Imaging Features and Misdiagnosis of Giant Cerebral Cavernous Malformations.

BACKGROUND: While cerebral cavernous malformations (CCMs) have been extensively described, few reports have described the imaging appearance of giant CCMs (GCCMs). OBJECTIVE: To describe the imaging characteristics of GCCMs and study the reasons for preoperative misdiagnosis. METHODS: We retrospectively analyzed the data of 12 patients (5 men, 7 women; mean age, 35.23 ± 12.64 years) with histopathologically confirmed GCCMs. Two radiologists analyzed the CT (n = 12) and MRI (n = 10) features: location, number, size, shape, boundary, signal intensity, and enhancement. RESULTS: The sellar region, cerebral hemisphere, skull bone, and ventricle were involved in 5, 4, 2, and 1 patients, respectively. Three tumors were irregularly shaped, while nine were oval. Eleven lesions showed slightly high- and/or high-density on CT; 1 lesion appeared as a low-density cyst. Calcifications were found in 11 lesions. Four tumors showed uniform hypointensity on T1-weighted imaging (T1WI) and hyperintense signals on T2-weighted imaging (T2WI). Six tumors showed mixed low-, equal-, and high-intensity signals on T1WI and T2WI. Noticeable contrast enhancement and gradual strengthening were noted on T1WI. Ten lesions showed hemorrhage and hemosiderin deposition. The GCCMs were wrongly diagnosed as cartilage-derived tumors/ meningioma (3 patients); tumor and hematoma (2 patients each); and pituitary tumor/ meningioma, chondroma, chordoma, ependymoma, and macroadenoma (1 patient each). CONCLUSIONS: GCCMs present as an oval mass with slightly high- and/or high-density calcifications on CT and show hemorrhage and hemosiderin accumulation on MRI. Therefore, slightly high- and/or high-density calcification and hemosiderin accumulation are critical clinical characteristics of GCCMs.

Oblique Axis Rib Stretch and Curved Planar Reformats in Patients for Rib Fracture Detection and Characterization: Feasibility and Clinical Application.

Objective: To assess the use of CT with oblique axis rib stretch (OARS) and curved planar reformats (CPRs) for rib fracture detection and characterization. Methods: A total of 108 forensically diagnosed patients with rib fractures were evaluated retrospectively. OARS and CPRs were independently used during the diagnosis in two groups. In each group, the final diagnosis was made after a junior radiologist's initial diagnosis was reviewed by a senior radiologist. The images were evaluated for the presence and characterization of rib fractures. Results: A total of 2,592 ribs were analyzed, and 326 fractured ribs and 345 fracture sites were diagnosed using reference standard. Two groups of radiologists identified 331 and 333 fracture sites using the OARS method, 291 and 288 fracture sites using the CPRs method, and 274 fracture sites in forensically diagnosed patients (CR: conventional reconstruction), respectively; and all missed diagnoses were nondisplaced rib fractures. The ROC Az value of OARS1,2 was 0.98, which is higher than CPRs1,2 0.91, and CR 0.90 (all p < 0.01). The Az value for detecting rib fractures using CPRs1,2 and CR has no statistical difference (p = 0.14 and 0.29). More misdiagnosed patients were found using CPRs1,2 (42 and 44 cases) than OARS1,2 (1 and 2 cases) and CR (2 cases). The displaced fracture detection ratio of all methods showed no difference. Conclusions: Doctors using the OARS method could improve diagnostic performance for detecting rib fractures without the requirement of specialized software and workstation when compared with CPRs.

Effects of combining multiple dose reduction techniques on coronary computed tomography angiography.

BACKGROUND: Coronary computed tomography angiography (CCTA) is the preferred non-invasive examination method for coronary heart disease. However, the radiation from computed tomography has become a concern since public awareness of radiation hazards continue to increase. AIM: To explore the value of multiple dose reduction techniques for CCTA. METHODS: Consecutive normal and overweight patients were prospectively divided into two groups: Group A1, patients who received multiple dose reduction scans (n = 82); and group A2, patients who received conventional scans (n = 39). The scan parameters for group A1 were as follows: Isocentric scan, tube voltage = 80 kV, and tube current control using 80% smart milliampere. The scan parameters for group A2 were as follows: Normal position, tube voltage = 100 kV, and smart milliampere. RESULTS: The average effective doses (EDs) for groups A1 and A2 were 1.13 ± 0.35 and 3.36 ± 1.30 mSv, respectively. There was a statistically significant difference in ED between the two groups (P < 0.01). Furthermore, noise was significantly lower, and both signal-to-noise ratio and contrast signal-to-noise ratio were higher in group A2 when compared to group A1 (P < 0.01). Moreover, the subjective image quality (IQ) scores were excellent in both groups, in which there was no significant difference in subjective IQ score between the two groups (P = 0.12). CONCLUSION: Multiple dose reduction scan techniques can significantly decrease the ED of patients receiving CCTA examinations for clinical diagnosis.

Diagnostic accuracy of ultra-low-dose CT compared to standard-dose CT for identification of non-displaced fractures of the shoulder, knee, ankle, and wrist.

OBJECTIVES: To compare the performance of ultra-low-dose computed tomography (ULD-CT) with standard-dose computed tomography (SD-CT) for the diagnosis of non-displaced fractures of the shoulder, knee, ankle, and wrist. METHODS: This prospective study enrolled 92 patients receiving conservative treatment for limb joint fractures who underwent SD-CT followed by ULD-CT at a mean interval of 8.85 ± 1.98 days. Fractures were characterized as displaced or non-displaced. Objective (signal-to-noise ratio, contrast-to-noise ratio) and subjective CT image quality were evaluated. Observer performance for ULD-CT and SD-CT detecting non-displaced fractures was estimated by calculating the area under the receiver operating characteristic (ROC) curve (Az). RESULTS: The effective dose (ED) for the ULD-CT protocol was significantly lower than the ED for the SD-CT protocol (F = 422.21~2112.25, p < 0.0001); 56 patients (65 fractured bones) had displaced fractures, and 36 patients (43 fractured bones) had non-displaced fractures. Two non-displaced fractures were missed by SD-CT. Four non-displaced fractures were missed by ULD-CT. Objective and subjective CT image quality was significantly improved for SD-CT compared to ULD-CT. The sensitivity, specificity, PPV, NPV, and diagnostic accuracy of SD-CT and ULD-CT for non-displaced fractures of the shoulder, knee, ankle and wrist were similar: 95.35% and 90.70%; 100% and 100%; 100% and 100%; 99.72% and 99.44%; and 99.74% and 99.47%, respectively. The Az was 0.98 for SD-CT and 0.95 for ULD-CT (p = 0.32). CONCLUSION: ULD-CT has utility for the diagnosis of non-displaced fractures of the shoulder, knee, ankle, and wrist and can support clinical decision-making.

Magnetic Resonance Imaging Features and Misdiagnosis of Spinal Epidural Cavernous Hemangioma.

OBJECTIVE: Spinal epidural cavernous hemangiomas (SECHs) are rare, and merely a few have previously been described in case reports. The present study aims to explore the magnetic resonance imaging (MRI) features of SECHs and analyze the causes of their preoperative misdiagnosis. METHODS: The present retrospective study included 11 patients (three male and eight female patients, mean age ± standard deviation: 47.55±17.39 years old) with histopathologically confirmed SECH between January 2015 and April 2021. The MRI features of SECH were analyzed by two radiologists. RESULTS: The cervical, thoracic and thoracolumbar segments were involved in 2, 7 and 2 patients, respectively. All lesions grew along the long axis of the spine. The tumors were shuttle-shaped in six patients, oval in two patients, pseudopodia-shaped in one patient, clamp-shaped in one patient, and growing outward along the intervertebral foramen in one patient. Nine SECHs had relatively uniform isointense or hypointense T1-weighted imaging (T1WI) and hyperintense T2-weighted imaging (T2WI) signals. On the T2WI, filamentary low-signal shadows (i.e., the hairline or grid sign) with significant contrast enhancement and asymptotic strengthening were observed. Two SECHs had mixed high and low signals on T1WI and T2WI, with significant heterogeneous enhancement, hemorrhage, and hemosiderin deposition. The SECH was misdiagnosed as meningioma, neurofibromatosis and schwannoma in 1, 1 and 4 patients, respectively, while this was not diagnosed in one patient. The preoperative diagnosis was correct in merely approximately 36% of patients. Among the four patients with a correct preoperative diagnosis, hemosiderin deposition was found in three patients and small tortuous vascular shadows were found in one patient. CONCLUSION: SECH presents as a long spindle-shaped mass, and the "'pen cap sign" is common at the lesion edges. SECH also exhibits a hairline or grid sign on T2WI. Furthermore, some lesions present with hemorrhage and hemosiderin deposition. Therefore, the hairline, grid sign and hemosiderin deposition are valuable diagnostic features of SECH.

Comparing the effectiveness of 3D printing technology in the treatment of clavicular fracture between surgeons with different experiences.

PURPOSE: This study aims to examine the use of 3D printing technology to treat clavicular fractures by skilled and inexperienced surgeons. METHODS: A total of 80 patients with clavicle fractures (from February 2017 to May 2021) were enrolled in this study. Patients were divided randomly into four groups: group A: Patients underwent low-dose CT scans, and 3D models were printed before inexperienced surgeons performed surgeries; group B: Standard-dose CT were taken, and 3D models were printed before experienced surgeons performed surgeries; group C and D: Standard-dose CT scans were taken in both groups, and the operations were performed differently by inexperienced (group C) and experienced (group D) surgeons. This study documented the operation time, blood loss, incision length, and the number of intraoperative fluoroscopies. RESULTS: No statistically significant differences were found in age, gender, fracture site, and fracture type (P value: 0.23-0.88). Group A showed shorter incision length and fewer intraoperative fluoroscopy times than groups C and D (P < 0.05). There were no significant differences in blood loss volume, incision length, and intraoperative fluoroscopy times between group A and group B (P value range: 0.11-0.28). The operation time of group A was no longer than those of groups C and D (P value range: 0.11 and 0.24). CONCLUSION: The surgical effectiveness of inexperienced surgeons who applied 3D printing technology before clavicular fracture operation was better than those of inexperienced and experienced surgeons who did not use preoperative 3D printing technology.

The clinical performance of ultra-low-dose shoulder CT scans: The assessment on image and physical 3D printing models.

OBJECTIVES: Evaluation of the clinical performance of ultra-low-dose computed tomography (CT) images of the shoulder joint on image-based diagnosis and three-dimensional (3D) printing surgical planning. MATERIALS AND METHODS: A total of 93 patients with displaced shoulder fractures were randomly divided into standard-dose, low-dose, and ultra-low-dose groups. Three-dimensional printing models of all patients' shoulder joints were fabricated. The subjective image quality and 3D-printing model were evaluated by two senior orthopedic surgeons who were blinded to any scanning setting. A 3-point scale system was used to quantitatively assess the image quality and 3D printing model, where more than 2 points meant adequate level for clinical application. RESULTS: Compared with the standard dose protocol, ultra-low-dose technique reduced the radiation dose by 99.29% without loss of key image quality of fracture pattern. Regarding the subjective image quality, the assessment scores for groups of standard, low, and ultra-low doses were 3.00, 2.76, 2.00 points on scapula and humerus, and 3.00, 2.73, 2.44 points on clavicle. Scores of the three groups for the assessment of 3D printing models were 3.00, 2.80, 1.34 on scapula and humerus, and 3.00, 2.90, 2.06 on clavicle. In the ultra-low-dose group, 24 out of 33 (72.7%) 3D printing models of scapula and humerus received lower than 2 points of the evaluation score, while nearly 94% of the clavicle models reached the adequate level. CONCLUSION: An ultra-low-dose protocol is adequate for the diagnosis of either displaced or non-displaced fractures of the shoulder joint even though minor flaws of images are present. Three-dimensional printing models of shoulder joints created from ultra-low-dose CT scans can be used for surgical planning at specific bone like the clavicle but perform insufficiently in the overall surgical planning for shoulder injuries due to the significant geometric flaws.

Feasibility study of three-dimensional printing knee model using the ultra-low-dose CT scan for preoperative planning and simulated surgery.

OBJECTIVE: To explore the feasibility of the three-dimensional printing (3DP) knee model using the ultra-low-dose computed tomography (CT) scan for preoperative planning and simulated surgery. METHODS: Thirty-six patients were divided into the standard-dose protocol group (A) and ultra-low-dose protocol group (B). The anteroposterior diameter, left and right diameter of femur, anteroposterior diameter of tibial plateau (APTP), left and right diameter, distance from the intercondylar ridge to tibial tuberosity, lower femur angle, and upper tibial angle were measured on CT images. On the 3D printed knee joint model, Vernier calipers were used to measure: anteroposterior diameter, left and right diameter of the internal and external condyles of femur; left and right diameters, anteroposterior diameters of tibial plateau; upper and lower meridian, left and right diameters of patella. RESULTS: With group A as reference, the effective radiation dose in group B was significantly reduced to 97.0% (36.4 ± 3.7 uSv and 1.1 ± 0.2 uSv, respectively). There was no difference in objective parameters for 3DP model (p = 0.31-0.84). None of the quantitative parameters of image quality showed significant difference (p = 0.11-0.96). Despite lower score of image quality and 3DP model in group B (3.0 ± 0.0 vs. 2.1 ± 0.2, 2.9 ± 0.3 vs. 2.2 ± 0.4; p < 0.05), the diagnostic performance was consistent in the two groups (all scores ≥ 2). Image quality and 3DP printed models were highly consistent (k = 0.97). CONCLUSIONS: Ultra-low-dose protocol reduces the radiation dose while maintaining the image quality of knee. It meets the requirement for 3DP model, internal fixation model selection, and simulated surgery.

Imaging Features of Lymphoepithelial-Like Carcinoma of the Salivary Glands.

OBJECTIVE: Lymphoepithelial-like carcinoma of the salivary glands (LELCSG) is a rare tumour of unknown aetiology. No studies have reported the imaging features of primary LELCSG. METHODS: The clinical information and imaging features of eight patients with LELCSG were reviewed. Computed tomography (n = 4 patients) and magnetic resonance imaging (n = 4 patients) features were analysed by two radiologists to identify the location, number, size, shape, boundary, signal intensity and enhancement of LELCSG. RESULTS: The study included four women and four men, and the mean size of the tumours was 32.88 ± 3.41 mm (range, 27-38 mm). The tumours affected the parotid gland in six cases and the submandibular gland in two cases. The eight cases were evaluated by radiologists. All tumours were lobulated; three had clear edges and five had blurred edges. There was no necrosis in six tumours, while two tumours exhibited slight necrosis without bleeding. All eight tumours showed multiple nodular changes and extensive fusion. Four tumours with magnetic resonance imaging (MRI) were isointense or slightly hyperintense on T1-weighted imaging (T1WI) and obvious homogeneous enhancement on contrasted enhanced T1WI scan, while slightly hyperintense on T2-weighted imaging (T2WI). The other four lesions were isodense on computed tomography (CT) scan. The degree of enhancement varied among the eight tumours. The necrotic zones of the eight tumours did not exhibit any enhancement. CONCLUSIONS: LELCSG is a lobulated, multi-nodular tumour, with some fused nodules. LELCSG lesions showed isointensity or slight hyperintensity on T1WI MRI, slight hyperintensity on T2WI MRI and isodense on CT scan. Larger tumours may exhibit some necrosis, but the necrotic cysts were relatively rare. Uniform enhancement was observed in non-necrotic areas on enhanced CT and MRI scan. The multi-nodular feature may be valuable for diagnosis.

The diagnostic performance of ultra-low-dose 320-row detector CT with different reconstruction algorithms on limb joint fractures in the emergency department.

BACKGROUND: The aim of the study was to evaluate whether ultra-low-dose computed tomography (ULD-CT) could replace conventional-dose CT (CD-CT) for diagnosis of acute wrist, ankle, knee, and shoulder fractures in emergency departments (ED). METHODS: We developed CD-CT and ULD-CT scanning schemes for the various joints of the four limbs and scanned emergency patients prospectively. When performing CD-CT, a conventional bone reconstruction algorithm was used, while ULD-CT used both soft tissue and bone algorithms. A five-point scale was used to evaluate whether ULD-CT image quality affected surgical planning. The image quality and diagnostic performance of different types of scanned and reconstructed images for diagnosing fractures were evaluated and compared. Effective radiation dose of each group was calculated. RESULTS: Our study included 56 normal cases and 185 fracture cases. The combination of bone and soft tissue algorithms on ULD-CT can improve diagnostic performance, such that on ULD-CT, the sensitivity improved from 96.7% to 98.9%, specificity from 98.2% to 100%, positive predictive value from 99.4% to 100%, negative predictive value from 90.2% to 96.6% and diagnostic accuracy ranged from 97.5% to 99.1%. There were no statistically significant differences between ULD-CT and CD-CT on diagnostic performance (p values, 0.40-1.00). The radiation doses for ULD-CT protocols were only 3.0-7.7% of those for CD-CT protocols (all p < 0.01). CONCLUSIONS: In the emergency department, the 320-row detector ULD-CT could replace CD-CT in the diagnosis of limb joint fractures. The combination of bone algorithm with soft tissue algorithm reconstruction can further improve the image quality and diagnostic performance.

Application of ultra-low-dose CT in 3D printing of distal radial fractures.

PURPOSE: To explore the effect of ultra-low-dose computed tomography (CT) on three-dimensional (3D) printing models and the diagnosis of wrist fractures. METHOD: This study enrolled 76 patients with distal radial fractures (DRFs). All patients underwent 320-row detector CT and were divided randomly into two groups. In Group A, 38 patients were scanned with the standard-dose protocol using a tube voltage of 120 kV and current of 100 mA. In Group B, 38 patients were scanned with the ultra-low-dose protocol using a tube voltage of 80 kV and current of 10 mA. For objective image quality assessment, the noise, CT number, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were measured. Subjectively, two experienced orthopaedic surgeons blinded to the scan parameters evaluated the clarity of the 3D printing model and fracture line using a 3-point scale (the diagnosis was considered acceptable with scores ≥2). The mean radiation dose was calculated. The diagnostic performances for the fractures between the two groups were compared. RESULTS: The effective radiation dose was significantly reduced by 97.1 % in Group B, compared to Group A (0.28 ± 0.05vs. 9.75 ± 2.23 µSv, respectively). Quantitative objective image quality parameters (e.g., CNR, SNR, and CT numbers) were higher in the standard-dose group (p < 0.001). However, there was no difference in subjective scoring of the 3D printing model. Although the fracture line score was higher in Group A (2.92±0.27 vs. 2.16 ± 0.37; p < 0.001), the diagnostic performance of the two groups was consistent (all scores ≥2). There were no statistically significant differences in the sensitivity, specificity or accuracy between standard-dose group and ultra-low-dose group. CONCLUSIONS: The ultra-low-dose protocol effectively reduced the radiation dose by 97.1 %, while maintaining the image quality for diagnosis of DRFs. Therefore, this protocol can meet the needs of 3D printing models for preoperative assessments.

[An abnormal deeper lateral femoral notch is an indirect evidence for anterior cruciate ligament tear].

OBJECTIVE: To investigate the relationship between degree of abnormal deeper lateral femoral notch between anterior cruciate ligament tear. METHODS: The radiograph and MRI image material of 16 patients with anterior cruciate ligament injury from January 2013 to November 2013 were reviewed including 14 males and 2 females with an average age of 28.3 years old ranging from 18 to 52 years. Eleven cases was on right side and 5 on left. Survey tool of PASC imaging system was used to measure the depth of lateral femoral notch in patients with abnormal indicated by lateral X-ray view or sagittal view of MRI in knee joint,while clinical data,physical examination,image material in arthroscopy of these patients were retrospective researched. RESULTS: Four patients had an abnormal lateral femoral notch with the depth of 2 mm on lateral X-ray and sagittal MRI, while positive anterior drawer sign and Lachman test as well as anterior cruciate ligament tears on MRI, and completed tears were comfirmed on the operation of arthroscopy. Two patients without abnomal lateral femoral notch on lateral view of X-ray while with the depth of 1 mm on sagittal view of MRI were also coupled with positive anterior drawer sign and Lachman test as well as anterior cruciate ligament tears on MRI, and one of them were comfirmed completed anterior cruciate ligament tears on the arthroscopy operation and completed tear could not comfirmed on another one because of disagreed with arthroscopy operation. CONCLUSION: There appears to be an association between abnormal lateral femoral notch on lateral view of knee with anterior cruciate ligament tears. An abnormal deeper lateral femoral notch is an indirect evidence for anterior cruciate ligament tears.