Serial Computed Tomography Examinations Research Articles

Splenomegaly versus pathological lung volume during COVID-19 infection with or without cytokine storm; a linear regression analysis using CT volumetry

BackgroundDue to the paucity of scientific evidence, it is unclear among pulmonologists and physicians in critical care units if and when splenomegaly in novel coronavirus disease (2019) (COVID-19) patients is worrisome. This study aims to evaluate the significance of splenic volume during COVID-19 infection with or without cytokine storm and correlates splenic volume to the volume of pathological lung changes through linear regression analysis.ResultsA retrospective study collected 509 polymerase chain reaction proved COVID-19 patients (399 males, 110 females; mean age 48 years, age range 24–78 years) between June and November 2021, without a history of splenic pathology. A control group of age and sex-matched 509 healthy subjects was used and analyzed according to the splenic volume. Five consulting radiologists evaluated initial and follow-up computed tomography (CT) examinations using lung CT volumetry and splenic volume calculation in consensus. Three consulting pulmonologists correlated the severity of clinical and laboratory findings, including oxygen requirements and interleukin-6 (IL-6) levels. The T test results for comparison between the COVID-19 patients and the healthy subjects control group regarding the splenic volume were significant (T value was − 4.731452 and p value was 0.00002). There was no significant correlation between the severity of the disease and normal-sized spleen (26% of patients, p = 0.916) or splenomegaly (24% of patients, p = 0.579). On the other hand, all patients with a small spleen or progressive splenomegaly during serial follow-up imaging had clinically severe disease with a statistically significant correlation (p = 0.017 and 0.003, respectively). Ninety-seven percent of patients with clinically mild disease and splenomegaly had 0–20% lung involvement (CT-severity score 1) while all patients with clinically severe disease and splenomegaly had 27–73% lung involvement (CT-severity score 2 and 3) (r = 0.305, p = 0.030).ConclusionsSplenomegaly is a non-specific sign that may be found during mild and severe COVID-19 infection, it was not statistically correlated with the clinical severity and a weak positive relationship was found between the splenic size and the CT-severity score of the pathological lung volume. On the other hand, the presence of splenic atrophy or progressive splenomegaly was correlated with severe COVID-19 presentation and “cytokine storm”. Therefore, the splenic volume changes should not be overlooked in COVID-19 serial CT examinations, particularly in severe or critically ill patients with cytokine storms.

Machine learning for lung texture analysis on thin-section CT: Capability for assessments of disease severity and therapeutic effect for connective tissue disease patients in comparison with expert panel evaluations.

The need for quantitative assessment of interstitial lung involvement on thin-section computed tomography (CT) has arisen in interstitial lung diseases including connective tissue disease (CTD). To evaluate the capability of machine learning (ML)-based CT texture analysis for disease severity and treatment response assessments in comparison with qualitatively assessed thin-section CT for patients with CTD. A total of 149 patients with CTD-related ILD (CTD-ILD) underwent initial and follow-up CT scans (total 364 paired serial CT examinations), pulmonary function tests, and serum KL-6 level tests. Based on all follow-up examination results, all paired serial CT examinations were assessed as "Stable" (n = 188), "Worse" (n = 98) and "Improved" (n = 78). Next, quantitative index changes were determined by software, and qualitative disease severity scores were assessed by consensus of two radiologists. To evaluate differences in each quantitative index as well as in disease severity score between paired serial CT examinations, Tukey's honestly significant difference (HSD) test was performed among the three statuses. Stepwise regression analyses were performed to determine changes in each pulmonary functional parameter and all quantitative indexes between paired serial CT scans. Δ% normal lung, Δ% consolidation, Δ% ground glass opacity, Δ% reticulation, and Δdisease severity score showed significant differences among the three statuses (P < 0.05). All differences in pulmonary functional parameters were significantly affected by Δ% normal lung, Δ% reticulation, and Δ% honeycomb (0.16 ≤r2 ≤0.42; P < 0.05). ML-based CT texture analysis has better potential than qualitatively assessed thin-section CT for disease severity assessment and treatment response evaluation for CTD-ILD.

Waxing and waning pattern of mTOR inhibitor-associated pneumonitis in renal cell carcinoma patients: A retrospective observational study

ObjectivemTOR inhibitor-associated pneumonitis is common and often asymptomatic. We describe a waxing and waning pattern of pneumonitis observed on computed tomography (CT) scans of patients with renal cell carcinoma who were being treated with mTOR inhibitor molecular targeted therapy. Materials and methodsIn this HIPAA-compliant, IRB-approved retrospective single-institution study, 25 renal cell carcinoma patients were identified who received single-therapy temsirolimus or everolimus between January 2011 and June 2015 and who had chest CT scans available for review both before and after initiation of mTOR inhibitor treatment. A detailed review of the electronic medical record and serial chest CT examinations was performed. ResultsRadiologic findings compatible with pneumonitis were identified in 13/25 (52%) patients on mTOR inhibitors in our study. Of the patients with CT findings of pneumonitis, 8/13 (62%) demonstrated a waxing and waning pattern; of whom 7 had clinical symptoms of pneumonitis. Of the 17 patients who received temsirolimus, 9/17 (53%) developed radiologic findings compatible with pneumonitis and 4/9 (44%) developed a waxing and waning pattern. Of the 8 patients who received everolimus, 4/8 (50%) had radiologic findings compatible with pneumonitis and 4/4 (100%) developed a waxing and waning pattern. ConclusionWaxing and waning is an unrecognized pattern of mTOR inhibitor-associated pneumonitis. Recognition of this pattern will promote clinical-radiologic concordance and may facilitate patient management.

Diameter and growth rate of the thoracic aorta-analysis based on serial computed tomography scans.

BackgroundAlthough there are studies on the growth of thoracic aorta in the general population, research based on serial computed tomography scan is rare. We investigated the influence of patient age and anthropometric variables on the size and growth rate of the thoracic aorta in the general hospital population.MethodsData on 2,353 adults [2003–2014] who underwent ≥2 serial computed tomography examinations with at least a 6-year interval were analyzed. There were 1,444 men (61%), and the mean age was 58±12 years (range, 17–92 years). Thoracic aortic diameters were measured at 5 levels (the sinus of Valsalva, ascending aorta, aortic arch, and proximal and distal descending thoracic aorta) in the first and last computed tomography scans taken at a median interval of 7.0 years (interquartile range: 6.4–8.0).ResultsThe mean aorta diameters were 34.9±4.7, 34.1±4.6, 28.0±3.8, 24.8±3.4, and 23.8±3.3 mm in the sinus of Valsalva, ascending aorta, arch, and proximal and distal descending thoracic aorta, respectively. The initial aorta diameter was larger in older subjects and in those with a larger body surface area (BSA). Female subjects had a significantly larger indexed diameter (diameter/BSA) than male subjects (P<0.001 at all five levels). In all thoracic aorta levels, the growth rate was the highest in subjects in their 40s, and the growth rate negatively correlated with the initial indexed diameter (P<0.001 at all five levels). In 40–50% of the subjects, thoracic aorta size remained stable during the interval.ConclusionsThe thoracic aorta dilated with aging and was larger in subjects with a larger body size. Sex differences in the gross aortic diameter might be related to differences in body size. The growth of the thoracic aorta was faster in younger subjects with a smaller indexed diameter.

Computed Tomography Pulmonary Vascular Volume Ratio Can Be Used to Evaluate the Effectiveness of Pulmonary Angioplasty in Peripheral Pulmonary Artery Stenosis.

To explore whether computed tomography (CT) pulmonary vascular volume ratio can be used to evaluate the effectiveness of pulmonary artery angioplasty in patients with peripheral pulmonary artery stenosis. Changes in CT pulmonary vascular volume ratio between serial cardiothoracic CT examinations were calculated in 38 patients. Fifteen patients underwent interim pulmonary artery angioplasty (group 1), while 23 did not (group 2). According to the effectiveness of pulmonary artery angioplasty, patients in group 1 were further divided into group 1A (improved or aggravated) and group 1B (ineffective). Changes in the pulmonary vascular volume percentages among the three groups (group 1A, group 1B, and group 2) on serial CT examinations were compared. Pulmonary artery angioplasty on serial CT examinations was successful in seven patients, ineffective in seven patients, and aggravated in one patient. As a result, eight patients were included in group 1A and seven were included in group 1B. Changes in the CT pulmonary vascular volume percentages in group 1A were statistically significantly greater than those in group 1B (11.6 ± 5.6% vs. 2.7 ± 1.6%, p < 0.003) and group 2 (11.6 ± 5.6% vs. 1.9 ± 1.4%, p < 0.002), while no statistically significant difference was found between group 1B and group 2 (2.7 ± 1.6% vs. 1.9 ± 1.4%, p > 0.1). CT pulmonary vascular volume ratio can be used to evaluate the effectiveness of pulmonary artery angioplasty in patients with peripheral pulmonary artery stenosis.

Alzheimer's disease or Alzheimer's syndrome?: a longitudinal computed tomography neuroradiological follow-up study of 56 cases diagnosed clinically as Alzheimer's disease.

Some 200 patients, including those with Alzheimer's disease and other types of dementia, stay year-round in Yokohama - Houyuu Hospital. They undergo computed tomography (CT) neuroradiological examination at least once or twice a year. For this study, the accumulative data, including clinical and neuroradiological, were analyzed. Differential diagnoses of Alzheimer's disease were performed in accordance with the National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer's Disease and Related Disorders Association criteria. The 56 patients (15 men, 41 women) included in this study underwent in-hospital observation on average for 4.4 years (range: 1-10 years). The patients were classified into four groups according to the age of disease onset. The CT findings were summarized for each group and then compared among the groups to determine if there were any differences related to age of onset and, if so, to identify and analyze them. (1) The duration of deceased cases' total clinical course (in years) compared among the four groups. In general, the degree of dementia was more severe among those with earlier disease onset. (2) In cases admitted within 2 years from onset (n =14), the suspected initiating focus of cortical atrophy occurred in the frontal lobe (n = 6), the temporal lobe (n = 6), or the fronto-temporal lobes (n = 2). (3) Although CT findings generally showed that the more severe cases had earlier onset, serial CT examinations in each case showed widely different pathologies in degree, nature and manner of progression, regardless of group classification. (4) The earliest sites of brain atrophy, sites of its severest involvement within the brain, and neuroradiological development of the cerebral cortex pathology in combination with hemispheric white matter, lateral ventricles, and third ventricles varied among the four groups and between case within each group. Alzheimer's disease could not be subclassified simply by the age of clinical onset. Cases of so-called Alzheimer's disease, as observed through continued clinical follow-up and serial CT examinations, appear so diverse in symptomatology and radiological pathomorphology that it is difficult to consider them a single nosological entity. The pathology of Alzheimer's disease has to be reconsidered in accordance with the variety observed in the sequential development of neuroradiological findings. The pathology must be reconstructed in terms of topographical dimensions and chronological developments. The diagnosis of Alzheimer's disease appears to be not so simple based on any conventional diagnostic operational standards.

Evaluation and management of pulmonary nodules: state-of-the-art and future perspectives

The imaging evaluation of pulmonary nodules, often incidentally detected on imaging examinations performed for other clinical reasons, is a frequently encountered clinical circumstance. With advances in imaging modalities, both the detection and characterization of pulmonary nodules continue to evolve and improve. This article will review the imaging modalities used to detect and diagnose benign and malignant pulmonary nodules, with a focus on computed tomography (CT), which continues to be the mainstay for evaluation. The authors discuss recent advances in the lung nodule management, and an algorithm for the management of indeterminate pulmonary nodules. There are set of criteria that define a benign nodule, the most important of which are the lack of temporal change for 2 years or more, and certain benign imaging criteria, including specific patterns of calcification or the presence of fat. Although some indeterminate pulmonary nodules are immediately actionable, generally those approaching 1 cm or larger in diameter, at which size the diagnostic accuracy of tools such as positron emission tomography (PET)/CT, single photon emission CT (SPECT) and biopsy techniques are sufficient to warrant their use. The majority of indeterminate pulmonary nodules are under 1 cm, for which serial CT examinations through at least 2 years for solid nodules and 3 years for ground-glass nodules, are used to demonstrate either benign biologic behavior or otherwise. The management of incidental pulmonary nodules involves a multidisciplinary approach in which radiology plays a pivotal role. Newer imaging and postprocessing techniques have made this a more accurate technique eliminating ambiguity and unnecessary follow-up.

Medial Patellofemoral Ligament Reconstruction Using Semitendinosus Tendons

Background: The comparative clinical outcome of medial patellofemoral ligament reconstruction (MPFLR) using semitendinosus tendons with and without polyester suture augmentation for recurrent patellar instability is unknown. Hypothesis: Medial patellofemoral ligament reconstruction with polyester suture augmentation will yield better results than MPFLR without augmentation for recurrent patellar instability in adults. Study Design: Randomized controlled trial; Level of evidence, 2. Methods: One hundred patients with recurrent patellar instability receiving MPFLR using semitendinosus tendons were randomly divided into 2 groups either with or without polyester suture augmentation. Tibial tubercle transfer was performed in most cases. Follow-ups were performed at 12, 24, and 60 months postoperatively, and computed tomography (CT) was performed immediately after the operation and at follow-up. The passive patellar glide test was performed before surgery, immediately after MPFLR during the operation, and at each follow-up point. The degree of knee function was evaluated preoperatively and at 2 and 5 years postoperatively using the International Knee Documentation Committee, Lysholm, and Kujala rating scales. Redislocation or multiple episodes of patellar instability were considered failures. Results: Forty-two patients in the augmentation group and 43 patients in the nonaugmentation group were followed for 5 years and received complete serial CT examinations and functional evaluations. The correction of the static patellar position deteriorated over time in the nonaugmentation group but not in the augmentation group. The results of the passive patellar glide test indicated stable patellae in all patients immediately after MPFLR and more stable patellae in the augmentation group at each follow-up point. Functional evaluations at 2 and 5 years revealed statistically significant superior results in the augmentation group. Finally, no patient in the augmentation group and 2 (4.7%) in the nonaugmentation group experienced episodes of redislocation, and 1 patient (2.4%) in the augmentation group and 8 (18.6%) in the nonaugmentation group experienced multiple episodes of patellar instability, resulting in failure rates of 2.4% and 23.3% in the augmentation group and nonaugmentation group, respectively (P = .004). Conclusion: Medial patellofemoral ligament reconstruction with polyester suture augmentation results in better static patellar position, dynamic stability, and functional outcome than without augmentation in the treatment of recurrent patellar dislocation in adults.

The Inferior Mesenteric Vein to the Left Gonadal Vein Shunt for Gastroesophageal Varices and Extrahepatic Portal Vein Thrombosis After Living Donor Liver Transplantation: A Case Report

This 59-year-old woman underwent living donor liver transplantation using a left lobe graft as an aid for autoimmune hepatitis in 2003. Splenectomy was also performed because of blood type incompatibility. Follow-up endoscopic and computed tomography examinations showed gastroesophageal varices with extra hepatic portal vein thrombosis in 2007 that increased (esophageal varices [EV]: locus superior [Ls], moderately enlarged, beady varices [F2], Blue varices [Cb], presence of small in number and localized red color sign [RC1] and telangiectasia [TE+], gastric varices [GV]: extension from the cardiac orifice to the fornix [Lg-cf], moderately enlarged, beady varices [F2], white varices [Cw], absence of red color sign [RC−]). Portal venous flow to the gastroesophageal varices was also confirmed from a large right gastric vein. The splenic vein was thrombosed. Blood flow to the liver graft was totally supplied from the hepatic artery. The graft was functioning well. Because these gastroesophageal varices had a high risk of variceal bleeding, we decided to proceed with a portal reconstruction of a surgical portosystemic shunt in 2008. Severe adhesions were observed around the portal vein. It was impossible to perform portal reconstruction. There were relatively fewes adhesious in the left lower side of the abdominal cavity. We decided to create an inferior mesenteric vein to left gonadal vein shunt. The portal vein pressure decreased from 31.0 to 21.5 cm H2O thereafter. The postoperative course was smooth without any complication. This patient was discharged on the postoperative day 15. Follow-up endoscopic study showed the improvement in the gastroesophageal varices (EV: Ls, F2, Cb, RC(−), GV: Lg-c, F2, Cw, RC−) at 3 months after the operation. We also comfirmed the patency of the shunt by serial computed tomography examinations.

Automated temporal tracking and segmentation of lymphoma on serial CT examinations

It is challenging to reproducibly measure and compare cancer lesions on numerous follow-up studies; the process is time-consuming and error-prone. In this paper, we show a method to automatically and reproducibly identify and segment abnormal lymph nodes in serial computed tomography (CT) exams. Our method leverages initial identification of enlarged (abnormal) lymph nodes in the baseline scan. We then identify an approximate region for the node in the follow-up scans using nonrigid image registration. The baseline scan is also used to locate regions of normal, non-nodal tissue surrounding the lymph node and to map them onto the follow-up scans, in order to reduce the search space to locate the lymph node on the follow-up scans. Adaptive region-growing and clustering algorithms are then used to obtain the final contours for segmentation. We applied our method to 24 distinct enlarged lymph nodes at multiple time points from 14 patients. The scan at the earlier time point was used as the baseline scan to be used in evaluating the follow-up scan, resulting in 70 total test cases (e.g., a series of scans obtained at 4 time points results in 3 test cases). For each of the 70 cases, a "reference standard" was obtained by manual segmentation by a radiologist. Assessment according to response evaluation criteria in solid tumors (RECIST) using our method agreed with RECIST assessments made using the reference standard segmentations in all test cases, and by calculating node overlap ratio and Hausdorff distance between the computer and radiologist-generated contours. Compared to the reference standard, our method made the correct RECIST assessment for all 70 cases. The average overlap ratio was 80.7 ± 9.7% s.d., and the average Hausdorff distance was 3.2 ± 1.8 mm s.d. The concordance correlation between automated and manual segmentations was 0.978 (95% confidence interval 0.962, 0.984). The 100% agreement in our sample between our method and the standard with regard to RECIST classification suggests that the true disagreement rate is no more than 6%. Our automated lymph node segmentation method achieves excellent overall segmentation performance and provides equivalent RECIST assessment. It potentially will be useful to streamline and improve cancer lesion measurement and tracking and to improve assessment of cancer treatment response.

Risk of Varices Bleeding after Spleen-Preserving Distal Pancreatectomy with Excision of Splenic Artery and Vein

Spleen-preserving distal pancreatectomy with excision of splenic vessels (SPDP-ESV) has been widely adopted because of its simplicity. However, this simplified technique may lead to gastric varices and bleeding. For better understanding of the hemodynamic changes and risk of gastric variceal bleeding, we instituted a prospective study to perform serial follow-up contrast abdominal computed tomography (CT) and endoscopy for patients after SPDP-ESV. There were 37 patients, with a mean follow-up period of 45.3 months (range 23-59 months), included in the analysis. Of the 37 patients studied, 11 (29.7%) had perigastric varices, 12 (32.4%) had splenomegaly, and 3 (8.1%) had gastric submucosal varices on follow-up CT performed 6 months after surgery. Endoscopy also showed gastric varices in three patients with gastric submucosal varices on CT scan. CT performed 18 months after surgery showed no progression of splenomegaly or gastric submucosal varices. Follow-up endoscopies also showed three gastric varices detected on endoscopy at 6 months to be stationary. Based on serial CT and endoscopic examinations, the first postoperative months will show who is at risk of gastric variceal bleeding.

A potential means of improving the evaluation of deformity corrections with Taylor Spatial Frames over time by using volumetric imaging: Preliminary results

Objective: In this study we explore the possibility of accurately and cost-effectively monitoring tibial deformation induced by Taylor Spatial Frames (TSFs), using time-separated computed tomography (CT) scans and a volume fusion technique to determine tibial rotation and translation.Materials and Methods: Serial CT examinations (designated CT-A and CT-B, separated by a time interval of several months) of two patients were investigated using a previously described and validated volume fusion technique, in which user-defined landmarks drive the 3D registration of the two CT volumes. Both patients had undergone dual osteotomies to correct for tibial length and rotational deformity. For each registration, 10 or more landmarks were selected, and the quality of the fused volume was assessed both quantitatively and via 2D and 3D visualization tools. First, the proximal frame segment and tibia in CT-A and CT-B were brought into alignment (registered) by selecting landmarks on the frame and/or tibia. In the resulting “fused” volume, the proximal frame segment and tibia from CT-A and CT-B were aligned, while the distal frame segment and tibia from CT-A and CT-B were likely not aligned as a result of tibial deformation or frame adjustment having occurred between the CT scans. Using the proximal fused volume, the distal frame segment and tibia were then registered by selecting landmarks on the frame and/or tibia. The difference between the centroids of the final distal landmarks was used to evaluate the lengthening of the tibia, and the Euler angles from the registration were used to evaluate the rotation.Results: Both the frame and bone could be effectively registered (based on visual interpretation). Movement between the proximal frame and proximal bone could be visualized in both cases. The spatial effect on the tibia could be both visually assessed and measured: 34 mm, 10° in one case; 5 mm, 1° in the other.Conclusion: This retrospective analysis of spatial correction of the tibia using Taylor Spatial Frames shows that CT offers an interesting potential means of quantitatively monitoring the patient's treatment. Compared with traditional techniques, modern CT scans in conjunction with image processing provide a high-resolution, spatially correct, and three-dimensional measurement system which can be used to quickly and easily assess the patient's treatment at low cost to the patient and hospital.

Can FDG-PET be used to predict growth of stage I lung cancer?

To determine the relationship between the metabolic activity measured by 2-[(18)F]-fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET) and computed tomography (CT)-derived tumour growth rates for stage 1 lung cancer. Stage I lung cancer patients at our institution who underwent FDG PET, and who had at least two pre-treatment chest CT examinations (n=51), were retrospectively identified. Metabolic activity was defined by maximum lesion standardized uptake value (SUV) and maximum lesion-to-mean background activity (LBR). Growth rates were determined from serial CT volume measurements and the doubling time (DT) was calculated. Tumour growth rates were divided into rapid (DT<180 days), intermediate (DT=180-270 days), and slow (DT>270 days) groups. Rapid, moderate, and slow DT were seen in 22, 19, and 10 patients, respectively. Means (standard deviations) of SUV in the three groups (from rapid to slow growth rate) were 8.2 (4.8), 5.5 (4.5), and 2.2 (1.1), respectively and of LBR were 22.7 (10.1), 15.1 (12.6), and 6 (2.6), respectively. There was a significant relationship between SUV and DT (p<0.05), as well as between LBR and DT (p<0.05). For stage I lung tumours, there is a significant relationship between growth rates, as measured by serial CT examinations, and the initial pre-treatment metabolic activities, as measured by FDG uptake. This suggests that in patients in whom it is difficult to decide on the aggressiveness on treatment, FDG-PET may be used as additional prognostic tool for determining management.

Acute and Chronic Complications of Aortic Intramural Hematoma on Follow-up Computed Tomography

To ascertain the incidence of acute and chronic complications of aortic intramural hematoma (IMH) and to analyze the predictors of the development of each complication. This retrospective study includes 107 consecutive patients diagnosed with aortic IMH by means of computed tomography (CT) during the period from January 1998 to December 2003 and followed up with serial CT examinations (median follow-up period, 320 days). There were 36 patients with type A and 71 with type B IMH. Initial and follow-up CT scans were reviewed, with special attention given to the development of complications, such as increase in the thickness of IMH, clinical and hemodynamic evolution requiring urgent surgery, and development of aortic dissection and/or aneurysm. If each complication developed within 30 days after the initial episode, we classified it as an acute complication; the others were classified as chronic complications. The time interval between the initial and the subsequent CT examination showing each complication was recorded. To identify the predictors of each complication, we analyzed the demographic and CT findings with regard to the following factors: age, sex, maximum thickness of the hematoma, maximum aortic diameter on initial CT examination, ulcerlike projection (ULP) on initial and follow-up CT examinations, and the degree of atherosclerosis. The Cox proportional hazards regression model with stepwise multivariate analyses was used to determine the significant predictors of each complication. Sixteen patients had acute complications consisting of aortic dissection (n = 7), aortic aneurysm (n = 6), and acute clinical and hemodynamic evolution requiring operation (n = 3). Three additional patients with aortic dissection (n = 1) and aneurysm (n = 2) underwent emergency surgery. Twenty-three patients with chronic complications had aortic dissection (n = 3), and aortic aneurysm (n = 20). Cox proportional hazards regression model revealed that the maximal diameter of involved aorta is the only significant predictor of the development of acute complications (P = 0.006), whereas the age (P = 0.040), type A IMH (P = 0.015), presence of ULP (P = 0.015), and newly developed ULP as revealed on follow-up CT examination (P = 0.032) were significant predictors of the development of chronic complications. With regard to the aortic dissection in 10 patients (9.3%; type A/B ratio, 5:5; median time interval, 34 days), Cox proportional hazards regression model revealed that the maximal thickness of the hematoma is the only significant predictor (P = 0.018). Twenty-one saccular and 5 fusiform aneurysms (24.3%) developed, as revealed on follow-up CT examinations (median time interval, 180 days). The presence of ULP (P = 0.030), type A (P = 0.038) and the maximal thickness of the hematoma (P = 0.017) were significant predictors for the development of an aneurysm. The maximum thickness of a hematoma on the initial CT is the significant factor predicting the development of aortic dissection and aortic aneurysm. Patients with type A IMH and ULP, as revealed by initial and short-term follow-up CT examinations, should be carefully followed up with subsequent CT examination to monitor the development of an aortic aneurysm, which is a relatively common chronic complication of IMH.

Biphasic CT with mesenteric CT angiography in the evaluation of acute mesenteric ischemia: initial experience.

To evaluate the sensitivity and specificity of biphasic computed tomography (CT) with mesenteric CT angiography in the diagnosis of acute mesenteric ischemia (AMI). Sixty-two patients with clinically suspected AMI underwent prospective imaging with biphasic multi-detector row CT. Mesenteric CT angiography was performed with 1.25-mm collimation starting 25 seconds after 140 mL of intravenous contrast agent was administered at a rate of 4 mL/sec, followed by portal venous phase imaging with 5-mm collimation and a 60-70-second delay. CT angiograms were reconstructed with multiplanar (including transverse), maximum intensity projection, and volume-rendered techniques. All scans were evaluated prospectively by two independent radiologists for CT evidence of ischemia. AMI was confirmed with surgical or pathologic proof in 25 of 26 patients. In one patient, AMI was confirmed with clinical findings and serial CT examinations. In patients with AMI, sensitivity and specificity of each CT sign were calculated retrospectively by using patients who did not have intestinal ischemia as a control group. CT criteria that optimized sensitivity and specificity for the diagnosis of AMI were then developed. AMI was diagnosed in 26 patients. The CT angiogram depicted arterial disease in eight patients and altered care in five. A finding of any one of pneumatosis intestinalis, venous gas, superior mesenteric artery occlusion, celiac and inferior mesenteric artery occlusion with distal SMA disease, or arterial embolism was 100% specific but only 73% sensitive. Alternatively, a finding of bowel wall thickening in addition to focal lack of bowel wall enhancement, solid organ infarction, or venous thrombosis was 50% sensitive and 94% specific. By using either of these criteria for the diagnosis, a sensitivity of 96% and a specificity of 94% can be achieved. Biphasic CT with mesenteric CT angiography is effective in the diagnosis of AMI.

Experimental clonorchiasis in dogs: CT findings before and after treatment.

To determine whether disease activity in clonorchiasis can be assessed with dynamic computed tomography (CT). Ten dogs infected with metacercariae of Clonorchis sinensis underwent serial dynamic CT examinations. Five dogs were sacrificed 14 weeks after infection, and another five infected dogs were treated with praziquantel at the 14th week and continued to undergo CT examinations until death or sacrifice at the 25th (n = 1) or 40th week (n = 4). CT images were evaluated for dilatation of the bile ducts, contrast enhancement of bile duct walls and adjacent hepatic parenchyma, visualization of flukes within the bile ducts, and presence of calcifications. Changes in CT findings were analyzed statistically by using a mixed linear model and a generalized estimating equations model. Dilatation of the bile ducts, contrast enhancement of the ductal walls, transient hepatic attenuation differences, and flukes per se were observed at CT from the 2nd through the 5th week, were most apparent between the 5th and 13th weeks, and disappeared or decreased markedly in degree after treatment in all dogs (P <.05). Nodular calcifications were observed at CT after treatment in two dogs. Histopathologic examination revealed proliferation and enlargement of arteries in the periductal area and the portal tracts and congestion of hepatic sinusoids during the acute phase. Treatment was associated with periductal hyalinization, degeneration of the periductal arteries, and calcification of the ductal epithelium. Disease activity in experimental canine clonorchiasis can be assessed with dynamic CT.

Ovarian cancer — difficulties in monitoring response.

Ovarian cancer — difficulties in monitoring response.

Idiopathic pulmonary fibrosis: progression of honeycombing at thin-section CT.

To evaluate the progression of honeycombing at computed tomography (CT) and to determine serial changes in the pattern of disease. CT scans, obtained in 29 patients with idiopathic pulmonary fibrosis who had undergone at least two serial CT examinations 1-52 months apart, were reviewed. Twelve patients had received no treatment, and 17 patients had received corticosteroids. Initial and follow-up CT scans were evaluated independently and then directly compared with each other. Twenty-six of the 29 patients showed progression of honeycombing, which was variable at CT (median, 0.4% [range, 0%-11%] per month) but not significantly different between untreated and treated patients. Areas of ground-glass attenuation on CT scans preceded and were predictive of the development of honeycombing in that location. Corticosteroid treatment reduced areas of ground-glass attenuation, but honeycombing on CT scans was irreversible. Low-dose therapy with corticosteroids does not suppress alveolitis sufficiently to prevent continued deterioration of the alveolar structures.

Complications of endoscopic retrograde sphincterotomy: Computed tomographic evaluation

Although the reported complication rate of endoscopic retrograde cholangiopancreatography (ERCP) with sphincterotomy is low, patients often experience abdominal pain postprocedure. When pain persists, or fever and leukocytosis develop, a procedure-related complication should be suspected. The authors reviewed a series of 36 patients referred to computed tomography (CT) for evaluation of possible complications following ERCP with sphincterotomy. Initial CT scans were obtained within 24 h in 19 patients, and during the second to seventh day in the remainder. Complications detected by CT included acute pancreatitis (23), duodenal perforation (11), retroperitoneal dissection of air (4), pneumoperitoneum (4), and development of retroperitoneal abscess (4). Eight patients had normal CT scans except for air and contrast material in the biliary tree. The severity and extent of injury were readily assessed by CT, and response to therapy effectively monitored by serial CT examinations. Thirty-one cases (31 of 36) were successfully managed conservatively with antibiotics, intravenous hydration, and restriction of oral intake. Four patients required surgical intervention for drainage of a retroperitoneal abscess (3) or a pseudocyst (1). A fifth patient required intensive care resuscitation for septic shock. We conclude that CT is the study of choice for evaluating the patient with suspected complication following ERCP and sphincterotomy.

Computed tomography in the evaluation of incidence and significance of post-traumatic hydrocephalus.

Two hundred consecutive patients with severe head injury underwent sequential computed tomography (CT) on admission, after 4, 14, and 90 days, and after one year. Ventricular enlargement was evaluated in the surviving patients, based upon serial CT examinations. Significant ventricular enlargement was further evaluated with radionuclide cisternography. A significant correlation was shown between clinical outcome and presence or absence of ventricular enlargement. Radionuclide cisternography provided an additional means of determining those patients whose recovery was impaired by persistent obstruction of cerebrospinal fluid circulation and who would therefore benefit from cerebrospinal fluid shunting.