Computed Tomography Scan Research Articles

Tumor aware recurrent inter-patient deformable image registration of computed tomography scans with lung cancer.

Voxel-based analysis (VBA) for population level radiotherapy (RT) outcomes modeling requires topology preserving inter-patient deformable image registration (DIR) that preserves tumors on moving images while avoiding unrealistic deformations due to tumors occurring on fixed images. We developed a tumor-aware recurrent registration (TRACER) deep learning (DL) method and evaluated its suitability for VBA. TRACER consists of encoder layers implemented with stacked 3D convolutional long short term memory network (3D-CLSTM) followed by decoder and spatial transform layers to compute dense deformation vector field (DVF). Multiple CLSTM steps are used to compute a progressive sequence of deformations. Input conditioning was applied by including tumor segmentations with 3D image pairs as input channels. Bidirectional tumor rigidity, image similarity, and deformation smoothness losses were used to optimize the network in an unsupervised manner. TRACER and multiple DL methods were trained with 204 3D computed tomography (CT) image pairs from patients with lung cancers (LC) and evaluated using (a) Dataset I (N = 308 pairs) with DL segmented LCs, (b) Dataset II (N = 765 pairs) with manually delineated LCs, and (c) Dataset III with 42 LC patients treated with RT. TRACER accurately aligned normal tissues. It best preserved tumors, indicated by the smallest tumor volume difference of 0.24%, 0.40%, and 0.13 % and mean square error in CT intensities of 0.005, 0.005, 0.004, computed between original and resampled moving image tumors, for Datasets I, II, and III, respectively. It resulted in the smallest planned RT tumor dose difference computed between original and resampled moving images of 0.01 and 0.013 Gy when using a female and a male reference. TRACER is a suitable method for inter-patient registration involving LC occurring in both fixed and moving images and applicable to voxel-based analysis methods.

Meckel's diverticulum as a cause of gastrointestinal bleeding.

Meckel's diverticulum, the most common congenital anomaly of the gastrointestinal tract, is often asymptomatic. Lack of complete resorption of the omphalomesenteric duct is an important cause of Meckel's diverticulum. Gastrointestinal (GI) bleeding is a major complication of Meckel's diverticulum. Herein, we reported a case of obscure gastrointestinal bleeding secondary to Meckel's diverticulum in small intestine detected by double-balloon enteroscopy. A 32-year-old male was admitted to the Department of Gastroenterology due to a 4-year history of intermittent hematochezia. Half a month before this admission, abdominal computed tomography scans showed high density in intestinal tract, and magnetron capsule endoscopy showed dark red blood from the end of the ileum to the ascending colon, but did not identify the source of bleeding. At this admission, hemoglobin concentration was 117 g/L. Double-balloon enteroscopy via anal route was performed, and found a large diverticulum in the middle part of the ileum, which was marked by two metal clips, with a superficial ulcer on its inner wall. Thus, Meckel's diverticulum was diagnosed. Subsequently, he underwent surgery. During surgery, a small intestinal diverticulum with a size of about 5.0cm×2.0cm was located nearly 120cm away from the ileocecal part. Small intestinal diverticulectomy was performed. He did not develop any recurrent hematochezia during follow-up.

CT radiation dose reduction with tin filter for localisation/characterisation level image quality in PET-CT: a phantom study

BackgroundThe tin filter has allowed radiation dose reduction in some standalone diagnostic computed tomography (CT) applications. Yet, ‘low-dose’ CT scans are commonly used in positron emission tomography (PET)-CT for lesion localisation/characterisation (L/C), with higher noise tolerated. Thus, dose reductions permissible with the tin filter at this image quality level may differ. The aim was to determine the level of CT dose reduction permitted with the tin filter in PET-CT, for comparable image quality to the clinical reference standard (CRS) L/C CT images acquired with standard filtration.Materials and methodsA whole-body CT phantom was scanned with standard filtration in CRS protocols, using 120 kV with 20mAs-ref for bone L/C (used in 18F-Sodium Fluoride (NaF) PET-CT) and 40mAs-ref for soft tissue L/C (used in 18F-Fluorodeoxyglucose (FDG) PET-CT), followed by tin filter scans at 100 kV (Sn100kV) and 140 kV (Sn140kV) with a range of mAs settings. For each scan, effective dose (ED) in an equivalent-sized patient was calculated, and image quality determined in 5 different tissues through quantitative (contrast-to-noise ratio) and qualitative (visual) analyses. The relative dose reductions which could be achieved with the tin filter for comparable image quality to CRS images were calculated.ResultsQuantitative analysis demonstrated dose savings of 50–76% in bone, 27–51% in lung and 8–61% in soft tissue with use of the tin filter at Sn100kV. Qualitative analysis demonstrated dose reductions using Sn100kV in general agreement with the dose reductions indicated by quantitative analysis. Overall, CT dose reductions of around 85% were indicated for NaF bone PET-CT, allowing whole-body CT at just 0.2mSv ED, and a 30–40% CT dose reduction for FDG PET-CT using Sn100kV (1.7-2.0mSv), providing comparable image quality to current CRS images with standard filtration. Sn140kV demonstrated limited value in CT dose reduction.ConclusionsLarge CT dose reductions can be made using the tin filter at Sn100kV, when imaging bone, lung and soft tissue at L/C level CT image quality in PET-CT. As well as reducing the risk of inducing a cancer in later life, such dose reductions may also impact PET-CT practice, such as justifying cross-sectional over planar imaging or justifying PET-CT in younger patients.

A Case of Nasal Dermoids Removed Via the Open Rhinoplasty Approach

Nasal dermoids are congenital midline nasal lesions that occur along with encephaloceles and gliomas. They can cause both deformity of nasal structure and intracranial infection as they grow. Treatment for these lesions is be concerned with two aspects, the complete removal of the lesions and making the surgical scar cosmetically acceptable. To that goal, many surgical approaches such as vertical incision, transverse incision, lateral rhinotomy and open rhinoplasty have been introduced. A 12-month male child presented with palpable mass at nasal root. The mass was easily movable, non-compressible and did not present fistula. A well-defined cystic mass without intracranial extension was found on the computerized tomography scans. Open rhinoplasty approach was opted for according to the guardians’ preference to avoid visible facial scar, and the lesions were completely resected. The pathologic examination confirmed the lesion to be nasal dermoids. The columellar scar was negligible and there was no recurrence at 5 year-follow up after surgery.

Success of Bone Ossification After Posterior Vault Distraction Osteogenesis in Patients With Craniosynostosis

Background: Posterior vault distraction osteogenesis (PVDO) is an effective treatment for multisuture and syndromic craniosynostosis. It remains unclear how well the calvarium ossifies after PVDO, especially in older patients when they have plateaued in their cranial growth phase. The purpose of this study is to report outcomes associated with PVDO across a wide range of ages at our institution. Methods: Operative details, distraction parameters, complications, and details of cranioplasty, if applicable, were obtained for all patients who underwent PVDO between March 2016 and July 2022. The surface areas of distraction sites and residual cranial defects were measured from computed tomography scans after a consolidation phase, and the percentages of the distraction regions with ossification were subsequently calculated. Results: Fifteen patients underwent PVDO at a mean age of 5.1 years (0.5–18.7 y). The mean percentage of ossification among all patients was 80.4% (59.1%–95.3%). The degree of ossification was not significantly associated with age at the time of surgery at the univariate level (Pearson-r=−0.15, P=0.573). Three patients (20.0%) required titanium mesh cranioplasty for definitive reconstruction, which was significantly more likely in patients who were >4 years old at the time of PVDO (P=0.04). Conclusions: Complete ossification of the distracted area of the cranium is unlikely after PVDO. Ossification appears less robust with increasing age, although not statistically significant in our study population, likely due to the limited sample size. Future studies should assess the role of age, latency period, and distraction rate in minimizing residual defects.

Extraction of clinical data on major pulmonary diseases from unstructured radiologic reports using a large language model.

Despite significant strides in big data technology, extracting information from unstructured clinical data remains a formidable challenge. This study investigated the utility of large language models (LLMs) for extracting clinical data from unstructured radiological reports without additional training. In this retrospective study, 1800 radiologic reports, 600 from each of the three university hospitals, were collected, with seven pulmonary outcomes defined. Three pulmonology-trained specialists discerned the presence or absence of diseases. Data extraction from the reports was executed using Google Gemini Pro 1.0, OpenAI's GPT-3.5, and GPT-4. The gold standard was predicated on agreement between at least two pulmonologists. This study evaluated the performance of the three LLMs in diagnosing seven pulmonary diseases (active tuberculosis, emphysema, interstitial lung disease, lung cancer, pleural effusion, pneumonia, and pulmonary edema) utilizing chest radiography and computed tomography scans. All models exhibited high accuracy (0.85-1.00) for most conditions. GPT-4 consistently outperformed its counterparts, demonstrating a sensitivity of 0.71-1.00; specificity of 0.89-1.00; and accuracy of 0.89 and 0.99 across both modalities, thus underscoring its superior capability in interpreting radiological reports. Notably, the accuracy of pleural effusion and emphysema on chest radiographs and pulmonary edema on chest computed tomography scans reached 0.99. The proficiency of LLMs, particularly GPT-4, in accurately classifying unstructured radiological data hints at their potential as alternatives to the traditional manual chart reviews conducted by clinicians.

Pulmonary infection with an unusual microorganism.

Pulmonary trichomoniasis is an underdiagnosed disease. In most cases, there is an underlying clinical condition related to immunosuppression. The results of molecular biology techniques indicate that trichomonad infections have been significantly underestimated. A 7-year-old girl with a medical history of suspected juvenile rheumatoid arthritis presented with a fever, chills, and a productive cough. Her chest computed tomography scan indicated a pericardial effusion and consolidation in the left lower lobe. In direct microscopy of the bronchoalveolar lavage fluid, we identified a motile and flagellated organism. Based on the morphology, size, and rolling motility, we identified this organism as Trichomonas hominis. The patient's fever stopped after 3 days of intravenous metronidazole administration. In immunocompromised patients with evidence of pneumonia, sputum or bronchial samples should be examined more carefully. The possibility of unusual pathogens should be considered if they do not respond to antibacterial treatments.

Value of Computed Tomography Scan for Detecting Lymph Node Metastasis in Early Esophageal Squamous Cell Carcinoma.

The necessity of computed tomography (CT) scan for detecting potential lymph node metastasis (LNM) in early esophageal squamous cell carcinoma (ESCC) before endoscopic and surgical treatments is under debate. Patients with histologically proven ESCC limited to the mucosa or submucosa were examined retrospectively. Diagnostic performance of CT for detecting LNM was analyzed by comparing original CT reports with pathology reports. The sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) were calculated. A total of 625 patients from three tertiary referral hospitals were included. The rate of pathologically confirmed LNM was 12.5%. Based on original CT reports, the sensitivity, specificity, accuracy, PPV, and NPV of CT to determine LNM in T1 ESCC were 41.0%, 83.2%, 77.9%, 25.8%, and 90.8% respectively. For mucosal cancers (T1a), these parameters were 50.0%, 81.7%, 80.9%, 6.8%, and 98.4%, respectively. For submucosal cancers (T1b), they were 40.0%, 85.0%, 75.0%, 43.0%, and 83.3%, respectively. Additionally, the diagnostic performance of CT for LNM was relatively better for ESCC in the lower esophagus. Pathologically, 69.2% of patients with LNM did not exhibit lymphovascular invasion (LVI), and the sensitivity of CT for recognizing LNM in these patients (33.3%) was lower than those with LVI (58.3%). Computed tomography can detect nearly half of the LNM cases in early ESCC with high specificity. The performance of CT further improved in LNM cases with LVI. Therefore, we conclude that routine preoperative CT for the assessment of potential LNM risk in patients with early ESCC is necessary.

Seromucinous hamartoma with unique clinical and histopathological features: a case report and review of the literature

BackgroundWe present this case to highlight the importance of considering seromucinous hamartoma in the differential diagnosis of nasal cavity lesions, particularly due to its rarity and potential for being mistaken for more aggressive pathologies. Seromucinous hamartoma, although benign, can exhibit clinical and histological features that overlap with those of malignant tumors, posing a diagnostic challenge. This case is especially noteworthy due to the unusual presentation of sebaceous differentiation within seromucinous hamartoma, a feature not previously documented in the literature. Recognizing such rare entities is crucial for ensuring appropriate patient management and avoiding unnecessary interventions.Case presentationWe report a unique case of a 41-year-old Caucasian man with seromucinous hamartoma, presenting with chronic left nasal obstruction and recurrent mild epistaxis. Nasal endoscopy revealed a well-defined, multilobulated lesion in the left nasal cavity. Computed tomography scans confirmed an anteromedial polypoid lesion, 31 mm × 15 mm. The lesion was endoscopically resected without complications, with no recurrence at 6-month follow-up. Pathological examination showed a filiform polypoid lesion with clusters of seromucinous glands, ducts, and tubules, and no invasive growth patterns. Immunohistochemical studies revealed distinct epithelial membrane antigen (EMA) and p63 staining patterns. Notably, mature sebaceous gland formation interspersed with seromucinous glands was observed, a novel finding in seromucinous hamartoma. Recognizing seromucinous hamartoma is crucial to avoid unnecessary treatments, and it should be included in differential diagnoses of nasal cavity lesions.ConclusionSeromucinous hamartoma is a rare and benign nasal cavity lesion that presents significant diagnostic challenges due to its potential to mimic more aggressive pathologies. This case highlights the importance of including seromucinous hamartoma in the differential diagnosis of sinonasal lesions, particularly when unusual histological features, such as sebaceous differentiation, are present.

Diagnostic evaluation of open knee injuries: a comparison of arthrography and CT scans.

Currently, traumatic arthrotomy of the knee could be diagnosed by saline loading test and computed tomography (CT) which reported excellent sensitivity and specificity. However, there are drawbacks associated with CT, such as cost and radiation hazards. This study aims to evaluate a new diagnostic tool using knee arthrography for individuals with suspected open knee injury and reported sensitivity and specificity using CT scan as the gold standard. A prospective diagnostic study, involving 43 patients who sustained laceration wounds over the knee, was conducted. The physical examination and conventional radiographic imaging were inconclusive in determining the presence of open joint injury. The established protocol involved directing the patients to undergo a CT scan, which is considered the gold standard for detecting open knee injuries. Subsequently, arthrography of the affected knee was performed. The diagnostic value was subsequently determined based on the outcomes derived from these procedures. There were 5/43 cases (11.6%) that diagnosed open knee injuries as determined by CT scans. The calculated diagnostic parameters of arthrography derived from these findings are as follows: The sensitivity was 83.3%, the specificity was 96.5%, the negative predictive value was 96.5%, the positive predictive value was 83.3%, the accuracy is 94.3%, the false positive rate is 16.7%, and the false negative rate was 3.4%. Interobserver reliability was substantial (Kappa 0.617). No complication was observed during the arthrography procedure. Knee arthrography demonstrated high sensitivity, specificity and accuracy for diagnosing open knee injuries, offering a viable alternative to CT scans in certain situations, such as when minimizing radiation exposure is a priority and cost considerations are paramount. Ultimately, careful clinical judgement should guide the choice of diagnostic modality based on individual patient circumstances.

Does the Intensity of Therapy Correspond to the Severity of Acute Respiratory Distress Syndrome (ARDS)?

Objectives: The intensity of respiratory treatment in acute respiratory distress syndrome (ARDS) is traditionally adjusted based on oxygenation severity, as defined by the mild, moderate, and severe Berlin classifications. However, ventilator-induced lung injury (VILI) is primarily determined by ventilator settings, namely tidal volume, respiratory rate, and positive end-expiratory pressure (PEEP). All these variables, along with respiratory elastance, are included in the concept of mechanical power. The aim of this study is to investigate whether applied mechanical power is proportional to oxygenation severity. Methods: We analyzed 291 ARDS patients (71 mild, 155 moderate, and 65 severe). We defined low, middle, and high mechanical power by dividing the entire population into tertiles with a similar number of patients. In each oxygenation class, we measured computed tomography (CT) anatomy, gas exchange, respiratory mechanics, mechanical power, and mortality rate. Results: ARDS severity was proportional to lung anatomy impairment, as defined by quantitative CT scans (i.e., lung volume and well-aerated tissue decreased across the ARDS classes, while respiratory elastance increased, as did mortality). Mechanical power, however, was similarly distributed across the severity classes, as the decrease in tidal volume in severe ARDS was offset by an increase in respiratory rate. Within each ARDS class, mortality increased from low to high mechanical power (roughly 1% for each J/min increase). Conclusions: Both lung severity and mechanical power independently impact mortality rates. It is tempting to speculate that ARDS severity primarily reflects the natural course of the disease, while mechanical power primarily reflects the risk of VILI.

Comparison of fusion rate, radiologic and clinical outcome between CaO-SiO2-P2O5-B2O3 bioactive glass-ceramics 7 (BGS-7) spacer and allograft spacer with iliac bone graft in multilevel ACDF.

CaO-SiO2-P2O5-B2O3 bioactive glass-ceramics7 (BGS-7) are known for their strong integration with bone and stability and are commonly used in spinal fusions. This study aimed to compare fusion rates and radiological and clinical outcomes between BGS-7 and allograft spacers with iliac bone grafts (IBG) in multilevel anterior cervical discectomy and fusion (ACDF) surgeries. This retrospective study was conducted at BRM Medical Center. We included patients who underwent multilevel ACDF at BRM Medical Center between January 2012 and December 2023. The patients had symptoms such as cervical radiculopathy and myelopathy due to cervical disc herniation, stenosis, and spondylosis. We evaluated the preoperative and postoperative Japanese Orthopedic Association (JOA) scores, neck disability index (NDI), functional rating index (FRI), and visual analog scale (VAS) scores for the neck, shoulder, and upper extremities at 6 months and 1 year after surgery. Fusion rates were assessed using dynamic radiography and computed tomography (CT) scans at 1 year postoperatively. Radiological measurements were obtained from preoperative and postoperative plain radiographs. At the 1-year follow-up, the fusion rates were 89.5% for BGS-7 and 92.2% for the allograft cage on dynamic radiographs (p=0.156) and 93.4% and 90.4%, respectively, on CT scans (p=0.319), confirming both internal and external osseointegration. Subsidence rates were 4% for BGS-7 and 10% for the allograft spacer group. Both groups showed increased cervical lordosis (CL), segmental lordosis (SL), and segmental height postoperatively, with maintained lower segmental height (LSH) in the BGS-7 group than in the allograft spacer group at postoperatively 1 year. No adjacent segmental disease (ASD) occurred in either group. The JOA, NDI, and FRI showed significant improvements in both groups. The VAS scores decreased significantly in both groups, indicating improved clinical outcomes. In multilevel ACDF, BGS-7 demonstrated fusion rates comparable to those of the allograft spacer with IBG, experiencing fewer instances of subsidence and cage fracture. Therefore, BGS-7 spacer can be safely utilized in multilevel ACDF as a substitute for traditional allograft spacers, without the need for additional IBG.

Urinary calculi successfully expelled in a patient through traditional Chinese exercise: A case report

Rationale: Urinary calculi are hard mineral deposits that typically require medication or surgery, such as lithotripsy. This case report presents traditional Chinese exercises (TCEs) as a potential alternative for stone expulsion. Patient concerns: A 41-year-old male with no history of urinary tract stones, experienced sudden severe lower back and abdominal pain accompanied by nausea and vomiting. Diagnosis: Computed tomography scan revealed a small calculus at the distal end of the left ureter (within the bladder wall), approximately 2 mm in size, with mild hydronephrosis in the ureter and renal pelvis. Interventions: The patient was initially prescribed medication for pain relief and was advised to engage in TCEs. Outcomes: Follow-up computed tomography scan after the exercise regimen showed complete expulsion and disappearance of the urinary calculi. The patient reported significant improvement in physical and mental health with no recurrence of calculi observed in subsequent checkups. Lessons: This case suggests that TCEs may facilitate the expulsion of small urinary calculi, offering a noninvasive treatment option. Further research is needed to confirm the therapeutic effects of TCEs on urinary calculi and to explore its potential mechanisms.

Association of patient comorbidities with colorectal cancer site as detected by computed tomography scan and colonoscopy: A retrospective study

Colorectal cancer (CRC) ranks as the third most common cancer worldwide. The most prevalent site is sigmoid. Comorbidities are common in patients with CRC and may be an important prognostic factor. This study investigated the prevalence of comorbidities among patients with CRC and assessed the association between the number of comorbidities and various factors including age, tumor site, smoking status, cancer stage, and mortality. This retrospective study included patients diagnosed with cancer at our hospital between January 2018 and November 2021. The association between comorbid illnesses (diabetes mellitus and hypertension) and patient characteristics such as sex, marital status, and smoking status was evaluated. The impacts of comorbid illnesses on CRC diagnosis and outcomes (cancer stage, primary site, and patient status) were analyzed. A chi-square test was performed to assess the relationship between sex, marital status, smoking status, and the presence of comorbid conditions (diabetes mellitus and/or hypertension). The majority of patients had at least 1 comorbid illness. A higher proportion of males had comorbid conditions compared to females. The proportion of patients with an early-stage cancer was higher among those without comorbidities. The proportion of surviving patients was higher among those without comorbidities, suggesting that patients with comorbid conditions may have an increased risk of death. The sigmoid colon was the most common site for colon cancer. Hypertension was the most common comorbidity followed by diabetes mellitus. Almost 50% of patients with CRC were smokers.

Laparoscopic Subtotal Splenectomy: A Feasible Option in the Treatment of Splenic Metastasis.

Laparoscopic subtotal splenectomy (LSS) is a procedure that helps avoid the consequences of asplenia. Given the spleen's importance and functionality, there may be specific indications and patient conditions in which partial splenectomy is beneficial. This case report aims to clarify the indications for LSS and outline the surgical technique. This multimedia article provides a comprehensive overview of the surgical procedure, emphasizing key steps to avoid postoperative bleeding and complications. The patient was hospitalized for 3 days without any complications observed. Postoperative hemoglobin levels were 11.2g/dL, with no signs of anemia. The patient was discharged with a follow-up visit after 2 weeks, showing no evidence of postoperative complications. The anatomopathological study revealed a nodular area with extensive tumoral necrosis. LSS is a safe surgical option that might help to mitigate the consequences of total splenectomy. Innovative technology in hemostasis, such as COOLINGBIS© (a monopolar electrosurgical electrode designed for hemostatic sealing and coagulation) can help manage this risk. Identifying the vascular pedicle via computed tomography scan is crucial to prevent unexpected bleeding. In selected cases, LSS is a feasible and safe procedure when performed with appropriate laparoscopic equipment and by experienced surgeons.

Acute Mesenteric Vein Thrombosis: A Case Report and Comprehensive Review

Acute mesenteric venous thrombosis (MVT) is a rare but potentially life-threatening condition, with the superior mesenteric vein (SMV) being the most frequently affected site of thrombosis. It is commonly observed in patients with underlying disorders that disrupt Virchow's Triad, which includes hypercoagulability, stasis, and endothelial injury [1]. In its acute form, SMVT is frequently associated with intestinal ischemia, complicating its clinical management and treatment [2]. The thrombotic occlusion of the mesenteric veins leads to impaired venous return, bowel ischemia, and in some cases, infarction, significantly impacting patient prognosis [3, 4]. We present a case of acute superior mesenteric venous thrombosis (SMVT) in a 42-year-old man who presented to our emergency walk-in clinic with acute onset of severe abdominal pain. He was referred to secondary care, where his contrast-enhanced abdominal Computerized Tomography (CT) scan revealed thrombosis of the superior mesenteric vein, splenic vein, and partial thrombosis of the intrahepatic part of the right portal vein. However, the CT scan showed no evidence of small bowel infarction or ischemia. He was subsequently managed with conservative measures.

Orbital computed tomography imaging characteristics of thyroid-associated ophthalmopathy

This study aims to investigate the distribution characteristics and correlations of orbital soft tissue volume expansion in patients with thyroid-associated ophthalmopathy (TAO) by analyzing orbital computed tomography (CT) data and to determine the most appropriate parameters and corresponding cut-off values for imaging classification. Patients with TAO who met the inclusion and exclusion criteria, along with those with lacrimal duct obstruction requiring orbital CT examination, were included in the study. Raw CT data were imported into Mimics and RadiAnt software for analysis, and measurements of orbital volume, orbital fat volume, extraocular muscle volume, optic nerve volume, and exophthalmos were obtained. The results demonstrated that the combination of Mimics and other softwares for processing orbital CT scans allows for the quantitative analysis of various soft tissue volumes within the orbit. The MV/FV ratio was found to effectively reflect the relative changes in extraocular muscle volume, serving as a valuable indicator for identifying different subtypes of TAO and providing significant clinical reference value.

Three-dimensional kinematic analysis of the cervical spine following posterior atlantoaxial fusion under physiological loading: An in vivo study

BackgroundThis study aimed to analyze the three-dimensional cervical motion characteristics in patients who underwent posterior atlantoaxial fusion surgeries using cone beam computed tomography and 3D3D registration technology. MethodsThe study selected 20 patients who underwent posterior atlantoaxial fusion surgery and 20 healthy people as the control group. All subjects underwent cone beam computed tomography scans of the occipital and cervical spine in 7 different functional positions, then 3D3D registration of Occipital-C7 was performed at each functional position to calculate the motion characteristics of each segment. The ranges of motion of the entire cervical spine and each segment were obtained in each functional position. FindingsIn the experimental group, ranges of motion of C1-C7 in flexion-extension and left-right twisting were significantly lower compared to controls (41.9° ± 13.8° vs. 56.6° ± 11.6°, 29.3° ± 9.6° vs. 91.2° ± 13.7°, respectively, P < 0.05). In the occipital-atlas segment, range of motion in flexion-extension was significantly smaller in the experimental group than controls (10.7° ± 3.2° vs. 19.4° ± 4.2°, P < 0.001), but it was larger in twisting (5.3° ± 4.2° vs. 2.1° ± 1.8°, P < 0.05). The twisting range of motion of C2-C3 was 4.7° ± 2.0° in the experimental group and 3.1° ± 1.6° in the control group (P < 0.05). Additionally, the alteration in ranges of motion during flexion-extension was primarily characterized by less extension. InterpretationThe posterior atlantoaxial fusion surgery induced biomechanical changes in the cervical spine. Following the procedure, the movement of C1-C7 during flexion-extension and twisting was significantly lower, with varying degrees of impact on adjacent and lower cervical segments. Moreover, the surgery had a greater effect on cervical extension than flexion.

Automatic patient centering in computed tomography: a systematic review and meta-analysis.

To comprehensively examine the influence of auto-patient centering technologies on positioning accuracy, radiation dose, image quality, and time efficiency of computed tomography (CT) scans. A systematic search of peer-reviewed English publications was performed between January 2000 and November 2023 in PubMed, Embase, CINAHL, Scopus, and Web of Science. Two postgraduate students and an academic lecturer independently reviewed the articles to verify adherence to the inclusion criteria. The QUADAS-2 tool was employed to evaluate study quality. We derived summary estimates on positioning accuracy, radiation dose reduction, image quality, and time efficiency using proportion and meta-analysis methodologies. Nine studies were identified comparing automatic and manual CT positioning. Automatic positioning improved accuracy by reducing vertical offsets to 7 mm and 4 mm for thorax and abdominal CTs, compared to 19 mm and 18 mm with manual methods. Most studies showed significant reductions in radiation dose, ranging from 5.71 to 31%. Image quality results were mixed, automatic methods generally produced images with less noise, but differences were minimal. Time efficiency was better, with automatic positioning reducing preparation time from 0.48 min versus 0.67 min for manual positioning. This review confirms that automatic patient-centering technologies enhance positioning accuracy and decrease preparation times in CT scans. While reductions in radiation doses and some improvements in image quality were observed, the evidence remains mixed. Findings support integrating these technologies into clinical practice to optimize patient care. Question Does automatic patient centering in CT enhance positioning accuracy, reduce radiation exposure, and improve image quality? Findings Findings indicate that automatic centering can optimize image quality, reduce examination times and contribute to overall improvements in imaging efficiency. Clinical relevance Automatic patient centering in CT improves positioning accuracy, minimizes radiation exposure, enhances image quality, and accelerates imaging workflows, contributing to safer, more efficient imaging procedures that benefit patient care.

Diagnosis and evaluation of cervical ossification of the posterior longitudinal ligament on Zero-Echo Time Magnetic Resonance Imaging: an illustrative case series.

Computed tomography (CT) scans are widely used clinically in the diagnosis of ossification of the posterior longitudinal ligament (OPLL). Conventionally acquired magnetic resonance imaging (MRI) is limited by insufficient signal intensity within bone tissue. Osseus conspicuity may be enhanced by applying sequences with "CT-like" bone contrast zero-echo time (ZTE) MRI. This is a case series aimed to understand if ZTE-MRI is sensitive in detecting cervical OPLL and if this modality is suitable for evaluating OPLL morphology. A retrospective review was performed to identify adult patients with available cervical ZTE-MRI and CT scans. ZTE-MRI and CT were evaluated for their ability to detect OPLL by 2 attending spine surgeons, 1 spine surgery clinical fellow, and 1 senior orthopedic resident. The phenotype of OPLL was then described and compared between the two modalities. A total of 50 patients were reviewed. All clinicians detected 4 cases of OPLL on CT, and the same cases were independently found on ZTE-MRI. The modalities were then compared to assess the phenotype of OPLL. ZTE-MRI may have the potential to obviate the need for concurrent CT scans in diagnosing OPLL. When OPLL was suspected on MRI, ZTE-MRI could confirm the OPLL diagnosis. With conventional MRI sequences that include additional post-processed ZTE-MRI, clinicians can also assess OPLL morphology and the resulting spinal cord change to make a complete diagnosis and identify patients at higher risk for progression or complications. ZTE-MRI avoids CT-related radiation, can improve diagnosis, and decrease health costs.