in four patients. At surgery, SLNs that were stained or not stained with blue dye were easily found with CT lymphographic guidance. Tumoral infiltration was not evident in any resected nodes, except for infiltration in one patient with micrometastasis in SLN alone and infiltration in four patients with massive metastasis in both SLN and distant nodes. Because preoperative CT lymphography-guided SLN mapping provides SLN position with detailed lymphatic anatomy, it may be useful for the direction of breast SLN biopsy.

Hereditary hemorrhagic telangiectasia: multi-detector row helical CT assessment of hepatic involvement.

To describe findings obtained with multi-detector row helical computed tomography (CT) of the liver in patients with hereditary hemorrhagic telangiectasia. Multiphasic multi-detector row helical CT was performed in 70 consecutive patients (29 females and 41 males; mean age, 48.5 years; age range, 15-75 years): 64 considered to have hereditary hemorrhagic telangiectasia and six suspected of having the disease. Scanning delay was achieved by using a test bolus of contrast medium to obtain early arterial phase, late arterial phase, and portal venous phase images. Multiplanar and angiographic reconstructions were then generated. The presence of shunts, hepatic perfusion disorders, telangiectases, other vascular lesions, indirect signs of portal hypertension, and vascular anatomic variants were evaluated by two radiologists in consensus. Fifty-two of 70 (74%) patients had hepatic vascular abnormalities. Only four of 52 (8%) patients were symptomatic. Arterioportal shunts were present in 27 of 52 (52%) patients, arteriosystemic shunts in eight of 52 (15%), and both shunt types in 17 of 52 (33%). In 34 of 52 (65%) patients, parenchymal perfusion disorders were detected. Telangiectases were found in 33 of 52 (63%) patients. Large confluent vascular masses were identified in 13 of 52 (25%) patients. In 31 of 52 (60%) patients, indirect CT signs of portal hypertension were detected, but only one had clinical signs of this condition. Vascular anatomic variants were detected in seven patients (13%). Multi-detector row helical CT and reconstructions depict the complex hepatic vascular alterations typical of hereditary hemorrhagic telangiectasia.

Thin-section CT of the lung: does electrocardiographic triggering influence diagnosis?

To determine the impact of prospective electrocardiographic (ECG) triggering on image quality and diagnostic outcome of thin-section computed tomography (CT) of the lung. Forty-five consecutive patients referred for thin-section CT of the lung were examined with prospectively ECG-triggered and nontriggered thin-section CT of the lung with a multi-detector row helical CT scanner. Subjective image quality criteria (image noise, motion artifacts, and diagnostic accessibility) were rated by three radiologists in consensus for the upper lobe, middle lobe and/or lingula, and lower lobe. Pathologic changes were assessed for the various lobes, and a diagnosis was assigned. The diagnoses were compared by two radiologists in consensus to determine the effects of CT technique on diagnostic outcome. Quantitative measurements were performed, including determination of image noise and signal-to-noise ratios in different anatomic regions. The Wilcoxon signed rank test and paired sign test (both with Bonferroni correction) were used for statistical analysis. Subjective assessment showed significant differences in motion artifact reduction in the middle lobe, lingula, and left lower lobe. The diagnostic assessibility of triggered CT was rated significantly higher only for the left lower lobe compared with nontriggered data acquisition. No differences in diagnostic outcome were determined between triggered and nontriggered techniques. Mean image noise in tracheal air was 68.2 +/- 17 (SD) for triggered CT versus 37.4 +/- 9 for nontriggered CT (P <.05). Mean signal-to-noise ratio in the upper versus lower lobes was 22.5 +/- 8 versus 25.4 +/- 10 for triggered and 35.6 +/- 9 versus 39.2 +/- 10 for nontriggered techniques (P <.05). Given the lack of improvement in diagnostic accuracy and the need for additional resources, ECG-triggered thin-section CT of the lung is not recommended for routine clinical practice.

The origin of right inferior phrenic artery on multidetector row helical CT

The origin of the right inferior phrenic artery (RIPA) was assessed in 216 patients using arterial-phase, contrast-enhanced multidetector row helical computed tomography (CT) and that of 26 patients was confirmed by angiography. One hundred and eighty patients showed the origin of the RIPA in aorta, the celiac artery, the right renal artery or the left gastric artery on CT. The sensitivity of CT was 92%. Multidetector row helical CT provides valuable anatomical information for angiographer.

Three-dimensional CT angiography of the hepatic artery: use of multi-detector row helical CT and a contrast agent.

The administration of a contrast agent to obtain optimal images at three-dimensional computed tomographic (CT) angiography of the hepatic artery by using multi-detector row helical CT was investigated. Three-dimensional CT angiographic images were evaluated visually, and quantitative evaluation was performed by measuring the postcontrast CT number of the aorta. The injection rate of 5 mL/sec was significantly superior to that of 4 mL/sec in both evaluations. At administration of a contrast agent with 300 or 350 milligrams of iodine per milliliter, there were no significant differences in either evaluations. The preferable injection rate to obtain sufficient three-dimensional CT angiographic data was 5 mL/sec.