The effects of location of alveolar crest on the vertical bone heights on panoramic radiographs

Objectives

This study aimed to show that the horizontal relationship between the mandibular canal and the alveolar crest can influence the available bone height (ABH) measurement on panoramic radiographs.

Methods

92 mandibular edentulous sites of panoramic computed radiographs and reformatted CT images of 77 patients were used. Selected CT images were categorized into four types according to the relative location of the peak of the alveolar crest to the mandibular canal. One oral and maxillofacial radiologist measured the ABH twice on both imaging modalities with an interval of 7 days and compared the measurement differences according to the type.

Results

The absolute average value of the differences in measurement between the values of ABHs on panoramic images and CT images was 0.97 mm. Significant difference was found only between the mean values of ABHs for Type 1 (0.60 mm), where the alveolar crest is located in the buccal side or central area with respect to the mandibular canal, and Type 4 (1.46 mm), where the alveolar crest is in the lingual side to the mandibular canal (p < 0.05).

Conclusions

The relative horizontal location of the alveolar crest with respect to the mandibular canal affected the ABH measurement on panoramic radiographs. In particular, ABH is overestimated when there has been resorption of the buccal aspect of the ridge, moving the alveolar crest lingually.     

Bifid mandibular canal: confirmation of limited cone beam CT findings by gross anatomical and histological investigations

Objectives

The aims of this study were (1) to assess the validity of limited cone beam CT (CBCT) in detecting the distribution of bifid mandibular canals in the retromolar region by comparing its findings with those of panoramic radiography and spiral CT imaging, and (2) to confirm the contents of such canals depicted on limited CBCT images by using gross anatomical and histological methods.

Methods

Bilateral bifid mandibular canals of a Japanese cadaver were investigated. The canals depicted on panoramic radiography, spiral CT and limited CBCT images were compared. Cross-sectional limited CBCT images of these canals were compared with gross anatomical sections of the mandible and their contents were confirmed histologically.

Results

The spiral CT and limited CBCT images showed the bilateral bifid mandibular canals in the retromolar region whereas the panoramic radiographs indicated the presence of only the left bifid mandibular canal. The canal distribution was more distinct in the limited CBCT images than in the spiral CT images and the cross-sectional limited CBCT images were consistent with the gross anatomical sections. Histologically, the canals contained several nerve bundles and arteries among which the largest nerve and artery were of a similar size.

Conclusion

Limited CBCT is valuable for assessing the distribution of bifid mandibular canals. It is clinically significant to accurately localize a bifid mandibular canal of the retromolar region because it contains a nerve bundle and artery.     

A false presence of bifid mandibular canals in panoramic radiographs

Objectives

This study was performed in order to verify bifid mandibular canals revealed from panoramic radiographic results.

Methods

1000 panoramic radiographs from dental patients and the panorama, cone beam CT (CBCT) and micro-CT from 40 dry mandibles were examined for bifid mandibular canals. The results were confirmed by a stereoscopic and histological examination of the cross-sectioned mandibles.

Results

The prevalence of bifid canals detected from the panoramic radiographs was 0.038. The panoramic radiographs from one dry mandible showed two separate radiolucent mandibular canal-like structures delineated by radio-opaque lines. However, a stereoscopic and histological examination of a cross-section of the mandible showed that only one canal was a true canal containing neurovascular bundles: the other was false, reflecting merely a bony trabecular pattern.

Conclusions

The presence of bifid mandibular canals determined by panoramic radiography should be judged with great caution in relation to dental surgery.     

Development and challenges of a new academic discipline, radiography science

Aim

The purpose of this article is to describe and discuss the development and challenges faced by radiography science as a new academic discipline.

Background

New academic disciplines develop continually from different circumstances and for different purposes. As they develop, they are faced with the challenge of justifying their status as independent academic disciplines in various ways. Radiography science is one of the youngest disciplines among health sciences in Finland, challenged by the academic community, society and clinical practice.

Conclusions

Radiography science in Finland has already shown considerable development and achieved many substantial and structural criteria set for independent academic disciplines. However, resources are still very limited and the profile of radiography science needs to be clarified. Challenges should be considered as inspirational opportunities and takeoff for the development of radiography science nationally and internationally.     

Proximal caries detection accuracy using intraoral bitewing radiography, extraoral bitewing radiography and panoramic radiography

Objective

To compare proximal caries detection using intraoral bitewing, extraoral bitewing and panoramic radiography.

Methods

80 extracted human premolar and molar teeth with and without proximal caries were used. Intraoral radiographs were taken with Kodak Insight film (Eastman Kodak Co., Rochester, NY) using the bitewing technique. Extraoral bitewing and panoramic images were obtained using a Planmeca Promax Digital Panoramic X-ray unit (Planmeca Inc., Helsinki, Finland). Images were evaluated by three observers twice. In total, 160 proximal surfaces were assessed. Intra- and interobserver kappa coefficients were calculated. Scores obtained from the three techniques were compared with the histological gold standard using receiver operating characteristic analysis. Az values for each image type, observer and reading were compared using z-tests, with a significance level of α = 0.05.

Results

Kappa coefficients ranged from 0.883 to 0.963 for the intraoral bitewing, from 0.715 to 0.893 for the extraoral bitewing, and from 0.659 to 0.884 for the panoramic radiography. Interobserver agreements for the first and second readings for the intraoral bitewing images were between 0.717 and 0.780, the extraoral bitewing readings were between 0.569 and 0.707, and the panoramic images were between 0.477 and 0.740. The Az values for both readings of all three observers were highest for the intraoral bitewing. Az values for the extraoral bitewing images were higher than those of the panoramic images without statistical significance (p > 0.05).

Conclusion

Intraoral bitewing radiography was superior to extraoral bitewing and panoramic radiography in diagnosing proximal caries of premolar and molar teeth ex vivo. Similar intra- and interobserver coefficients were calculated for extraoral bitewing and panoramic radiography.     

Performance of integrated FDG-PET/contrast-enhanced CT in the staging and restaging of colorectal cancer: Comparison with PET and enhanced CT

Objective

The purpose of this study was to assess the diagnostic value of PET/CT as a one step examination in patients with colorectal cancer. Therefore we proved whether diagnostic PET/CT adds information over PET or contrast-enhanced CT alone for staging or restaging of patients with colorectal cancer.

Methods

Seventy-three patients (46 males and 27 females; age range: 50-81 years; mean age: 67 years) with known colorectal cancer underwent 18F-FDG-PET/CT for staging or restaging.

Results

Of the 73 patients 26 patients underwent PET/CT for staging and 47 for restaging. 266 metastases could be detected in 60 patients. Contrast-enhanced PET/CT had a lesion-based sensitivity of 100%, contrast-enhanced CT of 91% and PET of 85%. PET/CT identified 2 lesions as false positive. PET/CT could also reach a patient-based sensitivity of 100%, which was superior to contrast-enhanced CT and PET.

Conclusion

Our study clearly demonstrated the added value of contrast-enhanced PET/CT in staging and restaging patients with colorectal cancer over CT and PET alone.     

Speckle reduction approach for breast ultrasound image and its application to breast cancer diagnosis

Objectives

To retrospectively evaluate the effects of a speckle reduction algorithm on radiologists’ diagnosis of malignant and benign breast lesions on ultrasound (US) images.

Methods

Using a database of 603 breast (US) images of 211 cases (109 benign lesions and 102 malignant ones), the original and speckle-reduced images were assessed by five radiologists and final assessment categories were assigned to indicate the probability of malignancy according to BI-RADS-US. The diagnostic sensitivity and specificity were investigated by the areas (Az) under the receiver operating characteristic (ROC) curves.

Results

The sensitivity and specificity of breast lesions on Ultrasound images improved from 88.7% to 94.3%, from 68.6% to 75.2%, respectively, and the area (Az) under ROC curve of diagnosis also increased from 0.843 to 0.939, Z = 4.969, there were significant differences in the Az between the original breast lesions and speckle-reduced ones on Ultrasound images (P < 0.001). The diagnostic accuracy of breast lesions had been highly improved from 78.67% to 92.73% after employing this algorithm.

Conclusions

The results demonstrate the promising performance of the proposed speckle reduction algorithm in distinguishing malignant from benign breast lesions which will be useful for breast cancer diagnosis.     

Dual energy CT at the synchrotron: A piglet model for neurovascular research

Background

Although the quality of imaging techniques available for neurovascular angiography in the hospital environment has significantly improved over the last decades, the equipment used for clinical work is not always suited for neurovascular research in animal models. We have previously investigated the suitability of synchrotron-based K-edge digital subtraction angiography (KEDSA) after intravenous injection of iodinated contrast agent for neurovascular angiography in radiography mode in both rabbit and pig models. We now have used the KEDSA technique for the acquisition of three-dimensional images and dual energy CT.

Materials and methods

All experiments were conducted at the biomedical beamline ID 17 of the European Synchrotron Radiation Facility (ESRF). A solid state germanium (Ge) detector was used for the acquisition of image pairs at 33.0 and 33.3 keV. Three-dimensional images were reconstructed from an image series containing 60 single images taken throughout a full rotation of 360°. CT images were reconstructed from two half-acquisitions with 720 projections each.

Results

The small detector field of view was a limiting factor in our experiments. Nevertheless, we were able to show that dual energy CT using the KEDSA technique available at ID 17 is suitable for neurovascular research in animal models.     

An in vitro comparison of diagnostic abilities of conventional radiography, storage phosphor, and cone beam computed tomography to determine occlusal and approximal caries

Aim

The aim of this study was to compare conventional radiography, storage phosphor plate, and cone beam computed tomography for in vitro determination of occlusal and approximal caries.

Methods

A total of 72 extracted human premolar and molar teeth were selected. Teeth were radiographed with conventional intraoral radiography, a storage phosphor plate system, and cone beam computed tomography and evaluated by two observers. The teeth were then separated and examined with a stereomicroscope and a scanner at approximately 8× magnification.

Results

CBCT was statistically superior to conventional radiography and phosphor plate for determining occlusal caries. No significant difference from CBCT, conventional radiography and the phosphor plate system for determining approximal caries was found.

Conclusion

The CBCT system may be used as an auxiliary method for the detection of caries.     

No correlation between glucose metabolism and apparent diffusion coefficient in diffuse large B-cell lymphoma: a PET/CT and DW-MRI study

Purpose

Both positron emission tomography/computed tomography (PET/CT) and diffusion-weighted magnetic resonance imaging (DW-MRI) are oncologic feasible techniques for evaluating the malignancy of tumors. Standardized uptake value (SUV) is a marker of tumor glucose metabolism detected by PET/CT. Apparent diffusion coefficient (ADC) measured by DWI can provide information about tissue cellularity. The aim of the study was to evaluate the correlation between SUV and ADC in untreated diffuse large B-cell lymphoma (DLBCL).

Materials and methods

Fifteen pre-therapy patients with histologically proven DLBCL underwent PET/CT and DWI examinations within two days. Tumor glucose metabolism was evaluated by the maximum and mean SUV (SUV_max and SUV_mean) on the PET/CT images. The mean ADC value was measured directly on the parametric ADC maps.

Results

In total, 28 lymphoma lesions with best match PET/CT and DWI were identified and evaluated. The mean SUV_max and SUV_mean were 16.8 and 11.1, respectively; the mean ADC was 0.74 × 10⁻³ mm²/s. There was no correlation between the mean ADC and the SUV_max or SUV_mean.

Conclusion

SUV determined from PET/CT and ADC value measured from DWI are different indices for the diagnosis of tumor malignancy, they may provide complimentary functional information of tumor tissue.     

Comparison of the manual and computer-aided techniques for evaluation of wrist synovitis using dynamic contrast-enhanced MRI on a dedicated scanner

Objective

Traditional methods for assessment of synovial inflammation in rheumatoid arthritis such as clinical examination, immunohistology of bioptic samples, scintigraphy, and radiography have several limitations, including lack of sensitivity, need of invasive techniques, and administration of radioactive material. MRI lacks on standardisation and the data are often analysed using laborious, relatively rigid scoring methods.

Materials and methods

This study introduces a standardized computer-aided method for quantitative analysis of MRI of the wrist on a dedicated scanner. Assessment of the synovial inflammation was performed using a semi-automated model-based method in conjunction with patient motion reduction algorithms. Further, the new method was compared with the traditional user-dependent ROI-based technique.

Results

The computer-aided technique generated robust and reproducible results. Application of motion reduction algorithms allowed for significant improvements of the signal to noise ratio, which is especially important in the datasets acquired with low-field scanners.

Conclusion

The use of the computer software can be beneficial for diagnostic decision in cross sectional as well as longitudinal MRI examinations of the wrist in rheumatoid arthritis.     

CT features of adenomyosis

Objectives

To determine the computed tomography (CT) features of adenomyosis in patients with known adenomyosis as established with magnetic resonance (MR) imaging.

Methods

A computerized search identified 16 women with pelvic MR diagnosis of adenomyosis who also had enhanced pelvic CT. Original CT reports were reviewed for potential prospective diagnosis of adenomyosis. CT images were reviewed for enhancement phase, inner and outer myometrium attenuation, uterine enlargement (width>6 cm), inner myometrial thickening (≥12 mm), and myometrial cysts.

Results

Adenomyosis was detectable on CT in 8 of 16 patients. For these 8 patients, inner and outer myometrium distinction was excellent in 7 (88%) and limited in 1 (12%), and mean inner myometrial thickness was 25 mm (range 14-47 mm). CT enhancement phase was parenchymal in 7 (88%), uterus was enlarged in 8 (100%), and 7 (88%) had myometrial cysts. Adenomyosis was focal in 5 (63%), diffuse in 2 (25%), and both in 1 (12%). None of the original CT reports included adenomyosis as a diagnosis.

Conclusions

CT can suggest a diagnosis of adenomyosis based on uterine enlargement, thickened inner myometrium, and/or myometrial cysts.     

Detection of bone invasion by gingival carcinoma of the mandible: a comparison of intraoral and panoramic radiography and computed tomography

OBJECTIVE: To assess the diagnostic accuracy of panoramic radiography (PR), panoramic radiography combined with intraoral radiography (PR+IR), and CT in detecting the supero-inferior extent of tumor invasion of the mandible by gingival carcinoma. METHOD: PR, PR+IR, and CT images of the mandible in 37 patients with gingival carcinoma were evaluated by five oral radiologists for the supero-inferior extent of bone invasion using ROC analysis. The mean ROC curve area (Az) of each observer for the different imaging modalities was analysed by nonparametric two-way ANOVA. P<0.05 was considered statistically significant. RESULTS: The mean Az for the detection of bone invasion were 0.88+/-0.03 for PR, 0.77+/-0.12 for PR+IR, and 0.87+/-0.03 for CT (P=0.0907). The mean Az for the detection of bone invasion beyond the alveolus was 0.89+/-0.07 for PR, 0.85+/-0.08 for PR+IR, and 0.83+/-0.06 for CT (P=0.5438). The mean Az for the detection of bone invasion beneath the mandibular canal were 0.94+/-0.04 for PR, 0.94+/-0.02 for PR+IR, and 0.91+/-0. 04 for CT (P=0.2466). No statistically significant differences were observed in Az between PR, PR+IR, and CT. CONCLUSION: We consider that PR+IR should be adopted as the initial imaging modality to determine the extent of supero-inferior invasion of the mandible in gingival carcinoma.     

Intrahepatic vascular shunts: Strategy for early diagnosis, evaluation and management

Purpose

To propose a strategy for early diagnosis and management of intrahepatic vascular shunts (IHVSs).

Patients and Methods

We systematically screened 3143 patients liable to develop IHVSs. Diagnosed patients were comprehensively evaluated using color Doppler and multiphasic CT. Our management strategy based on imaging and clinical findings and categorized patients into three groups with different lines of management and we assessed the degree of shunt occlusion and clinical outcome.

Results

IHVSs were diagnosed in 134 patients. Two types of shunts were identified; arteriovenous (72%) and venovenous (28%). Small simple shunts (32%) showed no morphological or hemodynamic changes. Small complex shunts (57%) showed mild alterations in Doppler spectra. Large and aneurismal shunts (11%) showed increased diameters and flow velocities of the shunt vessels with alteration of flow pattern. By CT the vessels opacified during the early arterial phases in arteriovenous, and during the portovenous phase in venovenous shunts. During management, group I included 42%; 38% were conservatively managed and 4% underwent TIPS. Group II included 57% who underwent successful embolization in 50%, and <80% reduction in 7% of patients who underwent surgery. Direct surgery was selected for 1% of patients.

Conclusion

Using color Doppler ultrasonography complemented by multiphasic CT allowed early diagnosis and evaluation of IHVSs and selection of the suitable treatment. Our management strategy allowed practical therapeutic implications and yielded good results.     

Wrist injuries in young adults: The diagnostic impact of CT and MRI

Purpose

To evaluate the diagnostic impact of MRI or/and multidetector CT in young patients with wrist injury and inconclusive or negative clinical examination and X-rays and to analyze variations in imaging strategies between a district general hospital (GH) and a university hospital (UH).

Materials and methods

A retrospective analysis of 34 young patients (mean age 23 years) with wrist trauma who underwent CT or/and MRI was performed. The injury was acute in 24, and chronic in 10 patients. Twenty-two patients were from a GH and 12 from a UH. Two experienced musculoskeletal radiologists blindly reviewed the imaging studies. The effect of cross-sectional imaging on patient care and treatment plan was evaluated.

Results

In 9 of 34 patients one or more fractures were diagnosed on cross-sectional imaging. The scaphoid was fractured in four patients, the lunate and/or the trapezium in three patients, the scaphoid together with the lunate in one patient, and finally the distal radius in one patient. Ligamentous trauma was identified solely on MRI in 11 patients (involving the TFCC in eight cases). In four patients with both imaging methods, CT revealed one fracture of the trapezium not seen on MRI, and one scapholunate fracture with MRI findings of distal radial fracture only. In two patients with normal CT, MRI revealed bone marrow oedema of the scaphoid in one and of the distal radius, lunate and triquetrum in the other.

Conclusion

Both CT and MRI might be considered in patients with acute or chronic wrist injury, clinical dilemma and normal initial radiographs, depending on the availability and the individual institution policies.     

Cherubism: panoramic and CT features in adults

Objectives:

To describe the panoramic radiographic and CT features of cherubism in an unselected series of 15 adults.

Methods:

In this cross-sectional study, 15 individuals aged 29–84 years with familial non-syndromal molecularly confirmed cherubism were examined with panoramic radiography and CT. Bone abnormalities were analysed and described.

Results:

11 (73%) of the 15 adults had mandibular abnormalities. These abnormalities ranged from subtly detectable to severe, and were less prevalent and expansive but could be rather similar to the characteristic image features in children. Unilocular radiolucencies were more common than multilocular radiolucencies, and a specific feature of these abnormalities was that they were exclusively found in the anterior mandible.

Conclusions:

The radiographic and CT abnormalities of cherubism in adults were frequent and extremely heterogeneous, with some distinct features.     

Radiation dose reduction in direct digital panoramic radiography

Objectives

(a) To measure the absorbed radiation doses at 16 anatomical sites of a Rando phantom and (b) to calculate the effective doses including and excluding the salivary gland doses in panoramic radiography using a conventional and a digital panoramic device.

Study design

Thermoluminescent dosimeters (TLD-100) were placed at 16 sites in a Rando phantom, using a conventional, Planmeca Promax and a digital, Planmeca PM2002CC Proline 2000 (Planmeca Oy, 00880 Helsinki, Finland) panoramic device for panoramic radiography. During conventional radiography the selected exposure settings were 66 kVp, 6 mA and 16 s, while during digital radiography two combinations were selected 60 kVp, 4 mA, 18 s and 66 kVp, 8 mA, 18 s with and without image processing function. The dosimeters were annealed in a PTW-TLDO Harshaw oven. TLD energy response was studied using RQN beam narrow series at GAEC's Secondary Standard Calibration Laboratory. The reader used was a Harshaw, 4500. Effective dose was estimated according to ICRP₆₀ report (E_ICRP60). An additional estimation of the effective dose was accomplished including the doses of the salivary glands (E_SAL). A Wilcoxon signed ranks test was used for statistical analysis.

Results

The effective dose, according to ICRP report (E_ICRP60) in conventional panoramic radiography was 17 μSv and E_SAL was 26 μSv. The respective values in digital panoramic radiography were E_ICRP60 = 23 μSv and E_SAL = 38 μSv; while using the lowest possible radiographic settings E_ICRP60 was 8 μSv and E_SAL was 12 μSv.

Conclusions

The effective dose reduction in digital panoramic radiography can be achieved, if the lowest possible radiographic settings are used.     

Mandibular lingual vascular canals (MLVC): Evaluation on dental CTs of a case series

Purpose

The aim of this study was to assess the anatomy of the mandibular lingual foramen (MLF) and its linked canals (mandibular lingual vascular canals - MLVC), describing their frequency, diameter, location, and course.

Materials and methods

One hundred and fourteen computed tomography (CT) images of the mandible (57 male and 57 female; mean age 44.70 ± 12.53; age range 13-75 years, were evaluated. The CT sections were obtained on axial plane by using a bone reconstruction algorithm and then processed with dedicated software (Dentascan), with a standard protocol.

Results

103 patients (90.35%) had at least one lingual vascular canal and 52 (45.61%) had multiple (two or three) canals. The typical locations of MLVC were the midline of the mandible (median lingual canal [MLC]). The mean diameter of the lingual canals in the midline (MLC) was 0.8 mm ± 0. The direction of MLC progresses in an anterior and slightly caudal sense.

Conclusions

Dental CT examination easily demonstrates the presence, position, direction and size of the lingual foramen and of the lingual vascular canals of the mandible. Radiologists and oral surgeons should be aware of these canals and their importance, in order to prevent bleeding complications during implants placement and other surgical procedures.     

CT and MR imaging characteristics of infantile hepatic hemangioendothelioma

Aim

This study aims to analyze computed tomography (CT) and magnetic resonance (MR) imaging features of infantile hepatic hemangioendotheliomas before and after treatment.

Materials and methods

CT and MR examinations of seven infants with biopsy proven hepatic hemangioendotheliomas were retrospectively analyzed. The distribution, number, size, imaging appearance, enhancement pattern and post-treatment changes of the tumors were evaluated.

Results

A total of 153 hepatic hemangioendotheliomas were detected on CT (111) and MR (42) imaging. In six infants, 109/111 (98.2%) tumors were hypodense and 2/111 (1.8%) lesions contained calcification on unenhanced CT. On MR imaging, all 42 lesions in one infant were heterogeneously T1-hypointense and T2-hyperintense compared to the normal liver parenchyma. Contrast-enhanced CT and MRI showed peripheral rim (51.6%), uniform (48.4%), fibrillary (33.3%), and nodular (28.8%) contrast enhancement in the hepatic arterial phase. Homogeneous (100%), rim (98.2%) and mixed enhancement patterns were noted in tumors <1.0 cm, >2.0 cm and 1.0-2.0 cm in diameter respectively in the hepatic arterial phase. In three patients who underwent steroid therapy, follow-up CT examination demonstrated tumor size reduction and increased intra-tumoral calcification in two patients.

Conclusion

Infantile hepatic hemangioendotheliomas show some typical imaging features and size-dependent pattern of contrast enhancement on CT and MR imaging, which allow accurate imaging diagnosis and post-treatment evaluation.     

Quantitative assessment of perirectal tumor infiltration with dynamic contrast-enhanced multi-detector row CT in rectal cancer

Objective

To evaluate the efficacy of discriminant function analysis of perirectal tumor infiltration with dynamic contrast-enhanced 64-detector row CT in rectal cancer.

Materials and methods

Forty-nine patients with rectal cancer underwent dynamic contrast-enhanced CT. A total of 96 axial CT slices containing the tumors were evaluated. The 96 images were separated into two groups with or without perirectal tumor infiltration based on pathological findings. The discriminant function was set-up using CT density differences between the mass and the adjacent perirectal tissue within 5 mm from the mass at 20 and 40 s as independent variables. The results of the discriminant function analysis were compared to those of CT morphology and pathology.

Results

CT morphological diagnosis was accurate on 71.9% (69/96) of the slices with 82.5% sensitivity and 64.3% specificity. Discriminant function analysis correctly identified 88.5% (85/96) of the slices with 85.0% sensitivity and 91.1% specificity. Overstaging occurred significantly more (P < 0.05) on morphological analysis (20.8%, 20/96) than discriminant function analysis (5.2%, 5/96) of the CT slices.

Conclusions

Discriminant function analysis of dynamic contrast-enhanced CT improves the diagnostic accuracy and specificity of perirectal tumor infiltration in rectal cancer.