Quantitative Measurement on Contrast-Enhanced CT Distinguishes Small Clear Cell Renal Cell Carcinoma From Benign Renal Tumors: A Multicenter Study

RATIONALE AND OBJECTIVES

To evaluate the potential of quantitative measurements on contrast-enhanced CT (CECT) in differentiating small (≤4 cm) clear cell renal cell carcinoma (ccRCC) from benign renal tumors, including fat-poor angiomyolipoma (fpAML) and renal oncocytoma (RO).

MATERIALS AND METHODS

244 patients with pathologically confirmed ccRCC (n = 184) and benign renal tumors (fpAML, n = 50; RO, n = 10) were randomly assigned into training cohort (n = 193) and test cohort 1 (n = 51), while external test cohort 2 (n = 50) was from another hospital. Quantitative parameters were obtained from CECT (unenhanced phase, UP; corticomedullary phase, CMP; nephrographic phase, NP; excretory phase, EP) by measuring attenuation of renal mass and cortex and subsequently calculated. Univariable and multivariable logistic regression analyses were performed to evaluate the association between these parameters and ccRCC. Finally, the constructed models were compared with radiologists' diagnoses.

RESULTS

In univariable analysis, UP-related parameters, particularly UPC-T (cortex minus tumor attenuation on UP), demonstrated AUC of 0.766 in training cohort, 0.901 in test cohort 1, 0.805 in test cohort 2. The heterogeneity-related parameter SD (standard deviation) showed AUC of 0.781, 0.834, and 0.875 respectively. In multivariable analysis, model 1 incorporating UPC-T, NPC-T (cortex minus tumor attenuation on NP), CMPT-UPT (tumor attenuation on CMP minus UP), and SD yielded AUC of 0.866, 0.923, and 0.949 respectively. When compared with radiologists, multivariate models demonstrated higher accuracy (0.800-0.860) and sensitivity (0.794-0.971) than radiologists' assessments (accuracy: 0.700-0.720, sensitivity: 0.588-0.706).

CONCLUSION

Quantitative measurements on CECT, particularly UP- and heterogeneity-related parameters, have potential to discriminate ccRCC and benign renal tumors (fpAML, RO).

Gold nanoshells for prostate cancer treatment: evidence for deposition in abdominal organs

PURPOSE

Gold-silica nanoshell therapy [AuroShells with subsequent focal laser therapy (AuroLase)] is an emerging targeted treatment modality for prostate cancer. We reviewed pre- and post-treatment unenhanced CT imaging to assess for retained gold-silica nanoshells in the abdomen and pelvis.

METHODS

This single-institution retrospective study identified patients in the AuroLase pilot who underwent pre- and post-treatment unenhanced abdominopelvic CT. The attenuation, before and after gold-silica nanoshell administration, of the liver, spleen, pancreas, kidneys, prostate, blood pool, paraspinal musculature, and abnormal lymph nodes were manually measured by two readers. After inter-reader agreement was calculated using intraclass correlation (ICC), a permutation test was used to assess pre- and post-therapy attenuation differences.

RESULTS

Four patients met the inclusion criteria. Mean age was 72.3 ± 5.9 years. Median time interval between pre-treatment CT and treatment, and between treatment and post-treatment CT, was 232 days and 236.5 days, respectively. The two readers' attenuation measurements had very high agreement (ICC = 0.99, p < 0.001). The highest differences in organ attenuation between pre- and post-therapy scans were seen in all four patients in the liver and spleen (liver increased by an average of 28.9 HU, p = 0.010; spleen increased by an average of 63.7 HU, p = 0.012). A single measured lymph node increased by an average of 58.9 HU. In the remainder of the measured sites, the change in attenuation from pre- to post-therapy scans ranged from -0.1 to 3.8 HU (p > 0.05).

CONCLUSION

Increased attenuation of liver and spleen at CT can be an expected finding in patients who have received gold-silica nanoshell therapy.

CT and MRI Findings of Low-Flow Mediastinal Vascular Malformation: A Case Report

Mediastinal vascular malformations are rare and their diagnosis can be challenging. Imaging is vital for diagnosing mediastinal vascular malformations and can help avoid unnecessary invasive procedures. Herein, we report the detailed CT and MRI findings of a rare low-flow mediastinal vascular malformation in an asymptomatic 63-year-old male.

Plasma metabolomics and quantitative interstitial abnormalities in ever-smokers

BACKGROUND

Quantitative interstitial abnormalities (QIA) are an automated computed tomography (CT) finding of early parenchymal lung disease, associated with worse lung function, reduced exercise capacity, increased respiratory symptoms, and death. The metabolomic perturbations associated with QIA are not well known. We sought to identify plasma metabolites associated with QIA in smokers. We also sought to identify shared and differentiating metabolomics features between QIA and emphysema, another smoking-related advanced radiographic abnormality.

METHODS

In 928 former and current smokers in the Genetic Epidemiology of COPD cohort, we measured QIA and emphysema using an automated local density histogram method and generated metabolite profiles from plasma samples using liquid chromatography-mass spectrometry (Metabolon). We assessed the associations between metabolite levels and QIA using multivariable linear regression models adjusted for age, sex, body mass index, smoking status, pack-years, and inhaled corticosteroid use, at a Benjamini-Hochberg False Discovery Rate p-value of ≤ 0.05. Using multinomial regression models adjusted for these covariates, we assessed the associations between metabolite levels and the following CT phenotypes: QIA-predominant, emphysema-predominant, combined-predominant, and neither- predominant. Pathway enrichment analyses were performed using MetaboAnalyst.

RESULTS

We found 85 metabolites significantly associated with QIA, with overrepresentation of the nicotinate and nicotinamide, histidine, starch and sucrose, pyrimidine, phosphatidylcholine, lysophospholipid, and sphingomyelin pathways. These included metabolites involved in inflammation and immune response, extracellular matrix remodeling, surfactant, and muscle cachexia. There were 75 metabolites significantly different between QIA-predominant and emphysema-predominant phenotypes, with overrepresentation of the phosphatidylethanolamine, nicotinate and nicotinamide, aminoacyl-tRNA, arginine, proline, alanine, aspartate, and glutamate pathways.

CONCLUSIONS

Metabolomic correlates may lend insight to the biologic perturbations and pathways that underlie clinically meaningful quantitative CT measurements like QIA in smokers.

[Spontaneous splenic rupture. Case report and literature review]

Background

Spontaneous splenic rupture is often life threatening due to delay in diagnosis and treatment. Abdominal pain, Kehr's sign, nausea, bloating, altered consciousness, and intestinal obstruction may be present. In larger splenic lesions, signs of peritonitis and hypovolemic shock are present. Contrast-enhanced computed tomography is the election study. Diagnosis is confirmed by negative viral serology and normal spleen on gross and histopathologic inspection. The most frequent treatment in splenectomy.

Clinic case

A 30-year-old male with no medical history presented with generalized abdominal pain accompanied by Kehr's sign. He is diagnosed with ruptured spleen by contrast-enhanced computed tomography and successfully treated with splenectomy. He was discharged 6 days after surgery.

Conclusions

Spontaneous rupture of the spleen is uncommon, but with high morbidity and mortality. It must be a differential diagnosis in the face of abdominal and/or chest pain, and the corresponding imaging studies should be carried out if the patient's conditions allow it, or their search during an exploratory laparotomy.

Extremely Rare CT and MRI Findings of Peritoneal Leiomyoma Mimicking Hepatic Mass: A Case Report

Leiomyoma is a common benign tumor from smooth muscle cells, mostly in the uterus. Peritoneal leiomyomas (PLs) are extremely rare and mostly reported as disseminated peritoneal leiomyomatosis. However, to the best of out knowledge, radiologic findings of isolated PL are not reported in English literature. Herein, we introduce the radiologic findings of PL mimicking hepatic mass in a 34-year-old female. CT showed a mass with curvilinear heterogeneous enhancement at the liver's peripheral area. On MRI, the mass showed gradual and heterogeneous enhancement on gadoxetic acid-enhanced MRI and diffusion restriction. The radiologic diagnosis was a benign hepatic tumor, such as degenerated hemangioma, adenoma, and inflammatory myofibroblastic tumor; however, the mass was diagnosed as PL pathologically.

Chest computed tomography analysis of lung sparing morphology: differentiation of COVID-19 pneumonia from influenza pneumonia and bacterial pneumonia using the arched bridge and vacuole signs

INTRODUCTION

This study evaluated the arched bridge and vacuole signs, which constitute morphological patterns of lung sparing in coronavirus disease 2019 (COVID-19), then examined whether these signs could be used to differentiate COVID-19 pneumonia from influenza pneumonia or bacterial pneumonia.

METHODS

In total, 187 patients were included: 66 patients with COVID-19 pneumonia, 50 patients with influenza pneumonia and positive computed tomography findings, and 71 patients with bacterial pneumonia and positive computed tomography findings. Images were independently reviewed by two radiologists. The incidences of the arched bridge sign and/or vacuole sign were compared among the COVID-19 pneumonia, influenza pneumonia, and bacterial pneumonia groups.

RESULTS

The arched bridge sign was much more common among patients with COVID-19 pneumonia (42/66, 63.6%) than among patients with influenza pneumonia (4/50, 8.0%; P<0.001) or bacterial pneumonia (4/71, 5.6%; P<0.001). The vacuole sign was also much more common among patients with COVID-19 pneumonia (14/66, 21.2%) than among patients with influenza pneumonia (1/50, 2.0%; P=0.005) or bacterial pneumonia (1/71, 1.4%; P<0.001). The signs occurred together in 11 (16.7%) patients with COVID-19 pneumonia, but they did not occur together in patients with influenza pneumonia or bacterial pneumonia. The arched bridge and vacuole signs predicted COVID-19 pneumonia with respective specificities of 93.4% and 98.4%.

CONCLUSION

The arched bridge and vacuole signs are much more common in patients with COVID-19 pneumonia and can help differentiate COVID-19 pneumonia from influenza and bacterial pneumonia.

A preliminary radiomics model for predicting perirenal fat invasion on renal cell carcinoma with contrast-enhanced CT images

OBJECTIVE

The aim is to develop a radiomics model based on contrast-enhanced CT scans for preoperative prediction of perirenal fat invasion (PFI) in patients with renal cell carcinoma (RCC).

METHODS

The CT data of 131 patients with pathology-confirmed PFI status (64 positives) were retrospectively collected and randomly assigned to the training and test datasets. The kidneys and the masses were annotated by semi-automatic segmentation. Eight types of regions of interest (ROI) were chosen for the training of the radiomics models. The areas under the curves (AUCs) from the receiver operating characteristic (ROC) curve analysis were used to analyze the diagnostic performance. Eight types of models with different ROIs have been developed. The models with the highest AUC in the test dataset were used for construction of the corresponding final model, and comparison with radiologists' diagnosis.

RESULTS

The AUCs of the models for each ROI was 0.783-0.926, and there was no statistically significant difference between them (P > 0.05). Model 4 was using the ROI of the outer half-ring which extended along the edge of the mass at the outer edge of the kidney into the perirenal fat space with a thickness of 3 mm. It yielded the highest AUC (0.926) and its diagnostic accuracy was higher than the radiologists' diagnosis.

CONCLUSION

We have developed and validated a radiomics model for prediction of PFI on RCC with contrast-enhanced CT scans. The model proved to be more accurate than the radiologists' diagnosis.

Deep learning model-assisted detection of kidney stones on computed tomography

Introduction:

The aim of this study was to investigate the success of a deep learning model in detecting kidney stones in different planes according to stone size on unenhanced computed tomography (CT) images.

Materials and Methods:

This retrospective study included 455 patients who underwent CT scanning for kidney stones between January 2016 and January 2020; of them, 405 were diagnosed with kidney stones and 50 were not. Patients with renal stones of 0–1 cm, 1–2 cm, and >2 cm in size were classified into groups 1, 2, and 3, respectively. Two radiologists reviewed 2,959 CT images of 455 patients in three planes. Subsequently, these CT images were evaluated using a deep learning model. The accuracy rate, sensitivity, specificity, and positive and negative predictive values of the deep learning model were determined.

Results:

The training group accuracy rates of the deep learning model were 98.2%, 99.1%, and 97.3% in the axial plane; 99.1%, 98.2%, and 97.3% in the coronal plane; and 98.2%, 98.2%, and 98.2% in the sagittal plane, respectively. The testing group accuracy rates of the deep learning model were 78%, 68% and 70% in the axial plane; 63%, 72%, and 64% in the coronal plane; and 85%, 89%, and 93% in the sagittal plane, respectively.

Conclusions:

The use of deep learning algorithms for the detection of kidney stones is reliable and effective. Additionally, these algorithms can reduce the reporting time and cost of CT-dependent urolithiasis detection, leading to early diagnosis and management.

Extradural Spinal Lymphoplasmacyte-Rich Meningioma in the Thoracic Spine: A Case Report and Literature Review

Most spinal meningiomas have an intradural or partly extradural location. The meningothelial origin is the most common pathologic type of spinal meningioma. Pure extradural spinal meningiomas are not common, and lymphoplasmacyte-rich meningioma (LPRM) is very rare. We report a case of isolated extradural spinal meningioma in the thoracic spine that was pathologically confirmed as LPRM.

Multiple fibro-osseous lesions of the jaws: A report of a rare case with a literature review

Fibro-osseous lesions are a poorly defined category of conditions affecting the jaws and craniofacial bones, and include developmental lesions, reactive or dysplastic lesions, and neoplasms. Fibrous dysplasia and ossifying fibroma are the 2 main types of fibro-osseous lesions affecting the jaw, and ossifying fibroma is a true benign neoplasm of the bone-forming tissues with several well-recognized variants ranging from innocuous to extensively aggressive lesions. However, multiple simultaneous fibro-osseous lesions of the jaw bones involving all quadrants are exceedingly rare. One such case diagnosed by conventional radiography and computed tomography is discussed here.

Quantification of liver extracellular volume using dual-energy CT for ruling out high-risk varices in cirrhosis

PURPOSE

To determine the performance of quantification of liver extracellular volume fraction (fECV) using dual-energy CT (DECT) compared with CT imaging for ruling out high-riskesophageal varices(HRV) in cirrhotic patients.

METHODS

We retrospectively analyzed 229 cirrhotic patients (training [n = 159] and internal validation cohorts [n = 70]) who underwent dual-source DECT, serum marker assessment, and esophagogastroduodenoscopy (EGD) from 2017 to 2020. The fECV score was measured using iodine maps from 3-minute delayed, equilibrium-phase images at 100/140 Sn kVp. The association of CT parameters and serum markers with HRV was investigated. Criteria combining the fECV score (≤ 25.1%) or CT imaging with platelet count (> 150,000/mm³) were created and compared to rule out HRV.

RESULTS

In the training cohort, the fECV score (odds ratio (OR), 1.20; 95% confidence interval (CI), 1.09, 1.32) and CT imaging (OR, 28.21; 95% CI, 9.31, 85.93) were independent predictors of HRV, along with platelet count (OR, 0.85 and 0.78). Criteria combining the fECV score with platelet count showed significantly better performance than those combining CT imaging with platelet count in ruling out HRV (p < 0.001). Applying the criteria could have safely avoided an additional 10.7% and 8.6% of EGDs in the training and validation cohorts, respectively, achieving a final value of 36.5% and 35.7% spared EGDs (0 HRV missed) compared to CT imaging with platelet count.

CONCLUSIONS

The combined DECT-based fECV score with platelet count is useful for ruling out HRV and can safely avoid more EGDs than CT imaging with platelet count.

Incidence and risk factors of late adverse reactions to low-osmolar contrast media: A prospective observational study of 10,540 exposures

PURPOSE

To evaluate the incidence and risk factors of late adverse reactions (ARs) to non-ionic low-osmolar contrast media (LOCM).

METHODS

The occurrence of late AR was monitored on day 1 and from day 7 to day 28 in all patients who received enhanced computed tomography using LOCM during a 5-week study period in a single tertiary hospital. Patients who experienced late AR were followed up for three years.

RESULTS

Among the total 10,540 LOCM exposures, 315 ARs (3.0%) were reported; acute ARs occurred in 108 LOCM exposures (1.0%) and late ARs occurred in 207 LOCM exposures (2.0%) (90.9% within one week, 9.1% developed afterwards by day 20). Previous history of drug allergy (odds ratio [OR] = 4.59; 95% confidence interval [CI] 2.17-9.71) and allergic diseases (OR = 2.54; 95% CI 1.32-4.91) were risk factors of late ARs to LOCM. Although the recurrence rate was lowered with premedication from 8.5% to 1.7% (8/94 vs. 3/178; p = 0.016), LOCM change did not make difference compared to reuse of the culprit LOCM (2/38 vs. 9/234; p = 0.655). In patients with a history of late AR to LOCM, the risk of recurrent reactions decreased with longer time intervals between exposures (OR = 0.86; 95% CI: 0.77-0.97; p = 0.025) and with the use of antihistamine premedication (OR = 0.27; 95% CI: 0.06-0.99; p = 0.049).

CONCLUSIONS

Late ARs to LOCM occurred mostly within one week. The use of premedication may be helpful in reducing the recurrence of late ARs.

From cold-blooded reptiles to embryological remnants: Persistent myocardial sinusoids

In nature, basically 2 types of myocardial vascular patterns exist: the sinusoidal and the coronary type. In the sinusoidal type, the sinusoid is completely fed by blood coming directly from the ventricle through a spongy sinusoidal network. This pattern is found in cold-blooded animals and in the early embryologic development of human (warm-blooded) hearts. A 61-year-old man with atrial fibrillation developed severe tachymyopathy with a severely reduced left-ventricular ejection fraction (LVEF) of 20%. The patient had no history of prior heart surgery or other cardiac interventions. He was referred for a computed tomography (CT) scan for assessment of pulmonary vein anatomy prior to their isolation. Incidentally, a focal myocardial defect of the midventricular infero-septal wall with tail-like extension into the right ventricular cavity was detected. In a cardiac magnetic resonance (CMR) scan there was no evidence of a myocardial infarction or fibrosis. In the absence of a ventricular septal defect by CT, CMR and echocardiography the diagnosis of a persistent myocardial sinusoid was evident. In this case, we used state-of-the art methods for pathology visualization, illustrating the effectiveness of CT and CMR in the precise detection and differential diagnosis of myocardial anomalies including a multi-coloured 3D-printed model that may further enhance visuospatial appreciation of those anomalies.

Usefulness of imaging studies for diagnosing and localizing cerebrospinal fluid rhinorrhea: A systematic review and meta-analysis

OBJECTIVES

To evaluate the usefulness of diagnosis by imaging studies for the localization of cerebrospinal fluid rhinorrhea.

METHODS

PubMed, SCOPUS, Embase, Web of Science, and Cochrane library databases were searched up to July 2021. True and false positive and negative data were collected along with the characteristics of each study. Methodological quality was assessed using the QADAS-2 tool.

RESULTS

Sixteen studies involving 472 patients were included. The diagnostic odds ratio of imaging studies was 13.6195 (95% confidence interval [7.4756; 24.8129]; I² = 28.1%). The area under the summary receiver operating characteristic curve was 0.712. Sensitivity, specificity, negative predictive value, and positive predictive value were 0.8507 ([0.7773; 0.9029]; 72.1%), 0.7827 ([0.6865; 0.8556], 26.8%), 0.5828 ([0.4398; 0.7132]; 67.4%), and 0.9407 ([0.8935; 0.9678]; 59.1%), respectively. In subgroup analysis, there were significant differences in sensitivity (computed tomography, 0.7421; computed tomography cisternography, 0.8872; magnetic resonance imaging, 0.8365; magnetic resonance cisternography, 0.8565; and intrathecal gadolinium magnetic resonance cisternography, 0.9307; radionuclide cisteronography, 0.7097; p  =  0.0481), and negative predictive value among imaging modalities (computed tomography, 0.3028; computed tomography cisternography, 0.4848; magnetic resonance imaging, 0.4658; magnetic resonance cisternography, 0.7465; and intrathecal gadolinium magnetic resonance cisternography, 0.8611, and radionuclide cisteronography, 0.5263; p  =  0.0046). There were no significant differences among imaging modalities in specificity, positive predictive value, or diagnostic odds ratio (p > 0.05).

CONCLUSION

Imaging studies can be used in the diagnosis of cerebrospinal fluid rhinorrhea. Gadolinium magnetic resonance cisternography showed the highest diagnostic accuracy. Also, magnetic resonance cisternography showed fair diagnostic accuracy without intrathecal injection. This article is protected by copyright. All rights reserved.

CT Examinations for COVID-19: A Systematic Review of Protocols, Radiation Dose, and Numbers Needed to Diagnose and Predict

Purpose

Although chest CT has been discussed as a first-line test for coronavirus disease 2019 (COVID-19), little research has explored the implications of CT exposure in the population. To review chest CT protocols and radiation doses in COVID-19 publications and explore the number needed to diagnose (NND) and the number needed to predict (NNP) if CT is used as a first-line test.

Materials and Methods

We searched nine highly cited radiology journals to identify studies discussing the CT-based diagnosis of COVID-19 pneumonia. Study-level information on the CT protocol and radiation dose was collected, and the doses were compared with each national diagnostic reference level (DRL). The NND and NNP, which depends on the test positive rate (TPR), were calculated, given a CT sensitivity of 94% (95% confidence interval [CI]: 91%-96%) and specificity of 37% (95% CI: 26%-50%), and applied to the early outbreak in Wuhan, New York, and Italy.

Results

From 86 studies, the CT protocol and radiation dose were reported in 81 (94.2%) and 17 studies (19.8%), respectively. Low-dose chest CT was used more than twice as often as standard-dose chest CT (39.5% vs.18.6%), while the remaining studies (44.2%) did not provide relevant information. The radiation doses were lower than the national DRLs in 15 of the 17 studies (88.2%) that reported doses. The NND was 3.2 scans (95% CI: 2.2-6.0). The NNPs at TPRs of 50%, 25%, 10%, and 5% were 2.2, 3.6, 8.0, 15.5 scans, respectively. In Wuhan, 35418 (TPR, 58%; 95% CI: 27710-56755) to 44840 (TPR, 38%; 95% CI: 35161-68164) individuals were estimated to have undergone CT examinations to diagnose 17365 patients. During the early surge in New York and Italy, daily NNDs changed up to 5.4 and 10.9 times, respectively, within 10 weeks.

Conclusion

Low-dose CT protocols were described in less than half of COVID-19 publications, and radiation doses were frequently lacking. The number of populations involved in a first-line diagnostic CT test could vary dynamically according to daily TPR; therefore, caution is required in future planning.

Computed-tomography based scoring system predicts outcome for clinical lymph node-positive patients undergoing radical cystectomy

Purpose:

Contrast-enhanced CT scan is the standard staging modality for patients with bladder cancer undergoing radical cystectomy (RC). Involvement of lymph nodes (LN) determines prognosis of patients with bladder cancer. The detection of LN metastasis by CT scan is still insufficient. Therefore, we investigated various CT scan characteristics to predict lymph node ratio (LNR) and its impact on survival. Also, pre-operative CT scan characteristics might hold potential to risk stratify cN+ patients.

Materials and Methods:

We analyzed preoperative CT scans of patients undergoing RC in a tertiary high volume center. Retrospectively, local tumor stage and LN characteristics such as size, morphology (MLN) and number of loco-regional LN (NLN) were investigated and correlation to LNR and survival was analyzed. CT scan characteristics were used to develop a risk stratification using Kaplan-Maier and multivariate analysis.

Results:

764 cN0 and 166 cN+ patients with complete follow-up and imaging data were included in the study. Accuracy to detect LN metastasis and locally advanced tumor stage in CT scan was 72% and 62%. LN larger than 15mm in diameter were significantly associated with higher LNR (p=0.002). Increased NLN correlated with decreased CSS and OS (p=0.001: p=0.002). Furthermore, CT scan based scoring system precisely differentiates low-risk and high-risk profiles to predict oncological outcome (p <0.001).

Conclusion:

In our study, solely LN size >15mm significantly correlated with higher LNR. Identification of increased loco-regional LN was associated with worse survival. For the first time, precise risk stratification based on computed-tomography findings was developed to predict oncological outcome for clinical lymph node-positive patients undergoing RC.

Letter to the Editor concerning "HIPTCN: Prospective Observational Study of Hypocoagulated Head Trauma Patients with Normal Admission Computed Tomography Scan"

N/a.

Blunt Chest Trauma Presenting with Acute Coronary Event

We present a case that was initially diagnosed as non-ST segment elevation myocardial infarction following a blunt chest trauma from left lateral contusion. Coronary angiography and later cardiac computed tomography were performed that showed narrowing and dissection of the distal circumflex and first obtuse marginal branch artery, which was treated medically without any coronary intervention.

A Monte Carlo Platform for Characterization of X-Ray Radiation Dose in CT Imaging

Background

Computed tomography (CT) is currently known as a versatile imaging tool in the clinic used for almost all types of cancers. The major issue of CT is the health risk, belonging to X-ray radiation exposure. Concerning this, Monte Carlo (MC) simulation is recognized as a key computational technique for estimating and optimizing radiation dose. CT simulation with MCNP/MCNPX MC code has an inherent problem due to the lack of a fan-beam shaped source model. This limitation increases the run time and highly decreases the number of photons passing the body or phantom. Recently, a beta version of MCNP code called MCNP-FBSM (Fan-Beam Source Model) has been developed to pave the simulation way of CT imaging procedure, removing the need of the collimator. This is a new code, which needs to be validated in all aspects.

Objective

In this work, we aimed to develop and validate an efficient computational platform based on modified MCNP-FBSM for CT dosimetry purposes.

Material and Methods

In this experimental study, a setup is carried out to measure CTDI₁₀₀ in air and standard dosimetry phantoms. The accuracy of the developed MC CT simulator results has been widely benchmarked through comparison with our measured data, UK's National Health Service's reports (known as ImPACT), manufacturer's data, and other published results.

Results

The minimum and maximum observed mean differences of our simulation results and other above-mentioned data were the 1.5%, and 9.79%, respectively.

Conclusion

The developed FBSM MC computational platform is a beneficial tool for CT dosimetry.

Surgical Treatment for a Super-Giant Right Coronary Artery Aneurysm Induced by Kawasaki Disease

A 32-year-old man diagnosed with Kawasaki disease at the age of three years presented with coronary artery aneurysm (CAA). The aneurysm increased in size, and the patient was referred to our hospital for surgery. Preoperative computed tomography scan showed a super-giant right CAA and giant left CAAs; surgery was performed. The super-giant right CAA was resected, and the ostium of the right coronary artery was closed; then, coronary artery bypass grafting was performed. The left CAAs were not treated surgically because the risk of rupture was low. Here, we describe the successful surgical treatment of a right super-giant CAA.

Implementation of a computed tomography dose management program across a multinational healthcare organization

OBJECTIVES

Radiation dose index monitoring (RDIM) systems may help identify CT dose reduction opportunities, but variability and complexity of imaging procedures make consistent dose optimization and standardization a challenge. This study aimed to investigate the feasibility to standardize and optimize CT protocols through the implementation of a Dose Excellence Program within a European healthcare network.

METHODS

The Dose Excellence Program consisted of a multidisciplinary team that developed standardized organizational adult CT protocols and thresholds for relevant radiation dose indices (RDIs). Baseline data were collected retrospectively from the RDIM (Phase I, 2015). Organization's protocols were implemented and monitored from the RDIM for deviations (Phase II, 2016). Following standardization, radiation dose optimization was initiated (Phase III, 2017). Data from the three most used protocols were retrospectively extracted and grouped by country for all phases. The mean number of series (RS) and RDIs were compared between phases and with organizational reference levels. A Mann-Whitney test was conducted; p < .05 was considered as significant.

RESULTS

Data from 9588, 12638, and 6093 examinations were analyzed from General Chest, General Head, and Thorax/Abdomen/Pelvis (TAP) multiphase respectively. Overall, after Phase III, mean RS and CTDI_vol p⁷⁵ were below the organizational reference levels in all countries for the three protocols. The CTDI_vol decreased by 45% in Switzerland (p < .00001), 32% in Turkey (p < .00001), and 28% in Switzerland (p = .0027) for General Chest, General Head, and TAP multiphase respectively.

CONCLUSIONS

The implementation of a Dose Excellence Program within a large-scale healthcare organization allowed unifying protocols and optimizing radiation dose across countries.

KEY POINTS

• Engaging a multidisciplinary team can enhance the use of an RDIM system for CT dose management in a multinational healthcare environment. • Deep dive of baseline data and standardization of CT practices by defining organizational clinical indication CT protocols with RPIDs is an essential step before optimization of radiation dose. • Following the implementation of the program, the mean RS and CTDIvol were below or equal to the organizational reference levels in all countries.

Early and Atypical Radiologic Presentations of Pulmonary Langerhans Cell Histiocytosis: A Report of Two Cases

Pulmonary Langerhans cell histiocytosis (PLCH) is a rare, multi-systemic disease primarily affecting young male adults with a history of smoking. The two patients with PLCH in our report showed relatively early and atypical radiologic presentations at initial evaluation. On chest CT, PLCH presents variable radiologic features depending on the evolutional stage of the disease. Atypical CT features of PLCH may render precise radiologic diagnosis difficult and usually require lung biopsy for a confirmation of the diagnosis. Our case review is aimed at raising the awareness of radiologists on the atypical CT features of PLCH, to help make accurate radiologic diagnosis and prevent unnecessary and invasive diagnostic procedures.

TOMOGRAPHIC ANALYSIS OF C7, T1 AND T2 VERTEBRAE ANATOMY IN CHILDREN

OBJECTIVE

To evaluate and compare anatomical measurements of C7, T1 and T2 vertebrae in children from 3 to 12 years of age to provide useful epidemiological data for determining the safe anatomical margin for transpedicular and translaminar fixation with screws in this population.

METHODS

This observational retrospective cross-sectional study evaluated 76 computed tomography scans obtained over 6 months, analyzing the following parameters: the angle of attack, length, thickness and diameter of the pedicle; and the angle of attack, length and thickness of the lamina.

RESULTS

The lamina length and thickness, as well as pedicle length varied in size according to age. Although the angle of attack was similar across different ages, age-dependent variation occurred in the T1 vertebra.

CONCLUSION

Screws with a 3.5 mm diameter are safe to use in the C7 and T2 pedicles, while the T1 pedicle allows the introduction of larger screws ranging from 3.5-4.5 mm in diameter. In the lamina, 3.5 mm screws are safe for use only in children older than 7 years. However, each case should be analyzed individually, with the present study not aiming to replace the preoperative use of CT. Level of Evidence III, Retrospective comparative study.

Ileocolic Intussusception Accompanied with Inflamed Appendix: 2 Case Reports

Intussusception and acute appendicitis are common emergency conditions in children. They should be promptly differentiated in pediatric patients presenting with suggestive symptoms. However, both diseases may occur simultaneously. Herein, we present two cases of intussusception of the appendix accompanied with appendicitis.

WEIGHT-BEARING CONE BEAM CT SCANS AND ITS USES IN ANKLE, FOOT, AND KNEE: AN UPDATE ARTICLE

Imaging plays a key role in the preoperative diagnosis, surgical planning, and postsurgical assessment of the foot, ankle, and knee pathologies. Interpreting diagnostic imaging accurately is crucial for the clinical practice of orthopedic surgeons. Although among the most used imaging modalities, radiographic assessments are amenable to errors for various technical reasons and superposition of bones. Computed tomography (CT) is a conventional imaging procedure that provides high-resolution images, but fails in considering a truly weight-bearing (WB) condition. In an attempt to overcome this limitation, WB cone beam CT technology has being successfully employed in the clinical practice for the past decade. Besides economically viable and safe, the WB cone beam CT considers WB conditions and provides high-quality scans, thus allowing an equitable and correct interpretation. This review aims to address extensive description and discussion on WBCT, including imaging quality; costs; time consumption; and its applicability in common foot, ankle, and knee, conditions. With this technology increasing popularity, and considering the extensive literature on medical research, radiologists and orthopedic surgeons need to understand its potential applications and use it optimally. Level of Evidence III, Systematic review of level III studies.

Prognostic Implications of CT Feature Analysis in Patients with COVID-19: a Nationwide Cohort Study

BACKGROUND

Few studies have classified chest computed tomography (CT) findings of coronavirus disease 2019 (COVID-19) and analyzed their correlations with prognosis. The present study aimed to evaluate retrospectively the clinical and chest CT findings of COVID-19 and to analyze CT findings and determine their relationships with clinical severity.

METHODS

Chest CT and clinical features of 271 COVID-19 patients were assessed. The presence of CT findings and distribution of parenchymal abnormalities were evaluated, and CT patterns were classified as bronchopneumonia, organizing pneumonia (OP), or diffuse alveolar damage (DAD). Total extents were assessed using a visual scoring system and artificial intelligence software. Patients were allocated to two groups based on clinical outcomes, that is, to a severe group (requiring O₂ therapy or mechanical ventilation, n = 55) or a mild group (not requiring O₂ therapy or mechanical ventilation, n = 216). Clinical and CT features of these two groups were compared and univariate and multivariate logistic regression analyses were performed to identify independent prognostic factors.

RESULTS

Age, lymphocyte count, levels of C-reactive protein, and procalcitonin were significantly different in the two groups. Forty-five of the 271 patients had normal chest CT findings. The most common CT findings among the remaining 226 patients were ground-glass opacity (98%), followed by consolidation (53%). CT findings were classified as OP (93%), DAD (4%), or bronchopneumonia (3%) and all nine patients with DAD pattern were included in the severe group. Uivariate and multivariate analyses showed an elevated procalcitonin (odds ratio [OR], 2.521; 95% confidence interval [CI], 1.001-6.303, P = 0.048), and higher visual CT scores (OR, 1.137; 95% CI, 1.042-1.236; P = 0.003) or higher total extent by AI measurement (OR, 1.048; 95% CI, 1.020-1.076; P < 0.001) were significantly associated with a severe clinical course.

CONCLUSION

CT findings of COVID-19 pneumonia can be classified into OP, DAD, or bronchopneumonia patterns and all patients with DAD pattern were included in severe group. Elevated inflammatory markers and higher CT scores were found to be significant predictors of poor prognosis in patients with COVID-19 pneumonia.

Do various imaging modalities provide potential early detection and diagnosis of medication-related osteonecrosis of the jaw? A review

OBJECTIVE

Patients with medication-related osteonecrosis of the jaw (MRONJ) often visit their dentists at advanced stages and subsequently require treatments that greatly affect quality of life. Currently, no clear diagnostic criteria exist to assess MRONJ, and the definitive diagnosis solely relies on clinical bone exposure. This ambiguity leads to a diagnostic delay, complications, and unnecessary burden. This article aims to identify imaging modalities' usage and findings of MRONJ to provide possible approaches for early detection.

METHODS

Literature searches were conducted using PubMed, Web of Science, Scopus, and Cochrane Library to review all diagnostic imaging modalities for MRONJ.

RESULTS

Panoramic radiography offers a fundamental understanding of the lesions. Imaging findings were comparable between non-exposed and exposed MRONJ, showing osteolysis, osteosclerosis, and thickened lamina dura. Mandibular cortex index Class II could be a potential early MRONJ indicator. While three-dimensional modalities, CT and CBCT, were able to show more features unique to MRONJ such as a solid type periosteal reaction, buccal predominance of cortical perforation, and bone-within-bone appearance. MRI signal intensities of vital bones are hypointense on T₁WI and hyperintense on T₂WI and STIR when necrotic bone shows hypointensity on all T₁WI, T₂WI, and STIR. Functional imaging is the most sensitive method but is usually performed in metastasis detection rather than being a diagnostic tool for early MRONJ.

CONCLUSION

Currently, MRONJ-specific imaging features cannot be firmly established. However, the current data are valuable as it may lead to a more efficient diagnostic procedure along with a more suitable selection of imaging modalities.

Usefulness of 18F-FDG PET/CT and Multiphase CT in the Differential Diagnosis of Hepatocellular Carcinoma and Combined Hepatocellular Carcinoma-Cholangiocarcinoma

PURPOSE

The purpose of this study was to evaluate the usefulness of multiphasic CT and ¹⁸F-fluorodeoxyglucose (FDG) PET/CT for the differentiation of combined hepatocellular carcinomacholangiocarcinoma (cHCC-CCA) from hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

From January 2007 to April 2016, 93 patients with pathologically confirmed HCC (n = 84) or cHCC-CCA (n = 9) underwent CT and PET/CT imaging. Contrast enhancement patterns were divided into three types based on the attenuation of the surrounding liver parenchyma: type I (early arterial enhancement with delayed washout), type II (early arterial enhancement without delayed washout), and type III (early hypovascular, infiltrative appearance, or peripheral rim enhancement).

RESULTS

cHCC-CCAs (89%) had a higher PET/CT positive rate than did HCCs (61%), but the PET/CT positive rate did not differ significantly (p = 0.095). Among the 19 cases of the type II enhancement pattern, 3 (21%) of 14 HCCs and 4 (80%) of 5 cHCC-CCAs were PET/CT positive. cHCC-CCAs had a significantly higher PET/CT positive rate (p = 0.020) in the type II enhancement pattern.

CONCLUSION

The PET/CT positive rate of cHCC-CCA was significantly higher than that of HCC in lesions with a type II enhancement pattern. The ¹⁸F-FDG PET/CT can be useful for the differentiation of cHCC-CCA from HCC in lesions with a type II enhancement pattern on multiphasic CT.

Renal Epithelioid Angiomyolipoma: A Case Report and Review of Literature

Epithelioid angiomyolipoma (EAML) is an uncommon renal neoplasm with malignant potential. It is classified under the group of perivascular epithelioid cell tumors and can be sporadic or as part of the tuberous sclerosis complex. On imaging, unlike classical AML that contains fat, EAML has a very low percentage of fat which can mimic the imaging findings of renal cell carcinoma. We reported a 31-year-old female who had a history of renal failure and bilateral renal masses. Magnetic resonance imaging of the abdomen revealed bilateral large renal masses replacing renal parenchyma with features suggestive of bilateral renal AML. The patient underwent left nephrectomy, and histopathology examination findings were consistent with the diagnosis of EAML.

Renal Epithelioid Angiomyolipoma: A Case Report and Review of Literature

Epithelioid angiomyolipoma (EAML) is an uncommon renal neoplasm with malignant potential. It is classified under the group of perivascular epithelioid cell tumors and can be sporadic or as part of the tuberous sclerosis complex. On imaging, unlike classical AML that contains fat, EAML has a very low percentage of fat which can mimic the imaging findings of renal cell carcinoma. We reported a 31-year-old female who had a history of renal failure and bilateral renal masses. Magnetic resonance imaging of the abdomen revealed bilateral large renal masses replacing renal parenchyma with features suggestive of bilateral renal AML. The patient underwent left nephrectomy, and histopathology examination findings were consistent with the diagnosis of EAML.

Petrous apex pneumatisation in children: a radiological study

OBJECTIVE

This study aimed to investigate petrous apex pneumatisation in children, as an understanding of petrous apex pneumatisation is useful in the diagnosis and surgical management of middle-ear disease.

METHODS

Computed tomography head scans from 1700 patients aged 0-16 years were assessed. Petrous apex bone and air cell volumes were calculated to determine the degree of petrous apex pneumatisation. Scans were analysed for communicating tracts between the middle ear and petrous apex.

RESULTS

Petrous apex pneumatisation was found in 21.0 per cent of patients. Positive relationships were found between age and petrous apex pneumatisation prevalence (rs = 0.990, p < 0.001), and between age and degree of petrous apex pneumatisation (rs = 0.319, p < 0.001). Petrous apex pneumatisation prevalence did not significantly differ by sex or ethnicity. Communicating tracts were identified in 84.3 per cent of patients with petrous apex pneumatisation, most commonly anterior to the otic capsule.

CONCLUSION

In children, the prevalence and degree of petrous apex pneumatisation increases with age, but prevalence is not affected by sex or ethnicity.

Generalist versus Abdominal Subspecialist Radiologist Interpretations of Abdominopelvic Computed Tomography Performed on Patients with Abdominal Pain and its Impact on the Therapeutic Approach

Introduction:

Abdominal pain is one of the most common patient complaints in the emergency department (ED) and abdominopelvic computed tomography (ACT) scan plays an important role in evaluation of these patients.

Objective:

The aim of this study was to determine the differences between interpretations by generalist radiologists and abdominal subspecialist radiologists regarding the abdominopelvic computed tomography (ACT) of patients who were admitted to the Emergency Department (ED) and to investigate its effect on the patients’ therapeutic approach.

Methods:

The records of 16452 patients who were admitted to the emergency department with complaint of abdominal pain between January 2015 and April 2017 were reviewed, retrospectively. Out of these patients, 245 (1.5%) underwent ACT for differential diagnosis and among them, 137 (0.8%) patients had their ACT reports evaluated by generalist radiologists in 45 minutes and by abdominal subspecialist radiologist 8–12 hours later and were included in the study. Patients were divided into three groups according to the effect of ACT reports on the performed treatment. Group 1: no effect on planned treatment, group 2: minor effect on planned treatment, which did not result in a change in the treatment process and group 3: major effect on planned treatment approach, which resulted in a change in the treatment process. These changes included at least one of the two criteria: changing the indication of surgery from emergency surgery to elective surgery and/or discharge of the patient from the ED, when actually hospitalization was required.

Results:

Out of the 137 patients, 87 (63.5%) were male, 50 (36.5%) were female and the patients’ mean age was 56 (27–93) years. There were 117 (85.4%) patients in group 1, 15 (10.9%) patients in group 2, and 5 (3.7%) patients in group 3. We determined minor inconsistency between the reports in group 2 and major inconsistency in group 3. Patients in group 3 suffered from delayed surgical intervention due to inconsistency of the CT reports resulting in prolonged hospital stay and increased morbidity. In 17 patients (four patients in Group 1 and 13 patients in Group 2) treatment plan was changed due to CT results; and while surgical treatment was planned for them prior to CT scan, they were discharged with medical treatment after that and overtreatment was prevented.

Conclusion:

Contribution of abdominal radiologists to evaluation of ACT images in the ED would reduce the inconsistency in ACT reports and prevent the patients from receiving insufficient treatment or overtreatment.

Pulmonary Alveolar Microlithiasis: A Case Report

Pulmonary alveolar microlithiasis (PAM) is a rare disease caused by a mutation in the SLC34A2 gene encoding the type IIb sodium phosphate cotransporter in alveolar type II cells. This results in the formation and accumulation of calcium phosphates crystals in the alveoli. Early in the disease, most patients are asymptomatic or might experience mild symptoms. However, in some patients, PAM can progress resulting in pulmonary fibrosis, cor pulmonale, and respiratory failure. We report the case of a 33-year-old Omani male who was referred to our institute with a history of fever and shortness of breath. A chest radiograph revealed bilateral dense consolidation. Chest computed tomography showed bilateral dense interlobular thickening and extensive consolidations with a lower lung predominance. Our findings were highly suggestive of PAM. The diagnosis was confirmed by bronchoalveolar lavage.

Computed tomography imaging characteristics of clear cell papillary renal cell carcinoma

Purpose:

Clear cell papillary (CCP) renal cell carcinoma (RCC) is a new subtype of RCC that was formally recognized by the International Society of Urological Pathology Vancouver Classification of Renal Neoplasia in 2013. Subsequently, CCP RCC was added to the 2016 World Health Organization Classification of Tumors of the Urinary System and Male Genital Organs. In this study, we retrospectively investigated the computed tomography (CT) findings of pathologically diagnosed CCP RCC.

Materials and Methods:

This study included 12 patients pathologically diagnosed with CCP RCC at our institution between 2015 and 2017. We reviewed the patient's CT data and analyzed the characteristics.

Results:

Nine solid masses and 3 cystic masses with a mean tumor size of 22.7±9.2mm were included. Solid masses exhibited slight hyper-density on unenhanced CT with a mean value of 34±6 Hounsfield units (HU), good enhancement in the corticomedullary phase with a mean of 195±34HU, and washout in the nephrogenic phase with a mean of 133±29HU. The walls of cystic masses enhanced gradually during the corticomedullary and nephrogenic phases. Solid and cystic masses were preoperatively diagnosed as clear cell RCC and cystic RCC, respectively.

Conclusions:

The CT imaging characteristics of CCP RCCs could be categorized into either the solid or cystic type. These masses were diagnosed radiologically as clear cell RCC and cystic RCC, respectively.

[Value of CT in the differential diagnosis of Pseudomonas aeruginosa sinusitis and fungal ball in paranasal sinus caused by Aspergilus flavus]

Objective: To evaluate the value of CT in the differential diagnosis of Pseudomonas aeruginosa sinusitis and fungal ball in paranasal sinus caused by Aspergilus flavus. Methods: In this retrospective study, CT results of 74 cases of Pseudomonas aeruginosa sinusitis including 31 male cases and 43 female cases with age onset from 15 to 74 years old (mean±SD was 50±13) and 72 cases of fungal ball in paranasal sinus caused by Aspergilus flavus including 28 male cases and 44 female cases with age onset from 25 to 78 years old (mean±SD was 53±15) at Beijing Tongren Hospital confirmed by histopathology were enrolled from January 2013 to May 2017. The CT characteristics of the two groups of cases were compared using χ(2) test, and P<0.05 was considered statistically significant. Results: Soft tissue opacification of the involved paranasal sinus was found on CT in each case of the two groups. There were significant differences in the rate of single sinus involvement (44.6% and 90.3% respectively), the incidence of lesion associated with maxillary sinus (91.9% and 70.8% respectively), ethmoid sinus (41.9% and 2.8% respectively), frontal sinus (29.7% and 0 respectively), calcification (50.0% and 72.2% respectively), and the enlargement of maxillary sinus opening (13.2% and 35.3% respectively), in addition to the central calcification (83.8% and 59.6% respectively) between the two groups (all P<0.05). However, the incidence of sphenoid sinus involvement (32.4% and 34.7% respectively), bone sclerosis (56.8% and 62.5% respectively) or destruction(18.9% and 16.7% respectively) were not found different between the two groups (P>0.05). Conclusion: Though the CT findings are similar between the two diseases such as soft tissue opacification of the involved paranasal sinus with calcification and bone sclerosis or destruction, there are still a few characteristics on CT in differentiating the one from the other. The involvement of multi-sinuses, maxillary sinus, ethmoid sinus and frontal sinus, the central calcification are more common in the Pseudomonas aeruginosa sinusitis. However, the CT features including single sinus involvement, calcification and enlargement of maxillary sinus opening, can be seen more often in the fungal ball in paranasal sinus caused by Aspergilus flavus.

Primary renal angiosarcoma with extensive hemorrhage: CT and MRI findings

Primary angiosarcomas of the kidney are very rare, but highly aggressive tumors showing poor prognosis. Patients frequently complain of flank pain, hematuria, or a palpable mass. We present a case of primary renal angiosarcoma occurring in a 61-year-old man. CT images depicted a huge exophytic mass (16 cm in diameter) in the right kidney, exhibiting extensive hemorrhage. The mass showed centripetal peripheral nodular enhancement on dynamic contrast-enhanced images. Furthermore, MR imaging revealed a tangled mesh of tumor vessels in the periphery of the mass. We suggest its inclusion in the differential diagnosis of cases of hemorrhagic renal tumors with prominent vasculature.

Diagnosis, management, and follow-up of extensive dermoid cyst of the submental region

Dermoid cyst (DC) is a cystic lesion of developmental origin and uncertain etiology that rarely affects the floor of the mouth. We report a case of a large lesion found in the submental and submandibular region in a 25-year-old male patient. Computed tomography revealed extensive hypodense lesion in the submental and submandibular space without peripheral enhancement. The microscopical analysis showed a cystic cavity lined by orthokeratinized stratified squamous epithelium. The cystic capsule was composed of dense fibrous connective tissue containing cutaneous attachments, such as sebaceous and sweat glands. The diagnosis of DC was made. The differential diagnosis of expansive sublingual lesions can be clinically challenging due to the similarity with several lesions frequently observed in this region. Herein, we describe a case of extensive DC arising in the floor of the mouth, presenting clinical, imaging, and microscopical features.

Utility of Computed Tomography in a Differential Diagnosis for the Patients with an Initial Diagnosis of Chronic Obstructive Pulmonary Disease Exacerbation

Background

The utility of computed tomography (CT) in the differential diagnosis of patients with chronic obstructive pulmonary disease (COPD) exacerbation remains uncertain. However, due to the low cost associated with CT scan along with the impact of Koreas' health insurance system, there has been a rise in the number of CT scans in the patients with initial diagnosis of COPD exacerbations. Therefore, the utility of CT in the differential diagnosis was investigated to determine whether performing CT scans affect the clinical outcomes of the patients with an initial diagnosis of COPD exacerbation.

Methods

This study involved 202 COPD patients hospitalized with an initial diagnosis of COPD exacerbation. We evaluated the change in diagnosis or treatment after performing a CT scan, and compared the clinical outcomes of patient groups with vs. without performing CT (non-CT group vs. CT group).

Results

After performing CT, the diagnosis was changed for two (3.0%) while additional diagnoses were made for 27 of the 64 patients (42.1%). However, the treatment changed for only one (1.5%), and six patients (9.3%) received supplementary medication. There were no difference in the median length of hospital stay (8 [6–13] days vs. 8 [6–12] days, p=0.786) and intensive care unit care (14 [10.1%] vs. 11 [16.7%], p=0.236) between the CT and non-CT groups, respectively. These findings remained consistent even after the propensity score matching.

Conclusion

Utility of CT in patients with acute COPD exacerbation might not be helpful; therefore, we do not recommend chest CT scan as a routine initial diagnostic tool.

Prognosis in case of nerve disturbance after mandibular implant surgery in relation to computed tomography findings and symptoms

Purpose

The aim of this study was to evaluate the computed tomography (CT) imaging findings and clinical symptoms of patients who complained of neurosensory disturbances after mandibular implant surgery, and to investigate the relationships of these parameters with the prognosis for recovery.

Methods

CT scans were reviewed in 56 patients with nerve disturbance after mandibular implant surgery. Two oral radiologists classified the imaging findings into intrusion, contact, close, and separate groups according to the distance from the inferior border of the implant to the roof of the mandibular canal (MC). The symptoms of 56 patients were classified into 8 groups and the frequency of each group was investigated. Patients were categorized according to symptom improvement into no recovery and recovery groups, and the relationships of recovery with the CT classification and specific symptom groups were analyzed.

Results

Thirty-eight of the 56 nerve disturbance cases showed improvement. The close and separate groups in the CT classification had a strong tendency for recovery (90.9% and 81.8%, respectively) (P<0.05). Although the lowest recovery rate was found in the intrusion group, it was non-negligible, at 50%. The 6 patients with a worm crawling feeling all improved, while the 8 cases with a tightening sensation showed the lowest recovery rate, at 12.5%, and the symptom of a tightening sensation occurred only in the intrusion and contact groups.

Conclusions

The closer the implant fixture was to the MC on CT images, the less likely the patient was to recover. Regarding paresthesia symptoms, while a worm crawling feeling is thought to be a predictor of recovery, a tightening sensation appeared to be associated with a lower recovery rate.

Interstitial Lung Disease Induced by Crizotinib in Non-Small-Cell Lung Cancer

The treatment of advanced non-small-cell lung cancer shifted with the development of molecular-targeted therapies, like the tyrosine kinase inhibitors. One example of tyrosine kinase inhibitors is crizotinib, an anaplastic lymphoma tyrosine kinase inhibitor, which targets an echinoderm microtubule-associated protein-like-4-anaplastic lymphoma kinase gene fusion. This mutation is found in only 2% to 7% of non-small-cell lung cancer cases. Although these new therapies have shown promising results, the occurrence of interstitial lung disease as a side effect could be problematic. As the diagnosis of drug-related-interstitial lung disease is difficult to make, computed tomography is an important diagnostic tool. The recognition of computed tomography manifestations of tyrosine kinase inhibitors -induced interstitial lung disease is the key for an early recognition and management of this pulmonary toxicity. We aim to raise awareness of tyrosine kinase inhibitors-induced interstitial lung disease, by reporting the first case of a Portuguese patient treated with crizotinib for non-small-cell lung cancer who developed drug-induced interstitial lung disease.

Tc-99m hydroxymethylene diphosphonate scintigraphy, computed tomography, and magnetic resonance imaging of osteonecrosis in the mandible: Osteoradionecrosis versus medication-related osteonecrosis of the jaw

Purpose

To present characteristic findings of Tc-99m hydroxymethylene diphosphonate (HMDP) scintigraphy, computed tomography (CT), and magnetic resonance (MR) imaging for osteonecrosis in the mandible, especially osteoradionecrosis (ORN) and medication-related osteonecrosis of the jaw (MRONJ).

Materials and Methods

Thirteen patients with MRONJ and 7 patients with ORN in the mandible underwent Tc-99m HMDP scintigraphy, CT, and MR imaging (T1-weighted images [T1WI], T2-weighted images [T2WI], short inversion time inversion recovery images [STIR]), diffusion-weighted images [DWI], and apparent diffusion coefficient [ADC] mapping). The associations of scintigraphy, CT, and MR imaging findings with MRONJ and ORN were analyzed using the chi-square test with the Pearson exact test.

Results

Thirteen patients with MRONJ and 7 patients with ORN in the mandible showed low signal intensity on T1WI and ADC mapping, high signal intensity on STIR and DWI, and increased uptake on scintigraphy. Periosteal bone proliferation on CT was observed in 69.2% of patients with MRONJ (9 of 13) versus 14.3% of patients with ORN (1 of 7) (P=0.019).

Conclusion

This study presented characteristic imaging findings of MRONJ and ORN on scintigraphy, CT, and MR imaging. Our results suggest that CT can be effective for detecting MRONJ and ORN.

Acute abdominal pain in patients with Crohn's disease: what urgent imaging tests should be done?

Crohn's disease is an autoimmune disease that predominantly affects the gastrointestinal tract. Crohn's disease is diagnosed at a young age and runs a chronic course with acute flare-ups. When patients with Crohn's disease present with flare-ups at the emergency department, they are usually managed in a way similar to patients with acute abdomen; there is no consensus about the most appropriate imaging work-up for patients with flare-ups of Crohn's disease. Thus, we decided to review the literature about the imaging tests indicated (whether related to their diagnostic performance or to lower exposure to ionizing radiation) for acute flare-ups in patients with Crohn's disease.

CT-guided minimally-invasive penile fracture repair

We present the case of a 28 year old patient with an incomplete tear of the tunica albuginea occurred after having sexual intercourse in the female superior position. The diagnostic assessment was performed first clinically, then with CT, owing to its high resolution, allowed to exactly detect the tear location leading to precise preoperative planning. After adequate diagnosis through imaging and proper planning, the patient was performed a selective minimally invasive surgical approach to repair the lesion. The patient had good erection with no angular deformity or plaque formation after a 3-month follow-up.

Impact of 68GA-PSMA PET / CT on treatment of patients with recurrent / metastatic high risk prostate cancer - a multicenter study

Purpose:

The purpose of our study was to evaluate the clinical impact of ⁶⁸Ga-PSMA PET / CT in the setting of biochemical recurrence of prostate cancer.

Materials and Methods:

We retrospectively evaluated 125 prostate cancer patients submitted to the ⁶⁸Ga-PSMA PET / CT due to biochemical recurrence. The parameters age, Gleason score, PSA levels, and the highest SUVmax were correlated to potential treatment changes. The highest SUVmax values were correlated with age and Gleason score. The median follow-up time was 24 months.

Results:

⁶⁸Ga-PSMA PET / CT led to a treatment change in 66 / 104 (63.4%) patients (twenty-one patients were lost to follow-up). There was a significant change of treatment plan in patients with a higher Gleason score (P = 0.0233), higher SUVmax (p = 0.0306) and higher PSA levels (P < 0.0001; median PSA = 2.55 ng / mL).

Conclusion:

⁶⁸Ga-PSMA PET / CT in prostate cancer patients with biochemical recurrence has a high impact in patient management.

Kidney Biopsy-Related Complications in Hospitalized Patients with Acute Kidney Disease

BACKGROUND AND OBJECTIVES

Patients are informed of the risk of kidney biopsy-related complications using data from nonhospitalized patients, which may underestimate the risk for hospitalized patients. We evaluated the rate and risk factors of kidney biopsy-related complications in hospitalized patients with acute kidney disease (AKD) to better estimate the risk in this population.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We used data from the Yale biopsy cohort to evaluate rates of kidney biopsy-related complications including adjudicated procedure-related bleeding requiring blood transfusions or angiographic interventions, medium- or large-sized hematomas, reimaging after biopsy including abdominal ultrasonography or computed tomography, and death in hospitalized patients with AKD (including AKI). We evaluated univariable and multivariable association of risk factors with transfusions. We compared rates of complications between hospitalized and nonhospitalized patients.

RESULTS

Between 2015 and 2017, 159 hospitalized patients underwent a kidney biopsy for AKD evaluation, of which 80 (51%) had stage 1 AKI, 42 (27%) had stage 2 (or higher) AKI, and 27 (17%) had AKD (without AKI). Of these, 12 (8%; 95% confidence interval [95% CI], 5% to 15%) required a transfusion, three (2%; 95% CI, 1% to 5%) required an intervention, 11 (7%; 95% CI, 4% to 12%) had hematoma, and 31 (20%; 95% CI, 14% to 26%) required reimaging after biopsy. Of the four (3%; 95% CI, 1% to 6%) deaths during hospitalization, none were related to the biopsy. Female sex, lower platelet count, and higher BUN were associated with postbiopsy transfusions on univariable and multivariable analyses. Trainee as proceduralist and larger needle gauge were associated with transfusions in univariable, but not multivariable, analysis. Nonhospitalized patients had lower rates of transfusion than hospitalized patients, although the latter also had lower prebiopsy hemoglobin and greater surveillance after biopsy.

CONCLUSIONS

Hospitalized patients experience higher risk of postbiopsy complications than previously reported and several factors, such as lower platelet count, female sex, and higher BUN, are associated with this risk.

Dynamic 11C-Choline PET / CT for the primary diagnosis of prostate cancer

OBJECTIVES

To test the ability of dynamic 11C-PET / CT to discriminate cancerous tissue from background tissue in patients with localized prostate cancer.

MATERIALS AND METHODS

Twenty-four consecutive patients with prostate cancer were prospectively evaluated with dynamic 11C-choline PET / CT prior to radical prostatectomy. The PET / CT scan was divided into 18 sequences of 5 seconds each, followed by 9 sequences of 60 seconds each. Whole-mount sections of harvested prostates served as reference standards. Volumes of interest were positioned on the dynamic PET / CT images and the following quantitative variables were calculated: perfusion coefficient (K1), washout constant (K2), area under the curve (AUC) at 175 and 630 seconds, and average and maximum standardized uptake values (SUVavg, and SUVmax). Wilcoxon signed-ranks test was used to compare benign and cancerous areas of the prostate.

RESULTS

Areas of cancerous tissue were characterized by higher SUVavg and SUVmax than areas of benign tissue (3.67 ± 2.7 vs. 2.08 ± 1.3 and 5.91 ± 4.4 vs. 3.71 ± 3.7, respectively, P < 0.001), in addition to a higher K1 (0.95 ± 0.58 vs. 0.43 ± 0.24, P < 0.001) and greater cumulative tracer uptake, represented by the AUC at 175 and 630 seconds (P <0.001). No associations were found between dynamic parameters and preoperative prostate specific antigen level or Gleason score.

CONCLUSIONS

In this pilot study, 11C-choline PET / CT demonstrated increased tracer uptake with higher values of static and dynamic parameters in areas of prostate cancer compared to areas of benign tissue. Larger studies are warranted to validate these results and examine the potential applicability of 11C-choline dynamic PET / CT for the diagnosis of prostate cancer.

CT texture analysis of pancreatic cancer

OBJECTIVES

We investigated the value of CT texture analysis (CTTA) in predicting prognosis of unresectable pancreatic cancer.

METHODS

Sixty patients with unresectable pancreatic cancers at presentation were enrolled for post-processing with CTTA using commercially available software (TexRAD Ltd, Cambridge, UK). The largest cross-section of the tumour on axial CT was chosen to draw a region-of-interest. CTTA parameters (mean value of positive pixels (MPP), kurtosis, entropy, skewness), arterial and venous invasion, metastatic disease and tumour size were correlated with overall and progression-free survivals.

RESULTS

The median overall and progression-free survivals of cohort were 13.3 and 7.8 months, respectively. On multivariate Cox proportional hazard regression analysis, presence of metastatic disease at presentation had the highest association with overall survival (p = 0.003-0.05) and progression-free survival (p < 0.001 to p = 0.004). MPP at medium spatial filter was significantly associated with poor overall survival (p = 0.04). On Kaplan-Meier survival analysis of CTTA parameters at medium spatial filter, MPP of more than 31.625 and kurtosis of more than 0.565 had significantly worse overall survival (p = 0.036 and 0.028, respectively).

CONCLUSIONS

CTTA features were significantly associated with overall survival in pancreas cancer, particularly in patients with non-metastatic, locally advanced disease.

KEY POINTS

• CT texture analysis is easy to perform on contrast-enhanced CT. • CT texture analysis can determine prognosis in patients with unresectable pancreas cancer. • The best predictors of poor prognosis were high kurtosis and MPP.