Tomography, Volume 12, Issue 8 (August 2026) – 11 articles

Background/Objectives: Computed tomography perfusion is widely used in acute ischemic stroke, but its performance is less reliable for lacunar and infratentorial infarcts. This technical review examines the acquisition and processing factors that influence their detectability. Methods: A targeted technical review of PubMed/MEDLINE, Scopus, and Web of Science was performed, focusing on acquisition, reconstruction, vascular input selection, deconvolution, filtering, spatial sampling, automated classification, posterior circulation stroke, and lacunar infarction. Results: Detectability depends on lesion size and contrast, posterior fossa artifacts, spatial and temporal resolution, vascular curve quality, mathematical stabilization, and automated thresholds. Larger cerebellar infarcts may remain visible, whereas brainstem, deep cerebellar, and perforator lesions are more vulnerable. Temporal maps and direct review of parametric images may reveal abnormalities absent from automated summaries. Conclusions: This technical review shows that computed tomography perfusion should be interpreted as a derived estimate rather than a direct representation of cerebral hemodynamics. Negative automated findings do not exclude lacunar or infratentorial infarction when clinical suspicion remains high. Full article

Background/Objectives: Surgically treated oral cancer patients often face velopharyngeal insufficiency, which adversely impacts their quality of life (QOL). Our past investigations revealed noticeable MR signal shifts in velopharyngeal-related muscles during water deglutition on CMR among healthy individuals. We hypothesized that analyzing these distinct signal fluctuations could offer a novel visual perspective for detecting deglutition anomalies in surgical oral cancer cases. This feasibility study aimed to assess velopharyngeal-related muscular performance via CMR in post-operative oral cancer patients. Methods: Nineteen patients with oral malignancies were prospectively evaluated pre- and post-operatively. Twelve quantitative CMR metrics alongside subjective dysphagia scores were investigated. We analyzed whether signal intensity (SI) ratio alterations in these muscles correlated with dysphagia severity and clinical parameters. Results: Although three specific CMR parameters significantly worsened post-operatively, muscle MR signal values increased during deglutition without significant variation between pre- and post-surgical states. Subjective swallowing assessments remained entirely normal across all subjects. Conclusions: This preliminary investigation indicates that CMR can visualize stable velopharyngeal-related muscle activity after surgery in oral cancer patients maintaining adequate swallowing status. Nevertheless, confirmation via larger, symptomatic patient cohorts alongside gold-standard techniques remains mandatory. Full article

Objective: Our objective was to describe morphologic features and longitudinal changes observed on high-resolution vessel wall imaging (HR-VWI) in a selected retrospective case series of patients evaluated for suspected inflammatory intracranial vasculopathy. Methods: This retrospective case series included patients who underwent 3T intracranial HR-VWI for suspected inflammatory intracranial vasculopathy. Clinical and imaging data were collected from medical records and imaging archives. Three radiologists reviewed baseline and follow-up examinations for vessel wall enhancement (VWE) pattern and grade, wall thickness, luminal narrowing, arterial distribution, diffusion-restricted lesions, and susceptibility-sensitive findings. Analyses were descriptive and patient-level. Each patient contributed one baseline and one final examination to longitudinal summaries; intermediate scans characterized individual trajectories only. Results: Nineteen patients were included, and 17 underwent serial HR-VWI. Median age was 46 years (IQR, 35.5–60.0 years), and 11 patients were female. Follow-up HR-VWI was available in 17 patients over a median of 391 days (IQR, 237–1819 days; range, 15–4034 days). VWE was present in all patients, with a purely concentric pattern in 15/19 (78.9%). The middle cerebral and internal carotid arteries were involved in 17/19 and 13/19 patients, respectively. Among the 17 patients with paired examinations, VWE grade decreased in 13 patients (76.5%) and remained stable in four patients (23.5%), with the median decreasing from 3.0 to 1.0. Maximum wall thickness decreased in 16 patients and remained stable in one, with the median changing from 2.0 mm to 1.4 mm. Conclusions: In this selected retrospective case series of patients evaluated for suspected inflammatory intracranial vasculopathy, 3T HR-VWI commonly demonstrated concentric VWE and provided descriptive longitudinal information regarding enhancement evolution. These findings should not be interpreted as evidence of diagnostic performance. Full article

Background/Objectives: Auditory verbal hallucinations (AVH) are clinically heterogeneous experiences that may occur across psychiatric, neurological, sensory, and non-clinical contexts. This controlled pilot study investigated multimodal structural and functional MRI features associated with persistent AVH in a psychiatric clinical population, recruited from outpatient psychiatric clinics and diagnosed with schizophrenia, schizoaffective disorder, or bipolar disorder with psychotic features. Neurological, sensory, and non-clinical presentations of AVH were not included. Methods: This observational controlled pilot study included 14 participants with persistent auditory verbal hallucinations and 15 age- and sex-matched healthy controls. Participants with AVH had experienced the current persistent hallucinatory phase for a mean of 3.1 ± 1.6 years (range of 1–7), with a mean overall psychiatric illness duration of 12.4 ± 4.8 years. Independent component analysis assessed resting-state functional connectivity, BrainVoyager QX measured cortical thickness, and diffusion tensor imaging (DTI) evaluated white matter microstructure. Multiple comparisons were controlled using false discovery rate correction followed by 5000-iteration Monte Carlo cluster-extent correction for fMRI and Monte Carlo cluster correction for whole-brain structural metrics. Results: Participants with AVH demonstrated increased functional connectivity across default mode network (DMN) hubs (precuneus, inferior frontal, and parahippocampal gyri) and superior temporal regions. Whole-brain cortical thickness analysis revealed no significant group differences; however, secondary exploratory analyses of six regions previously implicated in AVH showed cortical thinning in participants with AVH relative to the controls after FDR correction. DTI revealed no group differences surviving whole-brain permutation correction (TFCE, FWE-corrected p < 0.05); exploratory uncorrected findings are reported as hypothesis-generating. Conclusions: This pilot study identifies structural and functional network differences between medicated individuals with persistent AVH and healthy controls, centred on frontotemporal and default mode networks. Because no psychiatric control group without AVH was included, these differences cannot be attributed specifically to AVH as opposed to the underlying psychiatric disorders or their treatment. No diffusion findings survived whole-brain permutation correction; exploratory uncorrected results are reported but are not incorporated into these conclusions. Collectively, these findings identify candidate imaging markers that require validation against psychiatric control groups. Full article

Visualization of coronary computed tomography angiography (CCTA) in standard cardiac planes requires reorientation of the three-dimensional image volume because the heart is double-oblique relative to the axial scan plane. To standardize this process across multi-phase cine CCTA, we developed an automated framework that segments cardiac structures and detects anatomic landmarks to define a patient-specific cardiac coordinate system. Landmark-derived left ventricular (LV) long-axis and LV-to-right ventricular transverse vectors were used to compute a rotation matrix for reorienting all 20 cine CCTA volumes. Six fixed slice planes were then defined to extract three long-axis (LAX) and three short-axis (SAX) slices at each phase. Matched CCTA and cardiac magnetic resonance (MR) slices were compared in 25 patients at diastasis, end-diastole (ED), and end-systole (ES), using automated segmentation-derived measurements of the combined LV cavity and LV myocardium area (LV + LVM). Agreement was evaluated with intraclass correlation coefficients (ICCs), Bland–Altman analysis, and repeated-measures mixed-effects models. ICCs were 0.927 (95% CI, 0.895 to 0.950) at diastasis, 0.950 (95% CI, 0.928 to 0.966) at ED, and 0.919 (95% CI, 0.887 to 0.943) at ES. Bland–Altman analysis showed small CT-positive biases of 1.05, 0.47, and 1.86 cm² at diastasis, ED, and ES, corresponding to relative biases of 2.8%, 1.2%, and 5.8% of the phase-specific mean MR LV + LVM area. Mixed-effects models showed no statistically significant phase-level bias at diastasis or ED, whereas ES showed a small but significant CT-positive bias. These findings support automated CCTA reorientation as an interpretable framework for reproducible LAX/SAX slice extraction and future quantitative functional cine CCTA analysis. Full article

Background: Accurate fracture interpretation on plain radiographs is critical for both trauma care and medico-legal decision-making, where reproducibility is as important as point accuracy. Although vision language models (VLMs) have shown promising diagnostic performance, their temporal stability in forensic radiography remains unclear. Methods: We analyzed 300 forensic radiographs (150 fracture-positive, 150 fracture-negative) from six long bones, independently evaluated by three emergency medicine physicians, three forensic medicine physicians, and three VLMs (ChatGPT-5.2, Gemini 3 Pro, Claude Sonnet 4.5) using an identical task format. Assessments included fracture presence and structured fracture subtype description (bone, morphology, displacement). VLM evaluations were repeated after one month under identical conditions. Results: Physician accuracy ranged from 79.7% to 98.7%. Emergency physicians reached the higher median sensitivity (92.0% against 76.7%), while specificity among the forensic readers was the more tightly clustered (median 92.0%, range 87.3–100.0%). ChatGPT-5.2 was the most accurate model (83.0%; sensitivity 70.0%, specificity 96.0%), followed by Gemini 3 Pro (77.7%), whereas Claude Sonnet 4.5 reached only 46.3% because of an extreme false-positive tendency (specificity 11.3%). Over one month, accuracy changed by −5.2, −4.1 and +8.6 percentage points, but these net figures concealed considerable case-level movement: within-model agreement ranged from near chance to substantial (mean Cohen κ 0.131 to 0.622), and the F1-score of Claude Sonnet 4.5 fell by 13.1 points despite its higher accuracy. Subtype descriptions were frequently correct once a fracture had been detected, but end-to-end subtype accuracy remained low. Conclusions: Current vision language models demonstrate encouraging diagnostic performance; however, their temporal reproducibility remains inadequate for independent medico-legal fracture interpretation. These findings highlight that reproducibility, in addition to diagnostic accuracy, should be considered a core benchmark when evaluating VLMs for high-stakes clinical and forensic use. Larger multicenter studies using independent external datasets are needed before forensic application is considered. Full article

Objectives: To evaluate associations between shrinkage of ablated liver area on computed tomography (CT) over time after radiofrequency ablation (RFA) and clinical parameters related to liver function and fibrosis. Methods: Patients with hepatocellular carcinoma who underwent RFA and follow-up CT were retrospectively reviewed. The ablated area volume (AAV) on CT obtained within 1 week and around 6 months after RFA was measured, and reduction rate of AAV was calculated. The AAV reduction rate was compared among Child-Pugh classification, modified albumin-bilirubin (mALBI) grades, FIB-4 index categories, and lesion locations using generalized estimating equations (GEE). Univariable and multivariable GEE analyses were performed to evaluate associations between the AAV reduction rate and clinical parameters. Results: Fifty-three lesions in 41 patients (median age, 76 [range, 38–88] years, 24 men) were evaluated. The AAV reduction rate was significantly lower in Child-Pugh class B than class A (p < 0.001) and in mALBI grade 2b than grade 1 (p < 0.001) or grade 2a (p = 0.004). Significant differences were also observed among FIB-4 index groups (p < 0.001) and among lesion locations, with lower AAV reduction rates in medial and anterior segments than in lateral (p < 0.001) and posterior (p = 0.017) segments. Univariable GEE analyses showed significant associations between AAV reduction rate and cholinesterase, albumin, total bilirubin (T-Bil), prothrombin time, platelet count, and FIB-4 index (p < 0.05). Multivariable GEE analysis demonstrated that both albumin and T-Bil remained independently associated with AAV reduction rate (p < 0.001). Conclusions: The AAV reduction rate tended to be lower in patients with impaired liver function and advanced liver fibrosis. Full article

The carotid and vertebral arteries are critical components of the cerebral circulation, supplying the brain and spinal cord. Their embryologic development involves complex transformations of the aortic arches, paired dorsal aortae, and cervical intersegmental arteries. Congenital anomalies and variations involving their origin, course, and branching patterns are relatively common and are increasingly recognized using modern imaging. While many of these variants are incidental, some carry important clinical implications, particularly in contexts of stroke imaging, head and neck surgery, and neurointerventional procedures. This article reviews the embryologic development of the carotid and vertebral arterial systems, highlights normal and variant anatomy, and presents a case-based, illustrated overview of these congenital anomalies. Emphasis is placed on key findings utilizing computed tomography angiography (CTA), magnetic resonance angiography (MRA), and catheter angiography. Particular attention is given to structural and pathway variations, including vessel agenesis or hypoplasia, the aberrant internal carotid artery within the temporal bone, abnormal branching patterns, fenestrations, and persistent fetal anastomoses (such as the primitive trigeminal, hypoglossal, and proatlantal intersegmental arteries). Ultimately, familiarity with these anomalies, their embryological origins, and their distinct imaging characteristics is essential for ensuring accurate interpretation and avoiding diagnostic pitfalls and procedural complications. Full article

Background: Ischemia-related optical coherence tomography angiography (OCTA) signal degradation complicates cerebral vessel segmentation and quantitative analysis. We developed a structure-aware segmentation framework and applied it to exploratory longitudinal vascular quantification. Methods: Six adult male C57BL/6 mice were imaged at baseline and 0.5–10 h after photothrombotic induction. After geometric transformation, 345 image instances were separated by animal into training, validation, and test subsets of 240, 30, and 75 images from four, one, and one mouse; the 75 test instances originated from 25 source images. A separate sixfold subject-level cross-validation generated out-of-sample masks for longitudinal analysis. Results: The proposed method achieved a Dice coefficient of 0.887, a centerline Dice (clDice) of 0.953, a branch-point F1 score of 0.739, and an average surface distance (ASD) of 0.564 pixels, with significant improvements in Dice, clDice, and branch-point F1. Vascular perfusion density (VPD) and vessel length (VL) decreased significantly over time, vessel average diameter (VAD) remained stable, and average curvature (AC) and branch-point density (BPD) showed significant overall temporal effects. Conclusions: The framework improved technical segmentation performance and supported exploratory analysis of OCTA-derived vascular measurements in experimental ischemic stroke. Full article

Background: The thoracolumbar junction (TLJ) includes the T11–L2 vertebral segments. It is a pivotal biomechanical transition zone between the rigid thoracic spine and the more mobile lumbar spine. Accurate morphometric data from this region are crucial for understanding human axial biomechanics and supporting forensic investigations. Objective: This study was designed to establish a normative multi-detector computed tomography (MDCT) database of the human thoracolumbar junction (T11–L2) in an adult population. Specifically, the primary objectives were to quantify normal vertebral and pedicle dimensions and to investigate the prevalence of congenital rib anomalies. The ultimate clinical goal is to translate these anatomical metrics into practical guidelines for spinal surgery and tools for forensic sex estimation. Materials and Methods: A retrospective analysis of 517 adults (277 men, 240 women) who received thoracic CT for various clinical indications was conducted. Morphometric parameters, including anterior, middle, and posterior vertebral heights; transverse and sagittal pedicle diameters; pedicle length; and transverse pedicle angle, were systematically measured. Costal variations, including hypoplastic and supernumerary ribs, were carefully recorded. Results: Vertebral and pedicle linear dimensions were generally larger in men than in women. The mean transverse pedicle diameter (TPD) increased progressively from T11 to L2. Significant sexual dimorphism in TPD was observed at the T11, L1, and L2 levels (p < 0.05), whereas both transverse (p = 0.168) and sagittal (p = 0.251) pedicle dimensions remained statistically comparable between sexes exclusively at the T12 transitional segment. The transverse pedicle angle (TPA) showed a consistent, increasing medial trajectory from T11 (~21°) to L2 (~28°) in both sexes, with no significant sex-based difference (p > 0.05). The overall prevalence of congenital rib variations was 18.57%. The most frequent structural anomaly was 12th-rib hypoplasia. Conclusions: This study provides a detailed morphometric baseline for the TLJ in an adult cohort (n = 517) of Turkish adults. The findings show that while absolute pedicle size and volumetric mass are influenced by sexually dimorphic physical geometry, the spatial trajectory and angulation of the pedicles (TPA) are determined by biomechanical principles that are independent of sex. In addition, pronounced sexual dimorphism and a high prevalence of unique costal variations were observed. These factors provide valuable biological markers that serve as reliable radiological fingerprints for forensic anthropologists who estimate sex from skeletal remains and identify unknown individuals. Full article

Background/Objectives: Myocardial perfusion PET/CT, e.g., using Rb-82, enables the measurement of absolute myocardial blood flow (MBF) and, hence, the blood flow reserve, which plays a crucial role in the diagnosis of coronary artery disease. However, the values might depend on the observer’s analysis and, thus, depend on the observer’s experience. We investigated the inter-observer reliability of MBF measurements in Rb-82-PET/CT. Methods: Thirty consecutive patients who underwent Rb-82-PET/CT for suspected myocardial ischemia were analyzed. Stress conditions were simulated using 400 µg Regadenoson. MBF was measured using Corridor 4DM software. Myocardial flow reserve (MFR) is the ratio of absolute flow measurements under stress and rest conditions. Four different physicians with different levels of experience (two senior physicians and two residents) measured the MBF. The experience of the two residents was one year of experience and no previous experience, respectively. Intraclass correlation coefficients (ICC) were calculated for MBF and MFR in the three main vascular territories as well as in the whole left ventricle. Additionally, the left ventricular ejection fraction (EF) was determined. Results: The evaluation of MBF showed an excellent correlation between all observers, indicated by a low inter-observer variability. Comparing the two different levels of experience, senior physicians showed a slightly higher accordance in MBF assessment (ICC ranging from 0.9 to 0.98) than the residents (ICC ranging from 0.86 to 0.94). The MFR calculations showed a slightly lower reliability due to the accumulation of variability in rest and stress measurements (ICC between 0.78 and 0.81), still indicating a good reliability. The EF calculations also showed a good reliability among the different observers (ICC 0.83). Conclusions: Measurement of MBF, MFR and EF in Rb-82-PET/CT is highly robust with a very low inter-observer variability. A slightly higher inter-observer reliability was found for more experienced physicians. Full article