Current Medical Imaging - Volume 18, Issue 14, 2022

Aim: This study aimed to evaluate the contribution of the MRI and CT results to the differential diagnosis of histopathologically different odontogenic cysts. Background: Odontogenic cysts are commonly seen in the jaw bone and their surgical operations have an important place in the practice of maxillofacial surgery; treatment options for these cysts differ according to their histopathology. Differential results that can be obtained from the radiological evaluations of different cyst groups will allow the surgeon to plan a more accurate approach at the beginning of the operation. In this study, computed tomography (CT) and magnetic resonance imaging (MRI) results of different cyst groups were interpreted together with their histopathological diagnosis. Methods: CT and MRI results of 17 patients aged between 19-61 were evaluated, whose histopathological diagnosis consisted of 3 radicular cysts (RC), a total of 9 odontogenic keratocysts (OKC) of which 4 were inflamed, and a total of 5 dentigerous cysts (DC) of which one of them was inflammatory. Results: In the CT scan, all cysts showed lytic, a sclerotic surrounding, and showed MRI peripheral enhancement, whereas solid nodular enhancement was only observed in OKCs. Edema and/or air in the surrounding bone medulla was observed in the infected lesions. OKC was heterogeneous, whereas RC and DC were more homogeneous. Diffusion restriction was observed to be frequent in OKCs. The OKCs were ellipsoidal in appearance and were located parallel to the long axis of the bone, and their dimensions were observed to be larger than the other cysts. OKCs may be accompanied by unerupted teeth. Radicular cysts were located perpendicular to the long axis of the bone and were globular in appearance, and their dimensions were smaller and more homogeneous compared to the OKCs. Dentigerous cysts are also accompanied by an unerupted tooth, and their peripheral enhancement is minimal and homogeneous. However, dentigerous cysts can be dense in content and smaller in size, and ellipsoidal localization is more common than OKCs. Conclusion: In addition to classic panoramic radiography in the evaluation and differential diagnosis of maxillary and mandibular lesions, CT and MRI evaluations can provide helpful information to the surgeon and pathologist in making the diagnosis and may further help plan the operation.

Background: Intramedullary well-differentiated osteosarcoma (IMWDOS) is rare and may easily be misdiagnosed. Objective: This study aimed at investigating the clinical, imaging, and pathological features of IMWDOS for correct diagnosis. Materials and Methods: Seventeen patients with IMWDOS were enrolled, and their clinical, imaging, and pathological data were analyzed. Results: Total 13 males and 4 females aged 19-55 years (mean 36. 1) were selected. The lesion was located at long bones in 16 patients and the second region of the acetabulum in one patient. Except for three patients with limited areas of lesions, all the other patients had a wide distribution of tumor, and the lesion in long bones involved the metaphysis area with possible extension towards the diaphysis. In imaging, the lesion usually had an unclear boundary with the destruction of bone cortex, uneven thickness of the bone cortex, thick and coarse trabecula in the lesion, but few periosteal reactions and soft tissue masses. The lesion was histologically composed of spindle cells with slight atypia. Follow-up was performed 2-101 months (mean 31.9m) in 14 cases, 10 years in one case, and 26 years in the remaining two. At follow-up, 12 patients (12/17 or 70.6%) who had a complete resection, including amputation (n=2), wide excision (n=8), and endoprosthetic replacement (n=2), showed no recurrence or metastasis. Among five patients who underwent curettage, three (3/17 or 17.6%) had recurrent lesions, leading to death in two of them, and the third one died during post-operation chemotherapy. Conclusion: Intramedullary well-differentiated osteosarcoma tends to occur at the metaphysis of long bones, especially at the distal femur. Histological, clinical, and imaging findings lack specific characteristics and should be examined collectively to reach a correct diagnosis. The prognosis of patients with complete lesion resection is good, while incomplete lesion curettage or resection will lead to recurrence and transformation into a highly malignant tumor.

Background: COVID-19 patients' courses vary in length, indicating a variable prognosis. The disease duration revealed by different examination methods may differ. Objective: The study aims to compare the differences in the disease course of patients with COVID-19 by chest computed tomography (CT) and reverse-transcription polymerase chain reaction (RT-PCR) assay and explore the factors that affect the course of the illness. Methods: 106 patients confirmed with COVID-19 were enrolled and divided into two groups (age <60 years and age ≥60 years). The clinical characteristics of the two groups were analyzed. The intervals from symptoms onset to initial positive time point (ISIP), symptoms onset to the initial negative time point (ISIN), and initial positive to initial negative time point (IIPN) indicated by chest CT and RTPCR assay were analyzed. Multiple regression analysis was performed to assess the correlations between independent factors and the intervals. Results: Chest CT showed an earlier positive time point, a later negative time point, and a longer disease duration than the RT-PCR assay (P<.001, respectively). Older patients over 60 years old showed a later negative time point and a longer disease duration by chest CT than younger patients (P<.01 vs. P<.05, respectively). The CT score and clinical grades of older patients were greater than those of younger patients (P<.001, respectively). Age and clinical grades were significantly correlated with the disease course shown by chest CT (P<.05, respectively), and CT score was positively correlated with the illness course shown by chest CT and RT-PCR assay (P<.01, respectively). Conclusion: The disease course revealed by chest CT and RT-PCR assay was asynchronous. Chest CT showed a 17-day longer period compared to the RT-PCR assay. Older patients had a longer duration than younger ones. A prolonged course is predicted by increasing age, CT score, and clinical grades.

Background: The Bosniak classification system based on contrast-enhanced computed tomography (CECT) is commonly used for the differential diagnosis of cystic renal masses. Contrastenhanced ultrasound (CEUS) is a relatively novel technique, which has gradually played an important role in the diagnosis of cystic renal cell carcinoma (CRCC) due to its safety and lowest price. Objective: The aim of the study is to investigate the application value of CEUS and Bosniak classification into the diagnosis of cystic renal masses. Methods: 32 cystic masses from January 2018 to December 2019 were selected. The images of conventional ultrasound (US), CEUS and CECT from subjects confirmed by surgical pathology were retrospectively analyzed. The Bosniak classification system of cystic renal masses was implemented using CEUS and CECT, and the diagnostic ability was compared. Results: For the 32 cystic masses, postoperative pathology confirmed 11 cases of multilocular CRCC, 15 cases of clear cell carcinoma with hemorrhage, necrosis and cystic degeneration, 5 cases of renal cysts, and 1 case of renal tuberculosis. The Bosniak classification based on CEUS was higher than that based on CECT, and the difference was statistically significant (P = .024). The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of CEUS were comparable to CECT. There was no significant difference observed in the diagnosis of CRCC (P >.05). Conclusion: CEUS combined with Bosniak classification greatly improves the diagnosis of CRCC. CEUS shows a comparable diagnostic ability to CECT. In daily clinical routine, patients who require multiple examinations and present contraindications for CECT can particularly benefit from CEUS.

Objective: The objective of this study is to investigate the diagnosis of dynamic volume computed tomography (CT) for pulsatile tinnitus caused by sigmoid sinus diverticulum (SSD) and bone defects. Methods: Data obtained by dynamic volume CT from 35 patients with SSD were retrospectively collected. Then the ear morphological parameters, including bone defect, transverse sinus stenosis, position of the jugular bulb, jugular bulb diverticulum, defect of the jugular bulb wall, gross venous sinus thrombosis and SSD, and blood perfusion parameters, including cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT), were evaluated and compared between the tinnitus side and the asymptomatic side of the ear. Results: The maximum diameters of the bone defects on the tinnitus side were greater than those on the asymptomatic side (Horizontal 6.36±2.35mm vs. 1.12±0.78mm; Longitudinal 4.87±1.25 vs. 0.88±0.06mm). Dynamic volume CT visually displayed the SSD herniated into the adjacent mastoid via the bone defect. Transverse sinus stenosis, high position of the jugular bulb, jugular bulb diverticulum, defect of the jugular bulb wall, and gross venous sinus thrombosis were present more frequently on the tinnitus side than on the asymptomatic side (P < 0.05). Moreover, CBF, CBV, and MTT were significantly greater on the tinnitus side than on the asymptomatic side (P < 0.05). Conclusion: Dynamic volume CT examination is an effective method for the diagnosis of pulsatile tinnitus caused by SSD with bone defects.

Background: Ovarian tumor is a common female genital tumor, among which malignant tumors have a poor prognosis. The survival rate of 70% of patients with ovarian cancer is less than 5 years, while benign ovarian tumor is better, so the early diagnosis of ovarian cancer is important for the treatment and prognosis of patients. Objectives: Our aim is to establish a classification model for ovarian tumors. Methods: We extracted radiomics and deep learning features from patients’CT images. The four-step feature selection algorithm proposed in this paper was used to obtain the optimal combination of features, then, a classification model was developed by combining those selected features and support vector machine. The receiver operating characteristic curve and an area under the curve (AUC) analysis were used to evaluate the performance of the classification model in both the training and test cohort. Results: The classification model, which combined radiomics features with deep learning features, demonstrated better classification performance with respect to the radiomics features model alone in training cohort (AUC 0.9289 vs. 0.8804, P < 0.0001, accuracy 0.8970 vs. 0.7993, P < 0.0001), and significantly improve the performance in the test cohort (AUC 0.9089 vs. 0.8446, P = 0.001, accuracy 0.8296 vs. 0.7259, P < 0.0001). Conclusion: The experiments showed that deep learning features play an active role in the construction of classification model, and the proposed classification model achieved excellent classification performance, which can potentially become a new auxiliary diagnostic tool.

Background: It is important for orthopedic surgeons to follow the union of the fracture after surgery. This becomes even more important after nonunion surgery. The radiological union scale is popular in the follow-up of unions. However, the intraobserver and interobserver agreement of this scale in humeral nonunion surgery is still not found in the literature. Objective: This study aimed to reveal the intra/interobserver agreement of the Radiographic Union scale (RHUM) for the humerus as well as the relationship between this agreement, plate placement characteristics, and the number of plates in cases where plates were used for surgical treatment of humeral diaphysis nonunion. Materials and Methods: Twenty patients who received surgical treatment for aseptic humeral nonunion at our hospital between 2010-2019 were studied retrospectively. According to RHUM, two observers scored the patients' anteroposterior and lateral radiographs in the postoperative 12th week. The data obtained were statistically analyzed. Results: The mean age was 52.05±15.88 years. While a single plate was used in 14 cases, a double plate was used in 6 cases. Interobserver agreement was fair-moderate. The interobserver agreement values of the single plate group were significantly higher than those of the double plate group (p<0.05). Interobserver agreement in cases with a lateral plate was significantly higher than in the group where the lateral + posterior plate was applied (p:0.01). Conclusion: In humeral diaphyseal fracture nonunion cases, the number and location of the plate following surgery negatively impact the evaluation of RHUM scores. Given the importance of the union's follow-up and the decision to proceed with additional treatment in these cases, it may be necessary to develop a new method for determining and monitoring the union if a plate was used in the surgical treatment of humeral nonunion.

Background: Diagnosis of coronavirus disease 2019 (COVID-19) is mainly based on molecular testing. General population studies have shown that chest Computed Tomography (CT) can also be useful. Objective: The study aims to examine the usefulness of high-resolution chest CT for early diagnosis of patients with suspected COVID-19. Design And Setting: This is a cross-sectional study from May 1, 2020, to August 31, 2021, at the COVID Hospital, Mexico City. Methods: This study examined the clinical, high-resolution chest CT imaging, and laboratory data of 160 patients who were suspected to have COVID-19. Patients with positive Reverse Transcription- Polymerase Chain Reaction (RT-PCR) testing and those with negative RT-PCR testing but clinical data compatible with COVID-19 and positive antibody testing were considered to have COVID-19 (positive). Sensitivity and specificity of CT for diagnosis of COVID-19 were calculated. p < 0.05 was considered significant. Results: Median age of 160 study patients was 58 years. The proportion of patients with groundglass pattern was significantly higher in patients with COVID-19 than in those without COVID (65.1% versus 0%; P = 0.005). COVID-19 was ruled out in sixteen (11.1%). Only four of the 132 patients diagnosed with COVID-19 (3.0%) did not show CT alterations (p < 0.001). Sensitivity and specificity of CT for COVID-19 diagnosis were 96.7% and 42.8%, respectively. Conclusions: Chest CT can identify patients with COVID-19, as characteristic disease patterns are observed on CT in the early disease stage.

Background: β-blockers are widely used for lowering heart rate (HR) during coronary computed tomography angiography (CCTA); however, they should be used with caution for patients with heart failure as they may have a negative inotropic effect. Objective: To clarify the effects of β-blockers (oral and intravenous injection) on cardiac function using CCTA. Methods: A total of 244 patients (men: women = 166: 78; mean age, 64.4 years old) suspected of having ischemic cardiac disease and had undergone echocardiography within 3 months before and after CCTA were included in the study. Systematic errors in ejection fraction (EF) were corrected by calculating ΔEF from the EF difference between echocardiography and CCTA in patients not using β- blockers. Univariate and multivariate analyses were performed for factors affecting ΔEF. In addition, HR between, before, and during CCTA were compared by Wilcoxon’s test. Results: Temporary oral or intravenous administration of β-blockers at the CCTA had no significant effects on EF (p = 0.70), whereas HR was significantly decreased (p < 0.001). However, regular administration of β-blockers increases the EF on CCTA. Conclusion: The administration of β-blockers immediately before CCTA affects HR but not EF. Premedication with β-blockers can be safely used for patients who undergo CCTA, and CCTA is useful for EF evaluation, independent of the use of β-blockers.

Introduction: This is a rare case report of axillary intraductal papilloma arising in accessory breast tissue. Case Presentation: A 49-year-old woman presented to our clinic with a palpable right axillary mass that had first appeared 6 months earlier. Mammography and ultrasonography of the right axilla revealed an ovoid mass surrounding accessory breast tissue. Ultrasound-guided 14-G core-needle biopsy was performed and pathologically revealed intraductal papilloma without atypia. Conclusion: Since ectopic breast tissue is affected by the same pathologic processes as normal breast tissue, a core-needle biopsy can be used to identify the suspicious lesions in axillary breast tissue.

Introduction: The number of cesarean deliveries (CDs) has extremely increased in the last decades. Although it is a common and relatively safe surgical procedure, there are several potential complications. To the best of our knowledge, complete cervicouterine dissociation after several CDs has not been reported before in the medical literature. Case Report: A 28-year-old woman with a history of 6 CDs presented with abdominal pain and vaginal bleeding. The patient's most recent CD happened three weeks before the current presentation. Transabdominal ultrasonography examination and magnetic resonance imaging revealed the absence of continuity with the uterine cervix and corpus with associated pelvic hematoma. Laparotomy findings confirmed the imaging findings, and the displaced uterine corpus was removed with the evacuation of the associating pelvic hematoma. Conclusion: Uterine dehiscence and rupture are among the relatively common complications of CD. Uterine rupture and dehiscence are focal disorders, and complete cervicouterine dissociation has not been seen before. Multiple CDs are among the risk factors for complete cervicouterine dissociation, and abnormal uterine bleeding is the most common symptom. Imaging findings allow a quick and definitive diagnosis, and surgical intervention may be planned accordingly based on the imaging findings.

Background: A series of pneumonia cases with clinical presentations of viral pneumonia secondary to new coronavirus and subsequent global transmission arose in Wuhan, Hubei, China, in December 2019. Several cases of coronavirus disease 2019 (COVID-19) have been described incidentally in positron emission tomography-computed tomography (PET/CT) with ¹⁸F-fluorodeoxyglucose (FDG) as a result of the pandemic. Herein, we describe the findings of a patient with unknown COVID-19 in PET/CT with the other radiopharmaceutical, ⁶⁸Ga-labeled prostatespecific membrane antigen (⁶⁸Ga-PSMA). Case Report: A 69-year-old man had previously undergone radical prostatectomy for adenocarcinoma. ⁶⁸Ga-PSMA PET/CT imaging was performed due to biochemical recurrence. ⁶⁸Ga-PSMA uptake in the prostate bed suggestive of local recurrence was detected in PET/CT images. Also, bilateral groundglass opacities with slightly increased ⁶⁸Ga-PSMA uptake were seen in the lungs, suspected of COVID-19. A reverse transcription-polymerase chain reaction test has confirmed the infection. Conclusion: Even in asymptomatic patients, nuclear medicine departments must be aware of the possibility of COVID-19, take appropriate post-exposure procedures, and protect employees and other patients.

Background: Coronavirus disease 2019 (COVID-19, previously known as novel coronavirus [2019-nCoV]), first reported in China, has now been declared a global health emergency by World Health Organization. The clinical severity ranges from asymptomatic individuals to death. Here, we report clinical features and radiological changes of a cured family cluster infected with COVID-19. Case Presentation: In this report, we enrolled a family of 4 members who were admitted to our hospital in January 2020. We performed a detailed analysis of each patient’s records. All patients underwent chest computed tomography (CT) examination with 120 kilovolts peak and 150 kilovolt-ampere. Realtime polymerase chain reaction (RT-PCR) examinations for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleic acid were done using nasopharyngeal swabs. Conclusion: In the family members infected with COVID-19 who were accompanied by other diseases or had low immunity, the pneumonia was prone to be aggravated.

Background: Renal leiomyoma is a challenging diagnostic and therapeutic condition. Given that 90% of leiomyomas originate from the renal capsule, leiomyoma presenting as a renal parenchymal mass is extraordinarily rare. Case Presentation: Herein, we report the clinical and imaging features of a patient with renal leiomyoma occurring in the renal parenchyma and mimicking renal cell carcinoma. We also review the clinical, imaging, and histological features of renal leiomyoma. Conclusion: An initial partial, simple or radical nephrectomy according to tumor size and patient’s underlying condition is suitable for larger, heterogeneous, and non-peripherally located tumors, even if they demonstrate hypointensity on T1- and T2-weighted images, considering the possibility of other diagnoses.