Multidetector-row Helical CT Research Articles

Acute Massive Gastrointestinal Bleeding: Detection and Localization with Arterial Phase Multi–Detector Row Helical CT

Acute Massive Gastrointestinal Bleeding: Detection and Localization with Arterial Phase Multi–Detector Row Helical CT

Pulmonary Arteriovenous Malformation Treated with Embolotherapy: Systemic Collateral Supply at Multidetector CT Angiography after 2–20-year Follow-up

To retrospectively evaluate frequency of systemic arterial collateral supply to treated pulmonary arteriovenous malformations (PAVMs) in long-term follow-up with multi-detector row helical computed tomography (CT). Institutional review board approval was obtained, with waiver of informed consent. Thirty-two patients (19 male, 13 female; mean age, 43 years) underwent follow-up multi-detector row helical CT angiography of the chest (collimation, 16x0.75 mm) 2 or more years after embolotherapy of PAVMs. The study group had a history of successful embolotherapy of 53 PAVMs and a mean of 9 years of follow-up (range, 2-20 years). A search for abnormal systemic arteries was based on analysis of thin-collimated contiguous transverse CT scans and two- and three-dimensional images including maximum intensity projections and volume-rendered images. Statistical comparison was performed with the Fisher exact test (categoric variables) and Wilcoxon rank sum test (continuous variables). At CT, 13 patients (group 1) had abnormally enlarged systemic arteries and 19 patients (group 2) had no abnormal arteries. In group 1, 32 abnormally enlarged arteries were seen-five bronchial and 27 nonbronchial arteries (14 inferior phrenic, six musculophrenic, five internal mammary, two intercostal). The degree of enlargement was moderate for 26 arteries and marked for six. There were no significant differences between groups for (a) clinical characteristics of patients, including history of surgery before or after embolotherapy (P=.7); (b) anatomic structures of treated PAVMs; and (c) embolization procedures and their effectiveness. The number of patients with features suggestive of lung infarction in the days or months after embolotherapy was significantly higher in group 1 (P=.04). On CT angiograms, the number of patients with features suggestive of sequelae of lung infarction was significantly higher in group 1 (P=.02). There were no symptomatic differences attributable to systemic collateral supply between groups; in particular, there was no hemoptysis in group 1. Abnormally enlarged systemic arteries were present in 13 of 32 patients, in whom there was a significantly higher frequency of clinical and/or radiographic features suggestive of lung infarction after embolotherapy.

Characterization of Small Liver Lesions

The purpose of this study is to evaluate the added role of magnetic resonance imaging (MR) in characterizing subcentimeter focal liver lesion(s) detected on multidetector row helical computed tomography (MDCT). A retrospective analysis was performed in 59 noncirrhotic patients with focal subcentimeter liver lesion(s) detected on a 4- or 16-slice MDCT. All patients had a gadolinium enhanced liver MR on 1.5-T systems within 6 weeks after MDCT. Imaging diagnosis was graded on an ordinal scale of 0-5 (0, normal; 1, definitely benign; and 5, definitely malignant). The final diagnosis was established either by histopathology or follow-up imaging for a period of at least 6 months. Receiver operating characteristic analysis was performed to compare the performances of MDCT and MR in characterization of subcentimeter liver lesions. A total of 178 lesions were detected on MDCT in 59 patients. Of these lesions, 129 (72.5%) lesions were benign and the remaining 49 were malignant. The sensitivity, specificity, positive predictive value, and negative predictive value in differentiation of benign from malignant lesions on MDCT were 81.2%, 77.3%, 60.5%, 90.6 % and on MR were 83.3%, 97.5%, 92.1%, and 94.4 %, respectively. Comparative receiver operating characteristic analysis showed an area under curve for MDCT = 0.76 and MR = 0.95 (P < 0.001). Liver MR has significantly higher accuracy for characterization of subcentimeter focal liver lesions discovered on MDCT.

Invited Commentary

HomeRadioGraphicsVol. 26, No. 4 PreviousNext RSNA Education ExhibitsInvited CommentarySanjeev Bhalla1Sanjeev Bhalla1Author Affiliations1Mallinckrodt Institute of Radiology, St Louis, MissouriSanjeev Bhalla1Published Online:Jul 1 2006https://doi.org/10.1148/radiographics.26.4.0261117MoreSectionsFull textPDF ToolsImage ViewerAdd to favoritesCiteTrack CitationsPermissionsReprints ShareShare onFacebookTwitterLinked In References1 ArchieV, Kauh J, Jones DV Jr, Cruz V, Karpeh MS Jr, Thomas CR Jr. Gastric cancer: standards for the 21st century. Crit Rev Oncol Hematol2006;57:123–131. Crossref, Medline, Google Scholar2 WaneboHJ, Kennedy BJ, Chmiel J, Steele G Jr, Winchester D, Osteen R. Cancer of the stomach: a patient care study by the American College of Surgeons. Ann Surg1993;218:583–592. Crossref, Medline, Google Scholar3 LowVH, Levine MS, Rubesin SE, Laufer I, Herlinger H. Diagnosis of gastric carcinoma: sensitivity of double-contrast barium studies. AJR Am J Roentgenol1994;162:329–334. Crossref, Medline, Google Scholar4 LimJS, Yun MJ, Kim MJ, et al. CT and PET in stomach cancer: preoperative staging and monitoring of response to therapy. RadioGraphics2006; 26(1):143–156. Link, Google Scholar5 GanpathiIS, So JB, Ho KY. Endoscopic ultrasonography for gastric cancer: does it influence treatment? Surg Endosc2006;20(4):559–562. Crossref, Medline, Google Scholar6 KimJH, Eun HW, Goo DE, Shim CS, Auh YH. Imaging of various gastric lesions: new CT techniques including 2D MPR and CT gastrography performed with multidetector CT. RadioGraphics2006;26(4):1101–1118. Link, Google Scholar7 KumanoS, Murakami T, Kim T, et al. T staging of gastric cancer: role of multi–detector row CT. Radiology2005;237:961–966. Link, Google Scholar8 InamotoK, Kouzai K, Ueeda T, Marukawa T. CT virtual endoscopy of the stomach: comparison study with gastric fiberscopy. Abdom Imaging2005;30:473–479. Crossref, Medline, Google Scholar9 van GelderRE, Venema HW, Serlie IW, et al. CT colonography at different radiation dose levels: feasibility of dose reduction. Radiology2002;224: 25–33. Link, Google Scholar10 IannacconeR, Laghi A, Catalano C, et al. Detection of colorectal lesions: lower-dose multi–detector row helical CT colonography compared with conventional colonoscopy. Radiology2003;229: 775–781. Link, Google Scholar11 ChenMY, Scharling ES, Zagoria RJ, Bechtold RE, Dixon RL, Dyer RB. CT diagnosis of acute flank pain from urolithiasis. Semin Ultrasound CT MR2000;21:2–19. Crossref, Medline, Google Scholar12 CarrascosaP, Capunay C, Ulla M, Lopez EM, Corti R, Carrascosa J. Elevated gastric lesions: virtual gastroscopy. Abdom Imaging 2005 Nov 28; [Epub ahead of print]. Google Scholar13 SvenssonMH, Svensson E, Lasson A, Hellstrom M. Patient acceptance of CT colonography and conventional colonoscopy: prospective comparative study in patients with or suspected of having colorectal disease. Radiology2002;222:337–345. Link, Google ScholarArticle HistoryPublished in print: July 2006 FiguresReferencesRelatedDetailsCited ByMaterials Science-Poland, Vol. 34, No. 1Recommended Articles CT Colonography: Improving Interpretive Skill by Avoiding PitfallsRadioGraphics2019Volume: 40Issue: 1pp. 98-119Early Gastric Cancers: Is CT Surveillance Necessary after Curative Endoscopic Submucosal Resection for Cancers That Meet the Expanded Criteria?Radiology2016Volume: 281Issue: 2pp. 444-453Machine Learning–based Differentiation of Benign and Premalignant Colorectal Polyps Detected with CT Colonography in an Asymptomatic Screening Population: A Proof-of-Concept StudyRadiology2021Volume: 299Issue: 2pp. 326-335Ligaments and Lymphatic Pathways in Gastric AdenocarcinomaRadioGraphics2019Volume: 39Issue: 3pp. 668-689Colorectal Findings at Repeat CT Colonography Screening after Initial CT Colonography Screening Negative for Polyps Larger than 5 mmRadiology2016Volume: 282Issue: 1pp. 139-148See More RSNA Education Exhibits CT Gastrography for Gastric Tumors: What is the Current Role?Digital Posters2018CT-Colonography is Here to Stay: Emerging Role of Pre-Operative CT-Colonography(CTC) in the Management of Patients with Stenosing Colorectal CancerDigital Posters2018Clinical Implementation of Dual-Energy CT for Bowel Disease: It's Time to Embrace the ChangeDigital Posters2018 RSNA Case Collection Gastric metastatic breast Cancer RSNA Case Collection2022Gastric Mucinous AdenocarcinomaRSNA Case Collection2021Stroke following CT guided chest biopsy RSNA Case Collection2020 Vol. 26, No. 4 Metrics Altmetric Score PDF download

The impact of motion artifacts on the reproducibility of repeated coronary artery calcium measurements

The purpose of this study is, using a 16-section multidetector-row helical computed tomography (MDCT) scanner with retrospective reconstruction, to compare variability in repeated coronary calcium scoring and qualitative scores of the motion artifacts. One hundred forty-four patients underwent two subsequent scans using MDCT. According to Agatston and volume algorithms, the coronary calcium scores during mid-diastole (the center corresponding to 70% of the R-R cycle) were calculated and the inter-scan variability was obtained. Motion artifacts from coronary artery calcium were subjectively evaluated and classified using a 5-point scale: 1, excellent; no motion artifacts; 2, fine, minor motion artifacts; 3, moderate, mild motion artifacts; 4, bad, severe motion artifacts; 5, poor, doubling or discontinuity. Each reading was done by vessels (left main, left descending, left circumflex and right coronary arteries) and the motion artifact score (mean of the scales) was determined per patient. The variability in the low (1.2+/-0.2) and high (2.4+/-0.6) motion artifact score groups was 7+/-6 (median, 6)% and 19+/-15 (16)% on the Agatston score (P<0.01) and 7+/-7 (6)% and 16+/-13 (14)% on the volume score (P<0.01), respectively. In conclusion, motion has a significant impact on the reproducibility of coronary calcium scoring.

Screening for children from families with Rendu-Osler-Weber disease: from geneticist to clinician.

Rendu-Osler-Weber syndrome, or hereditary hemorrhagic telangiectasia (HHT), is an autosomal dominant vascular disorder. The syndrome is characterized by telangiectases and arteriovenous malformations (AVMs) affecting skin, mucosae and internal organs. AVMs often remain clinically silent until provoking sudden serious complications, responsible for important morbidity and mortality which can occur both in adulthood and in children. The incidence of AVMs in HHT pediatric populations is unknown. To describe the screening protocol performed in the first genotypically confirmed HHT pediatric population and to estimate the incidence of occult brain, lung and liver AVMs and the different disease phenotypes. Molecular analysis was performed on 35 children, both symptomatic and asymptomatic, who were family members of probands with a previously identified mutation. Clinical-instrumental examination was performed on the mutation positive cases. Nasal telangiectases were investigated by anterior rhinoscopy. Contrast echocardiography and high resolution thoracic multislice computed tomography (CT) were performed to detect pulmonary arteriovenous malformations (PAVMs), and echo-color Doppler, and abdominal CT to detect hepatic arteriovenous malformations (HAVMs). Brain magnetic resonance imaging was utilized to detect cerebral angiopathic involvement. Molecular analysis demonstrated the mutation-carrier status in 22/35 children. Nineteen children, 12 of whom had epistaxis, positive to molecular testing underwent clinical evaluation. Nasal teleangiectases were found in 68%, mucocutaneous telangiectases (fingers, lips and oral cavity) in 79%, PAVMs in 53%, HAVMs in 47% and cerebral anteriovenous malformations and/or cerebral ischemic changes secondary to PAVMs in 12%. We evidenced a high incidence of HHT children with occult visceral lesions suggesting that a diagnostic screening may be indicated to appropriately treat brain and lung malformations.

Assessing the Extent of Breast Cancer Using Multidetector Row Helical Computed Tomography

The aim of the study was to evaluate the usefulness of multidetector row helical computed tomography (MD-CT) in assessing the local extent of breast cancer. Seventy-five breast cancer patients were examined using MD-CT with scanning performed in the supine position at 1-mm collimation. The extent of the breast tumors determined using CT was compared with that based on histopathologic mapping with continuous 5-mm slices. The CT evaluation of the maximum diameter of the extent of breast cancer was much better correlated with the histopathologic diagnosis (correlation coefficient=0.90) than the pre-CT diagnosis (correlation coefficient=0.46). Computed tomography correctly detected mammographically and clinically occult cancer other than the index lesion in 14 of 15 patients. The sensitivity, specificity, and accuracy in the diagnosis of the additional lesions were 93.3%, 98.3%, and 97.3%, respectively. Because the images were obtained in the supine position, they were useful for surgical planning. The extent of breast cancer can be determined accurately using MD-CT.

Evidence-based diagnosis and staging of pancreatic cancer

Only 20% of patients who present with pancreatic cancer will be amenable to potentially curative resection. Therefore, it is necessary to reliably identify patients who might benefit from major surgical intervention by employing the appropriate staging methods. In this review, the pros and cons of each imaging technique are discussed and an algorithm for single and combined use of the different imaging modalities is proposed. To date, contrast-enhanced multi-detector row helical CT (MDR-CT) together with endoscopic ultrasound (EUS) remain the first staging methods of choice. MDR-CT has a high sensitivity for identifying vascular invasion and EUS is able to detect lesions as small as 2-3 mm. ERCP is performed mainly in patients with biliary obstruction with the option for therapeutic intervention during the same session. MRI with MR-angiography, MRCP, PET/CT and staging laparoscopy are additional modalities which might give further information in cases of equivocal findings by MDR-CT and EUS. The role of tumour markers such as CA 19-9 and CEA is reserved for monitoring and diagnosing post-surgery recurrence. Cytological or histological confirmation should usually be performed in patients that are not eligible for surgery prior to the commencement of palliative radio- or chemotherapy. In the routine clinical setting, MDR-CT and EUS play the predominant roles by providing the most cost-effective and accurate means for diagnosing and staging most cases of pancreatic cancer.

Optimal Delay Time for the Hepatic Parenchymal Enhancement at the Multidetector CT Examination

The objective of this study was to determine the optimal scan delay time after hepatic parenchymal enhancement using a 16-channel multidetector row helical CT (MDCT) scanner. Two hundred fifty-five consecutive patients underwent biphasic CT scans using a 16-channel MDCT. In group A (n = 125), two hepatic venous phase scans (HVP1 and HVP2) were obtained at 40 and 60 seconds, after 100-HU threshold time (T100HU) in the abdominal aorta. In group B (n = 130), HVP1 and HVP2 scans were obtained 50 and 70 seconds after T100HU. Both groups were divided into subgroups that were given different contrast media. Groups A1 and B1 received a contrast medium of 300 mgI/mL; groups A2 and B2 received a contrast medium of 370 mgI/mL. Each patient was injected with contrast medium at a dose of 2 mL/kg at a rate adjusted to the patient's body weight with a constant injection duration of 47 seconds. The attenuation values (HU) for the liver, portal vein, hepatic vein, and aorta were measured. The average HU was compared between the groups. Hepatic enhancement in the images obtained at 50 and 60 seconds after T100HU was greater (P < 0.05) than in images obtained at 40 and 70 seconds. These results were obtained with both contrast media. A few patients showed greater enhancement at a 40 seconds or 70 seconds. Hepatic enhancement was significantly greater in all scans using a contrast medium dose of 370 mgI/mL compared with the 300-mgI/mL dose (P < 0.05). Independent of the concentration of contrast medium, scan delays of 50 to 60 seconds after T100HU may provide optimal hepatic enhancement.

The value of drip infusion cholangiography using multidetector-row helical CT in patients with choledocholithiasis

The purposes of this study were to investigate the feasibility of drip infusion cholangiography computed tomography (CTCh) for choledocholithiasis and to compare the detection of the stone on CTCh with that of MR cholangiopancreatography (MRCP). CTCh examinations were performed after infusion of intravenous biliary contrast material (iotroxic acid meglumine, 100 ml) for patients with suspected biliary diseases and were reconstructed to maximum intensity projection (MIP) and multiplanar reformation (MPR). Of 432 patients who underwent CTCh, we identified 15 who underwent surgery or cholangioscopic removal for choledocholithiasis and 32 patients who underwent cholecystectomy due to cholecystolithiasis. Their MRCP images were compared with the CTCh images. The sensitivity and specificity of CTCh for detecting choledochal stones were 87% and 96% whereas those of MRCP were 80% and 88%. The sensitivity and specificity of CTCh for detecting gallstones were 78% and 100% whereas those of MRCP were 94% and 88%. CTCh allowed high sensitivity and specificity for detecting choledochal stones but diminished the detection for cholecystolithiasis compared with MRCP.

Acute Massive Gastrointestinal Bleeding: Detection and Localization with Arterial Phase Multi–Detector Row Helical CT

To prospectively evaluate accuracy of arterial phase multi-detector row helical computed tomography (CT) for detection and localization of acute massive gastrointestinal (GI) bleeding, with angiography as reference standard. Institutional review board approved this study; written informed consent was obtained from each patient or patient's family after procedures, including radiation dose, were explained. Twenty-six consecutive patients (17 men, nine women; age range, 18-89 years) had acute massive GI bleeding (defined as requirement of transfusion of at least 4 units of blood during 24 hours in the hospital or as hypotension with systolic blood pressure <90 mm Hg) and underwent arterial phase multi-detector row CT before angiography. Scans were obtained during arterial phase to identify extravasation of contrast material with attenuation greater than 90 HU within bowel lumen; this finding was considered diagnostic for active GI bleeding. Presence of contrast medium extravasation in each anatomic location was recorded. Sensitivity, specificity, positive and negative predictive values, and accuracy of multi-detector row CT for detection of acute GI bleeding were assessed. Accuracy for localization of acute GI bleeding was assessed by comparing locations of active bleeding at both multi-detector row CT and angiography in each patient who had active bleeding. Arterial phase multi-detector row CT depicted extravasation of contrast material in 21 of 26 patients. Overall location-based sensitivity, specificity, accuracy, and positive and negative predictive values of multi-detector row CT for detection of GI bleeding were 90.9% (20 of 22), 99% (107 of 108), 97.6% (127 of 130), 95% (20 of 21), and 98% (107 of 109), respectively. Overall patient-based accuracy of multi-detector row CT for detection of acute GI bleeding was 88.5% (23 of 26). The location of contrast material extravasation on multi-detector row CT scans corresponded exactly to that of active bleeding on angiograms in all patients with contrast medium extravasation at both multi-detector row CT and angiography. Arterial phase multi-detector row CT is accurate for detection and localization of bleeding sites in patients with acute massive GI bleeding.

Dynamic Computed Tomography Myelography for the Investigation of Cervical Degenerative Disease

Dynamic computed tomography (CT) myelography was conducted in 15 patients with cervical degenerative disease to assess the lesions responsible for their symptoms. CT myelography was performed using a multi-detector row helical CT system in dynamic positions (flexion or extension or both) in addition to the neutral position. Fine sagittal reconstructed images could be obtained in addition to axial images. This method provided static information including cervical vertebral body deformities, and good contrast images of the spinal cord, nerve roots, and cerebrospinal fluid space. In addition, laterality of the offending lesion and changes exaggerated by cervical motion were clearly shown in both axial and sagittal images. Ten of 15 patients demonstrated dynamic changes including dynamic canal stenosis or spinal cord impingement. The operative strategies were changed based on dynamic CT myelography findings in three of the 15 patients. Dynamic CT myelography can provide the axial and sagittal images required for flexion-extension studies, and in combination with conventional imaging modalities, provides valuable information for determining treatment strategies and objectives.

Three-dimensional computed tomographic images of pelvic muscle in anorectal malformations

Purpose The anatomy of the pelvic flower muscles based on investigation of gross section slides of a specimen does not always correspond with those described by Pena. Therefore, we restudied the anatomy with 3-dimensional (3D) images of the pelvic muscle produced with computed tomography. Methods Thirty-eight patients with anorectal malformations before anorectoplasty were investigated with a multi–detector row helical computed tomography (MRH-CT). Images of the pelvic part were obtained with a slice thickness of 1 mm and a reconstruction pitch of 0.5 mm. A 3D reconstruction was made with the volume rendering method. Lateral views of the 3D CT reconstructed images of the pelvic muscle were compared with the same views of the type corresponding to Pena's schematic drawings in the literature. Results Study of the 3D reconstructions demonstrated that the pelvic muscles of each type were less uniform than the ones described by Pena. There was a great difference even in the same type of anatomy. The differences between the 3D image and the description by Pena were most notable in the high type and particularly in the description of the vertical fibers and the parasagittal muscles. Conclusions A 3D image with MRH-CT can provide useful preoperative information about the anatomy of the pelvic flower muscles in each case.

Assessment of 100 Live Potential Renal Donors for Laparoscopic Nephrectomy with Multi–Detector Row Helical CT

To retrospectively review the authors' experience with multi-detector row helical computed tomography (CT) in assessing 100 consecutive live potential renal donors. Hospital ethical committee approval was obtained; informed patient consent was not required. One hundred potential renal donors underwent multi-detector row CT assessment. Nonenhanced, arterial phase, and nephrographic phase examinations were performed. Delayed topograms were acquired to visualize the collecting system anatomy. A vascular radiologist prospectively interpreted the multi-detector row CT images. A second vascular radiologist, blinded to the initial results, retrospectively reviewed the images. Eighty candidates subsequently underwent donor nephrectomy, including 70 laparoscopic donor nephrectomies (LDNs) and 10 open donor nephrectomies (ODNs). Surgical findings served as the reference standard for 80 kidneys. The imaging findings in all 100 candidates (200 kidneys) were reviewed, although these findings were considered observational data only because there was no reference standard for 120 kidneys. Multi-detector row CT findings predicted uncomplicated LDN in 67 of 70 patients. Small upper-pole capsular arteries arising from the distal main renal artery in two patients were not described in the multi-detector row CT report: In one patient, the arising vessels resulted in conversion to ODN because of bleeding; in the other patient, arterial reconstruction was performed. In another patient, conversion to ODN was necessary because of ongoing bleeding from an avulsed large lumbar venous tributary to the left renal vein. Observational data revealed that multiple renal arteries--most of which were accessory renal arteries--were seen in 52 (26%) kidneys. Early branching of the main renal artery was seen in 24 (12%) kidneys, and main renal arterial abnormalities were identified in six (3%). Capsular arteries were detected in 10 (5%) kidneys. Major variations in the anatomy of the main renal veins--including multiple right renal veins, a retroaortic left renal vein, and a circumaortic left renal vein--were seen in 28 (14%) kidneys. Large (>5 mm in diameter) systemic tributaries to the left renal vein were seen in 25 (25%) kidneys. There was no significant interobserver disagreement between the vascular radiologists. Multi-detector row CT findings can predict successful LDN in live potential renal donors.

Colorectal Polyps: Detection with Low-Dose Multi–Detector Row Helical CT Colonography versus Two Sequential Colonoscopies

To prospectively evaluate the diagnostic accuracy of low-radiation-dose computed tomographic (CT) colonography for detection of colorectal polyps by using two sequential colonoscopies, with the second colonoscopy as the reference standard. The study was local ethics committee approved, and all patients gave written informed consent. Colonographic images were acquired by using a low-dose multi-detector row CT protocol (effective milliampere-second setting, 10 mAs). Three observers interpreted the CT colonographic data separately and independently by using a two-dimensional technique. Initial conventional colonoscopy was performed by an endoscopist unaware of the CT colonographic findings. Second colonoscopy performed within 2 weeks by a colonoscopist aware of both the CT colonographic and the initial colonoscopic findings served as the reference standard. The sensitivities of CT colonography and initial colonoscopy were calculated on a per-polyp and a per-patient basis. Specificities and positive and negative predictive values also were calculated on a per-patient basis. Eighty-eight patients underwent CT colonography and initial conventional colonoscopy on the same day. Per-polyp sensitivities were 62% and 83% for CT colonography and initial colonoscopy, respectively. Sensitivities for detection of polyps 6 mm in diameter or larger were 86% and 84% for CT colonography and initial colonoscopy, respectively. Initial colonoscopy failed to depict 16 polyps, six of which were correctly detected with CT colonography. For identification of patients with polyps 6 mm in diameter or larger, CT colonography and initial colonoscopy, respectively, had sensitivities of 84% and 90%, specificities of 82% and 100%, positive predictive values of 70% and 100%, and negative predictive values of 91% and 95%. Low-dose CT colonography compares favorably with colonoscopy for detection of colorectal polyps 6 mm in diameter or larger, with markedly decreased performance for detection of polyps 5 mm in diameter or smaller.

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

No AccessJournal of UrologyUrological Survey: Imaging1 Oct 2005Bladder Cancer: Analysis of Multi-Detector Row Helical CT Enhancement Pattern and Accuracy in Tumor Detection and Perivesical Staging Cary SiegelM.D. Cary SiegelCary Siegel More articles by this author View All Author Informationhttps://doi.org/10.1097/S0022-5347(01)68587-2AboutFull TextPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail "Bladder Cancer: Analysis of Multi-Detector Row Helical CT Enhancement Pattern and Accuracy in Tumor Detection and Perivesical Staging." The Journal of Urology, 174(4 Part 1), pp. 1250–1251 © 2005 by American Urological Association, Inc.FiguresReferencesRelatedDetails Volume 174Issue 4 Part 1October 2005Page: 1250-1251 Advertisement Copyright & Permissions© 2005 by American Urological Association, Inc.MetricsAuthor Information Cary Siegel More articles by this author Expand All Advertisement Loading ...

The value of drip infusion cholangiography using multidetector-row helical CT in patients with choledocholithiasis

The purposes of this study were to investigate the feasibility of drip infusion cholangiography computed tomography (CTCh) for choledocholithiasis and to compare the detection of the stone on CTCh with that of MR cholangiopancreatography (MRCP). CTCh examinations were performed after infusion of intravenous biliary contrast material (iotroxic acid meglumine, 100 ml) for patients with suspected biliary diseases and were reconstructed to maximum intensity projection (MIP) and multiplanar reformation (MPR). Of 432 patients who underwent CTCh, we identified 15 who underwent surgery or cholangioscopic removal for choledocholithiasis and 32 patients who underwent cholecystectomy due to cholecystolithiasis. Their MRCP images were compared with the CTCh images. The sensitivity and specificity of CTCh for detecting choledochal stones were 87% and 96% whereas those of MRCP were 80% and 88%. The sensitivity and specificity of CTCh for detecting gallstones were 78% and 100% whereas those of MRCP were 94% and 88%. CTCh allowed high sensitivity and specificity for detecting choledochal stones but diminished the detection for cholecystolithiasis compared with MRCP.

Comparison of Artifacts on Coronal Reformation and Axial CT Pulmonary Angiography Images Using Single-detector and 4- and 8-Detector Multidetector-row Helical CT Scanners 1

The aim of this study is to compare the degree of stair-step artifact on coronal reformation computed tomographic (CT) pulmonary angiography images obtained using single-detector helical CT (SDCT), four-detector (4-MDCT), and eight-detector multidetector-row CT (8-MDCT) and compare the degree of motion artifact on the corresponding axial CT images. Three groups of consecutive patients imaged by means of CT angiography for suspected pulmonary embolus were retrospectively identified by using CT records at our institution: (1) group A (n = 38), SDCT; (2) group B (n = 36), 4-MDCT; and (3) group C (n = 74), 8-MDCT. For each case, coronal multiplanar volume reformation maximal intensity projection images were created by using a standard technique. All images were reviewed in a randomized fashion by two thoracic radiologists who were blinded to the type of CT scanner. Stair-step artifact of pulmonary arteries on coronal reformation images was graded by consensus agreement using a four-point scale (0 = no artifact to 3 = severe artifact). Axial images were assessed for six parameters of motion artifact. The sum of these grades resulted in a total motion score, with a potential range of 0 (no motion) to 12 (severe motion). Statistical analysis was performed using the Mann-Whitney test. Stair-step artifacts were significantly higher for SDCT (mean, 2.9; median, 3) compared with 4-MDCT (mean, 2.2; median, 2; P < .0001) and 8-MDCT (mean, 1.5; median, 1; P < .0001). Total motion scores were significantly higher for SDCT (mean, 9.3) compared with 4-MDCT (mean, 8.4; P = .03) and 8-MDCT (mean, 6.8; P < .0001). Stair-step artifacts are significantly higher with SDCT compared with MDCT. For MDCT, eight-detector scanners produce images with significantly less artifact than four-detector scanners.

Systemic Collateral Supply in Patients with Chronic Thromboembolic and Primary Pulmonary Hypertension: Assessment with Multi–Detector Row Helical CT Angiography

To compare retrospectively the frequency of systemic collateral supply in patients who have chronic thromboembolic pulmonary hypertension with the frequency of systemic collateral supply in patients who have primary pulmonary hypertension by using multi-detector row helical computed tomographic (CT) angiography. For this review, neither institutional board approval nor informed consent was required. Thirty-six consecutive patients, including 22 patients (four men, 18 women; mean age, 46.0 years) with chronic thromboembolic pulmonary hypertension (group 1) and 14 patients (five men, nine women; mean age, 63.0 years) with primary pulmonary hypertension (group 2), underwent multisection spiral CT angiography of the pulmonary and systemic circulations with a four- (n = 17) or 16- (n = 19) detector row scanner. CT angiograms were assessed for the presence of abnormal bronchial and/or nonbronchial systemic arteries, CT features of pulmonary hypertension, and right ventricular dysfunction. Vascular and parenchymal signs of chronic pulmonary embolism were specifically analyzed on CT angiograms of group 1 patients. Comparative analyses were performed by using the chi(2) or the Fisher exact test for categoric data. An unpaired bilateral Wilcoxon rank sum test was used for continuous data. A chi(2) goodness-of-fit test was used to compare observed proportions with equal proportions. The degree of pulmonary hypertension was comparable in groups 1 and 2. Abnormally enlarged systemic arteries were identified in 16 (73%) of 22 patients from group 1 and in two (14%) of 14 patients from group 2 (P = .002). The systemic collateral supply in group 1 comprised enlargement of both bronchial and nonbronchial systemic arteries in nine (56%) of the 16 patients; the remaining seven patients had an exclusive enlargement of bronchial systemic arteries (n = 6, 38%) or nonbronchial (n = 1, 6%) systemic arteries. A total of 31 enlarged nonbronchial systemic arteries were depicted, including 13 inferior phrenic arteries, 10 intercostal arteries, seven internal mammary arteries, and one lateral thoracic artery. The mean +/- standard deviation of abnormal nonbronchial systemic arteries per patient was 1.4 +/- 1.9. No relationship was found between the mean number of abnormally enlarged nonbronchial systemic arteries and the CT angiographic features of chronic pulmonary embolism. These results demonstrate the higher frequency of abnormally enlarged bronchial and nonbronchial systemic arteries in patients who have chronic thromboembolic pulmonary hypertension compared with patients who have primary pulmonary hypertension; this finding could help distinguish these two entities on CT angiograms.

Hepatocellular Carcinoma: Role of Unenhanced and Delayed Phase Multi–Detector Row Helical CT in Patients with Cirrhosis

To determine, by using multi-detector row helical computed tomography (CT), the added value of obtaining unenhanced and delayed phase scans in addition to biphasic (hepatic arterial and portal venous phases) scans in the detection of hepatocellular carcinoma (HCC) in patients with cirrhosis. Local ethical committee approval and patient consent were obtained. One hundred ninety-five patients (129 men, 66 women; mean age, 61 years; age range, 39-78 years) with 250 HCCs underwent multi-detector row helical CT of the liver. A quadruple-phase protocol that included unenhanced, hepatic arterial, portal venous, and delayed phases was performed. Analysis of images from hepatic arterial and portal venous phases combined, hepatic arterial and portal venous phases with the unenhanced phase, hepatic arterial and portal venous phases with the delayed phase, and all phases combined was performed separately by three independent radiologists. Relative sensitivity, positive predictive value, and area under the receiver operating characteristic curve (A(z)) were calculated for each reading session. Mean sensitivity and positive predictive values, respectively, for HCC detection were 88.8% (666 of 750 readings) and 97.8% (666 of 681 readings) for the combined hepatic arterial and portal venous phases, 89.2% (669 of 750 readings) and 97.8% (669 of 684 readings) for hepatic arterial and portal venous phases with the unenhanced phase, 92.8% (696 of 750 readings) and 97.3% (696 of 715 readings) for hepatic arterial and portal venous phases with the delayed phase, and 92.8% (696 of 750 readings) and 97.3% (696 of 715 readings) for all four phases combined. The reading sessions in which delayed phase images were available for interpretation showed significantly (P < .05) superior sensitivity and A(z) values. Unenhanced phase images are not effective for HCC detection. Because of the significant increase in HCC detection, a delayed phase can be a useful adjunct to biphasic CT in patients at risk for developing HCC.