Follow-up Computed Tomography Examinations Research Articles

Assessing abdominal aortic aneurysm growth using radiomic features of perivascular adipose tissue after endovascular repair

ObjectivesThe study aimed to investigate the relationship between the radiomic features of perivascular adipose tissue (PVAT) and abdominal aortic aneurysm (AAA) growth after endovascular aneurysm repair (EVAR).MethodsPatients with sub-renal AAA who underwent regular follow-up after EVAR between March 2014 and March 2024 were retrospectively collected. Two radiologists segmented aneurysms and PVAT. Patients were categorised into growing and non-growing groups based on volumetric changes observed in two follow-up computed tomography examinations. One hundred seven radiomic features were automatically extracted from the PVAT region. Univariable and multivariable logistic regression was performed to analyse radiomic features and clinical characteristics. Furthermore, the performance of the integrated clinico-radiological model was compared with models using only radiomic features or clinical characteristics separately.ResultsA total of 79 patients (68 ± 9 years, 89% men) were enroled in this study, 19 of whom had a growing aneurysm. Compared to the non-growing group, PVAT of growing AAA showed a higher surface area to volume ratio (non-growing vs growing, 0.63 vs 0.70, p = 0.04), and a trend of low dependence and high dispersion manifested by texture features (p < 0.05). The area under the curve of the integrated clinico-radiological model was 0.78 (95% confidence intervals 0.65–0.91), with a specificity of 87%. The integrated model outperformed models using only radiomic or clinical features separately (0.78 vs 0.69 vs 0.69).ConclusionsHigher surface area to volume ratio and more heterogeneous texture presentation of PVAT were associated with aneurysm dilation after EVAR. Radiomic features of PVAT have the potential to predict AAA progression.Clinical relevance statementRadiomic features of PVAT are associated with AAA progression and can be an independent risk factor for aneurysm dilatation to assist clinicians in postoperative patient surveillance and management.Key PointsAfter EVAR for AAA, patients require monitoring for progression.PVAT surrounding growing AAA after EVAR exhibits a more heterogeneous texture.Integrating PVAT-related features and clinical features results in better predictive performance.Graphical

Main Portal Vein Diameter Changes in Patients Undergoing Gastric Surgery for Malignancy: An Observational CT Study

Abstract Background In the follow-up computed tomography (CT) examinations of patients who had undergone gastrectomy for gastric malignancy in our center, we noticed by chance that there was an isolated increase in the diameter of the main portal vein (MPV) without other radiological findings of portal hypertension. Objectives In this study, we aimed to evaluate whether the MPV diameter of patients who had gastric surgery for malignancy differed in the preoperative and postoperative periods and its change over time in patients who underwent postoperative follow-up examinations. Materials and Methods The CT images of 240 patients who underwent abdomen CT for staging and follow-up gastric malignancy between January 2017 and September 2021 were evaluated retrospectively. The CT scans of the remaining 149 patients after the exclusion criteria were included in the study. All CT imaging was performed using multidetector CT (64 or 128 slice) in portal venous phases. The images were evaluated by two radiologists based on consensus. Maximum MPV diameter were measured outer wall to outer wall with calipers on axial images at the level of 1 cm distal to the portosplenic confluence. Results One hundred forty-nine patients included in the study had preoperative CT examination. Eighty-three patients had follow-up CT examination at third month, 89 patients at sixth month, and 99 patients at first year. The MPV diameters differed significantly between preoperative CT and postoperative third month, sixth month, and first year CT (p = 0.001, p = 0.001, and p = 0.001, respectively). There was no difference in MPV diameter between postoperative third month CT and postoperative 6th month and 1st year CT (p = 0.514 and p = 0.078, respectively). Conclusion There is an increase in MPV diameter in the first 3 months postoperatively in patients undergoing gastric surgery for malignancy. This enlargement continues unchanged in the first 1 year follow-up. The radiologists' awareness of this situation may prevent the wrong diagnosis of portal hypertension, unnecessary concern, and further investigation.

Insights about cervical lymph nodes: Evaluating deep learning–based reconstruction for head and neck computed tomography scan

PurposeThis study aimed to investigate differences in cervical lymph node image quality on dual-energy computed tomography (CT) scan with datasets reconstructed using filter back projection (FBP), hybrid iterative reconstruction (IR), and deep learning–based image reconstruction (DLIR) in patients with head and neck cancer. MethodSeventy patients with head and neck cancer underwent follow-up contrast-enhanced dual-energy CT examinations. All datasets were reconstructed using FBP, hybrid IR with 30 % adaptive statistical IR (ASiR-V), and DLIR with three selectable levels (low, medium, and high) at 2.5- and 0.625-mm slice thicknesses. Herein, signal, image noise, signal-to-noise ratio, and contrast-to-noise ratio of lymph nodes and overall image quality, artifact, and noise of selected regions of interest were evaluated by two radiologists. Next, cervical lymph node sharpness was evaluated using full width at half maximum. ResultsDLIR exhibited significantly reduced noise, ranging from 3.8 % to 35.9 % with improved signal-to-noise ratio (11.5–105.6 %) and contrast-to-noise ratio (10.5–107.5 %) compared with FBP and ASiR-V, for cervical lymph nodes (p < 0.001). Further, 0.625-mm-thick images reconstructed using DLIR-medium and DLIR-high had a lower noise than 2.5-mm-thick images reconstructed using FBP and ASiR-V. The lymph node margins and vessels on DLIR-medium and DLIR-high were sharper than those on FBP and ASiR-V (p < 0.05). Both readers agreed that DLIR had a better image quality than the conventional reconstruction algorithms. ConclusionDLIR-medium and -high provided superior cervical lymph node image quality in head and neck CT. Improved image quality affords thin-slice DLIR images for dose-reduction protocols in the future.

Effect of Frequent Computed Tomography Examinations with Contrast Media on the Renal Function of Patients with Oral Squamous Cell Cancer and an Evaluation of Risk Factors for Post-Operative Chronic Kidney Disease.

This retrospective study aimed to investigate the effect of frequent computed tomography (CT) examinations with contrast media on the renal function of patients with oral squamous cell cancer (OSCC) that underwent radical surgery, by using estimated glomerular filtration rate (eGFR); to identify risk factors of occurrence of post-operative chronic kidney disease (CKD) in these patients; and to explore the relationship between risk factors and occurrence of postoperative CKD during follow-up. Herein, 188 patients (107 male; 81 female) who underwent radical surgery for OSCC were included. We evaluated the risk factors for postoperative CKD after treatment, including demographic, perioperative, and postoperative factors by univariate and multivariate analyses. Patients were divided into post-operative CKD and control groups based on eGFR evaluation. Overall survival (OS) rates were compared between the groups. eGFR decreased over time after treatment in both patient groups. Postoperative CKD was diagnosed in 56 (29.8%) patients. The average number of contrast-enhanced CT examinations was not an independent risk factor for postoperative CKD. However, lower hemoglobin on hospital discharge [odds ratio (OR) = 0.53], lower eGFR on hospital discharge (OR = 0.84), and common use of nonsteroidal anti-inflammatory drugs (OR = 48.79) were significant risk factors associated with postoperative CKD. The control group was associated with a better OS than the postoperative CKD group; however, this difference was not significant. Clinicians should pay close attention to these risk factor of post-operative CKD during the management of patients with OSCC that undergo radical surgery and frequent follow-up CT examinations with contrast media.

Pericardial diverticulum arising from the right lateral superior aortic recess: a mimicker of cystic anterior mediastinal mass

To report the prevalence of pericardial diverticulum of the right lateral superior aortic recess (RSAR) on computed tomography (CT), to analyse the structural CT findings of whether or not the structure is large enough to be seen on chest radiographs, and to describe changes in size and shape of RSAR on follow-up CT. A well-circumscribed, fluid-attenuation lesion in the anterior mediastinum with the following CT features was defined as a pericardial diverticulum of the RSAR: no enhancing wall, communication with the RSAR, abutment to the heart with an acute angle, and moulding by adjacent structures. Chest CT images of 31 patients with the diverticulum were evaluated, including four selected from 1,130 consecutive patients (0.4%). The diverticulum projected ventrally from the RSAR and its largest size on axial CT ranged between 12-56 mm. Although the RSAR and the largest diverticular portion were usually seen on the same axial image (n=19), the latter sometimes lay above (n=1) or below (n=11) the former. On sagittal images, the last 11 diverticula resembled teardrops hanging from the RSAR by small stems. All of the 24 patients, each with 1-31 follow-up CT examinations, showed size fluctuations ranging between 1-46 mm (mean, 16 mm) during a follow-up period of 0.5-172 months (mean, 65 months). The diverticulum was not identifiable in five cases and was identifiable but did not show a connection with the RSAR in three cases when the diverticulum was smallest in size. In cases of cystic anterior mediastinal mass, a deliberate search for its connection with the RSAR on all available CT images including previous studies is necessary for the diagnosis of pericardial diverticulum of the RSAR.

Gastroinstestinal Fistula in Acute Necrotising Pancreatitis with Septicaemia: A Case Report

Acute Pancreatitis (AP) is an inflammatory condition with cumbersome side effects. Gastropancreatic (GI) fistula is a rare complication seen in cases with infected pancreatic or peripancreatic necrosis. GI fistulas can result in severe haemorrhage and septicemia. Hereby, the authors present a case of 36-year-old male with a chief complaint of abdominal pain associated with abdominal distension and non bilious vomiting after binge consumption of alcohol for the past 10 days. Computed Tomography (CT) scan showed the presence of free gas in the abdomen. Contrast-Enhanced CT (CECT) imaging revealed diffuse enlargement affecting the head, uncinate process, body, and tail of the pancreas. There were also a few necrotic peripancreatic fluid collections with extensive peripancreatic fat stranding. Based on these findings, the diagnosis of acute necrotising pancreatitis was suggested. Despite treatment with antibiotics and necrosectomy with drainage of the abscess collection, the patient showed no improvement. A repeat CECT examination was performed due to the deterioration of the patient’s clinical condition, which showed a complete non enhancing pancreas. Additionally, a large defect measuring approximately 16 mm was observed in the posteroinferior wall of the stomach at the middle third of the body, with extravasation of contrast material into the pancreatic collection, suggestive of fistula formation. Subsequently, the patient underwent pancreatic necrosectomy with closure of the gastric perforation using feeding jejunostomy. A follow-up CT examination was performed four days later due to the deteriorating status of the patient, as well as new onset haematemesis and bloody discharge from the surgical drain. The CT scan revealed a few peripancreatic soft tissue infiltrates adjacent to the pancreatic head. Persistent collections were noted along the anterolateral surface of the right psoas, extending to the adjoining right anterior pararenal space and the left anterolateral abdominal wall in the left hypochondriac region. Thickening of the bilateral lateroconal fascia and anterior and posterior renal fascia was observed, likely due to inflammation. Following this, the patient underwent another surgery, and percutaneous drainage was performed with antibiotic coverage. The patient showed a significant reduction in the collection and improved clinical condition after 10 days. Imaging plays a crucial role in diagnosing such complications, enabling early detection and reducing mortality in these patients.

Immunoglobulin G4-related disease diagnosed by prostate biopsy: a case report

BackgroundImmunoglobulin G4-related disease is characterized by swelling of various organs throughout the body and nodules/hypertrophic lesions. However, its cause remains unknown. We report a case of immunoglobulin G4-related disease that was diagnosed based on the histopathological findings of prostate biopsy.Case presentationA 72-year-old Japanese man had been treated by a nearby doctor for hypertension, but subsequently developed lower urinary tract symptoms and was prescribed an α1 blocker for 1 year. However, the patient was subsequently referred to our department because his symptoms did not improve. Prostate-specific antigen was 1.258 ng/ml; however, the nodule was palpable in the right lobe on digital rectal examination, and magnetic resonance imaging suggested Prostate Imaging and Reporting and Data System category 3. Therefore, transrectal prostate needle biopsy (12 locations) under ultrasound was performed. Histopathological examination revealed no malignant findings, although infiltration of lymphocytes and plasma cells, and partial fibrosis were observed. No remarkable findings of obstructive phlebitis were observed. Immunoglobulin G4-related disease was suspected, and immunoglobulin and immunoglobulin G4 immunostaining was performed. Immunoglobulin G4 positive plasma cells were observed in a wide range, immunoglobulin G4 positive cells were noted at > 10 per high-power field, and the immunoglobulin G4 positive/immunoglobulin G positive cell ratio was > 40%. Serum immunoglobulin G4 levels were high at 1600 mg/dl. Enhanced abdominal computed tomography findings suggested periaortitis. Additionally, multiple lymphadenopathies were observed around the abdominal aorta. The patient was accordingly diagnosed with immunoglobulin G4-related disease definite, diagnosis group (definite). We proposed steroid treatment for periaortic soft tissue lesions and lower urinary tract symptoms; however, the patient was refused treatment. A computed tomography scan 6 months after diagnosis revealed no changes in the soft tissue lesions around the aorta. Follow-up computed tomography examinations will be performed every 6 months.ConclusionIf immunoglobulin G4-related disease is suspected and a highly invasive examination is required for histopathological diagnosis, this can be performed by a relatively minimally invasive prostate biopsy for patients with lower urinary tract symptoms. Further evidence is needed to choose an optimal candidate for prostate biopsy for lower urinary tract symptoms patients with suspicion of immunoglobulin G4-related disease. For patients with lower urinary tract symptoms with immunoglobulin G4-related disease or a history, performing a prostate biopsy may avoid unnecessary treatment. However, if steroid therapy is ineffective, surgical treatment should be considered.

Evaluation of the air sac volume of penguins with respiratory diseases using computed tomography.

Captive penguins with respiratory diseases exhibit advanced pathological conditions upon the appearance of clinical signs. Therefore, the successful treatment of respiratory diseases remains difficult after the onset of clinical signs, leading to high mortality rates. In this study, we measured air sac volume using computed tomography (CT) to evaluate the respiratory condition of penguins. In a regular quarterly health checkup, blood samples were collected from 45 penguins housed at an aquarium in Hokkaido, Japan. A total of 12 penguins with abnormal blood parameters underwent CT. The air sac volumes were calculated in three-dimensional CT, and the scatter plots of the air sac volumes and body weights were analyzed. No correlation was found between the air sac volume and body weight in both the gentoo and king penguins. Two gentoo penguins with infiltration and one king penguin with multiple nodules on CT were tentatively diagnosed with aspergillosis and treated with oral administration of itraconazole. Follow-up CT examination was performed until the outcome: healed or died. The mean air sac volumes of the two gentoo penguins, which recovered after treatment, increased from 273.9 and 329.0 cm3 before healing to 449.0 and 424.6 cm3 after healing, respectively. Meanwhile, the air sac volume of the king penguin, which subsequently died, decreased from 1,556.9 to 920.6 cm3 despite treatment. Changes of the air sac volume in the same individual could be useful for evaluating the respiratory condition of penguins.

Relevance of CT for the detection of septic foci: diagnostic performance in a retrospective cohort of medical intensive care patients

To analyse the diagnostic yield of computed tomography (CT) in septic patients from a medical intensive care unit (ICU). A full-text search of the department's radiological information system (RIS) retrieved 227 body CT examinations undertaken to search for a septic focus in 2018 from medical ICU patients. CT reports were categorised according to the identified foci. Clinical and laboratory information was gathered. Data were analysed statistically using descriptive statistics, diagnostic test quality criteria, binomial tests and chi-square test. A total of 227 CT examinations from 165 septic patients detected 264 foci, which were distributed as follows: 58.3% (n=154/264) chest, 26.5% (n=70/264) abdomen, 5.3% (n=14/264) genitourinary system, and 9.8% (n=26/264) other body regions. In 15.9% (n=36/227) no focus was identified on CT. Based on CT reports, 37.5% (n=99/264) of foci were graded as certain, 18.9% (n=50/264) as likely, and 15.9% (n=42/264) as possible infectious sources. Septic foci were detected using CT with 75.8% sensitivity (95% confidence interval [CI] 69.6-81.9%) and 59.46% specificity (95% CI 42.9-76.1%). The positive predictive value was 90.6% (95% CI 86-95.2%), with a negative predictive value of 32.4% (95% CI 21-43.8%). The present results confirm that body CT is a suitable rule-in test for septic patients in medical intensive care, although it cannot reliably rule out a septic focus. Follow-up CT examinations may reveal a septic source in the further course of a patient's hospital stay.

Evaluation of systemic involvement of Coronavirus disease 2019 through spleen; size and texture analysis

Background/aimTo investigate the changes in the spleen size, parenchymal heterogeneity, and computed tomography (CT) texture analysis features of patients diagnosed with Coronavirus disease 2019 (COVID-19)Materials and methodsThe size and parenchymal structure of the spleen in 91 patients who underwent thoracic CT examination due to COVID-19 were evaluated. For the evaluation of parenchymal heterogeneity, CT texture analysis was performed using dedicated software (Olea Medical, France). The texture analysis of each case consisted of 15 first-order intensity-based features, 17 gray level co-occurrence matrix-based features, and 9 gray level run length matrix-based features.ResultsA total of 91 patients (45 males, 46 females) with a mean age of 54.31 ± 16.33 years (range: 18–81) were included in the study. A statistically significant decrease in spleen size was seen in the follow-up CT examinations (p < 0.001) whereas no statistically significant difference was found between the Hounsfield unit (HU) values. The radiomics consisted of first-order intensity-based features such as 90th percentile, maximum, interquartile range, range, mean absolute deviation, standard deviation, and variance, all of which showed statistically significant differences (p - values: < 0.001, < 0.001, 0.001, 0.003, 0.001, 0.001, and 0.004, respectively). “Correlation” as a gray level co-occurrence matrix-based feature and “gray level nonuniformity” as a gray level run length matrix-based feature showed statistically differences (p-values: 0.033 and < 0.001, respectively).ConclusionsAlthough COVID-19 manifests with lung involvement in the early stage, it can also cause systemic involvement, and the spleen may be one of its target organs. A decrease in the spleen size and parenchymal microstructure changes can be observed in the short follow-up time. It is hoped that the changes in the parenchymal microstructure will be demonstrated by a noninvasive method: texture analysis.

Changes in tonsillolith characteristics detected in a follow-up CT study

BackgroundTonsilloliths are related clinically to halitosis and tonsillar abscess. However, the dynamics of tonsilloliths over time are unknown. The aim of the study was to evaluate change in the characteristics of tonsilloliths in a time-dependent fashion by follow-up computed tomography (CT).MethodsTonsilloliths were analyzed in 326 CT scan pair sets of initial and at least two follow-up CT examinations of patients with whole palatine tonsils and various diseases of the oral and maxillofacial regions.ResultsOver the follow-up period, 12.1% of tonsilloliths disappeared. Approximately 26.1% of tonsilloliths changed in size during follow-up, mostly increasing in size. In tonsilloliths that showed enlargement, the mean (± standard deviation) growth rate was 0.61 ± 0.41 mm per year. Approximately 37.3% of tonsilloliths changed position during the follow-up period; of these, movement was toward the respiratory tract in 92% at a mean rate of − 1.38 ± 1.59 mm per year. The calcification levels of almost all tonsilloliths showed dynamic change: HU number increased in 84.3% and decreased in 12.7% of tonsilloliths over the follow-up period. The mean rate of HU increase was 63.8 ± 96.3 HU/year, and the mean rate of HU decrease was − 38.4 ± 66.8 HU/year.ConclusionsThe calcification levels of all tonsilloliths showed dynamic fluctuation, and a tendency for excretion of tonsilloliths from the body. Their dynamics over time suggest that tonsilloliths may be in a permanently active phase which functions to remove foreign matter.

Sclerotic changes of cavernous hemangioma in the cirrhotic liver: long-term follow-up using dynamic contrast-enhanced computed tomography.

To determine the intra- and extralesional factors that predict sclerotic degeneration of hepatic hemangiomas in the cirrhotic liver on long-term follow-up computed tomography (CT) examinations. Fifty-seven hepatic hemangiomas (> 5mm in diameter) in 41 cirrhotic patients, recruited over a 5-year period (January 2005-December 2009), were subjected to CT to determine which factors predict sclerotic contraction or degeneration in hemangiomas. Prior and follow-up CT examinations (from 2000 to 2018) were included to observe time-related changes. The patients' gender, age, cause of cirrhosis, progression of background liver cirrhosis, lesion size/location/contrast enhancement pattern, and serum aspartate transaminase to platelet ratio index were correlated with sclerotic changes of each lesion. According to the dynamic CT features, 36 of 57 (63%) hemangiomas were determined to have sclerotic changes during the follow-up period (1.1-14.4years, median: 7.8years), including 28 lesions (49%) reduced by ≥ 20% in diameter. In univariate analysis, age (p = 0.047) and morphological progression of background cirrhosis (p = 0.013) were significantly related to sclerotic change of hemangiomas. In the logistic regression analysis, only morphological progression of background liver cirrhosis independently predicted sclerotic change (odds ratio: 4.88, p = 0.007). With the exception of exophytic location free from size reduction (p = 0.023 in multivariate analysis), no other analyzed factors were significantly correlated with sclerotic changes. Overall, sclerotic changes of hepatic cavernous hemangioma followed the morphological progression of background liver cirrhosis, while exophytic lesions tended to be free of size reduction.

Assessment of myocardial extracellular volume on body computed tomography in breast cancer patients treated with anthracyclines.

Cancer treatment with anthracyclines may lead to an increased incidence of cardiac disease due to cardiotoxicity, as they may cause irreversible myocardial fibrosis. So far, the proposed methods for screening patients for cardiotoxicity have led to only limited success, while the analysis of myocardial extracellular volume (mECV) at cardiac magnetic resonance (CMR) has shown promising results, albeit requiring a dedicated exam. Recent studies have found strong correlations between mECV values obtained through computed tomography (CT), and those derived from CMR. Thus, our purpose was to evaluate the feasibility of estimating mECV on thoracic contrast-enhanced CT performed for staging or follow-up in breast cancer patients treated with anthracyclines, and, if feasible, to assess if a rise in mECV is associated with chemotherapy, and persistent over time. After ethics committee approval, female patients with breast cancer who had undergone at least 2 staging or follow-up CT examinations at our institution, one before and one shortly after the end of chemotherapy including anthracyclines were retrospectively evaluated. Patients without available haematocrit, with artefacts in CT images, or who had undergone radiation therapy of the left breast were excluded. Follow-up CT examinations at longer time intervals were also analysed, when available. mECV was calculated on scans obtained at 1, and 7 min after contrast injection. Thirty-two female patients (aged 57±13 years) with pre-treatment haematocrit 38%±4%, and ejection fraction 64%±6% were analysed. Pre-treatment mECV was 27.0%±2.9% at 1 min, and 26.4%±3.8% at 7 min, similar to values reported for normal subjects in the literature. Post-treatment mECV (median interval: 89 days after treatment) was 31.1%±4.9%, and 30.0%±5.1%, respectively, values significantly higher than pre-treatment values at all times (P<0.005). mECV at follow-up (median interval: 135 days after post-treatment CT) was 31.0%±4.5%, and 27.7%±3.7%, respectively, without significant differences (P>0.548) when compared to post-treatment values. mECV values from contrast-enhanced CT scans could play a role in the assessment of myocardial condition in breast cancer patients undergoing anthracycline-based chemotherapy. CT-derived ECV could be an imaging biomarker for the monitoring of therapy-related cardiotoxicity, allowing for potential secondary prevention of cardiac damage, using data derived from an examination that could be already part of patients' clinical workflow.

Post-traumatic arthritis of the sacroiliac joints mimicking inflammatory sacroiliitis: analysis of consecutive computed tomography examinations

To assess the presence, prevalence and characteristics of post-traumatic, inflammatory-like changes of the sacroiliac joint (SIJ) on pelvic computed tomography (CT). Sequential CT examinations from the acute (index) and follow-up post-traumatic periods of 24 patients that underwent pelvic trauma with SIJ involvement were evaluated and compared to 32 control patients with pelvic fractures that did not involve the SIJs. Index CT was evaluated for the presence of fracture, intra-articular step, and diastasis, whereas follow-up CT was scored for periarticular sclerosis, erosions, ankylosis, and backfill. Clinical follow-up was performed by pain provocation SIJ tests and a questionnaire (study representative subgroup, n=11, 46%) and from clinical files (control group, n=26, 31%). Pearson correlation coefficient was assessed between the index and follow-up CT variables. Linear regression was used to predict the influence of trauma variables on the development of inflammatory-like structural changes. Total "structural, arthritis-like lesions' score from the follow-up CT examination was significantly higher in the study compared to the control group (3.25 versus 0.05 respectively, p<0.001). The presence of intra-articular diastasis and fracture were significant risk factors for the development of structural inflammatory-like lesions in the SIJ (1.19 and 2.1 respectively, p<0.001). Painful SIJs by physical examination were found in 50% of the clinically evaluated subgroup which was mechanical by nature in 81.8%. Traumatic SIJ fracture or diastasis is associated with the development of post-traumatic SIJ structural inflammatory-like lesions on pelvic CT, mimicking sacroiliitis. These findings may be the result of focal, post-traumatic joint inflammation, which leads to mechanical rather than inflammatory symptoms.

Bismuth shield affecting CT image quality and radiation dose in adjacent and distant zones relative to shielding surface: A phantom study

BackgroundTo quantify image quality and radiation doses in regions adjacent to and distant from bismuth shields in computed tomography (CT). MethodsAn American College of Radiology accreditation phantom with four solid rods embedded in a water-like background was scanned to verify CT number (CTN) accuracy when using bismuth shields. CTNs, image noise, and contrast-to-noise ratios (CNRs) were determined in the phantom at 80–140 kVp. Image quality was investigated on image portions in the zones adjacent (A zone) to and distant (D zone) from a bismuth shield. Surface radiation doses were measured using thermoluminescent dosimeters. Streak artefacts were graded on a 3-point-scale. ResultsChanges in CTN caused by a bismuth shield resulted in changes in X-ray spectra. CTN changes were more apparent in the A zone than in the D zone, particularly for a low tube voltage. The degrees of CTN changes and image noise were proportional to the thickness of the bismuth shields. A 1-ply bismuth shield reduced surface radiation doses by 7.2%–15.5%. The overall CNRs were slightly degraded, and streak artefacts were acceptable. ConclusionsUsing a bismuth shield could result in significant CTN changes and perceivable artefacts, particularly for a superficial organ close to the shield, and is not recommended for quantification CT examinations or follow-up CT examinations.

Solid Indeterminate Pulmonary Nodules Less Than or Equal to 250 mm3: Application of the Updated Fleischner Society Guidelines in Clinical Practice.

Background The latest version of the Fleischner Society guidelines for management of incidental pulmonary nodules was published in 2017. The main purpose of these guidelines is to reduce the number of unnecessary computed tomography (CT) examinations during the follow-up of small indeterminate nodules. Objective The present study aimed to evaluate the performance of these guidelines for management of solid indeterminate pulmonary nodules (SIPNs) ≤ 250 mm3. Materials and Methods During a 7-year period, we retrospectively reviewed the chest CT scans of 672 consecutive patients with SIPNs. The study sample was selected according to the following inclusion criteria: solitary SIPN; diameter ≥ 3 mm; volume ≤ 250 mm3; two or more CT scans performed with the same scanner and same acquisition/reconstruction protocol; thin-section 1-mm images in DICOM format; histologic diagnosis or follow-up ≥ 2 years; and no oncological history. Applying these criteria, a total of 27 patients with single SIPNs ≤ 250 mm3 were enrolled. For each SIPN, the volume and doubling time were calculated using semiautomatic software throughout the follow-up period. For each SIPN, we applied the Fleischner Society guidelines, and the recommended management was compared to what was actually done. Results A significant volumetric increase was detected in 5/27 (18.5%) SIPNs; all growing nodules were observed in high-risk patients. In these SIPNs, a histologic diagnosis of malignancy was obtained. Applying the Fleischner Society recommendations, all five malignant nodules would have been identified. None of the SIPNs < 100 mm3 in low-risk patients showed significant growth during the follow-up period. The application of the new guidelines would have led to a significant reduction in follow-up CT examinations (Hodges-Lehmann median difference, -2 CT scans; p = 0.0001). Conclusion The application of the updated Fleischner Society guidelines has been shown to be effective in the management of SIPNs ≤ 250 mm3 with a significant reduction in radiation dose.

Spontaneous intramural hematoma of the duodenum secondary to anticoagulant drug intoxication

Introduction. Duodenal hematomas are commonly traumatic, caused by blunt abdominal trauma. Nontraumatic spontaneous intramural hematomas of the duodenum are rare, and in most cases induced by anticoagulant therapy. The diagnosis is based on clinical and biochemical parameters, endoscopy, and radiological examinations. The objective of this report was to present a clinical and radiological presentation of an intramural duodenal hematoma caused by anticoagulant therapy. Case outline. A 43-year-old female was presented with epigastric pain, nausea, hematemesis, and melena. She had a positive medical history of deep venous thrombosis of the pelvis, which was diagnosed the previous month, for which she received oral anticoagulant therapy (coumarin). Physical examination revealed diffuse abdominal tenderness, while laboratory analyses showed markedly elevated international normalized ratio (INR) of prothrombin time (INR &gt; 7), which indicated the anticoagulant intoxication. Computed tomography (CT) showed luminal narrowing with uniform circumferential wall thickening of the descendent and horizontal part of duodenum, which was hyper dense in the native series and slight and uniform ring-formed enhancement in post-contrast phases, a typical CT presentation of intramural duodenal hematoma. Periduodenal and right sided pararenal hematomas were also visualized. After stopping the anticoagulant therapy and performing conservative treatment (vitamin K) with good therapeutic effect being monitored by physical examination, laboratory analyses and transabdominal ultrasonography, spontaneous resolution of the duodenal hematoma was revealed by follow-up CT examination two weeks after the onset. Conclusion. Ultrasonography and CT are useful diagnostic tools in recognition of the intramural duodenal hematoma and other locations of hemorrhage and in monitoring therapeutic effects.

Giant Intrapericardial Myxoma Adjacent to the Left Main Coronary Artery

A 62-years-old woman was admitted to the hospital because of chronic cough, expectoration of thick mucus, hoarseness and tightness in the precordial area. Computed Tomography (CT) examination revealed the presence of a giant intrapericardial tumor with the dimensions of 80 × 38 × 32 mm. It was located anteriorly and laterally to the left atrium, posteriorly to the pulmonary trunk and the ascending aorta. This hypodense change modeled the left atrium without evidence of invasion. CT coronary angiography and 3-dimensional reconstruction were applied to enable precise planning of cardiac surgery. CT evaluation confirmed that it is possible to remove the tumor without damage to the adjacent left main coronary artery. The patient underwent cardiac surgery with sternotomy and cardiopulmonary bypass. A cohesive, smooth, vascularized tumor pedunculated to the left atrial epicardium was visualized. The location and dimensions corresponded to those determined by CT scan examination. The entire tumor was successfully dissected together with adjacent adipose and fibrous tissue. Histological evaluation revealed the presence of myxoid cells, blood vessels, degenerative changes, and microcalcifications embedded in profuse hyalinized stroma. Those histological features enabled identification of the intrapericardial tumor as a myxoma. Follow-up CT examination did not demonstrate any signs of recurrence of the myxoma. According to our knowledge, a myxoma located inside the pericardial sac has never been described before.

Imaging findings and complications of transcatheter interventional treatments via the inferior phrenic arteries in patients with hepatocellular carcinoma

ObjectiveTo evaluate imaging findings and complications from transcatheter interventional treatment of hepatocellular carcinoma via the inferior phrenic arteries. Material & Methods40 procedures in 25 patients (19 men; age range, 57–89 years) were retrospectively reviewed in this study. In all procedures, a micro-catheter was selectively inserted in the right inferior phrenic artery (n = 39) or left inferior phrenic artery (n = 1), and transcatheter arterial chemoembolization (n = 39) or transcatheter arterial embolization (n = 1) was performed. Imaging findings and patient charts were reviewed, and complications until time of discharge (median hospitalization period, 10.5 days; range, 3–21) were assessed. ResultsOn angiography or computed tomography during angiography, collateral circulation from the right inferior phrenic artery to the pulmonary artery was seen in eight of 39 procedures (seven patients, 28%). In seven of these procedures, Lipiodol deposition was seen on the unenhanced computed tomography just after the procedure (post-procedure computed tomography) in the pulmonary arteries or pleura, and in six procedures, the deposited Lipiodol was noted to have spread into adjacent lung fields on the one week follow-up computed tomography. Branches of the right inferior phrenic artery were seen along the right margin of the heart in 18 procedures, and Lipiodol deposition was seen along the right margin of the heart on post-procedure computed tomography in four procedures. Complications occurred in 21 of 39 procedures of right inferior phrenic artery intervention (53%): shoulder pain in 18 (45%), pleural effusion in 14 (35%), basal atelectasis in 11 (28%), paroxysmal atrial fibrillation in two (5%) and hemoptysis in one (3%). In 14 procedures (35.9%), pleural effusion was seen on follow-up computed tomography examinations, and 11 (28.2%) of these procedures also showed basal atelectasis. However, only three procedures with pleural effusion showed Lipiodol deposition on the post-procedure computed tomography. In one patient who underwent transcatheter arterial chemoembolization twice via the right inferior phrenic artery, atrial fibrillation occurred after both procedures. ConclusionsTranscatheter arterial chemoembolization or transcatheter arterial embolization via the inferior phrenic artery in patients with hepatocellular carcinoma was relatively safe. Shoulder pain was the most frequent complication, and required only conservative treatment. There was no clear connection between pleural effusion or basal atelectasis and collateral circulation from the right inferior phrenic artery to the pulmonary artery depicted on angiography, computed tomography during angiography or post-procedure computed tomography.

Radiation dose exposure in patients affected by lymphoma undergoing repeat CT examinations: how to manage the radiation dose variability.

To assess the variability of radiation dose exposure in patients affected by lymphoma undergoing repeat CT (computed tomography) examinations and to evaluate the influence of different scan parameters on the overall radiation dose. A series of 34 patients (12 men and 22 women with a median age of 34.4 years) with lymphoma, after the initial staging CT underwent repeat follow-up CT examinations. For each patient and each repeat examination, age, sex, use of AEC system (Automated Exposure Control, i.e. current modulation), scan length, kV value, number of acquired scans (i.e. number of phases), abdominal size diameter and dose length product (DLP) were recorded. The radiation dose of just one venous phase was singled out from the DLP of the entire examination. All scan data were retrieved by our PACS (Picture Archiving and Communication System) by means of a dose monitoring software. Among the variables we considered, no significant difference of radiation dose was observed among patients of different ages nor concerning tube voltage. On the contrary the dose delivered to the patients varied depending on sex, scan length and usage of AEC. No significant difference was observed depending on the behaviour of technologists, while radiologists' choices had indirectly an impact on the radiation dose due to the different number of scans requested by each of them. Our results demonstrate that patients affected by lymphoma who undergo repeat whole body CT scanning may receive unnecessary overexposure. We quantified and analyzed the most relevant variables in order to provide a useful tool to manage properly CT dose variability, estimating the amount of additional radiation dose for every single significant variable. Additional scans, incorrect scan length and incorrect usage of AEC system are the most relevant cause of patient radiation exposure.