Preoperative Computed Tomography Imaging Research Articles

Left bronchial compression after aortic arch reconstruction for coarctation of the aorta.

This study aimed to investigate the preoperative positional relationships between the blood vessels and the left bronchus during the development of left bronchial compression (LBC) after aortic arch reconstruction for coarctation of the aorta (CoA). We retrospectively reviewed data from 29 patients with CoA who underwent aortic arch reconstruction via median sternotomy between 2009 and 2019. The patients were divided into those who underwent aortic arch advancement (AAA) with (C group, six patients) or without (N group, 10 patients) postoperative LBC and those who underwent extended end-to-end anastomosis (E group, 13 patients). We determined the sterno-spinal axis (SSA) of the patients and evaluated the preoperative and postoperative positions of the vessels on the axial and three-dimensional multidetector row computed tomography (CT) angiographic images. The distance between the ascending and descending aortas was significantly smaller in both C and N groups postoperatively than preoperatively. The distance between the descending aorta and SSA in the C group was markedly smaller compared with that in the other groups preoperatively and was increased postoperatively. Preoperatively, the distance from the left bronchus to the aortic arch in the C group was significantly larger than that in the other groups and was decreased postoperatively. The postoperative arch angle in the C group was significantly smaller than that in the other groups. A preoperative midline position of the descending aorta and highly displaced aortic arch in relation to the left bronchus on preoperative CT images could cause the postoperative LBC after AAA.

Computed tomography (CT) characteristics and pathologic basis of ciliated muconodular papillary tumors of the lung.

Ciliated muconodular papillary tumor (CMPT) is a rare pulmonary tumor with papillary architecture. Most studies have focused on the clinicopathological features of CMPT, while computed tomography (CT) characteristics have rarely been systematically described. A cohort of 27 patients with surgically resected CMPT were identified. Clinical and demographic features were recorded. Preoperative CT images of the CMPTs and the corresponding histopathological basis were also retrospectively analyzed. All of the tumors appeared as solitary nodules. Pure ground glass, part-solid nodules and solid nodules were detected in 2/27 (7.4%), 17/27 (63.0%), and 8/27 (29.6%) patients, respectively. Twenty-one tumors (77.8%) were located in the lower lobe. The average tumor size was 1.21±0.74 (range, 0.44-3.46) cm. Eighteen (66.7%) of the 27 patients had tumors with well-defined margins and lobulated contours. Fifteen patients (55.6%) had air bronchograms in the tumor, and 19 patients (70.4%) had air-containing space. There were two patients whose tumor size was enlarged and accompanied by an increase in solid components, and one patient simply had an increase in tumor size at the preoperative follow-up duration. Notably, one patient with solid tumor components was finally diagnosed with CMPT accompanied by adenocarcinoma. CMPTs of the lung mostly manifest as solitary, lobulated, well-defined tumors with air-containing spaces on CT and often occur in the periphery of the pulmonary lower lobe. When CT findings meet these criteria, the possibility of CMPT should be considered. Additionally, CMPT can coexist with adenocarcinoma. Further investigation will contribute significantly to the biological properties of CMPT and its relationship to the potential for malignant transformation.

Hounsfield Unit values on the subchondral bone are related to clinical outcomes in bone marrow stimulation for osteochondral lesions of the talus

BackgroundPoor clinical outcomes in bone marrow stimulation (BMS) for the osteochondral lesion of the talus (OLT) are caused by subchondral bone deterioration. It is reported that microfracture induces endochondral ossification in the subchondral bone, which may affect the subchondral bone condition after BMS. This study analyzed osteosclerotic patterns of the bed in OLTs on computed tomography (CT) images and the relationship between the subchondral bone condition and clinical outcomes of BMS. MethodsSixty-nine ankles in 61 patients with OLT were included. Hounsfield unit (HU) on the bed of OLTs was measured on CT images and the pattern of osteosclerosis or absorption in the bed was analyzed. In these patients, 25 ankles in 24 patients underwent BMS. They were divided into 2 groups according to the presence of bone marrow edema (BME) one year after surgery, and clinical outcomes were compared. ResultsHUs in the anterior region were significantly higher than those of other areas. In patients with BMS, the JSSF scale for BME positive group (88.0 ± 7.7 points) was significantly lower than that for BME negative group (95.0 ± 6.1 points) (p < 0.05) at the final follow-up. On preoperative CT images, HU values of the central region in the BME-positive group were significantly lower than those in the BME-negative group (p < 0.05). ConclusionOsteosclerotic changes in the anterior part of the bed were frequently observed, and BMS for the area with low HU values decreased clinical outcomes. BMS should be performed with attention to subchondral bone condition to obtain good clinical outcomes. Level of evidence4, case series.

Impact of incidental findings in preoperative advanced imaging for total shoulder arthroplasty

BackgroundThe volume of shoulder arthroplasty continues to rise. Computed tomography (CT) is a valuable tool for preoperative planning and has been linked to decreased revision rates in patients undergoing anatomic or reverse total shoulder arthroplasty (TSA). As more patients undergo CT imaging prior to planned arthroplasty, the number of incidental findings (IFs) will likely increase. The purpose of this study was to quantify the frequency of IFs on preoperative shoulder CT scans prior to TSA, describe common IFs, and report the incidence of further medical or imaging evaluation of those findings. A secondary aim was to identify patient characteristics associated with the identification of IFs on preoperative CT imaging prior to TSA. MethodsA retrospective, single-center cohort study of 385 patients undergoing planned TSA between 2018 and 2022 was performed. Patients who underwent a preoperative CT were included. Data were extracted from the electronic medical records for each included patient. Patient factors associated with increased IFs on CT were identified using univariate logistic regression model. A total of 385 patients who underwent 416 anatomic or reverse TSA procedures were included in analysis. Overall, 208 (50.0%) patients were found to have IFs on CT. Pulmonary IFs were the most common type of IF (58.2%). ResultsA total of 57 IFs (27.9%) were deemed actionable and required further evaluation. The most common action performed was a chest CT scan (47.4%). Three patients (5.3%) required further biopsy of IFs, and 4 patients (7.0%) required surgical intervention. Smoking history was significantly associated with both identification of IFs (P = .017) and with that finding being actionable (P = .037). Male gender was associated with a decreased likelihood of actionable IFs (OR = 0.41, P = .004). ConclusionsIFs on preoperative imaging for TSA are common and may require further evaluation. Most IFs are related to pulmonary pathology, and a concern for lung cancer prompted further work-up in some patients. For high-volume TSA centers, it may be beneficial to establish protocols for care based on common IFs.

A computational program for automated surgical planning of fenestrated endovascular repair

An Abdominal Aortic Aneurysm (AAA) is a dilation of the aorta at the level of the abdomen. To reduce the risk of rupture, an endograft is often implanted inside the aneurysm to decrease pressure on the aneurysm sac. To maintain blood flow to major abdominal vessels, a fenestrated endograft can be used, whereby physicians modify commercial endografts by creating fenestrations based on preoperative computed tomography imaging. The manual process of aligning patient-specific visceral anatomy onto endografts can be tedious and subject to human error. Here we developed a computational program, ‘FenFit’, for automated fitting of fenestrations onto commercially available endografts. A pilot clinical study was conducted to evaluate the efficiency of FenFit compared to physician manual planning, showing FenFit can reduce planning time by 62-fold on average. Our program has potential to improve clinical outcomes by providing a user interface that is expeditious and far less susceptible to human error.

Effect of Lower Extremity Torsion on Clinical Outcomes After Medial Patellofemoral Ligament Reconstruction and Tibial Tubercle Transfer for Recurrent Patellofemoral Instability

Background: Increased femoral torsion (FT) or tibial torsion (TT) has been suggested to be a potential risk factor for recurrent patellofemoral instability. However, the influence of increased FT or TT on the postoperative clinical outcomes of recurrent patellofemoral instability has rarely been investigated. Purpose: To assess the effect of increased FT or TT on postoperative results in patients with recurrent patellofemoral instability after combined medial patellofemoral ligament reconstruction (MPFLR) and tibial tubercle transfer, along with the influence of other risk factors. Study Design: Cohort study; Level of evidence, 3. Methods: Out of 91 patients, the study’s analyses included 86 patients with recurrent patellofemoral instability who were treated with MPFLR and tibial tubercle transfer and enrolled between April 2020 and January 2021. FT and TT were assessed using preoperative computed tomography images. According to the torsion value of FT or TT, patients were categorized into 3 groups for each of FT and TT: group A (<20°), group B (20°-30°), and group C (>30°). Patellar height, femoral trochlear dysplasia, and the tibial tuberosity–trochlear groove (TT-TG) distance were also assessed. Patient-reported outcome scores (Tegner, Kujala, International Knee Documentation Committee [IKDC], Lysholm, and Knee injury and Osteoarthritis Outcome Score [KOOS]) were evaluated pre- and postoperatively. Clinical failure of MPFLR was recorded. Subgroup analysis was conducted to evaluate the effect of increased FT or TT on the postoperative outcomes. Results: A total of 86 patients were enrolled with a median follow-up time of 25 months. At the final follow-up, all functional scores improved significantly. Patella alta, high-grade trochlear dysplasia, and increased TT-TG distance did not have any significant effect on the postoperative functional scores. Regarding FT, subgroup analysis indicated that all functional scores of group C were lower than those of groups A and B except the KOOS knee-related Quality of Life score. For TT, group C had lower scores than group A for all functional outcomes except Tegner and KOOS Quality of Life and lower scores than group B for Kujala, IKDC, KOOS (Symptoms and Sport and Recreation subscales), Tegner, and Lysholm scores. The comparison between group A and group B, whether for FT or TT, revealed no significant differences. Conclusion: For patients with recurrent patellofemoral instability, increased lower extremity torsion (FT or TT >30°) was associated with inferior postoperative clinical outcomes after combined MPFLR and tibial tubercle transfer.

Malnutrition defined by GLIM criteria identifies a higher incidence of malnutrition and is associated with pulmonary complications after oesophagogastric cancer surgery, compared to ICD-10-defined malnutrition.

Low muscle mass, measured using computed tomography (CT), is associated with poor surgical outcomes. We aimed to include CT-muscle mass in malnutrition diagnosis using the Global Leadership Initiative on Malnutrition (GLIM) criteria, compare it to the International Classification of Diseases 10th Revision (ICD-10) criteria, and assess the impact on postoperative outcomes after oesophagogastric (OG) cancer surgery. One hundred and eight patients who underwent radical OG cancer surgery and had preoperative abdominal CT imaging were included. GLIM and ICD-10 malnutrition data were assessed against complication and survival outcomes. Low CT-muscle mass was determined using predefined cut-points. GLIM-defined malnutrition prevalence was significantly higher than ICD-10-malnutrition (72.2% vs. 40.7%, p < 0.001). Of the 78 patients with GLIM-defined malnutrition, low muscle mass (84.6%) was the predominant phenotypic criterion. GLIM-defined malnutrition was associated with pneumonia (26.9% vs. 6.7%, p = 0.010) and pleural effusions (12.8% vs. 0%, p = 0.029). Postoperative complications did not correlate with ICD-10 malnutrition. Severe GLIM (HR: 2.51, p = 0.014) and ICD-10 (HR: 2.15, p = 0.039) malnutrition were independently associated with poorer 5-year survival. GLIM criteria appear to identify more malnourished patients and more closely relate to surgical risk than ICD-10 malnutrition, likely due to incorporating objective muscle mass assessment.

Impact of preoperative computed tomography image slice thickness on the planning of deep brain stimulation surgery: A phantom study

BackgroundPreoperative Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) coregistration is often applied to perform deep brain stimulation (DBS) surgeries. Thin sliced (high dose) CT is used and recommended because of the high reported accuracy but there are no comparative studies. Thin sliced CT could lead to a higher radiation exposure for the patient in contrast to thicker sliced CT (low dose) due to a longer scanning time. In this study we investigated if the preoperative CT slice thickness had an effect on the registration accuracy in a preoperative simulated DBS setting. Material and methodsAn implanted phantom, a Citrullus lanatus (watermelon), was used to acquire an MRI data set (2 millimeter (mm) T2) with a fixed reference point. Two observers targeted the reference point independently and they recorded and compared the coordinates, ring, and arc angles from all coregistered series with different CT slice thicknesses of 0.5 mm, 1 mm, 1.5 mm, 2 mm, 3 mm, 4 mm, and 5 mm. Separately, both MRI and CT were used as reference series for coregistration and analysis. Lastly, inter-observer reliability was calculated with Kendall’s coefficient of concordance (W). With W> 0.9 defined as very good. ResultsOur results show no relevant effect on the preoperative registration accuracies for the different CT’s with all absolute differences in mm for the stereotactic coordinates< 0.5 and angles in degrees< 0.4. Additionally, the inter-observer reliability was high (W 0.991). ConclusionWe found no relevant effect of increased slice thickness of preoperative CT on the preoperative registration accuracy in a simulated DBS setting.

P60: The Psoas Muscle Index As A Predictor Of Long-Term Survival After Cardiac Surgery For Hemodialysis-Dependent Patients.

Study: Sarcopenia represented by skeletal muscle depletion has been identified as a useful prognostic tool for patients undergoing major surgeries. However, the impact of sarcopenia in HD-dependent patients undergoing cardiac surgery has not been investigated. We aimed to clarify the association between sarcopenia and outcomes of HD-dependent patients after cardiac surgery. Methods: We retrospectively reviewed 138 HD-dependent patients who underwent cardiac surgery between January 2006 and December 2017. Sarcopenia was assessed using the psoas muscle index (PMI), which was calculated using values measured on preoperative computed tomography images and the following formula: cross-sectional area of bilateral psoas muscle/height2. Patients were divided into two groups according to the PMI: the sarcopenia group (≤443 mm2/m2 for men and ≤326 mm2/ m2 for women; n=35) and the non-sarcopenia group (>443 mm2/m2 for men and >326 mm2/m2 for women; n=103). Preoperative characteristics and surgical outcomes were compared. Results: Overall in-hospital mortality did not differ between the sarcopenia and non-sarcopenia groups. However, the patients with sarcopenia had significantly decreased long-term survival. Multivariate analysis revealed that low PMI was a significant independent predictor of long-term mortality (hazard ratio, 1.92; 95% confidential interval, 1.19–3.17; p<0.01). Conclusion: Long-term survival rates in HD-dependent patients undergoing cardiac surgery are severely affected by the presence of preoperative sarcopenia defined by PMI.Figure 1. Kaplan-Meier curves of long-term survival in the sarcopenia and non-sarcopenia groups.

Update of T-branch use from the US Aortic Research Consortium.

Aortic endograft evolution has altered our approach to treating patients with both standard and complex aortic disease. In particular, fenestrated and branched aortic endografts have allowed for the expansion of therapy to include those patients with extensive thoracoabdominal aortic aneurysms (TAAAs). The fenestrations and branches allow for the aortic endografts to achieve a seal in the proximal and distal aspects of the aorto-iliac tree, to exclude the aneurysm, while maintaining perfusion to the renal and visceral vessels. Historically, many of the grafts used for this purpose are custom made devices designed for a specific patient based on their preoperative computed tomography imaging. One downside to this approach is the time it takes to construct these grafts. Given this, much effort has been directed towards developing "off-the-shelf" grafts which may be applicable to many patients in an immediate-need bases. The Zenith T-Branch device offers an off-the-shelf graft with four directional branches. Its utilization is not applicable to all patients, but can be applied to many patients with TAAAs. Large reported series on outcomes for these devices is limited to centers in Europe as well as within the United States Aortic Research Consortium. While early outcomes appear excellent, long-term outcomes related to aneurysm exclusion, branch patency, and freedom from reintervention are needed and will be forthcoming.

The 'double‑track sign': A novel CT finding suggestive of the diagnosis of T1a gastric cancer.

Effective identification of T1a stage cancer is crucial for planning endoscopic resection for early gastric cancers. The present study aimed to determine the diagnostic value of the double-track sign in patients with T1a gastric cancer using computed tomography (CT) imaging. A total of 152 patients diagnosed with pathologically proven T1a gastric cancer at The First Affiliated Hospital of Zhengzhou University (Zhengzhou, China) between July 2011 and August 2021 were retrospectively reviewed. The control group consisted of 2,926 patients with gastritis. Clinical data, including patient characteristics and preoperative CT imaging findings with gastric morphological features, were reviewed and analyzed. Out of 51 patients with T1a gastric cancer finally included, 31 (60.8%) exhibited local double-track enhancement changes of the stomach, referred to as the 'double-track sign', on CT images. In addition, four patients (7.8%) had well-enhanced mucosal thickening of the gastric wall. Of the 2,926 control subjects, none had any double-track sign and six patients (0.2%) had local gastric wall thickening with abnormally strengthened enhancement. In conclusion, a double-track sign on CT images is beneficial in the diagnostic differentiation of T1a gastric cancer.

Peritumoral Adipose Tissue Density Predicts the Malignancy in cT1 Renal Masses.

Not only the frequency of surgery for small renal masses has increased secondary to the improvements and frequent use of imaging techniques but also the frequency of detection of benign lesions in nephrectomy specimens has increased as well. We aimed to assess the predictive value of computed tomography density of perirenal adipose tissue and peritumoral adipose tissue in distinguishing between benign and malignant renal masses. The current study included 116 patients who underwent nephrectomy for renal masses between January 2015 and December 2020. Clinicodemographic and preoperative computed tomography features and final pathological findings of the patients were recorded. According to the final pathological results, the patients were divided into 2 groups benign (n = 32) and malignant (n = 84). Groups were compared statistically in terms of perirenal adipose tissue and peritumoral adipose tissue density. The median tumor size was 5.00 cm. The rate of benign tumors was higher in female patients (P = .005). The median peritumoral adipose tissue density among cT1 and cT1a tumors was higher in the malignant group (P < .001, for each). At a cutoff value of 97.50 Hounsfield Units, the peritumoral adipose tissue density had a sensitivity of 83.0% and a specificity of 79.2% for predicting the presence of malignant tumors in ≤7 cm renal masses. Using a cutoff value of -97.50 Hounsfield Units, the peritumoral adipose tissue density had a sensitivity of 88.9% and a specificity of 83.3% for predicting the presence of malignant tumors in ≤4 cm renal masses. The peritumoral adipose tissue density in the preoperative computed tomography images predicts the malignancy in cT1 renal masses.

Association of Sarcopenia with a Poor Prognosis and Decreased Tumor-Infiltrating CD8-Positive T Cells in Pancreatic Ductal Adenocarcinoma: A Retrospective Analysis

BackgroundSarcopenia, defined as a loss of skeletal muscle mass and quality, is found in 30–65% of patients with pancreatic ductal adenocarcinoma (PDAC) at diagnosis, and is a poor prognostic factor. However, it is yet to be evaluated why sarcopenia is associated with poor prognosis. Therefore, this study elucidated the tumor characteristics of PDAC with sarcopenia, including driver gene alterations and tumor microenvironment.Patients and MethodsWe retrospectively analyzed 162 patients with PDAC who underwent pancreatic surgery between 2008 and 2017. We defined sarcopenia by measuring the skeletal muscle mass at the L3 level using preoperative computed tomography images and evaluated driver gene alteration (KRAS, TP53, CDKN2A/p16, and SMAD4) and tumor immune (CD4+, CD8+, and FOXP3+) and fibrosis status (stromal collagen).ResultsIn localized-stage PDAC (stage ≤ IIa), overall survival (OS) and recurrence-free survival were significantly shorter in the sarcopenia group than in the non-sarcopenia group (2-year OS 89.7% versus 59.1%, P = 0.03; 2-year RFS 74.9% versus 50.0%, P = 0.02). Multivariate analysis revealed that sarcopenia was an independent poor prognostic factor in localized-stage PDAC. Additionally, tumor-infiltrating CD8+ T cells in the sarcopenia group were significantly less than in the non-sarcopenia group (P = 0.02). However, no difference was observed in driver gene alteration and fib.rotic status. These findings were not observed in advanced-stage PDAC (stage ≥ IIb).ConclusionsSarcopenia was associated with a worse prognosis and decreased tumor-infiltrating CD8+ T cells in localized-stage PDAC. Sarcopenia may worsen a patient’s prognosis by suppressing local tumor immunity.

A new predictor of the optimal pulmonary artery reconstruction method during the arterial switch operation.

To more accurately predict the optimal pulmonary artery (PA) reconstruction procedure (Lecompte manoeuvre or original Jatene procedure) during the arterial switch operation (ASO), we focused on the horizontal sectioning (HS) angle between the left hilum PA and the great arteries using preoperative computed tomography (CT) imaging. We defined the HS angle α (β) as the angle between the tangential line from the posterior (anterior) wall of the left PA at the hilum to the left anterior (right posterior) surface of the main PA and the tangential line from the left surface of the ascending aorta to the left anterior (right posterior) surface of the main PA. We identified 14 consecutive patients diagnosed with transposition of the great arteries (TGA) or TGA-type double-outlet right ventricle who underwent preoperative CT imaging. The original Jatene or Lecompte procedure was used for nine (OJ group) and five (L group) patients. Relationships of the great arteries of the OJ and L groups were side-by-side in eight and two patients, oblique in one and one patient, and anteroposterior in zero and two patients, respectively. In the OJ group, β was greater than α in all patients. The median α/β value was 0.618. In group L, α was greater than β in all patients. The median α/β was 1.307. Left PA stenosis caused by stretching was not observed in the L group. Coronary obstruction was not identified in the OJ group. Left PA stenosis behind the neo-ascending aorta was observed in one patient in the OJ group and required reoperation. The HS angle may be a useful predictor of optimal intraoperative PA reconstruction during ASO, especially for side-by-side or oblique relationships.

Effectiveness of individualized 3D titanium-printed Orthognathic osteotomy guides and custom plates

BackgroundComputer-aided design/manufacturing (CAD/CAM) technology was developed to improve surgical accuracy and minimize errors in surgical planning and orthognathic surgery. However, its accurate implementation during surgery remains a challenge. Hence, we compared the accuracy and stability of conventional orthognathic surgery and the novel modalities, such as virtual simulation and three-dimensional (3D) titanium-printed customized surgical osteotomy guides and plates.MethodsThis prospective study included 12 patients who were willing to undergo orthognathic surgery. The study group consisted of patients who underwent orthognathic two-jaw surgery using 3D-printed patient-specific plates processed by selective laser melting and an osteotomy guide; orthognathic surgery was also performed by the surgeon directly bending the ready-made plate in the control group. Based on the preoperative computed tomography images and intraoral 3D scan data, a 3D virtual surgery plan was implemented in the virtual simulation module, and the surgical guide and bone fixation plate were fabricated. The accuracy and stability were evaluated by comparing the results of the preoperative virtual simulation (T0) to those at 7 days (T1) and 6 months (T2) post-surgery.ResultThe accuracy (ΔT1‒T0) and stability (ΔT2‒T1) measurements, using 11 anatomical references, both demonstrated more accurate results in the study group. The mean difference of accuracy for the study group (0.485 ± 0.280 mm) was significantly lower than in the control group (1.213 ± 0.716 mm) (P < 0.01). The mean operation time (6.83 ± 0.72 h) in the control group was longer than in the study group (5.76 ± 0.43 h) (P < 0.05).ConclusionThis prospective clinical study demonstrated the accuracy, stability, and effectiveness of using virtual preoperative simulation and patient-customized osteotomy guides and plates for orthognathic surgery.

Dorsal Subcutaneous Fat Thickness as a Risk Factor for Pancreatic Fistula After Gastric Cancer Surgery.

Recently, there have been many reports on the use of preoperative body composition analysis to predict postoperative complications in gastric cancer surgery, most of which used 3D image analysis software for the measurements. This study aimed to evaluate the risk of postoperative infectious complications (PICs), especially pancreatic fistulas, using a simple measurement method incorporating only preoperative computed tomography images. A total of 265 patients with gastric cancer underwent laparoscopic or robot-assisted gastrectomy with lymph node dissection at Osaka Metropolitan University Hospital between 2016 and 2020. To simplify the measurement method, we measured the length of each region of the subcutaneous fat area (SFA). Each area included a) umbilical depth, b) thickness of the longest ventral subcutaneous fat, c) thickness of the longest dorsal subcutaneous fat, and d) thickness of the median dorsal subcutaneous fat (MDSF) measurements. PICs occurred in 27 of 265 cases, of which pancreatic fistula was present in 9. SFA for pancreatic fistulas showed high diagnostic accuracy (area under the curve=0.922). Among the subcutaneous fat lengths, the MDSF was the most useful, and the optimal cut-off value was 16 mm. MDSF and non-expert surgeons were found to be independent risk factors for pancreatic fistula. Since the possibility of developing pancreatic fistula is high in cases with MDSF ≥16 mm, careful surgical strategies, such as having a skilled physician, are necessary.

Atlantoaxial Stabilization Using C1 Lateral Mass and C2 Pedicle/Translaminar Screw Fixation by Intraoperative C1- and C2-Direct-Captured Navigation with Preoperative Computed Tomography Images.

In C1-C2 posterior fixation, the C1 lateral mass and C2 pedicle/translaminar screw insertion under spine navigation have been used frequently. To avoid the risk of neurovascular damage in atlantoaxial stabilization, we assessed the safety and effectiveness of a preoperative computed tomography (CT) image-based navigation system with intraoperative independent C1 and C2 vertebral registration. It is ideal when a reference frame can be linked directly to the C1 posterior arch for C1-direct-captured navigation, but there is a mechanical challenge. A new spine clamp-tracker system was implemented recently, which allows reliable C1- and C2- direct-captured navigation in nine patients with traumatic C2 fractures. In this way, there was no misalignment of C1-C2 screws. C1 lateral mass screws were used except for one case, and translaminar screws were primarily used as an anchor for C2. The C1 lateral mass screw locations, which are 19 mm laterally from the C1 posterior arch's center, are taken to be constant. However, there is one unusual circumstance in which using a C1 laminar hook instead of a C1 lateral mass screw appears to be a beneficial substitute. The increase of surgical accuracy for posterior C1-C2 screw fixation without cost constraints is significantly facilitated by intraoperative C1- and C2-direct-captured navigation with preoperative computed CT images.

Does Percutaneous Nephrolithotomy Cause a Local Decrease in Renal Parenchymal Thickness?

Introduction: This study aimed to investigate the effects of PCNL on the renal parenchymal thickness. Materials and Methods: Adult (≥18 years) patients who underwent percutaneous nephrolithotomy (PNL) in Health Sciences University Diskapi Training and Research Hospital between May 2016 and May 2021 constituted the target population of this descriptive study. Patient data were retrospectively reviewed. All patients had preoperative and postoperative sixth-month abdominopelvic computerized tomography (CT) scan images and preoperative and postoperative day 1 blood workup results. Stone surface areas (SSA) and stone densities were measured using preoperative CT scans. The renal parenchymal thickness (RPT) was calculated on preoperative and postoperative CT images. Preoperative and postoperative RPT values were compared. Results: 358 patients (232 men and 126 women) were included. Thirty-two (8.9%) patients had 2 PNL surgeries. Median SSA and stone density were calculated as 566.5 (100-2237) mm2 and 937.5 (304-1474) Hounsfield Units. The mean duration of hospital stay was 4.2±2.1 days. Our analysis revealed a significant reduction in RPT (p&lt;0.001). While the median RPT reduction was 2.5 (0-8) mm in patients who underwent PNL once, it was five (1-12) mm in patients who underwent PNL twice (p&lt;0.05). Correlation analysis revealed no correlation between RPT reduction and duration of hospital stay. Conclusion: A significant decrease in RPT was detected after PNL. No correlation was found between the decrease in renal parenchyma thickness and the length of hospital stay.

Quantitative imaging predicts pancreatic fatty infiltration on routine CT examination

PurposeThe purpose of this study was to assess the performance of quantitative computed tomography (CT) imaging for detecting pancreatic fatty infiltration, using the results of histopathological analysis as reference. Materials and methodsSixty patients who underwent pancreatic surgery for a pancreatic tumor between 2016 and 2019 were retrospectively included. There were 33 women and 27 men with a mean age of 56 ± 12 (SD) years (age range: 18–79 years). Patients with dilatation of the main pancreatic duct, chronic pancreatitis, or preoperative treatment were excluded to prevent any bias in the radiological-pathological correlation. Pancreatic fatty infiltration was recorded at pathology. Pancreatic surface lobularity, pancreatic attenuation, visceral fat area, and subcutaneous fat area were derived from preoperative CT images. The performance for the prediction of fatty infiltration was assessed using area under receiver operating characteristic curve (AUC) and backward binary logistic regression analysis. Results were validated in a separate cohort of 34 patients (17 women; mean age, 50 ± 14 [SD] years; age range: 18–73). ResultsA total of 28/60 (47%) and 17/34 (50%) patients had pancreatic fatty infiltration in the derivation and validation cohorts, respectively. In the derivation cohort, patients with pancreatic fatty infiltration had a significantly higher PSL (P < 0.001) and a lower pancreatic attenuation on both precontrast and portal venous phase images (P = 0.011 and 0.003, respectively), and higher subcutaneous fat area and visceral fat area (P = 0.010 and 0.007, respectively). Multivariable analysis identified pancreatic surface lobularity > 7.6 and pancreatic attenuation on portal venous phase images < 83.5 Hounsfield units as independently associated with fatty infiltration. The combination of these variables resulted in an AUC of 0.85 (95% CI: 0.74–0.95) and 0.83 (95% CI: 0.67–0.99) in the derivation and validation cohorts, respectively. ConclusionCT-based quantitative imaging accurately predicts pancreatic fatty infiltration.

Development and validation of a multiphase CT radiomics nomogram for the preoperative prediction of lymphovascular invasion in patients with gastric cancer

To develop a nomogram to predict lymphovascular invasion (LVI) in gastric cancer by integrating multiphase computed tomography (CT) radiomics and clinical risk factors. One hundred and seventy-two gastric cancer patients (121 training and 51 validation) with preoperative contrast-enhanced CT images and clinicopathological data were collected retrospectively. The clinical risk factors were selected by univariate and multivariate regression analysis. Radiomic features were extracted and selected from the arterial phase (AP), venous phase (VP), and delayed phase (DP) CT images of each patient. Clinical risk factors, radiomic features, and integration of both were used to develop the clinical model, radiomic models, and nomogram, respectively. Radiomic features from AP (n=6), VP (n=6), DP (n=7) CT images and three selected clinical risk factors were used for model development. The nomogram showed better performance than the AP, VP, DP, and clinical models in the training and validation datasets, providing areas under the curves (AUCs) of 0.890 (95% CI: 0.820-0.940) and 0.885 (95% CI:0.765-0.957), respectively. All models indicated good calibration, and decision curve analysis proved that the net benefit of the nomogram was superior to that of the clinical and radiomic models throughout the vast majority of the threshold probabilities. The nomogram integrating multiphase CT radiomics and clinical risk factors showed favourable performance in predicting LVI of gastric cancer, which may benefit clinical practice.