[The detecting value of virtual non-calcium technique of dual-energy CT for bone marrow edema around nontraumatic osteonecrosis of the femoral head]

Objective: To evaluate the value of virtual non-calcium (VNCa) technique of dual-energy CT (DECT) for detecting bone marrow edema (BME) around nontraumatic osteonecrosis of the femoral head (ONFH) using MRI as reference standard. Methods: Nontraumatic ONFH patients were prospectively studied in the Fourth Medical Center of Chinese PLA General Hospital from October 2022 to May 2023, and their MRI and DECT images were analyzed. The diagnostic efficiency of the subjective assessment of BME around ONFH by two radiologists in VNCa color-coded images were calculated using the MRI results as the reference standard. The BME ranges were compared between VNCa images and MRI. Traditional CT values and VNCa CT values were compared between normal bone marrow and BME. The receiver operator characteristic (ROC) curve was established based on the statistically different CT values, and the area under the curve (AUC) was calculated to find the threshold to distinguish normal bone marrow from BME and evaluate the diagnostic efficacy. Results: Thirty patients with ONFH were included, including 24 males and 6 females, aged (39±12) years. There were 18 bilateral hips and 12 unilateral hips, with a total of 48 hips, 34 hips of which showed BME on MRI. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of subjective detection of BME on VNCa color coded maps by two physicians were 97.1% (33/34) and 97.1% (33/34), 92.9% (13/14) and 71.4% (10/14), 97.1% (33/34) and 89.2% (33/37), 92.9% (13/14) and 90.9% (10/11), 95.8% (46/48) and 89.6% (43/48), respectively, with no statistical difference (all P>0.05).There was no statistical difference between VNCa color-coded images and MRI in the BME range (P=1.160). The traditional CT values measured by the two radiologists were in good agreement with VNCa CT values, with intraclass correlation coefficient (ICC) of 0.948 (95%CI: 0.908-0.971) and 0.982 (95%CI: 0.969-0.990), respectively. The traditional CT value of normal bone marrow was (400.7±82.8) HU, and that of BME was (443.7±65.7) HU, with no statistical difference (P=0.062). The VNCa CT value of normal bone marrow was (-103.1±27.8) HU, and that of BME was (-32.9±25.7) HU, with statistical difference (P<0.001). The AUC of distinguishing normal bone marrow from BME based on VNCa CT value was 0.958 (95%CI: 0.857-0.995). The best cut-off value was -74.5 HU, and when the VNCa CT value was higher than -74.5 HU, the sensitivity, specificity, PPV, NPV and accuracy of diagnosing BME were 97.1%, 92.9%, 97.1%, 92.9% and 95.8 %, respectively. Conclusion: The VNCa technique of DECT has high efficiency in detecting BME around ONFH, and can accurately demonstrate the range of BME.

[Neoadjuvant chemotherapy in the treatment of locally advanced olfactory neuroblastoma in 25 cases]

Objective: To evaluate the efficacy of neoadjuvant chemotherapy (NACT) in the treatment of locally advanced olfactory neuroblastoma (ONB), and to explore the factors related to the efficacy of NACT. Methods: A total of 25 patients with ONB who underwent NACT in Beijing TongRen Hospital from April 2017 to July 2022 were retrospectively analyzed. There were 16 males and 9 females, with an average age of 44.9 years (ranged 26-72 years). There were 22 cases of Kadish stage C and 3 cases of stage D. After multiple disciplinary team(MDT) discussion, all patients were treated sequentially with NACT-surgery-radiotherapy. Among them, 17 cases were treated with taxol, cis-platinum and etoposide (TEP), 4 cases with taxol, nedaplatin and ifosfamide (TPI), 3 cases with TP, while 1 case with EP. SPSS 25.0 software was used for statistical analysis, and survival analyses were calculated based on the Kaplan-Meier method. Results: The overall response rate of NACT was 32% (8/25). Subsequently, 21 patients underwent extended endoscopic surgery and 4 patients underwent combined cranial-nasal approach. Three patients with stage D disease underwent cervical lymph node dissection. All patients received postoperative radiotherapy. The mean follow-up time was 44.2 months (ranged 6-67 months). The 5-year overall survival rate was 100.0%, and the 5-year disease-free survival rates was 94.4%. Before NACT, Ki-67 index was 60% (50%, 90%), while Ki-67 index was 20% (3%, 30%) after chemotherapy [M (Q₁, Q₃)]. The change of Ki-67 before and after NACT was statistically significant (Z=-24.24, P<0.05). The effects of age, gender, history of surgery, Hyams grade, Ki-67 index and chemotherapy regimen to NACT were analyzed. Ki-67 index≥25% and high Hyams grade were related to the efficacy of NACT (all P<0.05). Conclusions: NACT could reduce Ki-67 index in ONBs. High Ki-67 index and Hyams grade are clinical indicators sensitive to the efficacy of NACT. NACT-surgery-radiotherapy is effective for patients with locally advanced ONB.

[Magnetic resonance imaging study of endolymphatic hydrops based on 3D-FLAIR sequence after single-dose intravenous gadolinium injection]

Objective: To investigate the visualization of endolymph in patients with otogenic vertigo by intravenous administration of single dose of gadolinium contrast agents and magnetic resonance three-dimensional fluid-attenuated inversion recovery sequence (3D-FLAIR MRI), and further assess the extent of endolymphatic hydrops. Methods: From Beijing Tongren Hospital of Capital Medical University between October 2017 and June 2018, 30 patients (16 males, 14 females) with unilateral otogenic vertigo were involved in this study, with the age of 30 to 68 years, mean age of (53±10) years. Eight hours after intravenous administration of single dose (0.1 mmol/kg, body weight) of gadopentetate (Gd-DTPA), 3D-FLAIR sequence was performed in 30 patients. The location of endolymphatic hydrops was observed and then the degree of hydrops was quantitatively elevated by two radiologists. The consistency test was used to analyze the location and degree of endolymphatic hydrops in the two radiologists and the paired t-test was used to compare the difference between the affected and healthy side of endolymphatic spaces of the patients with otogenic vertigo. Results: In 30 patients, the gadolinium distributed in all parts of the perilymph inside the inner ear, and can accurately outline the boundaries of the peri-and endolymph. Twenty-six patients (26/30, 86.7%) were found to have unilateral endolymphatic hydrops, including 18 mild hydrops, 8 significant hydrops. The two radiologists had a very good agreement on the assessment of endolymphatic hydrops(kappa=0.864, ICC=0.959). In the 3D-FLAIR MR images of 26 patients with endolymphatic hydrops, the saccule (26/26, 100%) had a higher rate of hydrops than the cochlea and utricle(16/26, 61.5%; 14/26, 53.8%), and two radiologists had a very good agreement on the location of endolymphatic hydrops(kappa=0.820). Moreover, there was a significantly statistical difference between the affected and healthy area of the endolymphatic space in this study (P<0.01). Conclusion: The technique of 3D-FLAIR MR imaging through single dose intravenous gadolinium injection is feasible, which can estimate endolymphatic hydrops in patients with otogenic vertigo, and accurately classify the degree of hydrops.

[Value of the apparent diffusion coefficient in diffusion weighted imaging at 3.0T MR for differentiating lacrimal gland tumors]

Objective: To investigate the diagnostic value of apparent diffusion coefficient in diffusion weighted imaging at 3.0 T MR for the differentiation in the larcrimal gland tumors. Methods: A total of 73 cases, 36 males and 37 female; mean age 14-81(44±15)years, with lacrimal gland tumors confirmed by pathology in Beijing Tongren Hospital were retrospectively analyzed between January 2011 and April 2016.All cases underwent the preoperative routine MRI and DWI scan, the ADC values were measured in region of interest within the solid zone. The cases were divided into benign and malignant group by the histopathology, according the different pathological categories, the malignant cases were further divided into the epithelial and non-epithelial malignacy. The receiver operating characteristic curve (ROC) was constructed using various cut points of ADC for different parameters to confirm the diagnostic threshold value and evaluate the diagnostic efficacy. Results: There were totally 77 lesions in 73 cases, of which 69 involved unilateral lacrimal gland,4 bilateral lacrimal glands. The mean ADC value of malignant and benign masses in lacrimal gland was (1.36±0.16) and (0.90±0.30)×10(-3) mm(2)/s respectively. There was significantly statistical difference between the both(t=-8.319, P<0.01). The mean ADC value of epithelial and non-epithelial malignacy in lacrimal gland was (1.08±0.18) and (0.54±0.09)×10(-3) mm(2)/s respectively. There was significantly statistical difference between the both(t=11.988, P<0.01). The area under the ROC for distinguishing malignant from benign lesions was 0.940. Using an ADC value of 1.275×10(-3) mm(2)/s as the threshold value, the best result obtained had a sensitivity of 94.4%(34/36), specificity of 82.9%(34/41), accuracy of 88.3%(68/77). The area under the ROC for differentiating non-epithelial from epithelial malignacy was 1.0. Using an ADC value of 0.736×10(-3) mm(2)/s as the threshold value, the best result obtained had a sensitivity of 100%, specificity of 100%, accuracy of 100%. Conclusion: The ADC value is helpful in differentiation among different kinds of tumors in lacrimal masses.

[The characteristics of CT scan and MRI images of middle ear adenomas]

Objective:To analyze characteristics of CT scan and MRI images of middle ear adenomas,and provide pre-operation diagnosis and differential diagnosis combined with clinical manifestation.Method:Retrospective analysis of 8 cases of middle ear adenomas which were diagnosed and treated with surgery in Beijing Tongren Hospital between 2004 and 2014, patients' complain, clinical manifestation, physical examination, pure tone analysis, CT scan and MRI images were collected.Result:A total of 8 cases were included in this study with 5 females and 3 males. Age of onset ranged from 21 to 51 years old, with an average age of 37.5 years old, and middle age of 37 years old. All patients suffered from single side middle ear adenomas, 5 of left side and 3 of right side. All 8 patients suffered from hearing loss with tinnitus or stuffy feelings, 2 cases with otalgia, 1 with facial nerve paralysis. Physical examination showed 5 cases of bulging of tympanic membrane, 2 cases of out growth of mass into the external ear canal, and 1 with normal tympanic membrane. CT scan of 7 patients showed mass in tympanum and mastoid, with packaged ossicular chain and with no significant bone damage. 2 cases showed out growth of mass into the external ear canal, and 1 case showed limited mass in middle tympanum. MRI images of 5 cases showed equal T1 and T2 signals with intensifying in tympanum. Long T1 or equal T1 and long T2 signal in mastoid showed obstructive inflammation.Conclusion:Characters of middle ear adenomas includes mass in tympanum without bone damage in CT scan, and equal T1 and T2 signal with significant intensifying in tympanum in MRI images. Combined with clinical manifestation, this radiological information may provide benefit for pre-operation diagnosis.

[Porphyromonas gingivalis FimA genotype distribution among periodontitis patients with type 2 diabetes]

OBJECTIVE

To investigate the distribution differences of Porphyromonas gingivalis(Pg) FimA genotypes between periodontitis patients with and without type 2 diabetes for a better understanding of the relationship between diabetes and periodontitis.

METHODS

Questionnaires and detailed periodontal examinations(6 sites per tooth) were conducted in 80 subjects with moderate-severe chronic periodontitis in the Department of Periodontology, Peking University School and Hospital of Stomatology. There were 40 type 2 diabetic patients and 40 systemicly healthy patients enrolled respectively. The periodontal parameters including plaque index(PLI), probing depth(PD), bleeding index(BI), attachment loss(AL) by 6 sites per tooth and numbers of missing teeth were also recorded. Pooled subgingival plaque samples using pocket method with Whatman No3 filterpaper were collectedat each of the 6 sites from one incisor and one molar. Pg and its FimA genotype distributions were investigated using DNA extrctedfrom plaque samples by PCR.

RESULTS

Diabetic patients had a significantly higher score of PLI[2.35(0.58) vs 1.64(0.76),P<0.05] , while rest of periodontal indexes observed(PD, BI and AL) did not differ significantly between diabetic patients and systemicly healthy controls(P>0.05). The detection rate of Pg did not show statistically significant difference between the two groups(50% vs 60%,P>0.05). However, the proportion of FimA Ⅱ was significantly higher in diabetic group than systemicly healthy group(80% vs 42%,P<0.05).

CONCLUSIONS

Type 2 diabetic patients were prone to be infected by highly virulent strains of Pg: FimA ⅡPg.

Routine and dynamic MR imaging study of lobular capillary hemangioma of the nasal cavity with comparison to inverting papilloma

BACKGROUND AND PURPOSE

Lobular capillary hemangioma is an uncommon lesion, and its MR imaging appearance has not been fully characterized. The purpose of this study was to determine the MR imaging features of nasal lobular capillary hemangioma and contrast its imaging characteristics to inverting papilloma.

MATERIALS AND METHODS

The MR imaging signals of 32 patients with histopathologically proven nasal lobular capillary hemangiomas and 53 patients with nasal inverted papillomas were retrospectively studied. The findings of dynamic contrast-enhanced MR imaging in 24 lobular capillary hemangiomas and in 53 inverted papillomas were also analyzed. The Monte Carlo exact test was used for comparison of the time-intensity curve patterns of lobular capillary hemangioma and inverted papilloma.

RESULTS

All lobular capillary hemangiomas appeared to be homogeneously isointense to gray matter on T1-weighted images. On T2-weighted images, all lesions showed heterogeneous hyperintensity, and a thin peripheral isointense or hypointense ring was seen in 28 patients. All lesions showed marked enhancement on enhanced images, with the exception of enhancement of the T2 isointense or hypointense ring. Forty-three (81.1%) inverted papillomas had moderate heterogeneous T2 signal intensity, and a characteristic "cerebriform" appearance was detected in 45 (84.91%) of 53 inverted papillomas. The time-intensity curves showed a washout pattern in 18 and a plateau pattern in 6 patients, whereas inverted papillomas showed a washout pattern in 12, a plateau pattern in 35, and a persistent pattern in 6 patients. There was a statistically significant difference as to time-intensity curve pattern between the 2 groups (P < .05).

CONCLUSIONS

Hyperintensity on T2-weighted images, marked enhancement of tumor with a nonenhancing thin peripheral ring, and a washout time-intensity curve pattern are characteristic MR imaging features of nasal lobular capillary hemangiomas.

Solitary fibrous tumor of the sinonasal cavity: CT and MR imaging findings

SUMMARY

SFT is a rare lesion of the sinonasal cavity. We retrospectively reviewed 5 patients with histopathologically proved sinonasal SFTs to determine their CT and MR imaging features. All patients underwent paranasal sinus CT and MR imaging. Four SFTs occurred in the nasal cavity, and 1, in the maxillary sinus. All SFTs had well-defined margins, and the mean maximum diameter was 55 mm. On nonenhanced CT, 5 SFTs appeared homogeneously isoattenuating to gray matter. The most common manifestations of bony involvement were bony remodeling and thinning. On MR imaging, 5 SFTs were isointense to gray matter on T1-weighted images, and the lesions were isointense in 3 and hypointense in 2 patients on T2-weighted images. The lesions showed heterogeneously marked enhancement on postenhanced MR images. Four patients underwent dynamic contrast-enhanced MR imaging, and the TICs showed a washout pattern. A familiarity with the imaging findings of sinonasal SFT may help to diagnose this entity.

CT and MR imaging findings of periorbital lipogranuloma developing after endoscopic sinus surgery

SUMMARY

Periorbital lipogranuloma is a rare complication after ESS and presently lacks specific imaging reports. The purpose of this study was to describe the CT and MR imaging features of periorbital lipogranuloma. We retrospectively reviewed 9 patients with histology-confirmed periorbital lipogranuloma. All 9 patients underwent CT and MR imaging. Five lipogranulomas were located in the right eyelid and 4 in the left eyelid, which extended into the extraconal space to some degree. The lesions displayed an irregular shape and had an ill-defined margin. Multiple, specked, or nodular foci containing fat were scattered within these lesions. The lesions demonstrated moderate heterogeneous contrast enhancement on contrast-enhanced MR imaging. The TICs showed a persistent pattern (type I) in 6 patients undergoing DCE MR imaging. Thus, an ill-defined, irregular-shaped periorbital mass with multiple foci containing fat, combined with an ESS history, can help to accurately diagnose this entity.

Imaging study of ossifying fibroma with associated aneurysmal bone cyst in the paranasal sinus

OBJECTIVE

To determine the CT and MR imaging features of ossifying fibroma with aneurysmal bone cyst of the paranasal sinus.

MATERIALS AND METHODS

We retrospectively reviewed 15 patients with histopathology-proven ossifying fibromas with aneurysmal bone cysts in the paranasal sinus. All 15 patients underwent CT and MR imaging. The following imaging features were reviewed: location, shape, margin, CT findings, and MR imaging appearances and time-intensity curve of dynamic contrast-enhanced MR imaging.

RESULTS

Ossifying fibromas occurred in the maxillary sinus in one patient, sphenoid sinus in 2, frontal sinus in 3, frontoethmoid sinuses in 3, and ethmoid sinus in 6 patients. Ossifying fibromas showed an elliptic-shape and aneurysmal bone cysts revealed a multicystic appearance, with well-demarcated margins. On unenhanced CT, ossifying fibromas appeared isodense to gray matter with scattered calcifications in nine, ground-glass appearance in 6 patients and aneurysmal bone cysts showed mixed density. Ossifying fibromas appeared isointense to gray matter in 12 and slightly hypointense in three patients on T1-weighted images, and isointense in 4 and hypointense in eleven patients on T2-weighted images, with moderate or marked enhancement after administration of contrast material. The time-intensity curves of eight ossifying fibromas exhibited a rapidly enhancing and rapid washout pattern. The intracystic components of aneurysmal bone cysts showed heterogeneous signal intensity on MR images, with fluid-fluid levels identified clearly by T2-weighted images, without enhancement. The periphery and septa of aneurysmal bone cysts appeared isointense on MR images, with marked enhancement.

CONCLUSIONS

Fluid-fluid levels within an elliptic-shape mass with scattered calcifications or ground-glass appearance is highly suggestive of this complicated entity in the paranasal sinus.

Imaging features of paediatric haemophilic pseudotumour of the maxillary bone: report of three cases and review of the literature

OBJECTIVES

Haemophilic pseudotumour (HP) is an extremely rare lesion. The purpose of this study was to describe the CT and MRI features of maxillary bone HPs and introduce the key points to differentiate HP from the mimicking entities in the region.

METHODS

We retrospectively reviewed three paediatric patients with histology-proven HPs arising from the maxillary bone. All three patients underwent CT and/or MRI. Combined with six previously reported cases in the literature, the imaging features were comprehensively analysed.

RESULTS

All HPs showed a well-demarcated, multilobulated expansile osteolytic lesion in the maxillary bone. On non-enhanced CT, HPs appeared of mixed density relative to grey matter. The lesions appeared to have markedly heterogeneous signal intensity on both T(1) and T(2) weighted images, with septa-like enhancement following the administration of contrast material, which corresponded to blood products in various stages of evolution. The lesions caused cortical thinning and even focal disappearance and multiple bone septa were identified within the involved maxillary bone. Some HPs were associated with radiated periosteal proliferation, which can easily be misdiagnosed as a malignant bone tumour.

CONCLUSION

A high index of suspicion for HP and a familiarity with imaging findings may help to accurately diagnose this rare entity.

MR evaluation of sinonasal angiomatous polyp

BACKGROUND AND PURPOSE

SAP is a rare lesion of the sinonasal cavity, which may be misdiagnosed as a benign or malignant neoplasm. The purpose of our study was to comprehensively evaluate the MR imaging features of SAP.

MATERIALS AND METHODS

Forty patients with SAP confirmed pathologically were retrospectively reviewed. Of the 40 patients undergoing MR imaging, 39 had postcontrast T1WI; 30, DCE MR imaging; and 17, DWI. The image features assessed included the location, shape, margin, size, signal intensity, and enhancement pattern on DCE MR imaging and ADC maps.

RESULTS

All 40 SAPs originated from the maxillary sinus, but the lesions frequently extended into the ipsilateral nasal cavity (38/40), toward the choana (19/40), and into the nasopharynx (8/40). The lesions demonstrated hypointensity on T1WI and heterogenous hyperintensity on T2WI. All 40 lesions showed a peripheral hypointense rim on T2WI. Postcontrast MR imaging revealed marked heterogeneous nodular and patchy enhancement. Progressive enhancement was found on DCE MR imaging in 30 cases. The TIC showed a steady enhancement pattern in 3 cases, a rapidly enhancing and slow washout pattern in 6 cases, and a rapidly enhancing and rapid washout pattern in 21 cases. On DWI, the mean ADC value was (1.40 ± 0.20) × 10(-3) mm(2)/s.

CONCLUSIONS

Distinctive features of SAP on conventional MR imaging include internal heterogeneous hyperintensity and a peripheral hypointense rim on T2WI, as well as strong nodular and patchy enhancement on postcontrast MR images. The progressive enhancement on DCE MR imaging can also suggest the diagnosis.

Nasal cavity eosinophilic angiocentric fibrosis: CT and MR imaging findings

BACKGROUND AND PURPOSE

EAF consists of exceedingly rare lesions and presently lacks specific imaging reports. The purpose of this study was to determine the CT and MR imaging features of nasal cavity EAF.

MATERIALS AND METHODS

We retrospectively reviewed 6 patients with histology-proven EAF in the nasal cavity. All 6 patients underwent CT and 3 patients also underwent MR imaging. The following imaging features were reviewed: 1) location, 2) shape, 3) margin, 4) CT attenuation, and 5) MR imaging signal intensity. In addition, the accompanying changes and the TIC of the DCE MR imaging were analyzed.

RESULTS

All occurrences of EAF were located at the anterior nasal cavity, arising from the nasal septum in 4 patients, with irregular shape, and the lateral nasal wall in 2, with oval configuration. The mean size was 29.8 mm (range 12-52 mm). On nonenhanced CT, EAF lesions appeared isoattenuated relative to gray matter. On the T1-weighted image, the lesions were isointense in 3 (100%) patients. On the T2-weighted image, the lesions were isointense in 1 (33.3%) patient and hypointense in 2 (66.7%) patients. Occurrences of EAF revealed moderate inhomogeneous contrast enhancement. Three patients underwent DCE MR imaging and the TICs exhibited a rapidly enhancing and slow washout pattern. One patient had bilateral lacrimal gland enlargement, which displayed low signal intensity on the T2-weighted image.

CONCLUSIONS

A familiarity with imaging findings, including lesion location, isoattenuation and bony changes, and hypointensity on T2-weighted images may help to accurately diagnose this rare entity.

Insulin promoter DNA methylation correlates negatively with insulin gene expression and positively with HbA(1c) levels in human pancreatic islets

AIMS/HYPOTHESIS

Although recent studies propose that epigenetic factors influence insulin expression, the regulation of the insulin gene in type 2 diabetic islets is still not fully understood. Here, we examined DNA methylation of the insulin gene promoter in pancreatic islets from patients with type 2 diabetes and non-diabetic human donors and related it to insulin expression, HbA(1c) levels, BMI and age.

METHODS

DNA methylation was analysed in 25 CpG sites of the insulin promoter and insulin mRNA expression was analysed using quantitative RT-PCR in pancreatic islets from nine donors with type 2 diabetes and 48 non-diabetic donors.

RESULTS

Insulin mRNA expression (p = 0.002), insulin content (p = 0.004) and glucose-stimulated insulin secretion (p = 0.04) were reduced in pancreatic islets from patients with type 2 diabetes compared with non-diabetic donors. Moreover, four CpG sites located 234 bp, 180 and 102 bp upstream and 63 bp downstream of the transcription start site (CpG -234, -180, -102 and +63, respectively), showed increased DNA methylation in type 2 diabetic compared with non-diabetic islets (7.8%, p = 0.03; 7.1%, p = 0.02; 4.4%, p = 0.03 and 9.3%, p = 0.03, respectively). While insulin mRNA expression correlated negatively (p < 1 × 10(-6)), the level of HbA(1c) correlated positively (p ≤ 0.01) with the degree of DNA methylation for CpG -234, -180 and +63. Furthermore, DNA methylation for nine additional CpG sites correlated negatively with insulin mRNA expression (p ≤ 0.01). Also, exposure to hyperglycaemia for 72 h increased insulin promoter DNA methylation in clonal rat beta cells (p = 0.005).

CONCLUSIONS/INTERPRETATIONS

This study demonstrates that DNA methylation of the insulin promoter is increased in patients with type 2 diabetes and correlates negatively with insulin gene expression in human pancreatic islets.

Fibrous dysplasia-like appearance of the frontal process of the maxilla on CT: prevalence in North China

The frontal process of the maxilla occasionally shows a localized FD-like appearance. The purpose of this study was to determine its prevalence and findings on CT. A retrospective study of 1000 consecutive paranasal sinus CT scans was preformed on outpatients without a history of trauma or previous surgery in our hospital during 6 months. CT images were interpreted independently by 2 experienced head and neck radiologists on a PACS system in a bone window setting. Of the 1000 patients (546 males; 454 females), 51 (5.1%,41 males and 10 females) had an FD-like appearance in the frontal process of the maxilla. There was a statistically significant difference between sexes (P < .001). Twenty-nine (56.9%) entities arose from the right frontal process and 22 (43.1%) from the left frontal process. These entities, with well-defined margins, were located at the base of the frontal process of the maxilla, appearing as an ovoid or triangular configuration on axial-plane CT and as a spindle or elliptic shape on the coronal plane. The mean maximal diameter was 9.8 mm (range, 3.6-16.1 mm). These entities exhibited a pagetoid appearance (type I) in 37 (72.5%), a ground-glass appearance (type II) in 8 (15.7%), and a cyst-like appearance (type III) in 6 (11.8%) patients on CT. The FD-like appearance of the frontal process of the maxilla is not rare and can be readily detected by CT.

Leiomyoma of the sinonasal cavity: CT and MRI findings

AIM

To determine the computed tomography (CT) and magnetic resonance imaging (MRI) features of leiomyoma of the sinonasal cavity.

MATERIALS AND METHODS

Six patients with histology-proven leiomyomas in the sinonasal cavity were retrospectively reviewed. All six patients underwent CT and three patients also underwent MRI. The following imaging features were reviewed: size, margin, CT attenuation, MRI signal intensity, and lesion extent. In addition, the time-intensity curve (TIC) of dynamic contrast-enhanced (DCE) MRI and diffusion-weighted imaging (DWI) were analysed in two patients.

RESULTS

All leiomyomas had well-defined margins. The mean size was 36 mm (range 20-51 mm). On unenhanced CT, the lesions appeared isodense to cerebral grey matter in four (67%) and slightly hypodense in two (33%) patients. Leiomyomas appeared isointense On T1-weighted imaging (WI) and slightly hyperintense on T2WI in three patients. The lesions showed moderate contrast enhancement. Two patients underwent DCE MRI, and the TIC showed a rapidly enhancing and slow washout pattern. The mean apparent diffusion coefficient (ADC) value were 1.66x10(-3) mm(2)/s and 1.78x10(-3) mm(2)/s for the two lesions, respectively.

CONCLUSIONS

Well-defined, homogeneous, expansile masses without bony erosion are typical features of leiomyoma. Althrough rare, this entity should be included in the differential diagnosis of benign tumours in this region.

Primary chordoma in the nasal cavity and nasopharynx: CT and MR imaging findings

BACKGROUND AND PURPOSE

Primary chordoma in the nasal cavity and nasopharynx is an extremely rare tumor in the extraosseous axial skeleton. Unlike intracranial chordomas, lesions in these sites primarily present as a soft tissue mass without involvement of the skull base bone (clivus), so the preoperative diagnosis of the tumor is possibly difficult. Here, we reviewed the imaging features of 5 cases of chordomas in the nasal cavity and nasopharynx that resulted in successful diagnosis and differential diagnosis of this rare tumor.

MATERIALS AND METHODS

We retrospectively studied 5 patients with histologically proven chordomas in the nasal cavity and nasopharynx. The lesion features of CT and MR imaging were reviewed, with emphasis on the size, shape, location, margin, calcification, CT attenuation characteristics, signal intensity, and degree of MR imaging enhancement.

RESULTS

Expansible and lobular soft tissue masses were mainly present, with irregular intratumor calcification in all 5 cases on CT examination. MR imaging revealed a well-defined tumor with heterogeneous signal intensity in 4 patients, whereas homogeneous signal intensity in 1 patient was present on all pulse sequences. Four cases of nasopharyngeal mass showed mild to moderate heterogenous enhancement. Intratumor septa could be seen in 2 cases.

CONCLUSIONS

Although no imaging features are pathognomonic, primary chordomas without skull base (clivus) bony changes in the nasal cavity and nasopharynx have some CT and MR imaging findings that are suggestive of diagnosis. The differential diagnosis of the soft tissue mass should be limited to these sites.

Sphenoid sinus ectopic pituitary adenomas: CT and MRI findings

Ectopic pituitary adenomas (EPAs) are rare lesions. The purpose of this study was to describe the CT and MRI features of sphenoid sinus EPAs. Eight patients with histology-proven EPAs in the sphenoid sinus, all of whom underwent CT and MRI, were reviewed retrospectively. The following imaging features were analysed: (i) size, (ii) margin, (iii) CT attenuation characteristics and (iv) MRI signal intensity. In addition, the involvement of adjacent structures and the time-intensity curve (TIC) of dynamic contrast-enhanced (DCE) MRI were analysed. All EPAs had well-defined margins and showed no relationship to the intrasellar pituitary gland. The mean size was 28 mm (range, 20-46 mm). On non-enhanced CT, the lesions appeared isodense to grey matter in 7 (88%) patients and hypodense in 1 (12%) patient. Only two patients underwent post-contrast CT, and they showed moderate enhancement. On T1 weighted images, EPAs appeared isointense in 6 (75%) patients and hypointense in 2 (25%). On T2 weighted images, the lesions appeared hyperintense in 2 (25%) patients and isointense in 6 (75%). EPAs showed mild to moderate heterogeneous contrast enhancement and exhibited a cribriform-like appearance. Two patients underwent DCE MRI; the TIC showed a rapidly enhancing and slow washout pattern. The following features were also seen: an empty sella, bone changes and involvement of the cavernous sinus (5 patients; 62.5%). In conclusion, a high index of suspicion for EPA and a familiarity with the imaging findings may help to diagnose this rare entity accurately.

MR imaging features of primary mucosal melanoma of the eustachian tube: report of 2 cases

We observed 2 cases of malignant melanoma arising from the eustachian tube with MR imaging. In this region, we explored further characteristics of primary mucosal melanoma. We discuss the value of using MR imaging to diagnose and treat patients with melanoma in the eustachian tube. In addition, we introduce the key points to differentiate melanoma from some common diseases in the region.