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ABSTRACT: OBJECTIVES: To investigate characteristic MRI findings of rheumatoid arthritis (RA) in the temporomandibular joints (TMJs). METHODS: 61 patients (122 TMJs) with RA in the TMJ and 50 patients (100 TMJs) with temporomandibular disorder (TMD) were included in this study. MR images of these patients were assessed by two oral radiologists for the presence or absence of osseous changes, disc displacement, joint effusion and synovial proliferation. These findings were compared between the two patient groups. RESULTS: Osseous changes in the condyle and articular eminence/fossa in the RA patient group were significantly more frequent than in the TMD patient group, and were often very severe. Joint effusion was also significantly more frequent in the RA patient group. Synovial proliferation was found in all TMJs in the RA patient group, whereas it was very uncommon in the TMD patient group. CONCLUSIONS: Severe osseous changes in the condyle and synovial proliferation were considered characteristic MRI findings of RA in the TMJs.
Dentomaxillofacial Radiology 07/2012; · 1.08 Impact Factor
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ABSTRACT: The aim of this study was to investigate the signal intensity characteristics of highly invasive and highly metastasizing transplanted human squamous cell carcinoma using ultra-small super-paramagnetic iron oxide (USPIO)-enhanced MRI and to correlate them with USPIO distribution to tumour components revealed by histological examination.
13 nude mice with transplanted human squamous cell carcinoma in the oral cavity were imaged before and 24 hours after intravenous administration of USPIO. The difference in signal intensity between pre-contrast and post-contrast MR images was visually evaluated. For quantitative analysis, signal intensity within a region of interest was measured. Histological findings were correlated with MR findings. The approximate USPIO concentration was evaluated using USPIO phantoms.
Seven tumours had an area showing signal intensity increase on post-contrast T₁ weighted images. Histopathologically, six of those tumours contained a small amount of iron particles in the stroma. The USPIO concentration was presumed low. Two tumours had an area showing signal intensity decrease on post-contrast T₁ and T₂ weighted images. The areas had a large amount of iron particles in the stroma and the USPIO concentration was presumed high. There was a minimal amount of iron particles in tumour parenchymal cells.
The amount of USPIO accumulation into tumour stroma was considered to affect MR signal intensity. A small amount increases T₁ weighted signal intensity, whereas a large amount decreases T₁ and T₂ weighted intensity. The USPIO accumulation into the tumour parenchyma was not thought to affect MR signal intensity.
Dentomaxillofacial Radiology 11/2011; 41(1):55-63. · 1.08 Impact Factor
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ABSTRACT: The location of a parotid tumor affects the choice of surgery, and there is a risk of damaging the facial nerve during surgery. Thus, differentiation between superficial and deep lobe parotid tumors is important for appropriate surgical planning.
To evaluate the usefulness of using the parotid duct, in addition to the retromandibular vein, for differentiating between superficial and deep lobe parotid tumors on MR images.
Magnetic resonance images of 42 parotid tumors in 40 patients were reviewed to determine whether the tumor was located in the superficial or deep lobe. In each case, the retromandibular vein and the parotid duct were used to locate the tumor. The parotid duct was only used in cases where the tumor and the duct were visualized on the same image.
Using the retromandibular vein criterion, 71% of deep lobe and 86% of superficial lobe tumors were correctly diagnosed, providing an accuracy of 81%. However, the accuracy achieved when using the parotid duct criterion was 100%, although it could be applied to only 28 of the 42 cases. Based on these results, we defined the following diagnostic method: the parotid duct criterion is first applied, and for cases in which it cannot be applied, the retromandibular vein criterion is used. The accuracy of this method was 88%, which was better than that achieved using the retromandibular vein criterion alone.
The parotid duct criterion is useful for determining the location of parotid tumors. Combining the parotid duct criterion with the retromandibular vein criterion might improve the diagnostic accuracy of parotid tumor location compared to using the latter criterion alone.
Acta Radiologica 08/2009; 50(7):806-11. · 1.37 Impact Factor
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ABSTRACT: Whether MR imaging is superior to CT in evaluating the presence and extent of mandibular invasion by squamous cell carcinoma remains controversial. The purpose of this study was to directly compare the diagnostic accuracy of MR imaging and that of CT.
MR and CT images in 51 patients with squamous cell carcinoma of the oral cavity were evaluated for the presence and extent of mandibular invasion. The results were correlated with histopathologic findings.
Twenty-five of 51 patients had histopathologic evidence of mandibular cortical invasion. The tumor involved both the cortex and the bone marrow in all 25 patients and involved the inferior alveolar canal in 5 patients. The sensitivity and specificity for mandibular cortical invasion were 96% and 54% for MR imaging and 100% and 88% for CT, respectively. Those for inferior alveolar canal involvement were 100% and 70% for MR imaging and 100% and 96% for CT, respectively. In both evaluations, the specificity of MR imaging was significantly lower than that of CT (McNemar test, P = .004 in the former and P = .002 in the latter). Chemical shift artifact by bone marrow fat was postulated to be the source of most false-positive cases on MR imaging findings for mandibular cortical invasion. Those for inferior alveolar canal involvement were due to MR imaging visualization of the tumor and surrounding inflammation with similar signal intensity.
In assessing the presence and extent of mandibular invasion by squamous cell carcinoma, the specificity of MR imaging was significantly lower than that of CT.
American Journal of Neuroradiology 02/2006; 27(1):114-22. · 2.93 Impact Factor
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ABSTRACT: The authors investigated the feasibility of performing diffusion-weighted (DW) magnetic resonance (MR) imaging with split acquisition of fast spin-echo signals (hereafter, split echo) for the assessment of salivary glands and salivary lesions. Eighteen patients without salivary disease and 10 patients with Sjögren syndrome, chronic parotitis, or focal salivary masses underwent split-echo and echo-planar DW MR imaging. DW MR images and apparent diffusion coefficient maps of the salivary gland had higher quality with split-echo rather than with echo-planar DW MR imaging.
Radiology 01/2002; 221(3):837-42. · 5.73 Impact Factor
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ABSTRACT: To determine signal intensity characteristics of the gastric wall layers and to assess the accuracy of the evaluation of early gastric carcinomas in vitro by using resected specimens studied with high-spatial-resolution magnetic resonance (MR) imaging.
Fifteen gastric specimens obtained from patients suspected of having early gastric carcinoma were studied with a 1.5-T MR system with a 4-cm-diameter loop coil. High-spatial-resolution spin-echo MR images were obtained with a field of view of 50 mm, a matrix of 256 x 256, and a section thickness of 2 mm, resulting in a voxel size of 0.08 mm(3). Findings from MR images were compared with histopathologic findings.
T1- and T2-weighted MR images clearly depicted the normal gastric wall as consisting of four and six layers, respectively, which corresponded well to the histologic layers. In 14 (93%) of 15 gastric carcinomas, the depth of mural invasion visualized with MR imaging correlated well with the histopathologic stage. The stage determined with MR imaging, however, was lower in one instance (7%) than the histopathologic stage. MR imaging also depicted the gross features of the tumor, presence of ulceration, and adjacent lymph node swelling.
High-spatial-resolution MR imaging has a high diagnostic accuracy in the evaluation of the mural invasion of early gastric carcinoma in vitro and thus potentially enables preoperative histopathologic staging.
Radiology 08/2001; 220(1):115-21. · 5.73 Impact Factor
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ABSTRACT: The purpose of this study was to determine the diagnostic accuracy of high-resolution MR imaging at 1.5T for evaluating the mural invasion of superficial esophageal carcinoma. Forty-one esophageal specimens taken from patients suspected of having superficial carcinoma were studied using a 1.5T MR system with a surface coil. Spin-echo MR images were obtained with a field of view of 50mm, matrix of 256 x 256, and section thickness of 2mm (voxel size = 0.08 mm3). MR findings were compared with histopathologic findings. T2-weighted images clearly depicted the normal esophageal wall as consisting of 8 layers. In 39 (95%) of 41 carcinomas, the depth of mural invasion determined by MR imaging correlated well with that determined with histopathologic examination. The MR-based stage was higher in 2 (5%) cases than the histopathologic stage. High-resolution MR imaging at 1.5T shows a high diagnostic accuracy for evaluating the mural invasion of superficial esophageal carcinoma, thus potentially enabling preoperative histopathologic staging.
Journal of Magnetic Resonance Imaging 03/2001; 13(2):225-31. · 2.70 Impact Factor
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ABSTRACT: To determine in vitro the potential of high-resolution MRI for evaluating the depth of tumor invasion of the tongue.
Twenty-one resected specimens of squamous cell carcinoma of the tongue were examined on a 1.5T MRI system with a 4 cm surface coil using four different sequences; T1W SE, T2W SE, 3D-FISP and 3D-CISS. The thickness of normal epithelium, tumor depth and width were measured on both MR images and histopathological sections.
The mucosal epithelium, lamina propria and muscles of the tongue were clearly identifiable on MRI. All 21 carcinomas, including three early invasive carcinomas, were clearly demonstrated. A high correlation was found between the values measured by MRI and histopathology for thickness of mucosal epithelium and both depth and width of tumors. There was a good agreement between the T2W SE and the other imaging sequences for measurements of both depth and width of tumors.
High-resolution MR imaging appears reliable for the in vitro evaluation of depth of tumor invasion in carcinoma of the tongue.
Dentomaxillofacial Radiology 02/2001; 30(1):14-21. · 1.08 Impact Factor
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ABSTRACT: We reviewed the MRI of 20 patients with a ranula (8 simple and 12 plunging) and ten with other cystic masses in the floor of the mouth and/or suprahyoid portion of the neck (three haemangiomas, two neuromas, one monomorphic adenoma, one lipoma, two lateral cervical cysts and one dermoid cyst). Histological diagnoses were obtained in all cases with the exception of one presumed haemangioma. Ranulas were all well-defined, homogeneous masses giving low signal on T1- and markedly high signal on T2-weighted images. While simple ranulas were all confined to the sublingual space, plunging ranulas were centered on the submandibular space and tended to spill into one or more adjacent spaces. They extended into the sublingual space anteriorly (producing a so-called tail sign) in eight of 12 cases and into the parapharyngeal space superiorly in five. Although they sometimes filled a considerable part of the parapharyngeal space, displacement of surrounding muscles or vessels was usually slight, which was thought to reflect the nature of extravasation pseudocysts. All other cystic masses in our study had one or more MRI finding different from those of ranulas and could be easily differentiated from them.
Neuroradiology 01/2001; 42(12):917-22. · 2.82 Impact Factor
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ABSTRACT: This study compared the quantitative parameters of salivary gland scintigraphy and the sialographic stages in patients with Sjögren's syndrome.
One hundred sixteen patients suspected of having Sjögren's syndrome were examined with salivary gland scintigraphy and contrast sialography. When contrast sialography was used as the gold standard, Sjögren's syndrome was diagnosed in 50 of these 116 patients; Sjögren's syndrome was not seen in the other 66 patients. After injection of 370 MBq 99mTc-sodium pertechnetate, dynamic salivary gland scintigraphy with lemon juice stimulation was performed for 50 min. Functional parameters for the parotid and submandibular glands were calculated, and scintigraphic and sialographic results were compared.
With the progression of sialographic stages from 0 to 4, the quantity of tracer accumulation decreased in the submandibular gland (P < 0.0001), and the quantity of tracer secretion decreased in the parotid gland (P < 0.0001). The sialographic stage in patients with Sjögren's syndrome was correlated with these scintigraphic parameters (P < 0.0001): sialographic stage = 3.243 - 0.337 x (submandibular gland uptake ratio) - 0.026 x (parotid gland maximum secretion).
The decreased accumulation in the submandibular gland and the decreased secretion in the parotid gland were highly sensitive indicators of salivary gland disease in Sjögren's syndrome. The sialographic stage was correlated with these scintigraphic parameters.
Journal of Nuclear Medicine 02/2000; 41(2):257-62. · 6.38 Impact Factor
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ABSTRACT: We evaluated the clinical effectiveness of contrast-enhanced three-dimensional (3D) magnetic resonance angiography (MRA) for diagnosing head and neck haemangiomas. We studied six patients using a magnetization prepared rapid acquisition gradient-echo (MP-RAGE) sequence on a 1.5-T system. Conventional T1- and T2-weighted and contrast-enhanced images were also obtained. The images were compared with histological findings. In four cavernous haemangiomas, a mass was partially visible as an enhancing lesion on the early phase of MRA, and was completely visible as a larger enhancing lesion in the late phase, showing slow blood flow. In two capillary haemangiomas, a mass was completely visible in the early phase showing fast flow. In all patients, MRA clearly showed both the haemangiomas and the external carotid artery branches. MRA allowed assessment of the relationship between the haemangiomas and the feeding arteries, and of the haemodynamics.
Neuroradiology 03/1999; 41(2):140-3. · 2.82 Impact Factor
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ABSTRACT: To compare the diagnostic accuracy of magnetic resonance (MR) sialography with that of conventional sialography in the assessment of salivary gland disease in Sjögren syndrome.
Thirty-five patients (32 women, three men; age range, 18-69 years) suspected of having Sjögren syndrome were examined with MR sialography and conventional sialography. Gradient and spin-echo MR sialography was performed with a 1.5-T system. MR sialographic findings were compared with conventional sialographic findings.
In 31 (89%) patients, the stage of salivary gland disease determined with MR sialography accurately correlated with that determined with conventional sialography. However, the stage at MR sialography was higher in two patients: They had stage I disease but were determined to have stage II disease. In two other patients, the stage at MR sialography was lower: A patient with stage II disease and a patient with stage III disease were determined to have stage I and stage II disease, respectively. The correlation between the stage at conventional sialography and that at MR sialography (P < .001) can be estimated with the following equation: conventional sialographic stage = 0.021 + 0.982 x (MR sialographic stage). Both the sensitivity and the specificity of MR sialography in the diagnosis of Sjögren syndrome were 100%.
MR sialography is highly accurate in the evaluation of salivary gland disease in Sjögren syndrome.
Radiology 01/1999; 209(3):683-8. · 5.73 Impact Factor
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ABSTRACT: To evaluate the CT findings of maxillofacial mass lesions in younger children and to discuss the effectiveness of CT in their differential diagnosis.
CT findings of 17 patients (age range, 0 years 5 months to 3 years 3 months) with histopathologically proven maxillofacial mass lesions were retrospectively evaluated. About two-thirds (11/17) comprised congenital lesions or more common lesions in infancy or younger children.
Hemangiomas, dermoid cysts and ranulas in this age group presented characteristic CT findings in common with those occurring in adults. Two invasive lesions (melanotic neuroectodermal tumor and aggressive fibromatosis) had irregular margins and the latter also showed aggressive bone destruction. Two angiomas had irregular margins. A fibrosarcoma showed expansile bone destruction but had a regular margin.
CT was useful in demonstrating the extent of maxillofacial mass lesions in children and for surgical treatment planning. Although some invasive lesions could be correctly diagnosed on the basis of CT, its diagnostic value in differentiating malignant from benign maxillofacial lesions in younger children was limited.
Dentomaxillofacial Radiology 12/1998; 27(6):334-40. · 1.08 Impact Factor
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ABSTRACT: To report on adverse reactions to intravenous nonionic iodine contrast media and evaluate the usefulness of monitoring vital signs.
A prospective study of 1537 consecutive patients who received contrast-enhanced CT with nonionic iodine was performed. Systolic and diastolic arterial blood pressure, pulse rate and arterial blood oxygen saturation were monitored. Severity of adverse reactions was classified as minor, intermediate and severe.
A total of 64 adverse reactions developed in 57 patients. The overall prevalence was 3.7% (57/1537). The most common symptom was nausea (18/64) followed by pharyngeal discomfort (11/64). One patient had a severe reaction consisting of prolonged hypotension. Four patients had an intermediate reaction, three transient hypotension or hypertension and one extensive urticaria and facial edema. In two out of four patients who became hypotensive or hypertensive, the reactions developed without any obvious clinical symptoms.
Severe or life-threatening acute adverse reactions to intravenous nonionic iodine contrast media may develop without any obvious clinical symptoms. Monitoring vital signs is very helpful for early detection.
Dentomaxillofacial Radiology 08/1998; 27(4):199-202. · 1.08 Impact Factor
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ABSTRACT: To evaluate the CT features of buccal space masses.
Fifty-three cases of buccal space masses were reviewed retrospectively. The diagnosis was confirmed histopathologically in all except two. CT images were assessed for the number, location, internal architecture and margin of the lesions and their relation to the surrounding structures.
The series comprised 44 tumors (33 benign and 11 malignant) and nine non-tumorous lesions. Buccal gland tumors were all found adjacent to the outer surface of the buccinator, in contrast to epidermoid cysts and accessory parotid tumors which were completely separate from it. Hemangiomas were characterized by multiple masses or the presence of phleboliths. When ill-defined margins, violation of fascial planes and aggressive bone destruction were used as the criteria for the malignancy, only seven out of 11 malignant tumors were correctly diagnosed (sensitivity 64%).
CT was useful in demonstrating the presence and location of the masses in the buccal space and sometimes in the differential diagnosis. For a mass of uncertain cause in the buccal space, a buccal gland tumor is the most likely diagnosis. The value of CT in differentiating malignant from benign buccal space lesions is limited.
Dentomaxillofacial Radiology 12/1997; 26(6):347-53. · 1.08 Impact Factor
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ABSTRACT: To define the CT criteria for differentiating malignant from benign tumours of the minor salivary glands of the palate and to evaluate their accuracy.
CT findings of 63 patients with histopathologically proven minor salivary gland tumours of the palate (23 malignant, 40 benign) were retrospectively evaluated.
Aggressive bone destruction was a specific finding of malignant tumours, but was seen in only 57% (13/23) of this series. Extension into the pterygopalatine fossa was observed in seven malignant and one benign tumour. Calcifications within a tumour were observed in four cases, all of which were malignant. These three CT findings were significantly more frequent in malignant tumours. Using any one of these as the criterion for the malignancy, the sensitivity was 78% (18/23), specificity 98% (39/40) and accuracy 90% (57/63).
Malignant tumours of the minor salivary glands of the palate are very likely to show any or all of aggressive bone destruction, extension into the pterygopalatine fossa and calcification, whereas benign tumours can almost always be correctly diagnosed by their absence.
Dentomaxillofacial Radiology 02/1997; 26(1):16-21. · 1.08 Impact Factor
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ABSTRACT: To clarify the usefulness and limitations of interventional radiology for sialolithiasis.
Sixteen patients (5 with parotid and 11 with submandibular sialolithiasis) were treated with a stone retrieval catheter (Dormia basket) under fluoroscopy. Digital subtraction sialography (DSS) and direct digital dental imaging (RVG) were performed in addition for 11 of the cases (DSS for 7 and RVG for 4 cases).
The sialolith was successfully removed in 10 cases. DSS and RVG were useful. Four cases failed because the stone was adherent to the ductal wall and two because the catheter could not reach the stone because of the ductal anatomy.
Interventional radiology is less invasive than surgical treatment and is the recommended first choice for treatment in the majority of cases of sialolithiasis.
Dentomaxillofacial Radiology 12/1996; 25(5):242-6. · 1.08 Impact Factor
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ABSTRACT: A new type of high sharpness, high speed film was evaluated in combination with rare-earth screens for modulation transfer function, root-mean-square granularity and characteristic curve, and compared with currently available film-screen combinations. The clinical applicability of the new system was also compared on the basis of resolution and the discrimination of anatomical features on radiographs of a skull phantom. The results indicated that the new type film provided a radiograph of higher image quality while at the same time reducing patient dose by about 20% compared with the present rare-earth screen systems, or with no loss of image quality while reducing patient dose by about 50% compared with the present calcium tungstate system.
Dentomaxillofacial Radiology 06/1991; 20(2):59-64. · 1.08 Impact Factor
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ABSTRACT: A microscopic and densitometric analysis of the high speed and fog density of E-speed film was conducted. The grain sizes of silver bromide (AgBr) and developed silver metals were measured, and the optical densities of the film were compared by means of various development procedures. Silver bromide grains were found to be large and accounted for the high speed of the film. Development caused chains of silver metal clusters to form, which contributed to the larger fog density as well as the higher speed.
Oral Surgery Oral Medicine Oral Pathology 02/1990; 69(1):113-9.
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ABSTRACT: RESULTS: Twenty-five of 51 patients had histopathologic evidence of mandibular cortical invasion. The tumor involved both the cortex and the bone marrow in all 25 patients and involved the inferior alveolar canal in 5 patients. The sensitivity and specificity for mandibular cortical invasion were 96% and 54% for MR imaging and 100% and 88% for CT, respectively. Those for inferior alveolar canal involvement were 100% and 70% for MR imaging and 100% and 96% for CT, respectively. In both evaluations, the specificity of MR imaging was significantly lower than that of CT (McNemar test, P.004 in the former and P.002 in the latter). Chemical shift artifact by bone marrow fat was postulated to be the source of most false-positive cases on MR imaging findings for mandibular cortical invasion. Those for inferior alveolar canal involvement were due to MR imaging visualization of the tumor and surrounding inflammation with similar signal intensity. CONCLUSION: In assessing the presence and extent of mandibular invasion by squamous cell carci- noma, the specificity of MR imaging was significantly lower than that of CT.
