Did radiation exposure increase with chest computed tomography use among different ages during the COVID-19 pandemic? A multi-center study with 42028 chest computed tomography scans

PURPOSE: To determine whether radiation exposure increased among different ages with chest computed tomography (CT) use during the coronavirus disease-2019 (COVID-19) pandemic. METHODS: Patients with chest CT scans in an 8-month period of the pandemic between March 15, 2020, and November 15, 2020, and the same period of the preceding year were included in the study. Indications of chest CT scans were obtained from the clinical notes and categorized as infectious diseases, neoplastic disorders, trauma, and other diseases. Chest CT scans for infectious diseases during the pandemic were compared with those with the same indications in 2019. The dose-length product values were obtained from the protocol screen individually. RESULTS: The total number of chest CT scans with an indication of infectious disease was 21746 in 2020 and 4318 in 2019. Total radiation exposure increased by 573% with the use of chest CT for infectious indications but decreased by 19% for neoplasia, 12% for trauma, and 43% for other reasons. The mean age of the patients scanned in 2019 was significantly higher than those scanned during the pandemic (64.6 vs. 50.3 years). A striking increase was seen in the 10-59 age group during the pandemic (P < 0.001). The highest increase was seen in the 20-29 age group, being 18.6 fold. One death was recorded per 58 chest CT scans during the pandemic. Chest CT use was substantially higher at the beginning of the pandemic. CONCLUSION: Chest CT was excessively used during the COVID-19 pandemic. Young and middle-aged people were exposed more than others. The impact of COVID-19-pandemic-related radiation exposure on public health should be followed carefully in future years.

Ancillary findings in distinguishing between anterior cruciate ligament mucoid degeneration and sprain on MRI: a practical approach.

BACKGROUND: Imaging findings of both anterior cruciate ligament (ACL) sprain and mucoid degeneration overlap in some cases, which may cause errors in magnetic resonance imaging (MRI) evaluation. PURPOSE: To determine the ancillary findings on MRI in distinguishing between ACL sprain and mucoid degeneration, and also to obtain a diagnostic scheme. MATERIAL AND METHODS: MRI scans of 77 patients with ACL mucoid degeneration and 77 cases with ACL sprain were retrospectively evaluated to compare with regard to parameters of age, sex, side, the status of posterior cruciate ligament - medial collateral ligament - lateral collateral ligament, bone marrow edema, intraosseous cyst, subchondral sclerosis, chondromalacia, meniscus tear, effusion, and osteochondral body. A decision tree algorithm was created to predict pathology in ACL, whether it was a sprain or mucoid degeneration. RESULTS: The prevalence of female sex, femoral intraosseous cyst, tibial intraosseous cyst, subchondral sclerosis, femoral chondromalacia, tibial chondromalacia, medial meniscus tear, and lateral meniscus tear were significantly higher in the ACL mucoid degeneration group (P < 0.001, P = 0.016, P < 0.001, P = 0.003, P < 0.001, P < 0.001, P < 0.001, and P < 0.001, respectively). The probability of being mucoid degeneration increased 41.2 times (95% confidence interval [CI] = 5.296-321.132) in cases with tibial intraosseous cyst and increased 1.05 times (95% CI = 1.010-1.080) with each one-year increase in age (P < 0.001 and P = 0.011, respectively). The decision tree algorithm had an overall accuracy of 79.2%. CONCLUSION: Ancillary findings are helpful in the diagnosis of suspicious cases for ACL mucoid degeneration and ACL sprain. The decision tree algorithm offers a practical and successful approach to this issue.

The diagnostic value of magnetic resonance imaging-based texture analysis in differentiating enchondroma and chondrosarcoma.

OBJECTIVE: To assess the diagnostic performance of MRI-based texture analysis for differentiating enchondromas and chondrosarcomas, especially on fat-suppressed proton density (FS-PD) images. MATERIALS AND METHODS: The whole tumor volumes of 23 chondrosarcomas and 24 enchondromas were manually segmented on both FS-PD and T1-weighted images. A total of 861 radiomic features were extracted. SelectKBest was used to select the features. The data were randomly split into training (n = 36) and test (n = 10) for T1-weighted and training (n = 37) and test (n = 10) for FS-PD datasets. Fivefold cross-validation was performed. Fifteen machine learning models were created using the training set. The best models for T1-weighted, FS-PD, and T1-weighted + FS-PD images were selected in terms of accuracy and area under the curve (AUC). RESULTS: There were 7 men and 16 women in the chondrosarcoma group (mean ± standard deviation age, 45.65 ± 11.24) and 7 men and 17 women in the enchondroma group (mean ± standard deviation age, 46.17 ± 11.79). Naive Bayes was the best model for accuracy and AUC for T1-weighted images (AUC = 0.76, accuracy = 80%, recall = 80%, precision = 80%, F1 score = 80%). The best model for FS-PD images was the K neighbors classifier for accuracy and AUC (AUC = 1.00, accuracy = 80%, recall = 80%, precision = 100%, F1 score = 89%). The best model for T1-weighted + FS-PD images was logistic regression for accuracy and AUC (AUC = 0.84, accuracy = 80%, recall = 60%, precision = 100%, F1 score = 75%). CONCLUSION: MRI-based machine learning models have promising results in the discrimination of enchondroma and chondrosarcoma based on radiomic features obtained from both FS-PD and T1-weighted images.

Isolated tympanic plate fracture frequency and its relationship to mandibular trauma.

PURPOSE: This study evaluated the prevalence of isolated tympanic fractures and their correlation with mandibular fractures by using maxillofacial computed tomography (CT). MATERIALS AND METHODS: We retrospectively evaluated the maxillofacial CT of 1590 patients who presented to our emergency department with maxillofacial trauma between December 2010 and December 2012. Maxillofacial CT was used as the criterion standard for evaluating patients with maxillofacial fractures. The CT images were evaluated by using an electronic picture archiving and communications system and interpreted independently by 2 radiologists. RESULTS: The maxillofacial CT images revealed mandibular fractures in 167 of the patients and isolated tympanic plate fractures in 35 of these 167 patients. Four patients (11%) had a bilateral tympanic plate fracture, and 31 patients (89%) had unilateral tympanic plate fracture. Of all the tympanic plate fractures, 19 (54%) were on the right side and 16 (46%) were on the left side (P > .05). In our results, a significant correlation between the presence of a right-sided tympanic plate fracture and fracture of the ipsilateral condylar process was found (P = .036). However, a statistically significant difference between the presence of a tympanic plate fracture and other mandible fractures, additional soft-tissue findings, or the number of fractures was not determined (P > .05). Sex had no impact on the presence of tympanic plate fracture (P > .05). CONCLUSION: The frequency of isolated tympanic plate fractures in maxillofacial trauma is low, but it is an important anatomic location. Condyle fractures are significantly associated with isolated tympanic plate fractures. The presence of these injuries should raise suspicion of a concomitant isolated tympanic plate fracture.

Magnetic resonance sialography findings of submandibular ducts imaging.

PURPOSE: We aimed to assess the problem solving capability of magnetic resonance sialography (MR sialography), a noninvasive method for imaging submandibular gland ducts and determining duct-related pathologies, by comparing diseased and healthy cases. MATERIALS AND METHODS: We conducted radiological assessment on a total of 60 submandibular glands (mean age 44.7) in 20 cases and 10 volunteers. MR sialography examinations were conducted with single-shot fast spin-echo sequence by using a surface coil placed on the submandibular gland. Each gland was evaluated in terms of the length, width and stricture of the main duct, as well as the difference between the intraparenchymal duct width, and the main duct width. Statistical analysis was performed. RESULTS: In the MR sialography the primary duct mean length was determined as 51 mm (40-57 mm) in all submandibular glands. On the MR sialography imaging, the visualization ratio of the ductal system of submandibular gland was evaluated in the cases and volunteers. CONCLUSION: MR sialography is an effective and a noninvasive method in imaging submandibular gland ducts, demonstrating the presence, location and degree of stricture/dilatation, and elucidating the disease etiology.

Carotid intima-media thickness increase in patients with habitual simple snoring and obstructive sleep apnea syndrome is associated with metabolic syndrome.

OBJECTIVES: Sleep disorders are emerging risk factors for atherosclerosis. Increased carotid intima-media thickness (CCA-IMT) is a surrogate marker of cardiovascular risk. The aim of the present study was to investigate the relationship between CCA-IMT and habitual simple snoring or obstructive sleep apnea syndrome (OSAS) and the other cardiovascular risk factors. METHODS: Sleep disorders were diagnosed and staged by polysomnography. Patients were then classified into either habitual simple snoring (n = 20, group 1) or OSAS (n = 67, group 2), which was subclassified as mild-moderate (n = 27) or severe (n = 40). CCA-IMT was measured by B-mode ultrasonography. The other major risk factors were investigated. RESULTS: The mean CCA-IMT was 0.65 ± 0.02 mm (mean ± SD) in group 1 versus 0.75 ± 0.02 mm in group 2 (p = 0.03). Using CCA-IMT ≥ 0. 9 mm as the threshold value also yielded significant results between the two groups (p = 0.03). The mean CCA-IMT did not differ between patients with mild-moderate and severe OSAS, whereas metabolic risk factors and metabolic syndrome (MS) were more prominent in the latter. Age, MS, neck and waist circumference, waist/ hip circumference, and fasting glucose level were higher in patients with CCA-IMT ≥ 0.9 mm. CONCLUSIONS: CCA-IMT increase was associated with OSAS, but did not correlate with its severity, which could be due to the higher incidence of MS in this group.

MRI assessment of internal acoustic canal variations using 3D-FIESTA sequences.

Magnetic resonance imaging (MRI) of the internal acoustic canal is the standard diagnostic tool for a wide range of indications in patients. This study aims to investigate the vascular variations and compression of the cranial nerves (CNs) VII and VIII at the cerebellopontine angle in patients with neuro-otologic symptoms using 3D-fast imaging employing steady-state acquisition (FIESTA) MR imaging. One hundred and eighty-seven patients (374 temporal bones) were examined on a 1.5-T MRI. In addition to conventional MR sequences, a 3D-FIESTA MR imaging was acquired. Magnetic resonance images thus obtained were evaluated with special regard to the presence of vascular contact to the CNs VII and VIII, as well as the presence of the vascular variations of the anterior inferior cerebellar artery (AICA) causing the compression of CNs. The Chi-squared test was used for statistical analysis. No statistically significant differences were found between the presence and absence of the AICA loop and/or vascular contact for the clinical symptoms of patients (P > 0.05). The cisternal and canalicular segments of CNs VII and VIII and adjacent vascular variations are well identified using 3D-FIESTA, especially by determining the relationship of the AICA variations between CNs.

Computed tomography findings of an unusual maxillary sinus mass: brown tumor due to tertiary hyperparathyroidism.

Brown tumor is a non-neoplastic bone lesion that develops secondary to hyperparathyroidism and it is very rare in the maxillofacial region. We report the case of a 59-year-old man who presented with pain and a swelling in the left cheek. Computed tomography (CT) demonstrated an expansile and radioluscent lesion in the left maxillary sinus. Incisional biopsy was performed, and the diagnosis was Brown tumor. Brown tumor must be considered in the differential diagnosis of expansile lesions of maxillary sinus.

An unusual Hodgkin's lymphoma case presenting with upper extremity multiple masses.

Almost always, Hodgkin's lymphoma presents with lymph node involvement. Primary extranodal lymphoma is rare and mostly has a type of non-Hodgkin's lymphoma. We present an unusual presentation of a Hodgkin's lymphoma in a 33-year-old man. There were numerous soft tissue masses localized in the subcutaneous tissue of the left arm along the neurovascular bundle and the ipsilateral axillary region. We found only one Hodgkin's lymphoma case that presented as an upper extremity mass reported in the literature. In cases where a great number of successively lined up soft tissue masses are detected on the extremity, lymphoma takes place among the differential diagnoses.

Puffed-cheek computed tomography: a dynamic maneuver for imaging oral cavity tumors.

We conducted a prospective study to compare the effectiveness of conventional computed tomography (CT) and puffed-cheek CT in detecting the presence and extension of oral cavity malignant tumors. We enrolled 11 patients--5 men and 6 women, aged 32 to 85 years--who had a primary squamous cell carcinoma of the oral cavity. These tumors were located in the floor of the mouth in 4 patients, in the buccal mucosa in 4, in both the buccal mucosa and retromolar trigone in 2, and in the retromolar trigone only in 1. First, conventional contrast-enhanced axial CT was obtained through the oral cavity and neck in each patient. Next, axial imaging was obtained through the oral cavity while patients inflated their cheeks, pursed their lips, and held their breath. We found that the puffed-cheek CTs provided more information regarding the size and extent of the squamous cell carcinomas than did the conventional CTs. For example, in 8 patients, conventional CT could not differentiate the tumor from the normal mucosal surface, but puffed-cheek images clearly showed the surface of the tumor as distinct from the normal mucosa. More disconcerting was the fact that in the other 3 patients, conventional CTs were evaluated as normal, even though puffed-cheek imaging clearly showed the mass in each case. We conclude that puffed-cheek CT is superior to conventional CT for evaluating the mucosal surfaces of the oral cavity. It provides a clearer and more detailed picture with no downside.

Echolucency of carotid plaques and cerebrovascular events.

OBJECTIVES: To assess the relationship between carotid plaque echogenicity and degree of stenosis with acute and chronic stroke. METHODS: A retrospective study of cerebral MRI and carotid B-mode and Doppler ultrasonography in 60 patients with stroke. Plaque echogenicity was graded as echolucent (1), predominantly echolucent (2), predominantly echogenic (3), or echogenic (4). Sonographic findings were compared between patients with acute (group 1) and chronic (group 2) stroke. RESULTS: In group 1 (n = 39 patients), the carotid plaques were grade 1 in 21, grade 2 in 22, grade 3 in 9, and grade 4 in 4 carotid arteries. In group 2 (n = 21), the carotid plaques were grade 1 in 2, grade 2 in 8, grade 3 in 4, and grade 4 in 11 carotid arteries. Plaque echogenicity was lower in group 1 than in group 2 (p < 0.05). Plaque echolucency was associated independently with acute stroke from the degree of stenosis. CONCLUSIONS: Patients with acute infarcts have predominantly echolucent plaques, regardless of the degree of stenosis.

CT and MRI findings of developmental abnormalities and ectopia varieties of the thyroid gland.

Ectopic thyroid tissue may be observed anywhere from the tongue base to the lower neck. It is rarely seen in the mediastinum and abdominal cavity. Computed tomography and magnetic resonance imaging are very sensitive for detection and localization of ectopic thyroid tissue. This pictorial essay presents the radiological characteristics of developmental abnormalities and ectopia varieties of the thyroid gland.

Posterior semicircular canal dehiscence in asymptomatic ears.

CONCLUSIONS: This study revealed that, in the adult population, the final diagnosis of this entity can only be made by combining imaging with clinical tests. OBJECTIVE: We developed the largest temporal bone multislice computed tomography (CT) scan study so far by including 410 cases to investigate the prevalence of posterior semicircular canal dehiscence in patients with symptoms unrelated to the inner ear. METHODS: A prospective study was performed in 410 consecutive adult individuals who underwent temporal bone multislice CT scan examinations. RESULTS: The prevalence of posterior semicircular canal dehiscence was determined to be 1.2%. No superior or lateral semicircular canal defect was detected in these five patients. All cases with posterior semicircular canal defect were male. In two cases the canal was located unilaterally, while in three cases the defects were present bilaterally. Otological examination and audiovestibular tests revealed no abnormal findings in any of the individuals.

[The importance of computed tomography examination of temporal bone in detecting tympanosclerosis]. / Timpanosklerozun saptanmasinda temporal kemik bilgisayarli tomografi incelemenin yeri ve önemi.

OBJECTIVES: The aim of this study was to show detectability of tympanosclerotic plaques with computed tomography (CT) which has an important role in the evaluation of temporal bone. PATIENTS AND METHODS: Our study group included 19 tympanoplasty cases (12 females, 7 males; mean age 31 years; range 12 to 57 years) who were operated on for hearing restoration due to chronic otitis media and conductive hearing loss between January 2006 and May 2006 at the Department of Otolaryngology, Head and Neck Surgery, Izmir Atatürk Training and Research Hospital. The tympanosclerotic plaques obtained from surgical specimens were sent for pathological confirmation and temporal bone CT scans which were obtained preoperatively were reevaluated by a blinded radiologist who was dealing with head and neck radiology. RESULTS: All histopathological specimens obtained from tympanosclerotic plaques showed hyaline degeneration and increased collagen formation, resulting in increased epithelial thickness, calcification and in some cases ossification. Tympanosclerosis was identified in CT scans as ossified or calcified high density regions in the soft tissue in middle ear cavity, leading to ovoid, linear or weblike forms. Of those 19 cases, who were unilaterally operated on, eight cases had findings suggestive of tympanosclerosis in CT only in tympanic membrane (42.1%), two in only middle ear (10.5%) and eight in both middle ear and tympanic membrane (42.1%). In only one case (5.2%), tympanosclerosis was not identified radiologically. CONCLUSION: This study shows that temporal bone CT scan is a valuable method to diagnose the etiology of hearing loss and to detect the localization of the tympanosclerosis, in patients with chronic otitis media and conductive hearing loss. When combined with clinical findings, CT scans can be an informative guide to otolaryngologists for preoperative evaluation of tympanosclerosis.

A prospective study of paranasal sinus osteomas in 1,889 cases: changing patterns of localization.

OBJECTIVES/HYPOTHESIS: We developed the largest paranasal sinus computed tomography (CT) scan study so far by including 1,889 cases to investigate the prevalence, localization, age distribution, and the secondary complications of paranasal sinus osteomas. STUDY DESIGN: Prospective study. METHODS: A prospective study was performed on 1,889 consecutive adult individuals who underwent paranasal sinus CT examinations with suspected sinus disease. RESULTS: The prevalence of paranasal sinus osteomas was determined to be 3%. Osteomas were located most frequently in the ethmoid sinuses. The size of the osteomas varied from approximately from 2 to 30 mm. Of the osteomas found, 37%were accompanied by pathological sinonasal findings. CONCLUSIONS: The prevalence of sinonasal osteoma in the paranasal sinus region detected by CT scan is supporting the literature, whereas the localization pattern challenges it.

A rare cause of exophthalmos: cemento-ossifying fibroma.

Cemento-ossifying fibroma is a benign fibroosseous lesion that contains fibrous tissue and calcified tissue resembling bone, cementum or both. It is frequently seen in the mandibula and maxilla, but it may rarely affect the ethmoid sinus. In this report, we presented computed tomography findings of an ossifying fibroma of the ethmoid sinus associated with exophthalmos. A 25-year-old woman presented with complaints of exophthalmos, headache, and nasal congestion of six-month history. Physical examination showed a firm mass on the right side of the nasal septum and right-sided exophthalmos. Eye movements, vision, and the fundus were normal. Axial and coronal computed tomography scans showed a well-delineated, round mass, 4x4.5x3 cm in size, in the right ethmoid sinus, extending from the right orbital rim to the right nasal cavity. Near-total excision of the mass was performed by a lateral rhinotomy and medial maxillotomy approach. Based on histologic and radiological findings, the diagnosis was made as ossifying fibroma.

An adult choledochal cyst--the magnetic resonance cholangiopancreatography findings: report of a case.

We herein report an unusual adult patient with a congenital choledochal cyst. A 28-year-old woman presented with recurrent episodes of abdominal pain in the right upper quadrant. Abdominal ultrasonography showed fusiform dilatation of the common bile duct without any obstruction. Endoscopic retrograde cholangiopancreatography (ERCP) and magnetic resonance cholangiopancreatography (MRCP) were performed to make a precise diagnosis. No abnormal pancreatobiliary junction was detected on ERCP. The MRCP images more clearly defined the type and extent of the choledochal cyst as observed at surgery. The cyst and gallbladder were excised and a Roux-en-Y hepaticojejunostomy was performed. We also reviewed the relevant English literature and concluded that MRCP offers diagnostic information that is equivalent or superior to that of ERCP for the evaluation of type I choledochal cysts in adults and because this modality is noninvasive, it should therefore be the preferred imaging technique for an examination of adult patients with choledochal cysts.

Cranial MR imaging with clinical correlation in preeclampsia and eclampsia.

PURPOSE: Our aim was to determine the distribution and nature of cranial MRI findings in preeclampsia/eclampsia, and also to correlate them with clinical and laboratory data. MATERIALS AND METHODS: MR imaging was performed in 39 patients with preeclampsia (n=30) and eclampsia (n=9), and the distribution and signal patterns of the lesions were documented. Clinical findings, blood pressures, and laboratory data were compared statistically in patients with and without MR imaging findings. RESULTS: MR imaging was normal in 21 of the patients. In 18 patients, cortical-subcortical lesions, which appeared iso-/hypointense on T1W and hyperintense on T2W images, were detected. The occipital lobe was involved in all patients, followed by the parietal, frontal, and temporal lobes, and basal ganglia and pons. The lesions showed watershed distribution in 13 patients. When the patients with and without MR imaging findings were compared, there was a statistically significant difference regarding visual disturbances, depression of consciousness, and seizures (p=0.042, p=0.006, p=0.000, respectively). Although patients with MR imaging findings showed higher blood pressures as compared to those without MR imaging findings, there was no statistically significant difference (p=0.074). In patients with MR imaging findings, lactate dehydrogenase (LDH), uric acid, and creatinine levels were significantly higher than those without MR imaging findings (p=0.006, p=0.010, p=0.005, respectively). CONCLUSION: Increased permeability of the blood-brain-barrier related to endothelial injury plays a major role in the pathogenesis of preeclampsia/eclampsia. Relatively minor increases in blood pressure may cause cerebral lesions. However, when the cerebral autoregulation mechanism is considered, the distribution of cerebral lesions in the posterior circulation and watershed zones, which are relatively sparsely innervated by sympathetic nerves, provides evidence that the main determinant of pathogenesis is acute fluctuations in blood pressure.

Traumatic posterior fossa hematomas.

PURPOSE: Posterior fossa epidural hematomas are much less common than supratentorial epidural hematomas. The incidence of posterior fossa epidural hematomas among intracranial epidural hematomas has been reported to be 4% to 7%. Seven cases of posttraumatic posterior fossa epidural hematomas diagnosed by computed tomography (CT) are reported with radiological and clinical findings. MATERIALS AND METHODS: This study consisted of 7 posterior fossa epidural hematoma cases, out of 585 severe head trauma patients admitted and hospitalized in an 18-month period. The patients were evaluated regarding age, gender, type of trauma, cranial CT and Glasgow coma score in admittance, treatment and follow-up. RESULTS: Average age was 24.2 years and 85.7% of the cases were male. All cases had occipital fracture. Fifty-seven percent of the cases had only occipital fracture and posterior fossa epidural hematoma. All of the cases in this group were neurologically intact except for one who had a Glasgow coma score of 9 in admission. Two cases of this group were conservatively treated. In the others posterior fossa epidural hematomas got larger and they were treated surgically; these two cases recovered after surgery. Three of the 7 cases had the supratentorial region lesions; one of these cases died before operation. Two of them were treated surgically, one of them died and the other showed recovery after surgery. CONCLUSION: Acute posterior fossa epidural hematomas are usually symptom-free initially. After this silent period, clinical deterioration is quick to become fatal in most of patients. Surgery can be life-saving when performed in a timely manner. Therefore, CT should always be performed when an occipital trauma is diagnosed.