Computed Tomogram Research Articles

ОБОСНОВАНИЕ ПОДБОРА ВНУТРИКОСТНОГО ФИКСАТОРА И ТОЧКИ ЕГО ВВЕДЕНИЯ ПРИ ОСТЕОСИНТЕЗЕ МЫЩЕЛКОВОГО ОТРОСТКА НИЖНЕЙ ЧЕЛЮСТИ

This article observes the anatomical subtleties of the structure of the condylar process, branch and angle of the mandible. A retrospective study of 141 cone-beam computer tomograms of patients aged 3 to 72 years old was conducted in the period from 2014 to 2019. Among the patients who underwent CBCT were 105 adults and 36 children. The following parameters were studied: the length of the mandible branch, the presence of a bend of the mandible branch in its lower part outward at the level of tuberositas masseterica and anteriorly from it, the linear dimensions of the spongy substance in the neck of the condylar process of the mandible. All parameters were determined on both sides of the jaw. CBCT was performed on a panoramic X-ray dental device with a Gendex CB-50 tomography function. The tomograms were performed according to the standard procedure. Calculations of computer tomograms were carried out in the I-CATVision program. Statistical methods were used using Microsoft Excel 2010 to process the array of data obtained. Due to the analysis of tomograms, the linear dimensions of the spongy substance in the neck of the condyle process were determined. The nuances of the structure of the posterior part of the lower jaw body are described. Taking into account these data, the technique of intraosseous osteosynthesis of the condyle of the mandible is justified.

Features of the anatomical structure of the wedge-shaped sinus in various age periods in children and in adolescence

The possibility of morphometric variability of parameters and variant anatomy of the sphenoid sinus at different age periods in children and adolescents was considered based on computed tomography data. Further, 425 computer tomograms of the head area of children and young people between the ages of 1 and 21 years, regardless of sex, were studied. According to the accepted age periodization, the studied material was divided into six age periods. The development of pneumatization of the sinuses is detected at the age of 11.5 years and continues in adolescence. The shape of the sinuses changes with age accordingly with increase in its pneumatization: in 11.5 and 23 years, the sphenoid sinus has only a precellular shape and in adolescence, the post-cellular shape prevails. The linear parameters of sphenoid sinus are minimal at 11.5 years (height, 1.7 mm; width, 1.7 mm; length, 1,3 mm) and 23 years (height, 6.7 mm; width, 5 mm; length, 5.1 mm). The sinus significantly grows in all directions at age 47. Hyperpneumatization of sphenoid sinuses with formation of side pockets is defined from 47 years in four variants: 1, maxillary; 2, lower-sided; 3, rostral; and 4, wing-shaped. In adolescence, there are all pockets of sphenoid sinuses, which are described in the manuals. The frequency of occurrence of intra-sinus septum increases with age; in almost all cases, incomplete bone intra-sinus septum is found. Onodi cells are found in almost each age group; their presence does not depend on the age of the child. If they are present, the spread of pneumatization of the lattice maze into adjacent surrounding anatomical structures is noted. When planning endonasal surgery on the sphenoid sinus in children and adolescents, the morphometric anatomy of the nasal cavity, variant anatomy of the structure of the sphenoid sinuses, and nearby structures of the inner base of the skull should be studied in detail.

Correcting for distal femoral asymmetry is necessary to determine postoperative alignment deviations from planned alignment of the femoral component

BackgroundOne method for assessing the accuracy of manual, patient-specific, navigational, and robotic-assisted total knee arthroplasty (TKA) instrumentation is to use a post-operative computer tomogram and determine the deviation of the femoral component alignment relative to the planned alignment in the native (i.e. healthy) contralateral distal femoral epiphysis. However, side-to-side asymmetry might introduce errors which inflate alignment deviations. This study quantified asymmetry in the distal femoral epiphysis. MethodsHigh resolution CT images (0.5 mm slice thickness) were acquired from bilateral lower limb specimens of 13 skeletally mature subjects with no skeletal abnormalities. Images were segmented to generate 3D femur models. Asymmetry was quantified by differences in positions and orientations required to shape-match the distal epiphysis of the mirror 3D femur model to the distal epiphysis of the contralateral 3D femur model. ResultsAsymmetry was due to random rather than systematic differences. Random differences (i.e. standard deviations) in proximal–distal (P-D) and anterior-posterior (A-P) positions were 1.1 mm and in varus-valgus (V-V) and internal-external (I-E) orientations were 0.9° and 1.3°, respectively. These represented substantial relative errors of up to 50 % in previously reported overall alignment deviations. ConclusionsAlthough small in an absolute sense, asymmetry of the distal femur epiphysis introduced substantial relative errors when assessing accuracy of femoral component alignment in TKA. When post-operative computer tomograms are used to assess the accuracy of manual, patient specific, navigational, and robotic-assisted TKA instrumentation, the overall deviation should be corrected for asymmetry to better indicate the accuracy of the surgical technique.

Identification of Clinically Insignificant Renal Calculi on Sonography

To determine factors predicting if a radiologists... report of a ..stone... on ultrasound (US) was not actually a clinically significant stone, based on subsequent computed tomogram (CT). US often overestimates stone size and various pathologic entities are also hyperechoic;.ßthus, a subsequent CT without a clinically significant stone may represent unnecessary radiation exposure. A decision-tree and nomogram were developed to predict when stones are unlikely on subsequent CT. Retrospective analysis of patients, of any age, receiving CT within 24.ßhours of a sonographic report documenting a single renal stone, during 2019...2020, in any phase of care, at one institution. Novel stone-likelihood-systems for US and CT (US-SLS, CT-SLS) were devised and validated to classify stones as clinically significant or insignificant, with CT as the gold standard. Binomial logistic regression predicting clinically significant stones was performed with sonographic and patient characteristics. Eight hundred twenty patients had US followed by CT, 228 (27.8%) reported documented stones, 140 (17.1%) reported a single stone. Clinically significant stones were associated with larger stone size (P: .002), location (P: .002), hydronephrosis (P: .04), shadowing-artifact (P: .02) depth.ßto.ßstone (P: .008), and Body mass Index (BMI) (P: .01). US-SLS had higher sensitivity (95.4%) and negative-predictive-value (81.8%) compared to a multivariate model of significant variables. US-SLS appears to exclude clinically irrelevant ..stones... better than established criteria including twinkle or shadow in this retrospective analysis. A diagnostic algorithm and nomogram are presented. US-SLS and the associated decision tree can assist providers in avoiding unnecessary radiation when clinically significant stones are unlikely.

THE POSITION OF THE TONGUE AND VOLUME OF THE UPPER RESPIRATORY TRACT IN PATIENTS WITH MALOCCLUSION

This study is a fragment of the planned research work "Features of rehabilitation of orthodontic patients in various ages" state registration No. 022U201229.
 Malocclusion and functional disorders that accompany them are not only a health problem, but also a rather important aspect in the process of personality formation and adaptation in society. To increase the effectiveness at the beginning of orthodontic treatment and stability in the retention period, it is important to take into account the etiological factor that led to the occurrence of malocclusion.
 In order to study and evaluate the position of the tongue in patients with malocclusion, to identify the influence and relationship on the patency of the upper respiratory tract, the volume of the oropharyngeal area was measured according to the McNamara’s method, the size and position of the tongue on cone-beam computer tomograms of orthodontic patients on the Donders’s residual space.
 The average indicators of the volume of the upper respiratory tract in patients with class I are 10.103±1.27 cm3, in patients with class II by 0.8 cm3 less 9.3±0.706 cm3.
 In patients with class I, the average parameters of the space of Donders are 4.4379±0.8077 mm. In patients with class II, the average values were lower 2.6667±0.3609 mm (р˂0.5). The distribution of patients by gender shows that in men the position of the tongue (space of Donders) had average indicators of 2.411±0.318 mm, in women the average indicators were almost 2 times higher and amounted to 4.603±0.754 mm, which is typical for the displacement of the tongue to the bottom, i.e. lower position of the tongue (р˂0.01). That is, the volume of the respiratory tract depends on the skeletal structure of the pathology, in other words, the morphology of the thoracic duct in the sagittal plane.
 Cephalometric analysis of the interaction of the airways and the tongue in orthodontic patients on TRG is quite limited compared to the CBCT image, as the CBCT enables a three-dimensional study of the shape and volume of the upper respiratory tract, the position of the tongue at rest.
 The position of the tongue has a rather insignificant effect on the type of malocclusion in the sagittal plane, but it has a rather large effect on the formation of the pathology in the vertical plane, which is the subject of research in future works.

Possibilities of CT angiography of the inferior mesenteric artery in planning resections of the left half of the colon in patients with colorectal cancer

During laparoscopic surgery for colorectal cancer, vascular structures may be incorrectly identified and damaged due to ignorance of the variant anatomy of the inferior mesenteric artery (IMA), lack of tactile sensations, narrowed field of vision, which leads to complications such as massive bleeding and intestinal ischemia. Therefore, the preoperative study of the variant anatomy of the IMA is of paramount importance. Knowing the variant anatomy of the vessels before surgery, you can make an operation plan in advance, which will ensure fast and safe vascular ligation at the required level and lymph dissection.Aim: To develop a classification of IMA variability for practical use in operations for colorectal cancer. Optimize the standard abdominal scanning protocol to improve the accuracy of MSCT and the best visualization of the IMA and its branches.Material and methods. From February 2013 to March 2022, 214 computed tomograms (CT) of abdominal organs with intravenous contrast were analyzed. We studied the variant anatomy of the IMA. The abdominal cavity scanning protocol was optimized using a 100 kV tube voltage, the contrast density of the NBA and its branches was compared using standard and optimized scanning protocols during a retrospective analysis of 105 CT studies of abdominal organs.Results. We proposed the classification of structure of the IMA and its branches. This is especially important when the safe lymph node dissection along the IMA is necessary. I type – several colonic branches derivate from the IMA by independent trunks (54%); II type – all colon branches derivate from the IMA in one point like a “goose paw” (25%); III type – one colon branch departs from the IMA by a single trunk; then it divides into colonic branches (21%).The accuracy of MSCT of the abdominal organs with intravenous contrast, which was determined by comparing the results of studies with intraoperative data, was 97.9%. The sensitivity of the method is 95.8%, the specificity of the method is 100%.The use of a scanning protocol with a tube voltage of 100 kV makes it possible to simplify and speed up the determination of the anatomical type of structure, improve the visualization of the IMA and its branches.Conclusion. CT with 3D-reconstruction of vessels allows the surgeon to perform an extended LND for colorectal cancer with a minimal risk of complications.

The Sonographer’s Role in Assessing Celiac Artery Stenosis, to Confirm the Diagnosis: A Case Study

Celiac artery stenosis may occur in patients with a known history of atherosclerosis and should also be considered in those who present with abdominal pain. Sonography is specific and necessary when the information is correlated with a computed tomogram (CT), as it helps to determine patency and velocity within mesenteric vessels. When stenosis is severe, chronic mesenteric ischemia results, as vascular perfusion is diminished to the intestinal organs. In the case presented with severe atherosclerosis, both CT and sonography were helpful in confirming the diagnosis. Sonography can help in evaluating celiac artery stenosis, caused by atherosclerosis versus median arcuate ligament syndrome, by considering the normal velocities of the vessel.

Feasibility of intrathecal therapeutic injections in spinal muscular atrophy patients via a percutaneous transsacral hiatus route: An initial neuroimaging morphometric study.

Standard fluoroscopic lumbar puncture (LP) can be impossible in patients with severe spinal deformities from spinal muscular atrophy (SMA) who require intrathecal nusinersen therapy. There usually exists a straight trajectory in the lower sacral canal (SC) that could allow image-guided percutaneous transsacral hiatus puncture of the lumbosacral dural sac. In this study we determine whether sacra are comparatively straighter in SMA patients (SMAps) vs healthy controls (HCs), which may facilitate unhindered transsacral hiatus spinal needle insertion for intrathecal nusinersen therapy. We retrospectively analyzed lumbosacral spine computed tomograms (CTs) or CT-myelogram images of 38 SMAps and age- and sex-matched HCs. We digitally measured ventrodorsal sacral curvatures, SC surface areas, dural sac termination levels, and distances from sacral hiatus to the most caudad aspects of dural sacs ("needle distance"). Mean ages of HCs and SMAps were 32.7 and 31.7 years, respectively, with dural sacs terminating at similar levels. Mean values for morphometrics were: (a) midsagittal SC surface area for HCs=701.2 mm2 , and for SMAps=601.5 mm2 (not statistically significant [ns]); (b) using a "line method," sacral curvature for HCs=61.9°, and SMAp=35.7° (P= .0009), and was similar when using an "angle summation method"; (c) width of sacral hiatus for HCs=14.9 mm, and SMAps=15.0 mm (ns); and (d) "needle distance" for HCs=54.7 mm, and SMAps=49.9 mm (ns). SMAps have significantly straighter sacra compared with HCs, which theoretically renders them more amenable to percutaneous transsacral hiatus puncture of the dural sac.

Oxalate Nephropathy.

Oxalate Nephropathy.

A computed tomographic evaluation of femoral and tibial rotational reference axes in total knee arthroplasty

The surgical trans epicondylar axis (sTEA) is considered the gold standard for optimum rotation of the femoral component; however, no consensus exists on tibial component positioning. The objectives of this study were to determine the relationship of sTEA to various femoral and tibial reference axes in varus osteoarthritis (OA) knees and (ii) to study the intra-observer and inter-observer variability of the axis relationships. The study was done on preoperative computerised tomogram (CT) scans of 110 varus knees to assess the rotational relationships respectively of femoral side sTEA with whitesides line (WSL), posterior condylar axis (PCA), clinical trans epicondylar axis (cTEA) and on the tibial side sTEA with posterior tibial margin (PTM), anterior condylar axis (ACA), Akagi's line and line from the geometric centre of the tibial plateau to 1/3rd tibial tubercle (line GC 1/3rd TT). On the femoral side the mean angles of sTEA with WSL, PCA, cTEA were 95.64°±2.85°, 1.77°±1.88°, 4.19°±0.99° respectively. On the tibial side, the mean angles of sTEA with, PTM, ACA, Akagi's line, and line GC 1/3rd TT were 1.10°±4.69°, 11.98°±4.51°, 2.43°±4.35°, 16.04°±5.93° respectively. Contrary to the generalization, TEA has variable relationships. The surgical trans epicondylar axis was not at the assumed 3° of external rotation to PCA in 85% of knees, nor perpendicular to WSL in >95%of knees. Of the four tibial axes, Akagi's line was the least variable with sTEA. Furthermore, surgeons should also be aware of the multiple reference axes and the range of deviation from sTEA to optimize the rotational alignment of components.

Підвищення якості діагностики зубощелепних деформацій на фоні хронічних звичок

The aim of the study. Improving the effectiveness of the diagnosis of maxillomandibular anomalies among the patients with pathological occlusion, existing bad habits is relevant due to the spread of social stress among young people and the search for its compensation through the development of bad habits. Research methods. We conducted clinical and radiological methods of examination of 60 patients aged 15–17 with acquired maxillomandibular anomalies, deformities, and 15 people in the comparison group. We studied the data of computer tomograms, performed stereotopometric analysis (threedimensional cephalometry), determination of the thickness of the masticatory muscles in symmetrical areas of the face. Patients underwent a secret questionnaire to identify stressors that affected the body, studied the relationship between the presence of stress and the appearance of changes in cephalometric parameters. Scientific novelty. Clinical studies and survey results have shown that 95 % of patients surveyed have bad habits that are associated with chronic social stress. The results of examination of cephalometric analysis and photoprotocol confirm the expressed disproportions of one of the jaws, where there is a oral habit; confirm the presence of acquired rather than congenital deformity of the facial skeleton, which is associated with changes in the thickness of the masticatory muscles on the side of the deformation. Conclusions. Our research has shown that bad habits progress in the presence of chronic social stress, which according to the survey results in 95% of patients. Distance learning is the most important stress factor in most patients surveyed.3D cephalometric analysis should be included in the mandatory methods for the diagnosis of acquired deformities of the maxillofacial area. Clinical and radiological research methods help the orthodontist to identify a whole range of interrelated etiological factors in the development of dental anomalies and acquired deformities of the maxillofacial area and make a correct plan of complex treatment. Key words: Stress, Sleeping Habits, Tongue Habits, Cephalometry, Face, Orthodontic, Deformities.

Automatic segmentation of the gross target volume in radiotherapy for lung cancer using transresSEUnet 2.5D Network

ObjectiveThis paper intends to propose a method of using TransResSEUnet2.5D network for accurate automatic segmentation of the Gross Target Volume (GTV) in Radiotherapy for lung cancer.MethodsA total of 11,370 computed tomograms (CT), deriving from 137 cases, of lung cancer patients under radiotherapy developed by radiotherapists were used as the training set; 1642 CT images in 20 cases were used as the validation set, and 1685 CT images in 20 cases were used as the test set. The proposed network was tuned and trained to obtain the best segmentation model and its performance was measured by the Dice Similarity Coefficient (DSC) and with 95% Hausdorff distance (HD95). Lastly, as to demonstrate the accuracy of the automatic segmentation of the network proposed in this study, all possible mirrors of the input images were put into Unet2D, Unet2.5D, Unet3D, ResSEUnet3D, ResSEUnet2.5D, and TransResUnet2.5D, and their respective segmentation performances were compared and assessed.ResultsThe segmentation results of the test set showed that TransResSEUnet2.5D performed the best in the DSC (84.08 ± 0.04) %, HD95 (8.11 ± 3.43) mm and time (6.50 ± 1.31) s metrics compared to the other three networks.ConclusionsThe TransResSEUnet 2.5D proposed in this study can automatically segment the GTV of radiotherapy for lung cancer patients with more accuracy.

Nonaneurysmal subarachnoid hemorrhage associated with COVID-19 infection: A case report

Most coronavirus disease 2019 (COVID-19)-related cerebrovascular disorders are ischemic while hemorrhagic disorders are rarely reported. Among these, subarachnoid hemorrhage (SAH) is very rarely reported and nonaneurysmal SAH has been reported in only about a dozen cases. Here, we report a case of nonaneurysmal SAH as the only clinical manifestation of COVID-19 infection. In addition, we reviewed and analyzed the literature data on cases of nonaneurysmal SAH caused by COVID-19 infection. A 50-year-old woman presented to an emergency department with a sudden headache, right hemiparesis, and consciousness disturbance. At that time, no fever or respiratory failure was observed. Laboratory data were within normal values but the rapid antigen test for COVID-19 on admission was positive, resulting in a diagnosis of COVID-19 infection. Computed tomograms (CTs) showed bilateral convexal SAH with a hematoma but three-dimensional CT angiograms showed no obvious sources, such as a cerebral aneurysm. Therefore, the patient was diagnosed with nonaneurysmal SAH associated with COVID-19 infection. With conservative treatment, consciousness level and hemiparesis both improved gradually until transfer for continued rehabilitation. Approximately 12 weeks after onset, the patient was discharged with only mild cognitive impairment. During the entire course of the disease, the headache, hemiparesis, and mild cognitive impairment due to nonaneurysmal SAH with small hematoma were the only abnormalities experienced. Since COVID-19 infection can cause nonaneurysmal hemorrhaging, it should be considered (even in the absence of characteristic infectious or respiratory symptoms of COVID-19) when atypical hemorrhage distribution is seen as in our case.

RAPIDLY RESOLVING LUNG MASS: BETTER SAFE THAN SORRY

RAPIDLY RESOLVING LUNG MASS: BETTER SAFE THAN SORRY

INTRACEREBRAL HEMORRHAGE POSTPHARMACOMECHANICAL CATHETER-DIRECTED THROMBOLYSIS: CAN WE PREVENT IT?

INTRACEREBRAL HEMORRHAGE POSTPHARMACOMECHANICAL CATHETER-DIRECTED THROMBOLYSIS: CAN WE PREVENT IT?

RELATIONSHIP BETWEEN THE POSITION OF HEADS OF TEMPOROMANDIBULAR JOINT AND UPPER RESPIRATORY TRACT IN MALOCCLUSION CLASS I AND II

The respiratory organs and the maxillofacial apparatus are quite closely related to each other. Reducing the size of the upper respiratory tract is a factor that contributes to the development and formation of bite pathology and even dysfunction of the temporomandibular joint (TMJ). In recent years, there has been an increase in the prevalence of maxillofacial anomalies among children. The aim of the study Is to determine and to compare the position of the TMJ heads and the anatomical dimensions (anterior-posterior dimensions) of the upper respiratory tract in patients with malocclusion class I and II bite based on cone beam computed tomography findings. The analysis of 39 cone-beam computer tomograms of patients was carried out. According to the ANB angle, all patients were divided into two groups based on the type of malocclusion: group I included patients with malocclusion class I, and group II included patients with malocclusion class II. Measurement and interpretation of cone-beam computer tomography was carried out according to the method of N.A. Rabukhina and the McNamara’s method. The dimensions of the joint space of the temporomandibular joint in three sections (front, top and back both on the right and on the left) had no statistically significant differences. The average value of the joint space on the left and right in the patients of the first group in the front section was 2.5±0.27mm, in the patients of the second group – 3.01±0.35. In the upper part these indicators in patients of the first group were 2.76±0.37 mm, in the second group - 2.65±0.32 mm. In the posterior part the average value of the joint’s gap was 3.06±0.01 mm in patients of the first group and 2.28±0.27 mm in the second group. Measurements of the oropharyngeal area on cone-beam computed tomography were (according to the McNamara’s method): the width of the upper part of the pharynx in the first group - 17.41±0.44 mm, and in the second group averaged 15.82±0.61 mm with statistical significance (р˂0.05). In patients with bite pathology of both classed, according to the McNamara’s method, the lower part of the pharynx is narrowed compared to the norm. The study demonstrated the patients of the II group have a statistically significant difference in the reduction of the pharyngeal upper part width compared to I group and the displacement of the TMJ heads upwards and backwards.

Nodules detection on computer tomograms using neural networks

Results of neural networks (NN) application to the problem of detecting neoplasms on computer tomograms of the lungs with limited amount of data are presented. Much attention is paid to the analysis and preprocessing of images as a factor improving the NN quality. The problem of NN overfitting and ways to solve it are considered. Results of the presented experiments allow drawing a conclusion about the efficiency of applying individual NN architectures in combination with data preprocessing methods to detection problems even in cases of a limited training set and a small size of detected objects.

Neck Lymph Node Recurrence in HNC Patients Might Be Predicted before Radiotherapy Using Radiomics Extracted from CT Images and XGBoost Algorithm.

The five-year overall survival rate of patients without neck lymph node recurrence is over 50% higher than those with lymph node metastasis. This study aims to investigate the prognostic impact of computed tomogram (CT)-based radiomics on the outcome of metastatic neck lymph nodes in patients with head and neck cancer (HNC) receiving definitive radiotherapy or chemoradiotherapy for organ preservation. The pretreatment 18F-FDG PET/CT of 79 HNC patients was retrospectively analyzed with radiomics extractors. The imbalanced data was processed using two techniques: over-sampling and under-sampling, after which the prediction model was established with a machine learning model using the XGBoost algorithm. The imbalanced dataset strategies slightly decreased the specificity but greatly improved the sensitivity. To have a higher chance of predicting neck cancer recurrence, however, clinical data combined with CT-based radiomics provides the best prediction effect. The original dataset performed was as follows: accuracy = 0.76 ± 0.07, sensitivity = 0.44 ± 0.22, specificity = 0.88 ± 0.06. After we used the over-sampling technique, the accuracy, sensitivity, and specificity values were 0.80 ± 0.05, 0.67 ± 0.11, and 0.84 ± 0.05, respectively. Furthermore, after using the under-sampling technique, the accuracy, sensitivity, and specificity values were 0.71 ± 0.09, 0.73 ± 0.13, and 0.70 ± 0.13, respectively. The outcome of metastatic neck lymph nodes in patients with HNC receiving radiotherapy for organ preservation can be predicted based on the results of machine learning. This way, patients can be treated alternatively. A further external validation study is required to verify our findings.

Retrospective three-dimensional analysis of bone resorption volumes of free microvascular scapular and fibular grafts

Defects in head and neck regions are standardly treated with microvascular grafts, such as free scapular (SFF) and fibular flaps (FFF), which are subject to a certain amount of bone resorption over time. The aim of this study was the 3-dimensional evaluation of bone resorption volume in both grafts. Over a period of 10 years, computed tomograms (CT) of patients with mandibular reconstructions with SFFs and FFFs were examined. The respective grafts were segmented as well as 3-dimensionally measured. Furthermore, factors such as gender, age, nicotine abuse, previous disease with type 2 diabetes, and adjuvant therapies, were examined for their influence. A total of 211 CT scans from 67 patients (40 SFFs and 27 FFFs) were included in the study. SFFs showed slightly higher median bone volumes (87.60% at 730 days and 86.55% at 1500 days) than FFFs (84.40% at 730 days and 82.10% at 1500 days). When final volumes were considered, FFFs had higher mean volume values (88.22%) than SFFs (83.82%), with significant correlation between resorption volume and time progression (r = 0.357, p = 0.024). All previously mentioned factors had no significant effect on bone resorption. Bone volumes of FFFs showed postoperative volume reductions similar to those of SFFs, with isolated SFFs having markedly lower volume values. The choice of a microvascular graft for reconstruction in the mandible proves difficult regarding bone resorption. The presented results may support decisions about future transplantations.

The role of variant anatomy of the inferior mesenteric artery in segmental colon resections with lymphodissection in patients with colorectal cancer

During laparoscopic surgery for colorectal cancer, vascular structures may be incorrectly identified and damaged due to ignorance of the variant anatomy of the inferior mesenteric artery (IMA), lack of tactile sensations, narrowed field of vision, which leads to complications such as massive bleeding and intestinal ischemia. Therefore, the preoperative study of the variant anatomy of the IMA is of paramount importance. Knowing the variant anatomy of the vessels before surgery, you can make an operation plan in advance, which will ensure fast and safe vascular ligation at the required level and lymph node dissection. Aim: To develop a classification of IMA variability for practical use in operations for colorectal cancer. Material and methods: From February 2013 to March 2022, 214 computed tomograms (CT) of abdominal organs with intravenous contrast were analyzed. We studied the variant anatomy of the IMA. Results: We proposed the classification of structure of the IMA and its branches. This is especially important when the safe lymph node dissection along the IMA is necessary. I type — several colonic branches derivate from the IMA by independent trunks (54,2 %); II type — all colon branches derivate from the IMA in one point like a “goose paw” (25,2 %); III type — one colon branch departs from the IMA by a single trunk; then it divides into colonic branches (20,6 %). The frequency of coincidence of intraoperative data with preoperative CT data was 95.8 %. The sensitivity of the method is 95.8 %, the specificity of the method is 100%. Conclusion: CT with 3D vascular reconstruction allows the surgeon to perform extended lymph node dissection in colorectal cancer with minimal risk of complications.