Head Computed Tomography Studies Research Articles

Analysis of the approach angle to medial orbitotomy that avoids accidental neurotrauma in the mesaticephalic dog skull utilizing 3D computer models and virtual surgical planning.

This study was conducted to determine an approach angle to medial orbitotomy that avoids accidental neurotrauma in mesaticephalic dogs. Medical records of dogs with mesaticephalic skulls that were presented to the veterinary medical teaching hospital for head computed tomography (CT) between September 2021 and February 2022 were reviewed. Descriptive data were queried, and CT findings were analyzed. Dogs greater than 20 kg and possessing a disease-free orbitozygomaticomaxillary complex (OZMC) on at least one side of the skull were included in this study. Digital imaging and communications in medicine (DICOM) files of head CT studies were imported into medical modeling software, and the safe approach angle for medial orbitotomy was determined using three-dimensional (3D) computer models and virtual surgical planning (VSP) principles. Angles were measured along the ventral orbital crest (VOC) from the rostral cranial fossa (RCF) to the rostral alar foramen (RAF). The safe approach angle at four points from rostral to caudal along the VOC was measured. The results at each location were reported as mean, median, 95% CI, interquartile ranges, and distribution. The results were statistically different at each location and generally increased from rostral to caudal. The variances between subjects and the differences between locations were large enough to suggest a standard safe approach angle in mesaticephalic dogs cannot be determined and should be measured for each patient. A standardized approach angle to medial orbitotomy is not possible in the mesaticephalic dog. Computer modeling and VSP principles should be implemented as part of the surgical planning process to accurately measure the safe approach angle along the VOC.

Artificial Intelligence Model Trained with Sparse Data to Detect Facial and Cranial Bone Fractures from Head CT.

The presence of cranial and facial bone fractures is an important finding on non-enhanced head computed tomography (CT) scans from patients who have sustained head trauma. Some prior studies have proposed automatic cranial fracture detections, but studies on facial fractures are lacking. We propose a deep learning system to automatically detect both cranial and facial bone fractures. Our system incorporated models consisting of YOLOv4 for one-stage fracture detection and improved ResUNet (ResUNet++) for the segmentation of cranial and facial bones. The results from the two models mapped together provided the location of the fracture and the name of the fractured bone as the final output. The training data for the detection model were the soft tissue algorithm images from a total of 1,447 head CT studies (a total of 16,985 images), and the training data for the segmentation model included 1,538 selected head CT images. The trained models were tested on a test dataset consisting of 192 head CT studies (a total of 5,890 images). The overall performance achieved a sensitivity of 88.66%, a precision of 94.51%, and an F1 score of 0.9149. Specifically, the cranial and facial regions were evaluated and resulted in a sensitivity of 84.78% and 80.77%, a precision of 92.86% and 87.50%, and F1 scores of 0.8864 and 0.8400, respectively. The average accuracy for the segmentation labels concerning all predicted fracture bounding boxes was 80.90%. Our deep learning system could accurately detect cranial and facial bone fractures and identify the fractured bone region simultaneously.

Rhinocerebral Mucormycosis in Patients with Diabetes Mellitus After a New Coronavirus Infection (COVID-19): СT and MRI Patterns Data

Objective: to study the computed tomography (CT) and magnetic resonance imaging (MRI) manifestations of rhinocerebral mucormycosis (RCM) in patients with diabetes mellitus and new coronavirus infection, to develop attentive attitude of radiologists for early detection of this pathology, rapid surgery and followup examinations.Material and methods. Totally 53 head (facial skull, soft facial tissues and brain) CT and MRI studies were performed in 13 patients with RCM. The number of CT and MRI studies varied from 1 to 9 per one patient, depending on the severity of his condition and clinical indications; the follow-up period was 1–4 months. All patients received surgical aid; diagnosis was verified by microscopy of surgical samples of excised necrotic tissues. A detailed descriptive analysis of pathological changes on CT and MRI characterizing RCM was carried out. The sequence of pathological signs manifestations was described, the prevalence of the lesion was estimated for planning the scope of surgical intervention. A comparative analysis of the identified RCM signs with the literature data was performed.Results. Lesions of the nasal cavity and paranasal sinuses in RCM were found in 100% of our observations, with approximately equal single and bilateral lesions of 54% and 46%, respectively. Lesions of the perimaxillar fatty tissue and pterygoid fossa were determined in 77% of patients, unilateral orbital lesions – in 23%, superior orbital vein and cavernous sinus thrombosis – in 31%, facial soft tissue lesion – in 15.5%, intracranial spread through the perineural spaces – in 7.7%, internal carotid artery arteritis – in 15.5%. Brain substance and meninges involvement in the pathological process was observed in the form of cerebritis in 23% of patients and meningitis in 46%. The formation of brain abscess was noted in follow up examinations in 15.5% of patients, skull bones osteomyelitis was diagnosed in 46%. The mortality rate was 15%. In cases of long-term observation, the manifestations of pathological changes started from the nasal cavity, then spreaded in the perimaxillary adipose tissue and orbit, and were followed by the development of intracranial complications.Conclusion. The accumulated experience in identifying the combination of CT and MRI signs and patterns of RCM combined with clinical and anamnestic data allows to increase the alertness of clinicians and radiologists for earlier diagnosis and selection of the optimal volume of surgical intervention.

Frequency of Anatomical Variants of Paranasal Sinuses (PNS) on Computed Tomography (CT)

Background: The para nasal sinuses be collection of air filled spaces adjoining the nasal cavity. Para nasal sinuses build up as of the primitive choana at 25–28 weeks of gestation. Three projections ascend from the lateral wall of the nose and work as the commencement of the growth of the para nasal sinuses. The Frequency of Anatomical Variants of Para nasal Sinuses (PNS) may be illustrated on Computed Tomography (CT) by using double slice CT machine. Aim: To reveal the anatomy of the para nasal sinuses as shown on the CT along with point out the variants lead to chronic sinusitis and escort obstacles in sino nasal operations. Methodology: This study was conducted in Ibnae-e Sieena Hospital and MMDC Multan during September 2019 to December 2019. In 50 patients without para nasal sinus diseases symptoms, head computed tomography studies were carried out after having consent from them and IRB. Para nasal sinuses coronal sections were taken. The CT studies were performed by using Dual Source multi slice CT Scanner. Results: 50 participants included in the study, 25 men with 25 women. Out of them, 22 having anatomical variants were noticed. Most common anatomical variants found were pneumatisation of center nasal turbinates (30%) then agger nasi cells 25%, Haller’s cells 20%, along with septal deviation 13% and sphenoid sinus septation (12%). Conclusion: This study shows that nasal cavity and para nasal sinuses anatomical variations are common. For the radiologic analysis of the para nasal sinuses, as of diagnosis of the pre and post -surgical evaluation and sino-nasal lesions, CT is the gold standard procedure. It can outline and explain the anatomical variants in para nasal sinuses. CT not only detect the lesion to vital constitutions which lined the para nasal sinuses but also repeated lesions that extra mural cells. CT of the para nasal sinuses has vital importance and should be passably analyze before FESS. Keywords: Para nasal sinuses, Computed tomography, Nasal turbinate, Ostiomeatal complex

Acute cerebral venous thrombosis - still an underdiagnosed pathology in emergency computed tomography of the brain.

PurposeAcute cerebral venous thrombosis (CVT) is a rare condition that can lead to a serious clinical state; thus, prompt diagnosis and treatment are mandatory. Head computed tomography (CT) plays a crucial role in the initial prompt diagnosis in the emergency setting. The aim of the study was to retrospectively analyse emergency head CT studies and the rate of incorrect diagnoses and main sources of pitfalls.Material and methodsRetrospective analysis of 31 emergency CT studies (22 without contrast, 19F/12M, age range: 4-94 years) of patients with confirmed acute CVT.ResultsThrombosed dural sinuses were found in 24/31 (77.4%) cases, thrombosed veins in 7/31 (22.6%) cases, no lesions within vessels in 2/31 (6.5%) cases. Haemorrhagic brain lesions were found in 9/31 (29%) cases, hypodense oedema in 6/31 (19.6%) cases, brain swelling in 1/31 (3.2%) cases, and no parenchymal lesions were revealed in 15/31 (48.4%) cases. Correct diagnosis of CVT was established in 15 cases (48.4%); however, it was incorrect in 16 cases (51.6%). Incorrect cases consist of 4 groups: 1 – with both vascular and parenchymal lesions that were overlooked (50%), 2 – with vascular lesions only, which were either overlooked, misinterpreted, or covered by artefacts (31.3%,), 3 – with parenchymal lesions only, which were misinterpreted (12.5%), and 4 – with no lesions present in the emergency head CT (6.2%).ConclusionsThe high rate of incorrect diagnoses of acute CVT based on emergency head CT requires constant training of radiologists and their close cooperation with clinicians because a delayed diagnosis may be lethal to the patient.

Advanced machine learning in action: identification of intracranial hemorrhage on computed tomography scans of the head with clinical workflow integration

Intracranial hemorrhage (ICH) requires prompt diagnosis to optimize patient outcomes. We hypothesized that machine learning algorithms could automatically analyze computed tomography (CT) of the head, prioritize radiology worklists and reduce time to diagnosis of ICH. 46,583 head CTs (~2 million images) acquired from 2007–2017 were collected from several facilities across Geisinger. A deep convolutional neural network was trained on 37,074 studies and subsequently evaluated on 9499 unseen studies. The predictive model was implemented prospectively for 3 months to re-prioritize “routine” head CT studies as “stat” on realtime radiology worklists if an ICH was detected. Time to diagnosis was compared between the re-prioritized “stat” and “routine” studies. A neuroradiologist blinded to the study reviewed false positive studies to determine whether the dictating radiologist overlooked ICH. The model achieved an area under the ROC curve of 0.846 (0.837–0.856). During implementation, 94 of 347 “routine” studies were re-prioritized to “stat”, and 60/94 had ICH identified by the radiologist. Five new cases of ICH were identified, and median time to diagnosis was significantly reduced (p < 0.0001) from 512 to 19 min. In particular, one outpatient with vague symptoms on anti-coagulation was found to have an ICH which was treated promptly with reversal of anticoagulation, resulting in a good clinical outcome. Of the 34 false positives, the blinded over-reader identified four probable ICH cases overlooked in original interpretation. In conclusion, an artificial intelligence algorithm can prioritize radiology worklists to reduce time to diagnosis of new outpatient ICH by 96% and may also identify subtle ICH overlooked by radiologists. This demonstrates the positive impact of advanced machine learning in radiology workflow optimization.

Dose monitoring in pediatric and young adult head and cervical spine CT studies at two emergency duty departments

As the number of pediatric computed tomography (CT) imaging is increasing, there is a need for real-time radiation dose monitoring and evaluation of the imaging protocols. The aim of this study was to present the imaging data, patient doses, and observations of pediatric and young adult trauma-and routine head CT and cervical spine CT collected by a dose monitoring software. Patient age, study date, imaging parameters, and patient dose as volume CT dose index (CTDIvol) and dose length product (DLP) were collected from two emergency departments' CT scanners for 2-year period. The patients were divided into four age groups (0-5, 6-10, 11-15, and 16-20years) for statistical analysis and effective dose determination. The 75th percentile doses were evaluated to be used as local diagnostic reference levels (DRLs). Six hundred fifteen trauma head, 318 routine head, and 592 trauma cervical spine CT studies were assessed. All mean CTDIvol values were statistically lower in hospital B (40.3 ± 12.3, 30.03 ± 11.1, and 6.9 ± 3.1mGy, respectively) than in hospital A (53.0 ± 12.9, 43.2 ± 8.7, and 18.3 ± 7.3mGy, respectively). Statistically significant differences were observed on scanning length between hospitals and between CTDIvol values when protocol was updated. The 75th percentiles of trauma cervical spine in hospital B can be used as local DRL. Non-optimized protocols were also revealed in hospital A. Dose monitoring software offers a valuable tool for evaluating the imaging practices and finding non-optimized protocols.

Testing of the assisting software for radiologists analysing head CT images: lessons learned

BackgroundAssessing a plan for user testing and evaluation of the assisting software developed for radiologists.MethodsTest plan was assessed in experimental testing, where users performed reporting on head computed tomography studies with the aid of the software developed. The user testing included usability tests, questionnaires, and interviews. In addition, search relevance was assessed on the basis of user opinions.ResultsThe testing demonstrated weaknesses in the initial plan and enabled improvements. Results showed that the software has acceptable usability level but some minor fixes are needed before larger-scale pilot testing. The research also proved that it is possible even for radiologists with under a year’s experience to perform reporting of non-obvious cases when assisted by the software developed. Due to the small number of test users, it was impossible to assess effects on diagnosis quality.ConclusionsThe results of the tests performed showed that the test plan designed is useful, and answers to the key research questions should be forthcoming after testing with more radiologists. The preliminary testing revealed opportunities to improve test plan and flow, thereby illustrating that arranging preliminary test sessions prior to any complex scenarios is beneficial.

An Evidence-Based Approach to the Efficient Use of Computed Tomography Imaging in the Neurosurgical Patient

Computed tomography (CT) is the current standard for rapidly diagnosing some of the more common structural pathologies that affect the neurosurgical patient perioperatively. With this convenience comes the potential for its overuse. To investigate the utility of head CT scans ordered for various clinical indications. All head CT studies ordered by the UCLA Neurosurgery Department from August 15, 2011 through December 15, 2011, were prospectively studied. Variables collected included demographic information, diagnosis, surgical procedures, indication for CT, CT findings, and whether the study led to a documentable change in management. There were 801 head CT studies ordered for the 462 patients who were admitted to the neurosurgical service. The authors identified 14 indications for ordering a head CT with the following probabilities of a positive finding: examination change (17/56, 30.3%), follow-up (4-6 hours after intracerebral hemorrhage; 16/126, 12.7%), CT angiography (11/30, 36.7%), routine postoperative imaging (6/126, 4.7%), postventriculostomy placement (4/62, 6.5%), immediately before (4/31, 12.9%) or after removal of (2/42, 4.8%) a ventriculostomy, surveillance (>24 hours after intracerebral hemorrhage or external ventricular drain placement) (3/66, 4.5%), headaches (2/8, 25%), ground level fall (1/8, 12.5%), intracranial pressure spikes (2/6, 33.3%), and delayed (6-24 hours after intracerebral hemorrhage; 1/25, 4%). The probability of discovering a clinically significant finding varies widely for each of the listed study indications. This prospective analysis of all CT scans ordered at a single institution suggests that imaging studies obtained without a change in neurological status were unlikely to produce a positive finding, and even when there was a positive finding, it was extremely unlikely to result in any intervention.

National Variation of Technical Factors in Computed Tomography of the Head

The objectives of this study were to describe head computed tomography (CT) technical factors used in the United States; assess guideline compliance and variability by sex, geographic region, institution, and manufacturer; and compare with NEXT (Nationwide Evaluation of X-ray Trends) survey. Two thousand thirty-five head CT studies from 895 sites were analyzed. Peak kilovoltage, exposure, slice and image number, slice thickness, field of view, interslice gap, reformations, examination inclusiveness, use of contrast, and reconstruction filter were compared by sex, geographic region, institution type, and manufacturer. One hundred twenty to 140 kVp (peak kilovoltage) was used by 99.8% of the sites. There was no correlation between mAs and kVp. There was a 30-fold increase in number of images and nearly 9-fold increase in number of slices from least to most. Nearly 4% use slice thickness and interslice gap greater than guidelines. There were significant regional differences in field of view, image number, and slice thickness. Some variation related to manufacturers was found. Minor difference was also found between academic and nonacademic institutions. There were significant differences in kVp and mAs compared with NEXT. Significant variations in head CT technique exist in the United States.

Recommendations for additional imaging on emergency department CT examinations: comparison of emergency- and organ-based subspecialty radiologists

Past studies have identified a high frequency of recommendations for additional imaging (RAI) for computed tomography (CT) studies performed in an emergency department (ED), thereby potentially contributing to increased imaging utilization and costs. The purpose of this study was to compare rates of RAI within the ED setting between ED-based and organ-based subspecialty radiologists. We identified 600 ED CT studies, comprising 200 head, chest, and abdominal CT studies, split equally between cases reviewed by ED-based and organ-based radiologists. Frequency of RAI for the three examinations was compared between these subspecialty groups. Frequencies of RAI were 21.5 %, 13.5 %, and 5.5 % for CT examinations of the chest, abdomen, and brain, respectively. There was a significantly higher frequency of RAI for chest CT studies interpreted by chest radiologists than by ED radiologists (28.0 % vs. 15.0 %, respectively, p = 0.036), largely due to a higher rate of RAI for incidentally detected lung nodules and masses as well as other pulmonary parenchymal abnormalities by chest radiologists. There was no significant difference in RAI on brain or abdominal CT studies between the two groups (p = 0.426-1.0). However, on abdominal studies, only ED-based radiologists provided RAI for abnormalities of the bowel or uterus, while only organ-based radiologists provided RAI for pancreatic abnormalities. Only 25.6 % of RAI were subsequently performed at our institution. For chest CT studies performed at the authors' institution, differences in management of incidental pulmonary nodules contributed to a significantly higher frequency of RAI by chest radiologists than by ED-based radiologists. Further investigation of the impact of these differences on cost and patient outcomes is warranted.

Head Computed Tomography Scanning During Pediatric Neurocritical Care: Diagnostic Yield and the Utility of Portable Studies

We report our use of portable head computed tomography (CT) and the diagnostic yield and radiation dose from head CT in the pediatric intensive care unit (PICU). 204 PICU patients underwent head CT during 2008-2009. Therapeutic interventions and resource intensity during CT were categorized. Severity of illness was summarized using the pediatric risk of mortality (PRISM-III) model. Estimates of patient radiation dose were based on dose measurements made in four anthropomorphic head phantoms. 242 (62%) out of 391 head CT studies were portable. New pathology was identified on 80 (40%) scans. CT findings prompted a change in management in 46 (23%) patients; 25 of these resulted in life-extending treatments and 21 had forgoing of life-sustaining treatments within 24 hours. 26 patients with PRISM score greater than 30% underwent CT; 23 (88%) of these were portable. More portable versus fixed examinations were performed in patients requiring extracorporeal membrane oxygenation, inhaled nitric oxide, high levels of positive end expiratory pressure, and those with high vasopressor scores (P < 0.05). Estimated patient dose from portable CT was 83 ± 6 mGy compared to 72 ± 5 mGy for patients imaged on a fixed scanner (P < 0.0001). Two-thirds of CT scans obtained in the PICU were portable because of patients' intensity of therapy and illness severity. Portable CT showed major new pathology in greater than 1/3 and led to a change in management in 1/4 of higher acuity patients scanned. The estimated radiation dose from portable CT is within the current national guidelines.

Intracranial hypotension and recurrent pleural effusion after snow-boarding injury: a manifestation of cerebrospinal fluid–pleural fistula

Background data Intracranial hypotension causing postural headaches has been described after occult and postsurgical cerebrospinal fluid (CSF) leaks and rarely isolated lumbar punctures. The occurrence of a CSF-pleural communication is much rarer, and a high level of suspicion aids in prompt recognition. Purpose Early detection and anatomic delineation of the site of CSF-pleural fistula allows prompt intervention, results in resolution of symptoms and prevents the complication of meningitis. Study design A case of intracranial hypotension with postural headaches is described after spinal surgery, with demonstration on computed tomography (CT) myelography of a rare CSF-pleural fistula. Methods The clinical presentation, postoperative intervention and imaging as well as laboratory data are presented. Results Chest X-ray showed recurrent pleural effusion after placement of chest tube, and serial head CT studies revealed decreasing ventricular size with development of severe headaches. Myelogram and CT postmyelogram demonstrate the CSF-pleural communication, allowing appropriate surgical repair. Conclusion Severe headaches with a recurrent pleural effusion after thoracic spinal surgery may indicate presence of a CSF-pleural fistula, an unusual complication of thoracic spinal surgery.

Reducing radiation to children: the resident’s role

Reducing radiation to children: the resident’s role

Overlooked metastatic lesions of the occipital condyle: a missed case treasure trove.

Radiologic images obtained in nine patients with known primary cancer and occipital or head and neck pain were retrospectively reviewed after having been initially interpreted as normal. Imaging studies included head computed tomography (CT) in five cases, brain magnetic resonance (MR) imaging in six cases, cervical spine CT and MR imaging in five cases, radiography in two cases, and scintigraphy in two cases. This reevaluation demonstrated lesions of the occipital condyles in all patients. Seven patients had unilateral occipital condyle masses, and two patients had bilateral condyle lesions. Lesions were found to either involve only the occipital condyle (n = 4), extend to the adjacent occipital bone (n = 3), or extend to the ipsilateral clivus (n = 2). Misinterpretation of radiologic examinations resulted in an average delay in diagnosis of 10 weeks from the onset of symptoms to definitive therapy (irradiation). It is important to evaluate the occipital condyles in all patients with occipital pain, especially those with cancer. Neoplastic disease involving the occipital condyles is not common; however, it is frequently missed at imaging. Careful review of unenhanced sagittal and axial T1-weighted MR images and of the inferior sections from axial head CT studies will make it possible to avoid this potential pitfall.

Computed tomography in evaluation of patients with stage III melanoma.

Metastatic disease is detected infrequently by computed tomography (CT) in early stage melanoma. The diagnostic yield of routine CT for stage III melanoma is less established, despite extensive use in clinical practice. Charts from 347 asymptomatic patients with stage III melanoma were reviewed. Findings suggestive of metastatic melanoma identified by head or body CT, chest radiography, bone scan, or liver function studies were confirmed histologically or by progression of disease. Individual CT scans identified 33/788 (4.2%) instances of metastatic melanoma, with 66/788 (8.4%) false positive studies. No metastases were identified among 104 head CT scans. Chest CT had the highest yield in patients with cervical adenopathy (7/35, 20%), and the lowest yield with groin adenopathy (1/50, 2%). Pelvic CT diagnosed metastases in 7/94 (7.4%) patients with groin adenopathy, but no patients with palpable axillary (n = 76) or cervical (n = 21) nodes. Metastatic melanoma was diagnosed in 11/136 (8.1%) patients having complete body CT imaging (chest, abdomen, and pelvis), including six patients (4.4%) identified by CT alone. Routine CT in patients with clinical stage III melanoma infrequently identifies metastatic disease. Head CT in the asymptomatic patient, chest CT in patients with groin adenopathy, and pelvic CT in the presence of axillary or cervical adenopathy are not indicated. Selective use of chest CT in patients with cervical adenopathy or pelvic CT in the presence of groin disease may be useful.