Consecutive CT Scans Research Articles

Preoperative prediction of post hepatectomy liver failure after surgery for hepatocellular carcinoma on CT-scan by machine learning and radiomics analyses.

No instruments are available to predict preoperatively the risk of posthepatectomy liver failure (PHLF) in HCC patients. The aim was to predict the occurrence of PHLF preoperatively by radiomics and clinical data through machine-learning algorithms. Clinical data and 3-phases CT scans were retrospectively collected among 13 Italian centres between 2008 and 2022. Radiomics features were extracted in the non-tumoral liver area. Data were split between training(70%) and test(30%) sets. An oversampling was run(ADASYN) in the training set. Random-Forest(RF), extreme gradient boosting (XGB) and support vector machine (SVM) models were fitted to predict PHLF. Final evaluation of the metrics was run in the test set. The best models were included in an averaging ensemble model (AEM). Five-hundred consecutive preoperative CT scans were collected with the relative clinical data. Of them, 17 (3.4%) experienced a PHLF. Two-hundred sixteen radiomics features per patient were extracted. PCA selected 19 dimensions explaining >75% of the variance. Associated clinical variables were: size, macrovascular invasion, cirrhosis, major resection and MELD score. Data were split in training cohort (70%, n=351) and a test cohort (30%, n=149). The RF model obtained an AUC=89.1%(Spec.=70.1%, Sens.=100%, accuracy=71.1%, PPV=10.4%, NPV=100%). The XGB model showed an AUC=89.4%(Spec.=100%, Sens.=20.0%, Accuracy=97.3%, PPV=20%, NPV=97.3%). The AEM combined the XGB and RF model, obtaining an AUC=90.1%(Spec.=89.5%, Sens.=80.0%, accuracy=89.2%, PPV=21.0%, NPV=99.2%). The AEM obtained the best results in terms of discrimination and true positive identification. This could lead to better define patients fit or unfit for liver resection.

A Multidisciplinary Assessment of Standard Low Dose Versus Ultra-low Dose Chest CT Scans for Pectus Excavatum Imaging

AimEvaluation of ultra-low dose chest CT imaging for the assessment of pectus excavatum severity as determined by pediatric radiologists and pediatric surgeons using Haller (HI) and Correction indices (CI). MethodsA single institution, prospective evaluation of patients being evaluated for pectus excavatum were scanned with a standard low-dose chest CT protocol (CARE) followed by a consecutive ultra-low dose CT scan (ULTRA). 3 surgeons and 4 radiologists were instructed to determine HI and CI in each series. The Intraclass Correlation Coefficient (ICC) was used to calculate the agreement level between CARE and ULTRA. Bland–Altman (BA) and scatter plots were also performed to determine bias of each approach. Results32 patients had CARE and ULTRA consecutively. The ICC for HI demonstrated good reliability with a value of 0.89 and excellent reliability for CI with a value of 0.91. The reliability for HI was greater in the surgeon group (0.89) compared to the radiologist group (0.88). The reliability for CI was greater in the radiologist group (0.92) compared to the surgeon group (0.90). The Bland Altman plots for the HI and CI demonstrate no consistent bias for CARE or ULTRA approach when evaluating HI and CI. ConclusionUltra-low dose CT scan imaging compared to standard low-dose CT appears to be a reliable alternative for evaluating PE severity as assessed by HI and CI. This work supports the evaluation and potential development of a standardized CT imaging protocol capable of reducing radiation exposure without sacrificing imaging for PE patients. Level of Evidence2.

Evaluation of treatment response with serial CT in patients with non-tuberculous mycobacterial pulmonary disease.

In patients with non-tuberculous mycobacterial pulmonary disease (NTM-PD), the response to treatment is evaluated based on microbiological, clinical, and radiological data. However, little is known about the dynamics of CT findings. The aim of this study was to evaluate CT changes in NTM-PD in order to define radiological criteria for treatment success. Retrospective multicenter study (Hannover, Heidelberg, Gauting). Sixty patients with NTM-PD and at least two consecutive CT scans were included. Scoring for NTM-PD was performed by evaluating variables of bronchiectasis, mucus plugging, bronchiolitis, cavities, nodules, and consolidations on an ordinal scale from 0 to 3. Differences between baseline and follow-up were calculated, and patients with/without cultural conversion were compared using the Mann-Whitney U-test. For paired comparison of the two consecutive CT scans the Wilcoxon test was used. Comparing patients with and without culture conversion, there were significant differences in temporal changes of bronchiectasis (p < 0.001), cavities (p = 0.006), bronchiolitis (p < 0.001), consolidations (p = 0.004), and total score (p < 0.001). Nodules showed no significant differences between groups (p = 0.060). The Wilcoxon test showed significant differences between both CTs in patients with a microbiological cure for the total score (p < 0.001), cavities (p = 0.005), bronchiolitis (p < 0.001), and consolidations (p = 0.021) with a decrease after microbiological cure, whereas bronchiectasis (p = 0.102) and nodules (p = 0.18) stayed stable. In the case of persistently positive cultures, there was an increase in the total score (p = 0.010) which was attributable to progressivebronchiectasis (p < 0.001). Cavities, consolidations, and bronchiolitis are useful to assess treatment response, whereas bronchiectasis and nodules may remain stable despite successful treatment. Cavities, consolidations, and bronchiolitis can assess treatment response whereas bronchiectasis and nodules may remain stable despite successful treatment. In persistently positive cultures, bronchiectasis showed an increase over time indicating that NTM-PD is a progressive chronic disease. Little is known about CT changes in nontuberculous mycobacteriapulmonary disease (NTM-PD) and criteria to evaluate treatment response. In the case of culture conversion, cavities and bronchiolitis decreased whereas bronchiectasis and nodules remained stable. Cavities and bronchiolitis can evaluate treatment response in NTM, but bronchiectasis and nodules may persist despite successful treatment.

Role of 3D CT with Humeral Subtraction in Assessing Anteromedial Facet Coronoid Fractures

BackgroundThe anteromedial facet (AMF) of the coronoid is a key structure in resisting varus posteromedial rotatory instability (PMRI) of the elbow. However, not all isolated coronoid fractures involve the AMF and not all fractures involving the AMF are the result of a PMRI mechanism. There is debate regarding the management of isolated coronoid fractures. A reliable method of differentiating this heterogeneous group of isolated coronoid fractures is essential to develop an appropriate management algorithm. The aim of this study was to evaluate the role of additional humeral subtraction 3D images in the detailed assessment of the known radiographic features of AMF fractures with PMRI mechanism. MethodsThree upper extremity fellowship-trained orthopedic surgeons evaluated 32 consecutive CT scans in patients with isolated coronoid fractures, on two occasions separated by at least 5 months. On each occasion, CT scan images were evaluated for fracture morphology and orientation in two rounds. In the first round, the evaluation was made based on all 2D and 3D reconstruction images of the entire elbow; in the second round, the surgeons had access to images from the first round plus 3D reconstruction with humeral subtraction. Statistical analysis to assess agreement amongst the surgeons was performed using the kappa multi-rater analysis. Intraobserver agreement was evaluated using Pearson’s correlation coefficient. ResultsThe addition of the humeral subtraction view significantly improved the interobserver agreement for fracture morphology from 0.28 (95% CI 0.07-0.49) to 0.66 (95% CI 0.46-0.87), p< 0.001; and for orientation from 0.31 (95% CI 0.09-0.52) to 0.54 (95% CI 0.31-0.77), p<0.001. Similarly, the intraobserver Pearson correlation improved from 0.28-0.38 to 0.48-0.76 for fracture morphology, and from 0.36-0.77 to 0.51-0.69 for fracture orientation. Conclusion3D CT reconstruction with humeral subtraction improved surgeons’ ability to characterize radiographic features of AMF coronoid fractures. Future studies are required to determine whether better characterization of the morphology and orientation of AMF fractures allows for the categorization of these fractures into more homogenous groups and the development of more consistent management algorithms.

Influence of weight-adjusted contrast enhancement on computed tomography-derived skeletal muscle measures: a retrospective proof-of-concept comparative study between Danish females and males

BackgroundComputed tomography (CT) has an underutilized potential for evaluating body composition in clinical settings. Often conducted with intravenous contrast (IVC), CT scans yield unused body composition data due to unclear effects on skeletal muscle area (SMA), skeletal muscle index (SMI), and muscle density (SMD). ObjectivesThis study investigates whether weight-adjusted IVC influences SMA, SMI, and SMD differently in females and males compared with noncontrast abdominal CT. In addition, the study explores associations between contrast and noncontrast-assessed SMA, SMI, SMD, and demographic factors. MethodsA comparative observational retrospective study was conducted on Danish patients who underwent consecutive 4-phased contrast-enhanced abdominal CT scans (noncontrast, arterial, venous, and late venous phases). Muscle measures were evaluated using validated semiautomated threshold-based software by 3 independent raters. ResultsThe study included 72 patients (51 males and 21 females) with a mean age of 59 (55 and 62) y. Weight-adjusted IVC increased SMA by ≤3.28 cm2 (95% confidence interval [CI]: 2.58, 3.98) corresponding to 2.4% (1.8, 2.9) in the late venous phase compared with noncontrast CT. Analysis between sexes showed no difference in the effects of IVC on SMA and SMI between females and males. However, females exhibited a higher increase in SMD during the venous by a mean of 1.7 HU (0.9; 2.5) and late venous phases with a mean HU of 1.80 (1.0; 2.6) compared with males. Multivariate regression analysis indicated an association between the differences in SMD and sex during venous (–1.38, 95% CI: –2.48, –0.48) and late venous phases (–1.23, 95% CI: –2.27, –0.19). ConclusionsWeight-adjusted IVC leads to increased SMA, SMI, and SMD. Although SMA and SMI differences were consistent across the sexes, females exhibited a significantly higher SMD increase than males in the venous and late venous phases. Further investigations are necessary to determine the applicability of SMD as a muscle quality proxy in IVC CT scans.

Computed-tomography assessment of the lumbar spine body/canal index and review of the literature

Lumbar spinal stenosis (LSS) involves narrowing of the lumbar spinal space due to various factors. Torg-Pavlov Index measures predict LSS. The objective was to define the mean characteristics of the lumbar spine body/canal index in a Hispanic population stratified by age and sex. A retrospective, observational, transverse, and descriptive study was performed. Imaging studies included consecutive bone window full abdominal CT scans, in adult patients (≥18 years), without evidence of bone disease, musculoskeletal pathology, or traumatic event and a fully visible lumbar spine (L1-L5). The anteroposterior diameter (APD) and midsagittal diameter (MSD) of each vertebral level were measured using the Carestream image reformatting program at each lumbar vertebral level from L1 to L5 of the CT scan. A total of 400 CTs of subjects with a mean age of 47.7±14.8 (range 18-80 years) were evaluated, of which 59.3% (n 237/400) were women. The presence of a ≤0.5 body/canal index was 31.6% (n 126). The MSD/APD lumbar index did not differ significantly between age groups in any of the vertebrae. However, there was a tendency to decrease with age. An mean index higher than 0.5 was the mean found in the patients evaluated where there was no previous data of spinal cord involvement. This study provides an accurate description of the normal morphometric parameters of the lumbar body/canal ratio in a Mexican population to assess clinical scenarios of lumbar spinal stenosis. Few studies evaluate the use of cut-off points to define an LSS.

Postmortem CT analysis of paranasal sinuses using an experimental model of drowning

Fluid-filled paranasal sinuses are suggested to be a valuable tool to distinguish between drowning and non-drowning postmortem, yet the mechanisms governing fluid entry remains unknown. We investigate if fluid-filled paranasal sinuses are caused by a passive influx from submersion or an active aspiration mechanism during drowning. The ovine nasal cavity and maxillary sinuses are remarkably similar anatomically to humans, and have been used for endoscopic surgical training in recent decades. We submerged 15 decapitated ovine heads from agricultural waste at a depth of 2 m in flowing water for 1, 8, and 24 h and 7 days. Paranasal sinuses were CT imaged and compared pre- and post-submersion to non-submerged controls. Furthermore, we examined the paranasal sinuses of a single homicide case of a non-drowned submerged subject. Results demonstrate that fluid passively enters the maxillary sinus postmortem in the non-drowned ovine heads following 1 h of submersion. Fluid volume was independent of submersion time and influenced by time out of water as well as handling, since volume was reduced between consecutive CT scans. In contrast to our hypothesis, the filling of the paranasal sinuses is due to passive influx of fluid from submersion rather than an active aspiration during drowning. The observation that paranasal sinuses were fluid-filled in a single medico-legal case of postmortem submersion supports the finding of passive influx. Consequently, careful interpretation of fluid-filled paranasal sinuses is required when bodies are found in water, as the finding cannot distinguish between postmortem submersion and drowning.

Defining threshold for sagittal correction in lumbar fractures.

Surgical indications for thoraco-lumbar fractures are driven both by neurological status, fractures instability and kyphotic deformity. Regarding kyphotic deformity, an angulation superior to 20° is considered by many surgeons as a surgical indication to reduce the disability induced by post-traumatic kyphosis. However, there is a lack of data reporting the ideal or theoretical lordosis that one must have in a particular lumbar segment on CT-scan. The main goal of this study was to determine the mean value for segmental lumbar lordosis according to pelvic incidence (PI) on a cohort of normal subjects. The consecutive CT-scan of 171 normal adult subjects were retrospectively analyzed. The PI and the segmental lordosis (L4S1, L3L5, L2L4, L3L1, L2T12 and T11-L1) were measured on all CT-scan. The mean values were calculated for the global cohort and a sub-group analysis according to IP ranges (< 45°, 45 < IP < 60° and > 60°) was performed. The mean angular values for the whole cohort were IP: 54, 9°; L4S1: - 38, 1°; L3L5: - 30, 6°; L2L4: - 14, 1°; L1L3: - 4, 9°; T12L2: + 1, 9° and T11L1: + 5, 4°. The segmental values vary significatively with PI ranges, as for L3L5: - 26, 8° (PI < 45°); - 30° (45 < PI < 60°) and - 35, 1° (PI > 60°). These results provide a referential of theoretical values of segmental lordosis according to PI. This abacus may help spinal surgeon in their decision-making process regarding lumbar fractures, to determine the amount of sagittal correction needed, according to the PI range, to be adapted to the sagittal morphology of the patient. III.

Chronological Changes in Sagittal Femoral Bowing after Primary Cementless Total Hip Arthroplasty: A Comparative 3D CT Study.

Little is known about dynamic changes of femoral anatomy after total hip arthroplasty (THA), in particular about sagittal femoral bowing (SFB). A 3D CT study was designed to evaluate the chronological changes of SFB after cementless femoral stem implantation for primary THA. Ten patients who underwent unilateral primary THA with a cementless femoral stem, with 2 consecutive CT scans (extending from the fourth lumbar vertebra to the tibial plateaus), performed before THA and at least 3 years after THA, were enrolled. The 3D models of femurs were created using image segmentation software. Using the two CT scans, SFB values of the proximal and middle thirds were calculated on the replaced and untreated sides by two different observers. Eight anatomical stems and two conical stems were involved. The post-operative CT was performed at an average follow-up of 6.5 years after THA (range: 3-12.5). The measurements performed by the two observers did not differ in the proximal and middle regions. A significant difference between the pre-operative and post-operative SFB compared to the untreated side was found in the proximal femur segment (p = 0.004). Use of a cementless stem in THA induced chronological changes in SFB of the proximal femur, after a minimum timespan of 3 years.

Diagnostic Accuracy and Performance Analysis of a Scanner-Integrated Artificial Intelligence Model for the Detection of Intracranial Hemorrhages in a Traumatology Emergency Department.

Intracranial hemorrhages require an immediate diagnosis to optimize patient management and outcomes, and CT is the modality of choice in the emergency setting. We aimed to evaluate the performance of the first scanner-integrated artificial intelligence algorithm to detect brain hemorrhages in a routine clinical setting. This retrospective study includes 435 consecutive non-contrast head CT scans. Automatic brain hemorrhage detection was calculated as a separate reconstruction job in all cases. The radiological report (RR) was always conducted by a radiology resident and finalized by a senior radiologist. Additionally, a team of two radiologists reviewed the datasets retrospectively, taking additional information like the clinical record, course, and final diagnosis into account. This consensus reading served as a reference. Statistics were carried out for diagnostic accuracy. Brain hemorrhage detection was executed successfully in 432/435 (99%) of patient cases. The AI algorithm and reference standard were consistent in 392 (90.7%) cases. One false-negative case was identified within the 52 positive cases. However, 39 positive detections turned out to be false positives. The diagnostic performance was calculated as a sensitivity of 98.1%, specificity of 89.7%, positive predictive value of 56.7%, and negative predictive value (NPV) of 99.7%. The execution of scanner-integrated AI detection of brain hemorrhages is feasible and robust. The diagnostic accuracy has a high specificity and a very high negative predictive value and sensitivity. However, many false-positive findings resulted in a relatively moderate positive predictive value.

Calcium score of the entire thoracic aorta is an independent predictor of all-cause mortality in patients referred to chest computed tomography.

Thoracic arterial calcifications (TAC) are not routinely reported or quantified in chest CT scans. We aimed to evaluate the association between TAC of the entire thoracic aorta and all-cause mortality (ACM) in patients referred to standard chest CT. A retrospective analysis of consecutive standard chest CT scans (non-gated, non-contrast) for the quantification of TAC, CAC and aortic valve calcification. TAC was divided into 4 sample-derived categories (TAC 1 = 0, TAC 2 = 1-65, TAC 3 = 66-439 and TAC 4 ≥ 440). Data regarding ACM was retrieved from the health care provider database. Multivariate Cox proportional regression models were used to assess associations between the TAC categories and ACM. The study cohort included 415 patients (mean age 67 years, 52% male); 107 ACM events were recorded during a median follow-up of 9 years (inter-quartile range: 7.4-10.4). The rate of ACM was 13%, 25%, 32%, 41% according to TAC category (p < 0.001). The highest TAC category (≥ 440) was a strong and independent predictor of ACM [HR = 1.69 (1.13-2.52; 0.01)] in multivariate analysis. Other independent predictors of ACM included age [HR = 1.07 (1.04-1.10; p < 0.001)], male sex [HR = 2.27 (1.49-3.46; 0.001)] and malignancy [HR = 2.21 (1.49-3.23; < 0.001)]. Severe TAC (≥ 440) was found to be an independent predictor of ACM. Thus, we suggest that documenting and quantifying TAC should be routinely incorporated into standard chest CT reports.

Large variation in radiation dose for routine abdomen CT: reasons for excess and easy tips for reduction

ObjectiveTo characterize the use and impact of radiation dose reduction techniques in actual practice for routine abdomen CT.MethodsWe retrospectively analyzed consecutive routine abdomen CT scans in adults from a large dose registry, contributed by 95 hospitals and imaging facilities. Grouping exams into deciles by, first, patient size, and second, size-adjusted dose length product (DLP), we summarized dose and technical parameters and estimated which parameters contributed most to between-protocols dose variation. Lastly, we modeled the total population dose if all protocols with mean size-adjusted DLP above 433 or 645 mGy-cm were reduced to these thresholds.ResultsA total of 748,846 CTs were performed using 1033 unique protocols. When sorted by patient size, patients with larger abdominal diameters had increased dose and effective mAs (milliampere seconds), even after adjusting for patient size. When sorted by size-adjusted dose, patients in the highest versus the lowest decile in size-adjusted DLP received 6.4 times the average dose (1680 vs 265 mGy-cm) even though diameter was no different (312 vs 309 mm). Effective mAs was 2.1-fold higher, unadjusted CTDIvol 2.9-fold, and phase 2.5-fold for patients in the highest versus lowest size-adjusted DLP decile. There was virtually no change in kV (kilovolt). Automatic exposure control was widely used to modulate mAs, whereas kV modulation was rare. Phase was the strongest driver of between-protocols variation. Broad adoption of optimized protocols could result in total population dose reductions of 18.6–40%.ConclusionThere are large variations in radiation doses for routine abdomen CT unrelated to patient size. Modification of kV and single-phase scanning could result in substantial dose reduction.Clinical relevanceRadiation dose-optimization techniques for routine abdomen CT are routinely under-utilized leading to higher doses than needed. Greater modification of technical parameters and number of phases could result in substantial reduction in radiation exposure to patients.Key Points• Based on an analysis of 748,846 routine abdomen CT scans in adults, radiation doses varied tremendously across patients of the same size and optimization techniques were routinely under-utilized.• The difference in observed dose was due to variation in technical parameters and phase count. Automatic exposure control was commonly used to modify effective mAs, whereas kV was rarely adjusted for patient size. Routine abdomen CT should be performed using a single phase, yet multi-phase was common.• kV modulation by patient size and restriction to a single phase for routine abdomen indications could result in substantial reduction in radiation doses using well-established dose optimization approaches.

Long-Term Follow-Up of Interstitial Lung Abnormality: Implication in Follow-Up Strategy and Risk Thresholds.

Rationale: The optimal follow-up computed tomography (CT) interval for detecting the progression of interstitial lung abnormality (ILA) is unknown. Objectives: To identify optimal follow-up strategies and extent thresholds on CT relevant to outcomes. Methods: This retrospective study included self-referred screening participants aged 50 years or older, including nonsmokers, who had imaging findings relevant to ILA on chest CT scans. Consecutive CT scans were evaluated to determine the dates of the initial CT showing ILA and the CT showing progression. Deep learning-based ILA quantification was performed. Cox regression was used to identify risk factors for the time to ILA progression and progression to usual interstitial pneumonia (UIP). Measurements and Main Results: Of the 305 participants with a median follow-up duration of 11.3 years (interquartile range, 8.4-14.3 yr), 239 (78.4%) had ILA on at least one CT scan. In participants with serial follow-up CT studies, ILA progression was observed in 80.5% (161 of 200), and progression to UIP was observed in 17.3% (31 of 179), with median times to progression of 3.2 years (95% confidence interval [CI], 3.0-3.4 yr) and 11.8 years (95% CI, 10.8-13.0 yr), respectively. The extent of fibrosis on CT was an independent risk factor for ILA progression (hazard ratio, 1.12 [95% CI, 1.02-1.23]) and progression to UIP (hazard ratio, 1.39 [95% CI, 1.07-1.80]). Risk groups based on honeycombing and extent of fibrosis (1% in the whole lung or 5% per lung zone) showed significant differences in 10-year overall survival (P = 0.02). Conclusions: For individuals with initially detected ILA, follow-up CT at 3-year intervals may be appropriate to monitor radiologic progression; however, those at high risk of adverse outcomes on the basis of the quantified extent of fibrotic ILA and the presence of honeycombing may benefit from shortening the interval for follow-up scans.

Salvage surgery for local recurrences after stereotactic ablative radiotherapy of colorectal pulmonary metastases.

Local control following stereotactic ablative radiotherapy (SABR) for patients with colorectal pulmonary metastases is reportedly lower than for metastases from other tumors. Such recurrences may still be amenable to salvage therapy. We describe our experience with salvage surgery in 17 patients. Patients who underwent salvage metastasectomy for a local recurrence following SABR for colorectal pulmonary metastases were identified from the surgical institutional databases of three Dutch major referral hospitals. Kaplan-Meier survival analysis was performed to determine survival. Seventeen patients underwent 20 salvage resections for local recurrence of colorectal pulmonary metastases. All patients had a progressive lesion on consecutive CT scans, with local uptake on 18 fluorodeoxyglucose-positron emission tomography computed tomography (FDG-PET CT), and were discussed in a thoracic oncology tumor board. Median time to local recurrence following SABR was 20 months (interquartile range [IQR]: 13-29). Fourteen procedures were performed minimally invasively. Extensive adhesions were observed during three procedures. A Clavien-Dindo grade III-IV complication occurred after four resections (20%). The 90-day mortality was 0%. The estimated median overall survival and progression-free survival following salvage resection were 71 months (confidence intervals [CI]: 50-92) and 39 months (CI: 19-58), respectively. Salvage resections were significantly more extensive, compared to the potential resection assessed on pre-SABR imaging. Our experience with 20 salvage pulmonary metastasectomy procedures for local recurrences following SABR in colorectal cancer patients demonstrates that salvage resection is a feasible option with acceptable morbidity and good oncological outcome in a highly selected cohort.

A quantitative CT analysis of fibula inlayed in a massive allograft for femoral diaphysis reconstruction

IntroductionIn diaphyseal reconstructions for bone tumor resection, massive bone allografts (MBA) are historically regarded as the gold standard. However, these are not without complications, and they present an elevated risk of infection, nonunion and structural failure that increases over time as the graft remains largely avascular. To counteract this disadvantage, a combination of allograft with a vascularized fibula has been proposed. The aim of our study was to objectively review the results of combined vascularized fibula-allograft constructs compared to plain allograft reconstruction for bone defects in tumor patients and to assess fibular vitality predictive factors from imaging studies. Materials and methodsOur data was retrospectively reviewed for patients with femoral diaphysis reconstructions in the past ten years. Ten patients (six males and four females) with a mean average follow-up time of 43.80 months (range 20–83, SD 18.17) with combined graft (Group A) were included in the study. As a control group 11 patients (six males and five females) with a mean average follow-up of 56.91 months (range 7–118, SD 41.33) with a simple allograft reconstruction were analyzed (Group B). Demographic and surgical data, adjuvant therapy as well as complications were analyzed in both groups. Both groups were assessed with plain radiographs for bony fusion at the osteotomy sites. Patients in “Group A” had consecutive CT scans at 6 months and then annually to check for potential bone stock and bone density changes. We analyzed total bone density as well as incremental changes in three different areas of the reconstruction. This was done at two defined levels for each patient. Only patients with at least two consecutive CT scans were included in the study. ResultsThere were no statistical differences between the groups in terms of demographics, diagnosis or adjuvant therapy (p = 1.0). The mean average surgical time (599.44 vs 229.09) and mean average blood loss (1855.56 ml vs. 804.55 ml) were significantly higher in the combined graft group A (p < 0.001 and p = 0.01, respectively). The mean average length of resection (19.95 cm vs. 15.50 cm) was higher in the combined graft group (p = 0.04). The risk for non-union and infectious complication was higher in the allograft group, however, the difference was not significant (p = 0.09 and p = 0.66, respectively). The mean average time to union at junction sites was 4.71 months (range 2.5–6.0, SD 1.19) for cases of successful fibula transfer, 19.50 months (range 5.5–29.5, SD 12.49) for the three cases where we presumed the fibula was not viable and 18.85 months (range 9–60, SD 11.99) for the allograft group. The difference in healing time was statistically significant (p = 0.009). There were four cases of non-union in the allograft group.Seven out of ten patients in Group A exhibited incremental changes in all CT scan measured values. This difference was statistically significant already at 18 months from the index surgery (p = 0.008). The patients with a non-viable fibula had a smaller increase in the percentage of total bone density area measured in the CT scan compared to those patients with a successful fibula transfer (4.33, SD 2.52 vs. 52.29, SD 22.74, p = 0.008). The average bone density incremental increase in-between the fibula and allograft was different among patients with an unsuccessful fibula transfer (32.22, SD 10.41) and the ones with a viable fibula (288.00, SD123.74, p = 0.009). Bony bridges were observed in six cases of viable fibula and in none of the tree presumably dead fibulas (p = 0.03). The mean average MSTS score was higher for the subgroup of successful fibular transfer (26.7/30, SD 2.87) when compared to the group of non-viable fibular graft (17.00/30, SD 6.08) and this was also statistically significant (p = 0–007). ConclusionA viable fibula enhances incorporation of the allograft and decreases the risk for both structural failure as well as infectious complications. Viable fibula also contributes to better functional status of the recipient. Consecutive CT scans proved to be a reliable method for assessing fibular vitality. When no measurable changes are present at 18-month follow-up, we can declare the transfer unsuccessful with a good amount of certainty. These reconstructions behave as simple allograft reconstructions with analogue risk factors. The presence of either axial bridges between the fibula and allograft or newly formed bone on the inner surface of the allograft is indicative of a successful fibular transfer. The success rate of fibular transfer in our study was only 70% and skeletally mature and taller patients seem to be at increased risk for failure. The longer surgical times and donor site morbidity therefore warrant stricter indications for this procedure.

Longitudinal lung cancer prediction convolutional neural network model improves the classification of indeterminate pulmonary nodules

A deep learning model (LCP CNN) for the stratification of indeterminate pulmonary nodules (IPNs) demonstrated better discrimination than commonly used clinical prediction models. However, the LCP CNN score is based on a single timepoint that ignores longitudinal information when prior imaging studies are available. Clinically, IPNs are often followed over time and temporal trends in nodule size or morphology inform management. In this study we investigated whether the change in LCP CNN scores over time was different between benign and malignant nodules. This study used a prospective-specimen collection, retrospective-blinded-evaluation (PRoBE) design. Subjects with incidentally or screening detected IPNs 6–30 mm in diameter with at least 3 consecutive CT scans prior to diagnosis (slice thickness ≤ 1.5 mm) with the same nodule present were included. Disease outcome was adjudicated by biopsy-proven malignancy, biopsy-proven benign disease and absence of growth on at least 2-year imaging follow-up. Lung nodules were analyzed using the Optellum LCP CNN model. Investigators performing image analysis were blinded to all clinical data. The LCP CNN score was determined for 48 benign and 32 malignant nodules. There was no significant difference in the initial LCP CNN score between benign and malignant nodules. Overall, the LCP CNN scores of benign nodules remained relatively stable over time while that of malignant nodules continued to increase over time. The difference in these two trends was statistically significant. We also developed a joint model that incorporates longitudinal LCP CNN scores to predict future probability of cancer. Malignant and benign nodules appear to have distinctive trends in LCP CNN score over time. This suggests that longitudinal modeling may improve radiomic prediction of lung cancer over current models. Additional studies are needed to validate these early findings.

Evaluation of the Normal Craniocervical Junction Craniometry in 137 Asymptomatic Patients

To our best knowledge, most of the craniometric studies on the normal craniocervical junction (CCJ), are still poorly studied and based on measurements taken from plain radiographs. In this study, the authors conducted a craniometric evaluation of the CCJ in a population without known CCJ abnormalities. The purpose of the study was to assess the normal CCJ craniometry based on measures obtained from CT scans. The authors examined 137 consecutive CCJ CT scans obtained in patients evaluated at their hospital for treatment of non-CCJ conditions between 2018 and 2019. Twelve craniometrical dimensions were conducted, including the relation of the odontoid with the cranial base, the atlantodental interval (ADI), the clivus length, and the clivus-canal angle (CCA).

Standardized Reporting on the Preoperative CT Assessment of Potential Living Renal Transplant Donors: Can We Create a Universal Report Standard to Meet the Needs of Transplant Urologists?

Purpose: Determine whether standardized template reporting for the preoperative assessment of potential living renal transplant donors improves the comprehensiveness of radiology reports to meet the needs of urologists performing renal transplants. Methods: Urologist and radiologist stakeholders from renal transplant centres in our province ratified a standardized reporting template for evaluation of potential renal donors. Three centres (A, B, and C) were designated "intervention" groups. Centre D was the control group, given employment of a site-specific standardized template prior to study commencement. Up to 100 consecutive CT scan reports per centre, pre- and post-implementation of standardized reporting, were evaluated for reporting specific outcome measures. Results: At baseline, all intervention groups demonstrated poor reporting of urologist-desired outcome measures. Centre A discussed 5/13 variables (38%), Centre B discussed 6/13 variables (46%), and Centre C only discussed 1/13 variables (8%) with ≥90% reliability. The control group exhibited consistent reporting, with 11/13 variables (85%) reported at ≥90% reliability. All institutions in the intervention group exhibited excellent compliance to structured reporting post-template implementation (Centres A = 95%, B = 100%, and C = 77%, respectively). Additionally, all intervention centres demonstrated a significant improvement in the comprehensiveness of reports post-template implementation, with statistically significant increases in the reporting of all variables under-reported at baseline (P > .01). Conclusion: Standardized templates across our province for CT scans of potential renal donors promote completeness of reports. Radiologists can reliably provide our surgical colleagues with needed preoperative anatomy and incidental findings, helping to determine suitable transplant donors and reduce potential complications associated with organ retrieval.

Appendiceal wall thickness and Alvarado score are predictive of acute appendicitis in the patients with equivocal computed tomography findings

Around 8–13% of the patients who underwent CT scan for diagnosis of appendicitis had equivocal CT results. About one-third of these patients had acute appendicitis and this caused diagnostic challenge to the clinicians. This study was conducted to identify clinical and imaging features that were predictive of acute appendicitis in patients who had equivocal CT findings. During January 2015 to June 2021, we retrospectively included 103 consecutive CT scans of adult patients (22 men and 81 women; mean age, 39.1 ± 17.5 years) who had equivocal CT findings of acute appendicitis. Two readers, blinded to the clinical data, independently assessed CT images for the relevant CT findings of appendicitis. Any disagreement between the readers was solved by consensus. The clinical parameters and CT findings were analyzed and compared between the patients who had appendicitis and patients who did not have appendicitis. Thirty-one (30.1%) patients had appendicitis, all of which were non-complicated. The appendiceal wall thickness of ≥ 2 mm and the Alvarado score of ≥ 7 were independent predictors of appendicitis with adjusted odds ratios (ORs) of 2.76 (95% CI, 1.09–7.02) and 1.47 (95% CI, 1.12–1.94), respectively. The maximal appendiceal diameter was higher in the appendicitis group (7.2 ± 1.2 mm vs. 6.5 ± 1.0 mm), but not predictive of appendicitis. The rest of the clinical parameters and CT findings, including mucosal hyperenhancement, periappendiceal fat reticulation, thickening of peritoneal reflection, appendicolith, focal cecal thickening, and content in appendiceal lumen showed no significant difference between two groups. The appendiceal wall thickness and the Alvarado score were able to predict appendicitis in patients who had equivocal CT findings.

Differentiation of Intracerebral Tumor Entities with Quantitative Contrast Attenuation and Iodine Mapping in Dual-Layer Computed Tomography.

Purpose: To investigate if quantitative contrast enhancement and iodine mapping of common brain tumor (BT) entities may correctly differentiate between tumor etiologies in standardized stereotactic CT protocols. Material and Methods: A retrospective monocentric study of 139 consecutive standardized dual-layer dual-energy CT (dlDECT) scans conducted prior to the stereotactic needle biopsy of untreated primary brain tumor lesions. Attenuation of contrast-enhancing BT was derived from polyenergetic images as well as spectral iodine density maps (IDM) and their contrast-to-noise-ratios (CNR) were determined using ROI measures in contrast-enhancing BT and healthy contralateral white matter. The measures were correlated to histopathology regarding tumor entity, isocitrate dehydrogenase (IDH) and MGMT mutation status. Results: The cohort included 52 female and 76 male patients, mean age of 59.4 (±17.1) years. Brain lymphomas showed the highest attenuation (IDM CNR 3.28 ± 1,23), significantly higher than glioblastoma (2.37 ± 1.55, p < 0.005) and metastases (1.95 ± 1.14, p < 0.02), while the differences between glioblastomas and metastases were not significant. These strongly enhancing lesions differed from oligodendroglioma and astrocytoma (Grade II and III) that showed IDM CNR in the range of 1.22–1.27 (±0.45–0.82). Conventional attenuation measurements in DLCT data performed equally or slightly superior to iodine density measurements. Conclusion: Quantitative attenuation and iodine density measurements of contrast-enhancing brain tumors are feasible imaging biomarkers for the discrimination of cerebral tumor lesions but not specifically for single tumor entities. CNR based on simple HU measurements performed equally or slightly superior to iodine quantification.