Enhanced Computed Tomography Imaging Research Articles

Primary Pulmonary Synovial Sarcoma in a Tertiary Referral Center: Clinical Characteristics, CT, and 18F-FDG PET Findings, With Pathologic Correlations.

The purpose of this study was to describe the patient characteristics, computed tomography (CT) and F-fluorodeoxyglucose positron emission tomography (FDG PET) findings, and clinical outcomes of primary pulmonary synovial sarcoma (PPSS), together with their pathologic correlations. The medical records of 14 patients with pathologically proven PPSS in a tertiary hospital from January 1997 to December 2014 were retrospectively reviewed. The CT findings were evaluated. The maximum standardized uptake value (maxSUV) of the tumors was obtained, and clinical outcomes with respect to tumor recurrence and mortality were assessed by Kaplan-Meier analysis. The median tumor size was 10.2 cm and the most common anatomic location was the lung followed by the pleura/chest wall and mediastinum. Most of the tumors appeared as single lesions and had circumscribed margins. All the cases showed heterogeneous enhancement with necrotic or cystic portions, and intratumoral vessels were frequently seen. Half of the tumors had intratumoral calcifications, and tumor rupture, pleural/chest wall extension, and pleural effusion occurred frequently. However, lymph node enlargement was rare. The median maxSUV of the tumors was 4.35. Patient outcomes with respect to tumor recurrence (n = 8, 57.1%) and death (n = 3, 21.4%) were poor despite their young age, and the mean follow-up period was 28.5 months.In conclusion, PPSS usually occurs in young adults, generally in the lung, presents as a large, circumscribed mass, and tumor rupture or extension of the pleura/chest wall may occur. The tumors often contain calcifications and vessels; they may exhibit triple attenuation on enhanced CT images, and clinical outcomes are poor.

Delayed Contrast-enhanced Computed Tomography for Adrenal Masses in 3 Dogs

Three dogs having adrenal masses detected on ultrasonographic examination were underwent computed tomography (CT) for surgery. After adrenalectomy, each mass was diagnosed pheochromocytoma with myelolipoma, adrenocortical carcinoma and adrenal adenoma through histopathology. Five minutes were used to get delayed enhanced CT images. Attenuation value was measured in each mass and the absolute and relative percentage of enhancement washout were calculated.

Automatic Segmentation of Liver Tumor in CT Images with Deep Convolutional Neural Networks

Liver tumors segmentation from computed tomography (CT) images is an essential task for diagnosis and treatments of liver cancer. However, it is difficult owing to the variability of appearances, fuzzy boundaries, heterogeneous densities, shapes and sizes of lesions. In this paper, an automatic method based on convolutional neural networks (CNNs) is presented to segment lesions from CT images. The CNNs is one of deep learning models with some convolutional filters which can learn hierarchical features from data. We compared the CNNs model to popular machine learning algorithms: AdaBoost, Random Forests (RF), and support vector machine (SVM). These classifiers were trained by handcrafted features containing mean, variance, and contextual features. Experimental evaluation was performed on 30 portal phase enhanced CT images using leave-one-out cross validation. The average Dice Similarity Coefficient (DSC), precision, and recall achieved of 80.06% ± 1.63%, 82.67% ± 1.43%, and 84.34% ± 1.61%, respectively. The results show that the CNNs method has better performance than other methods and is promising in liver tumor segmentation.

Wavelet-based Image Fusion for Enhancement of ROI in CT Image

This paper proposes a novel method for enhancing Computed Tomography (CT) image. In this proposed method, the entropy-based histogram algorithm was applied to detach significant values in CT image to produce a detached image. In addition, wavelet transforms were employed for both the original CT image and the detached image to create image fusion. Therefore, an enhanced image with tumor region was obtained for diagnosis using an inverse wavelet transform. The result is that the processed region in the enhanced image shows more prominent points than that in the original image. This result can allow physicians or doctors diagnose and predict more accurately tumor regions in the enhanced CT image

Findings from imaging stercoral colitis associated with colonic perforation.

A 78-year-old woman presented to the emergency department with severe abdominal pain. Her WBC count was within normal limits, and a physical examination revealed abdominal distention and perianal tenderness. Written informed consent was obtained from patient for computed tomography (CT). Scout radiography revealed signs of colonic obstruction and fecal impaction in the colon (Figure 1). According to CT, the colon was distended with intraluminal fecalomas, pericolonic/perirectal fat stranding, wall edema and extraluminal bubbles of gas in the rectum, suggesting that perforation had already occurred (Figures 2a, b). On the 3-dimensional CT image, densities due to fecalomas were observed (Figure 3). During surgery, focal perforation on the posterior wall of the rectum was found to be consistent with stercoral ulceration. Despite fecal diversion and antibiotic therapy, the patient died secondary to sepsis. Figure 1. Abdominal scout image shows a dilated colon with paucity of gas in the rectal region. Figure 2. a, b. Axial contrast enhanced CT image of the pelvis demonstrates fecal impaction resulting in rectal dilatation. A. Perirectal fat tissue shows stranding indicative of inflammatory change (white arrows). Colonic wall thickening and ulceration (arrowhead) ... Figure 3. Three-dimensional CT image of pelvis shows fecaloma (arrows) (F; fecaloma). Stercoral colitis is an inflammatory colitis that is caused by increased intraluminal pressure from impacted fecal material in the colon. When stercoral colitis is associated with colonic perforation, a 35% mortality rate has been reported [1]. In approximately 75% of such cases, ulcers are found in the sigmoid colon or rectum [2]. If stercoral colitis with ulceration is present, focal thickening or pericolonic fat stranding can be observed by CT. The presence of extraluminal gas or an abscess suggests that perforation has already occurred. Surgery should be a last resort for stercoral colitis. If necessary, treatment with surgery usually includes resection of the affected bowel, colostomy and a Hartmann’s pouch. In conclusion, it is important to recognize this serious condition and begin treatment as soon as possible.

치성각화낭의 외과적 소파술 후 하치조 동맥에 발생한 가성 동맥류: 증례보고

Pseudoaneurysms are rare complications of orgthognathic surgery, trauma or other surgical procedures in the head and neck regions. Surgical approach is a routine procedure of bleeding control. However, bleeding control using angiography and embolization can also be an excellent method. We experienced pseudoaneurysm of the inferior alveolar artery occurring after surgical curettage of cystic lesion. The 33-year-old man who underwent surgical curettage of keratocystic odontogenic tumor was presented with severe bleeding in the right mandible ramal inner surface 14 days after the surgical curettage. After hemostasis with vaseline gauze packing and pressure, bleeding temporarily stopped. However, bleeding started after 14 days and soon it has been continued. Finally, the patient was diagnosed as pseudoaneurysm of the inferior alveolar artery from the enhanced-computed tomography images, and angiographic embolization was performed successfully. We report a rare case of pseudoaneurysm of the inferior alveolar artery after benign tumor curettage and review of the previewer's literature.

Facile synthesis of acetylated dendrimer-entrapped gold nanoparticles with enhanced gold loading for CT imaging applications.

We describe a facile approach to synthesizing acetylated dendrimer-entrapped gold nanoparticles (Au DENPs) with enhanced Au loading in the dendrimer interior. In this study, amine-terminated generation 5 poly(amidoamine) (PAMAM) dendrimers (G5.NH2) were used as templates to form Au DENPs via a stepwise Au salt complexation/reduction approach, followed by acetylation of the dendrimer terminal amines. The formed Au DENPs before and after acetylation were characterized with different techniques. We show that the stepwise complexation/reduction of HAuCl4 is able to significantly improve the loading amount of Au within the dendrimer interior. UV-Vis spectroscopy reveals that the intensity of the surface plasmon resonance (SPR) band increases with the Au loading, confirming the stepwise loading synthesis of Au DENPs. TEM images show that the synthesized Au DENPs have a quite uniform size distribution with sizes tunable in the range of 2-4 nm depending on the Au loading. The formed acetylated Au DENPs with enhanced Au loading are very stable under different pH and temperature conditions. Importantly, computed tomography (CT) imaging experiments reveal that the formed acetylated Au DENPs have higher attenuation intensity than a clinically used iodinated contrast agent, Omnipaque, at the same molar concentration of active elements (Au or iodine), and enable significantly enhanced CT imaging of rat heart in vivo. The acetylated Au DENPs with enhanced Au loading formed via the facile stepwise approach may be used as contrast agents for highly sensitive CT imaging applications.

Comparative study of thin sectional anatomical images from Chinese Visible Human data set and computed tomography images of superior mediastinum

The structures of superior mediastinum and their spatial relationships are complex and difficult to master. This study aimed to compare visualization of the superior mediastinum based on computed tomography (CT) images and on the thin sections of the Chinese visible human (CVH) data set to provide a sectional anatomical basis for diagnostic imaging of superior mediastinal pathology. CVH sections of the mediastinum of a 35-year old male were compared with plain and enhanced CT images of a 45-year old male without apparent abnormalities in the upper chest. In addition, a three-dimensional model based on the CVH sections was compared with a model based on CT images. Although CT imaging is noninvasive and can be carried out in many individuals, its weakness is clearly the visualization of small soft tissue structures. In this respect, the sectional anatomical approach of the CVH images is complementary, as it visualizes these small soft tissue structures due to the higher resolution in the plain of sectioning and the color of the different structures in the section. Three-dimensional surface and volume rendering of reconstructions of the CVH data set can help medical students and less experienced thoracic surgeons to familiarize themselves with the topographic anatomy of the superior mediastinal structures and their spatial relationships, and thus with interpreting CT images of patients.

Can the localization of primary colonic tumors be improved by staging CT without specific bowel preparation compared to optical colonoscopy?

ObjectivesTo investigate the ability of staging computed tomography (CT) without bowel preparation to accurately localize colonic tumors compared to optical colonoscopy. MethodsThe local institutional review board approved this retrospective and HIPAA-compliant study. Forty-six patients with colonic adenocarcinoma, preoperative colonoscopy, and staging CT within 60 days of resection were included. Patients underwent contrast enhanced CT imaging without bowel preparation or oral contrast. The colon was divided into four segments with the operative reports used as the standard. Rectal and cecal cancers were excluded. CT scans were reviewed by 5 readers in a segmental binary fashion using a 5-point confidence scale in two sessions blinded and unblinded to the colonoscopy report. ResultsAt surgery 49 tumors were found in 46 patients. Readers detected 86.1%, 74.3%, and 66.9% of lesions with 92.0%, 94.1%, and 95.4% accuracy for confidence scores of ≥3, ≥4, and 5. CT interobserver agreement was good (κ=0.82) for the unblinded and moderate (κ=0.60) for the blinded read. Colonoscopic localization was only 78.7% accurate with 2 tumors undiscovered. Colonoscopic accuracy was low in the descending colon (57.1%) and the transverse colon (55.6%). ConclusionsPreoperative staging CT is more accurate than colonoscopy in the localization of colonic tumors.

Assessment of texture measures susceptibility to noise in conventional and contrast enhanced computed tomography lung tumour images

Noise is one of the major problems that hinder an effective texture analysis of disease in medical images, which may cause variability in the reported diagnosis. In this paper seven texture measurement methods (two wavelet, two model and three statistical based) were applied to investigate their susceptibility to subtle noise caused by acquisition and reconstruction deficiencies in computed tomography (CT) images. Features of lung tumours were extracted from two different conventional and contrast enhanced CT image data-sets under filtered and noisy conditions. When measuring the noise in the background open-air region of the analysed CT images, noise of Gaussian and Rayleigh distributions with varying mean and variance was encountered, and Fishers’ distance was used to differentiate between an original extracted lung tumour region of interest (ROI) with the filtered and noisy reconstructed versions. It was determined that the wavelet packet (WP) and fractal dimension measures were the least affected, while the Gaussian Markov random field, run-length and co-occurrence matrices were the most affected by noise. Depending on the selected ROI size, it was concluded that texture measures with fewer extracted features can decrease susceptibility to noise, with the WP and the Gabor filter having a stable performance in both filtered and noisy CT versions and for both data-sets. Knowing how robust each texture measure under noise presence is can assist physicians using an automated lung texture classification system in choosing the appropriate feature extraction algorithm for a more accurate diagnosis.

CT Scan for Suspected Acute Abdominal Process: Impact of Combinations of IV, Oral, and Rectal Contrast

BACKGROUND There are limited data available on the ability of computed tomography (CT) to accurately diagnose abdominopelvic pathology in acutely ill inpatients suspected of having an acute abdominal process. The purpose of this study was to evaluate the diagnostic accuracy of abdominal/pelvic CT with varying use of contrast agents in hospitalized patients. METHODS A retrospective review of all hospital inpatients (3/1/07-5/31/07) who underwent urgent or emergent abdominal/pelvic CT with any combination of contrast, intravenous (IV), oral, rectal, or unenhanced for a suspected acute abdominal process was performed. Data collected included demographics, combination of contrast used, CT diagnosis, time from CT scan to subsequent intervention, intervention type, and actual diagnosis of the acute abdominal process. Accuracy of CT was compared between enhanced and unenhanced imaging using Fisher's exact test. RESULTS A total of 661 patients were identified. Use of IV contrast alone was found in 54.2% of CT scans and was correct in 92.5% of cases. IV and oral contrast was used in 22.2% of CT scans and was 94.6% correct. Unenhanced imaging was performed in 16.2% and was correct in 92.5%. Oral contrast alone was used in 7.0% and was 93.5% correct. There was no significant difference in the ability to correctly diagnose a suspected acute abdominal process when enhanced CT imaging was compared to unenhanced (p > 0.05). CONCLUSIONS CT contrast administration in critically ill hospitalized patients is not necessary to accurately diagnose an acute abdominal process. Eliminating the use of contrast may improve patient comfort, decrease patient risk, and minimize financial cost.

The association of lymph node volume with cervical metastatic lesions in head and neck cancer patients

The aim of this study was to determine if volume of cervical lymph node measured via computed tomography (CT) could differentiate metastatic from benign lesions in head and neck cancer patients. We conducted a retrospective review of chart and images in a tertiary referring center in Taiwan. Patients with head and neck cancers underwent radical, modified radical or functional neck dissection were enrolled. The CT images before operation were reassessed by a radiologist and were compared with the results of pathological examination. A total of 102 patients were included for final analyses. Most patients were male (n = 96, 94%) and average age was 50.1 years. Although the average nodal volume in patients with cervical metastases was higher than those of patients without cervical metastases, it was not an independent factor associated with cervical metastasis after controlling for other variables; however, central nodal necrosis on enhanced CT image [odds ratio (OR) 18.95, P = 0.008) and minimal axial diameter >7.5 mm (OR 6.868, P = 0.001) were independent factors correlated with cervical metastasis. Therefore, the volume of cervical lymph node measured from CT images cannot predict cervical metastases in head and neck cancer patients. Measurement of minimal axial diameter of the largest lymph node is a simple and more accurate way to predict cervical metastasis instead.

Effectiveness of real‐time virtual sonography‐guided radiofrequency ablation treatment for patients with hepatocellular carcinomas

Real-time virtual sonography (RVS) can synchronize B-mode ultrasound (US) images with multiplanar reconstruction (MPR)-computed tomography (CT) images on the same screen in real time. The purpose of this study was to evaluate the effectiveness of RVS for radiofrequency ablation therapy (RFA) of hepatocellular carcinomas (HCC) in which it was difficult to identify contours or margins by B-mode US. Sixty-three consecutive patients with a solitary HCC of less than 3.5 cm in diameter were enrolled in this study. Thirty-nine patients with HCC clearly detectable by B-mode US underwent conventional RFA, while the remaining 24 with obscure tumor lesions underwent RVS-guided RFA. A follow-up study of RFA treatment was performed every 3 months using enhanced CT imaging of the arterial and portal phase (at least 24 months). The accuracy of needle insertion was confirmed by measuring the gap between the needle insertion line and the center of the tumor from MPR-CT images. The local recurrence rate of the RVS-guided RFA group was similar to that of the conventional RFA group (8.3% vs 7.7%), despite the difficulty of detecting tumor lesions in the former group. The mean gap between the needle insertion line and the center of the tumor was 1.6 mm (0-3.2 mm) in eight patients treated with RVS-guided RFA. RVS-guided RFA can be useful for treating HCC that are difficult to detect by B-mode US.

Renal Abscess with Morganella morganii Complicating Leukemoid Reaction

We report a case of leukemoid reaction (LR) complicating renal abscess caused by Morganella morganii infection in an 80-year-old man. On administration, laboratory tests revealed white blood cell count of 76160 /microL and C reactive protein 3.09 mg/dL. Although chronic myeloid leukemia was suspected, bcr/abl fusion transcript was not observed. Contrast enhanced computer tomography imaging of the abdomen showed abscess in the right kidney. M. morganii was detected repeatedly in material of liquid from the abscess and arterial blood culture. To our knowledge, this is the first case of M. morganii infection complicating LR.

DYNAMIC COMPUTED TOMOGRAPHY OF THE PANCREAS IN NORMAL DOGS AND IN A DOG WITH PANCREATIC INSULINOMA

To establish optimal imaging conditions for enhanced computed tomography (CT) for canine pancreatic tumors, 10 healthy beagles were subjected to dynamic CT. This technique was then applied to a dog with suspected insulinoma. The changes in mean peak enhancement and the delay time of the aorta and pancreas were determined. In normal beagles, maximal arterial and pancreatic CT enhancement was observed at 15 +/- 2 s (795 +/- 52 Housfield unit [HU]) and 28 +/- 9 s (118 +/- 16HU) after contrast medium injection, respectively. Multiphase enhanced CT was performed in a pug with suspected insulinoma using the CT protocol defined for the normal beagles with some parameters modified; the images were acquired at the arterial (14 s after contrast medium injection), pancreatic (after 28 s), and equilibrium (after 90 s) phases; scanning was followed by exploratory laparotomy. CT images were characterized by an enhanced mass in the left pancreatic lobe at the arterial phase, during which the difference between the CT values of the mass and normal pancreas was the highest. Histopathologic diagnosis of the pancreatic mass was insulinoma. Thus, it appears that enhanced CT imaging can be used to delineate the pancreas from a pancreatic mass, and it may be helpful in deciding the need for surgery.

腎動態シンチグラフィにおける Ｃｏｍｐｕｔｅｄ Ｔｏｍｏｇｒａｐｈｙ（ＣＴ）画像を用いた自動解析法の開発

Determination of the region of interest (ROI) for dynamic renal function has been highly discordant among operators because of the dependence on factors such as the rate of injection of radioactive medicines, constitution, and renal function. To simplify this problem, we developed a computer algorithm that provides automatic analysis for both localization of the kidney and automatic determination of ROIs using computed tomographic (CT) images. The bilateral kidneys were extracted from enhanced CT images, and the CT pixel size was adjusted to dynamic renal function images. The template-matching technique was used for these images, and the kidney renal location was analyzed on additional functional images constructed by dynamic renal function images. As a result, we were able to obtain time-activity curves of both renal function and quantified glomerular filtration rate (GFR). In conclusion, the computer algorithm we developed was considered to provide reliable results, apart from the variability among operators, because of its good reproducibility.

A primordial cyst without keratinization in the maxillary molar region: a case report

In this article we report a case of a 54-year-old man with a primordial cyst in the left maxillary molar region. We performed conventional radiographs and computed tomography (CT) without contrast enhancement, but it was difficult to determine whether the lesion was a tumor or a cyst. CT images with contrast medium showed a cyst, not a tumor. Histopathologically, the cyst wall was composed of fibrous connective tissue lined by nonkeratinized squamous epithelium. Based on its clinical, radiological, and histopathological findings, this lesion was diagnosed as a primordial cyst. This case indicated that enhanced CT imaging is useful for differentiating between cysts and benign tumors and that there are no specific differences in the radiological appearance between primordial cysts and odontogenic keratocysts

Diagnostic value of computed tomography in recurrent pain after discectomy.

Intravenously enhanced computed tomography (CT) was used in patients in whom the differential diagnosis between recurrent herniated disc and postoperative scar was considered. Enhanced CT images demonstrated postoperative herniated discs more accurately than clinical criteria, myelography, or plain or postmetrizamide CT. The scar tissue shows contrast enhancement, but recurrent disc herniation does not. Therefore, contrast-enhanced CT is considered to be a valuable aid in distinguishing between recurrent disc herniation and hypertropic scar formation.