Contribution of diffusion-weighted imaging to diagnosis and staging of cervical cancer.

BACKGROUND: Cervical cancer is the second most common female malignancy worldwide. Although its incidence has decreased in developed countries due to screening with Papanicolaou test, it is still the leading cause of cancer-related female death in developing countries. AIMS: The aim of this study was to determine whether the apparent diffusion coefficient (ADC) measurements calculated from diffusion-weighted imaging (DWI) images had any contribution in differentiation of normal cervical tissue from malignant lesions preoperatively, and whether there was a correlation between the mean ADC values and tumor type, grade, or stage in malignant lesions. STUDY DESIGN: Case-control study. METHODS: Mean ADC values in 25 patients who had cervical cancer proved histopathologically, and 20 patients with otherwise normal uterus were compared. Also in the study group, mean ADC values were compared between histopathologic subtypes, tumor grades, and stages. RESULTS: In the study group the mean ADC values (0.96±0.15×10(-3) mm(2)/s) were statistically lower than that of the control group (1.67±0.17×10(-3) mm(2)/s) (p<0.05). According to histopathologic sub-types there was no significant difference between mean ADC values of squamous cell cancer and adenocarcinoma (0.95×10(-3) mm(2)/s and 0.91×10(-3) mm(2)/s, respectively) (p>0.05). There was also no significant difference between the mean ADC values of the tumor grades (p>0.05). The mean ADC values in early stage cervical cancer (0.86±0.05×10(-3) mm(2)/s) were significantly lower than the mean ADC values in late stage disease (0.98±0.06×10(-3) mm(2)/s) (p<0.05). CONCLUSION: ADC value measurements may provide useful information in diagnosis of cervical cancer as well as in preoperative assessment of the tumor stage.

Computed tomography imaging findings of craniofacial fibrous dysplasia.

INTRODUCTION: The purpose of this study was to retrospectively describe demographic characteristics and computed tomography (CT) imaging findings of craniofacial fibrous dysplasia (FD). PATIENTS AND METHODS: Between February 2010 and February 2013, we retrospectively studied 64 patients described as FD at CT imaging. Site of involvement and CT imaging findings of craniofacial FD were recorded for each patient. RESULTS: Our patients are described as FD at CT imaging with the following findings: expansion, ground glass density, expansion and sclerosis, expansion with sclerosis and lytic appearance, expansion and lytic appearance, and only sclerosis. Expansion was the main feature which was seen with other findings (85%). The most common finding was ground glass density and the least appearance was expansion with lytic areas and only sclerosis. DISCUSSION: Our study has shown that it is very effective to know about CT findings and localizations of craniofacial FD to reduce unnecessary biopsy rates and increase the true diagnosis.

Use of sonography for evaluation of the cervical and thoracic esophagus in children.

OBJECTIVES: The purpose of this study was to determine the normal sonographic appearance of the cervical and thoracic esophagus and to provide corresponding measurements in healthy children. METHODS: In this prospective study, 93 children (51 girls and 42 boys) 1 to 15 years of age were examined sonographically. With the patient in a supine position for evaluation of the cervical esophagus, the ultrasound transducer was placed on both sides of the trachea. To evaluate the thoracic esophagus, the hands were raised over the head, and the ultrasound transducer was placed along the left side of the sternum. The length of the cervical esophagus was measured longitudinally, and the anteroposterior and transverse diameters of the cervical and thoracic esophagus were measured transversely, as was the thickness of the cervical esophageal wall. RESULTS: The cervical esophagus was identified in all of the children, whereas the thoracic esophagus was shown in 41 (44%) of the 93 participants. The length of the cervical esophagus and anteroposterior and transverse diameters of the cervical and thoracic esophagus increased with age. The mean thickness of the cervical esophagus was 2.8 mm at all ages. The cervical esophageal wall appeared as 5 layers on the sonograms, and the lumen was distinct. CONCLUSIONS: Evaluation of the cervical esophagus was readily achievable with sonography in children, whereas visualization of the thoracic esophagus was difficult because of the deep location, small size, and influence of bones and gas in the lungs. Conventional sonography can be easily used in the evaluation of cervical esophageal diseases in children.

Utility of diffusion-weighted imaging in the evaluation of liver fibrosis.

OBJECTIVES: To evaluate the usefulness of diffusion- weighted MRI (DWI) in the detection and staging of liver fibrosis and inflammation. METHODS: DWI was performed with b-factors of 0, 500 and 1000 s/mm². ADC values were obtained by placing circular regions of interest in four segments of the liver. Differences between the study (n = 34) and control groups' (n = 25) ADC values were examined. Further, this study investigated if and how ADC values were related to fibrosis stages and histological activity index (HAI) scores. RESULTS: The mean ADC value of the liver was smaller in the study group compared with the control group (P < 0.001). Spearman rho correlation analyses showed lower ADC values were associated with higher fibrosis and HAI scores (P < 0.01). There were statistically significant differences in liver ADC values between each combination of fibrosis stages (e.g. stages 0 and 1, 0 and 2) except for stages 1 and 2. CONCLUSIONS: ADC values prove to be a valuable technique for the diagnosis of liver fibrosis and inflammation. They can also be useful in fibrosis staging, particularly in distinguishing later stages of fibrosis from intermediate and early stages. KEY POINTS: Diffusion Weighted MRI is a promising technique for diagnosis of liver fibrosis. Apparent Diffusion Coefficients provide valuable information for staging of liver fibrosis. DWI may offer alternative to biopsy for assessing liver fibrosis.

Multidetector CT angiography versus arterial duplex USG in diagnosis of mild lower extremity peripheral arterial disease: is multidetector CT a valuable screening tool?

OBJECTIVE: To prospectively compare the efficacy of 40-row multidetector computed tomography angiography (MDCTA) and duplex ultrasonography (DUS) to diagnose mild peripheral arterial occlusive disease (PAOD) in lower leg and to search whether MDCTA can be used as a screening tool. METHODS: Forty-three patients with intermittent claudication and leg pain, diagnosed as mild PAOD, had undergone DUS and MDCTA of lower limb. The arteries of lower leg were initially scanned by DUS, followed by MDCTA. Both modalities were compared for detecting the obstructed and stenotic segments. RESULTS: A total of 774 vessel segments were imaged by both modalities. When all arteries were considered, MDCTA detected obstructed or stenotic lesions in 16.8% of arteries, versus 11.1% compared to DUS. When suprapopliteal arteries alone were considered, MDCTA detected lesions in 15.0% of arteries, versus 11.0% with DUS. When infrapopliteal arteries only were considered, MDCTA detected lesions in 19.6% of arteries, versus 11.3% with DUS. MDCTA showed 5.7% (95% CI: [3.5%, 7.9%]) more lesions than DUS when all arteries were considered together, 8.3% (95% CI: [4.6%, 12.0%]) more lesions when only the infrapopliteal arteries were compared, and 4.0% (95% CI: [1.3%, 6.8%]) more lesions when only suprapopliteal arteries were compared (p<0.01 for all comparisons). CONCLUSION: 40-row MDCTA may be used as a screening tool in patients with mild lower extremity PAOD as it is a non-invasive and more accurate modality when compared to DUS.

Diffusion-weighted magnetic resonance imaging in evaluation of primary solid and cystic renal masses using the Bosniak classification.

PURPOSE: Our purpose was to determine whether quantitative diffusion-weighted MR imaging (DWI) could be used in discrimination of benign and malignant primary solid and cystic renal tumors. MATERIALS AND METHODS: A total of 105 consecutive patients with renal masses and 30 healthy controls were enrolled in this prospective study. Dynamic contrast enhanced routin renal images and DWI (with b factors of 0, 500 and 1000 s/mm(2)) was performed at 1.5 T unit. Renal masses were divided into two groups as cystic or solid and all cystic lesions were prospectively assigned to a Bosniak classification number. The median apparent diffusion coefficient (ADC) values along with b 500 and 1000 signal intensities of normal kidneys, solid components of mixed renal masses and total of cystic lesions were calculated. RESULTS: The mean ADC value of normal renal parenchyma in control group was 2.18 ± 0.13 × 10(-3)mm(2)/s. Solid renal tumors had significant lower ADC values (median: 1.16 ± 0.27 × 10(-3)mm(2)/s), in contrast to cystic tumors (median: 2.73 ± 0.44 × 10(-3)mm(2)/s). The mean ADC value of the Bosniak Category I cysts was significantly higher (3.09 ± 0.14 × 10(-3)mm(2)/s) than normal renal parenchyma (p<0.01). A statistical significance was achieved between the signal intensity of Bosniak Category I and Category II-III cysts with b 1000 (p<0.05). Among the different histologic subtypes of renal cell carcinoma, the mean ADC value of chromophobe cell carcinoma (1.41 ± 0.09 × 10(-3)mm(2)/s) was significantly higher than that of papillary cell carcinoma (0.90 ± 0.16 × 10(-3)mm(2)/s) and clear cell carcinoma (1.23 ± 0.13 × 10(-3)mm(2)/s). CONCLUSION: Accurate assessment of renal masses is important for establishing whether tumors require surgical intervention or not. While MRI is a useful modality as an investigative tool for diagnosing, characterizing and staging renal masses, DWI contributes additional value by promising differentiation benign from malignant renal tumors, even histologically subtyping of renal cell cancer.

Efficiency of unenhanced MRI in the diagnosis of acute appendicitis: comparison with Alvarado scoring system and histopathological results.

PURPOSE: The purpose of this study was to assess the diagnostic value of unenhanced magnetic resonance imaging (MRI) in the diagnosis of acute appendicitis and compare with Alvarado scores and histopathological results. MATERIALS AND METHODS: The study included 85 consecutive patients (mean age, 26.5±11.3 years) who were clinically suspected of having acute appendicitis. Each patients Alvarado scores were recorded and unenhanced MRI was performed, consisting of T1-weighted, T2-weighted and fat-suppressed T2-weighted fast spin-echo sequences. The MR images were prospectively reviewed in consensus for the presence of acute appendicitis by two radiologists who were blinded to the results of the Alvarado scores. The study population were divided into three subgroups based on the MRI findings: Group I: definitely not appendicitis, Group II: probably appendicitis, Group III: definitely appendicitis. All patients were divided into two subgroups according to Alvarado scores as Group A (low: 1-6), and Group B (high: 7-10). MR findings were compared with Alvarado scores and histopathological findings. RESULTS: Sixty-six (77.6%) of the 85 patients with clinically suspected acute appendicitis, had undergone surgery. The diagnosis of appendicitis could be correctly achieved with MRI in 55 (83.3%) of 57 (86.4%) patients with histopathologically proven acute appendicitis. The sensitivity, specificity, positive predictive value and negative predictive value of MRI examination and Alvarado scoring system in the diagnosis of acute appendicitis were 96.49%, 66.67%, 94.83%, 75.0% and 84.21%, 66.67%, 94.12%, 40.0%, respectively. CONCLUSIONS: MRI is a valuable technique for detecting acute appendicitis even in the cases with low Alvarado scores. To increase the diagnostic accuracy and preventing unnecessary laparotomies for suspected appendicitis, shorter and cheaper unenhanced basic MRI may be performed.

Utility of diffusion-weighted imaging in the diagnosis of acute appendicitis.

OBJECTIVES: To evaluate the value of diffusion-weighted MRI (DWI) in the diagnosis of acute appendicitis. METHODS: 119 patients with acute appendicitis and 50 controls were enrolled in this prospective study. DWI was obtained with b factors 0, 500 and 1000 s/mm² and were assessed with a visual scoring system by two radiologists followed by quantitative evaluation of the DW images and ADC maps. RESULTS: Histopathology revealed appendicitis in 79/92 patients (78%) who had undergone surgery. On visual evaluation, except for one patient with histopathologically proven appendicitis all inflamed appendixes were hyperintense on DWI (98.7%). Quantitative evaluation with DW signal intensities and ADC values revealed a significant difference with normal and inflamed appendixes (p < 0.001). The best discriminative parameter was signal intensity (b 500). With a cut-off value of 56 for the signal intensity the ratio had a sensitivity of 99% and a specificity of 97%. The cut-off ADC value at 1.66 mm²/s had a sensitivity of 97% and a specificity of 99%. CONCLUSION: DWI is a valuable technique for the diagnosis of acute appendicitis with both qualitative and quantitative evaluation. DWI increases the conspicuity of the inflamed appendix. We recommend using DWI to diagnose acute appendicitis.

Is quantitative diffusion-weighted MRI a reliable method in the assessment of the inflammatory activity in ulcerative colitis?

PURPOSE: We investigated the relationship between the apparent diffusion coefficient (ADC) values of the colonic wall and the pathologic pericolonic lymph nodes (PCLNs) and inflammatory activity in ulcerative colitis patients by diffusion-weighted magnetic resonance imaging (DW-MRI). MATERIALS AND METHODS: A total of 28 ulcerative colitis patients (9 endoscopically active, 10 subacute and 9 in remission) were evaluated by DW-MRI with 0, 500 and 1000 s/mm² b-values. The ADC values of the rectum and sigmoid colon walls and the adjacent PCLNs were obtained for quantitative analysis. The DW-MRI findings were compared to the disease activity. RESULTS: The ADC values of the sigmoid colon were similar in patients with active, subacute and remissive ulcerative colitis (P = 0.472). The ADC values of the rectum were different (P = 0.009) between patients in the active (1.08 ± 0.14×10⁻³ mm²/s) and subacute phases (1.13 ± 0.23×10⁻³ mm²/s) of disease and those in remission (1.29 ± 0.17×10⁻³ mm²/s). The ADC values of the PCLNs (P = 0.899) did not differ with respect to disease activity. CONCLUSION: DW-MRI is useful in identifying disease activity in ulcerative colitis patients, especially with respect to the rectum. The ADC values of the rectum increase during remission and decrease in patients with active distal colitis. The ADC values of the PCLNs were not useful in determining disease activity.

Virtual and fiber-optic bronchoscopy in patients with indication for tracheobronchial evaluation.

OBJECTIVE: The aim of this study was to compare the results of virtual bronchoscopy (VB) images in defining tracheobronchial pathologies with those of fiber-optic bronchoscopy (FOB) in patients with clinical indication for bronchoscopy. METHODS: Twenty-two patients with bronchoscopy indication were evaluated with FOB and VB. The VB results were evaluated blindly, independent of the FOB results. RESULTS: In 19 of the 22 patients, tracheobronchial abnormalities were present on FOB, whereas 3 patients had normal findings on FOB. In 17 of 19 patients, VB demonstrated the FOB diagnosis of tracheobronchial abnormality. While FOB detected 11 endoluminal lesions, VB detected 6. While FOB detected 20 obstructive lesions, VB detected 26. In evaluating external compression, FOB detected 2 lesions and VB detected 15. CONCLUSIONS: VB is a non-invasive, uncomplicated, and reproducible examination method in patients with an indication for thorax examination. Virtual bronchoscopy could find a clinically broader field of application in the future.

T2-weighted MRI of the upper abdomen: comparison of four fat-suppressed T2-weighted sequences including PROPELLER (BLADE) technique.

RATIONALE AND OBJECTIVES: The aim of this study was to compare four different fat-suppressed T2-weighted sequences with different techniques with regard to image quality and lesion detection in upper abdominal magnetic resonance imaging (MRI) scans. MATERIALS AND METHODS: Thirty-two consecutive patients referred for upper abdominal MRI for the evaluation of various suspected pathologies were included in this study. Different T2-weighted sequences (free-breathing navigator-triggered turbo spin-echo [TSE], free-breathing navigator-triggered TSE with restore pulse (RP), breath-hold TSE with RP, and free-breathing navigator-triggered TSE with RP using the periodically rotated overlapping parallel lines with enhanced reconstruction technique [using BLADE, a Siemens implementation of this technique]) were used on all patients. All images were assessed independently by two radiologists. Assessments of motion artifacts; the edge sharpness of the liver, pancreas, and intrahepatic vessels; depictions of the intrahepatic vessels; and overall image quality were performed qualitatively. Quantitative analysis was performed by calculation of the signal-to-noise ratios for liver tissue and gallbladder as well as contrast-to-noise ratios of liver to spleen. RESULTS: Liver and gallbladder signal-to-noise ratios as well as liver to spleen contrast-to-noise ratios were significantly higher (P < .05) for the BLADE technique compared to all other sequences. In qualitative analysis, the severity of motion artifacts was significantly lower with T2-weighted free-breathing navigator-triggered BLADE sequences compared to other sequences (P < .01). The edge sharpness of the liver, pancreas, and intrahepatic vessels; depictions of the intrahepatic vessels; and overall image quality were significantly better with the BLADE sequence (P < .05). CONCLUSION: The T2-weighted free-breathing navigator-triggered TSE sequence with the BLADE technique is a promising approach for reducing motion artifacts and improving image quality in upper abdominal MRI scans.

Respiratory gated multidetector computed tomography: applicable for diagnostic abdominal imaging?

PURPOSE: To evaluate the ability and accuracy of a respiratory gated technique used with contrast enhanced MDCT of the upper abdomen with focus on diagnostic image quality and depiction of organs and major vessels. MATERIALS AND METHODS: Forty-five adult patients who were referred to our institution for follow-up dynamic contrast enhanced abdominal CT imaging were included in this study. Respiratory gated CT scans were performed with the use of a dedicated hardware. A multiphasic CT scan was performed for each patient. Respiratory gated images were obtained between early arterial and portal venous phases during free breathing. Images of respiratory gated (RG) and breathhold (BH) phases were compared qualitatively and quantitatively by two radiologists. Definitive statistical methods were used for evaluating the scoring data, while Mann Whitney U test was used for comparison. Statistical significance was accepted for p values <0.05. RESULTS: Statistical significant difference was found for comparison of scores regarding luminal opacification and contoural integrity of intrahepatic vascular structures with scores of RG scans rated poor to moderate (e.g. 2.86+/-1.07 for luminal opacification of intrahepatic portal veins as well as border detectability) in comparison to scores of BH scans rated good to excellent (e.g. 1.37+/-1.31 for luminal opacification, 1.35+/-1.28 for border detectability of intrahepatic portal veins, p<0.001). Furthermore, statistical significant differences were found for general image noise levels (p<0.001). CONCLUSIONS: Further technical advances of RG technique could enable routine use of this technique for selected patient groups.

Diffusion-weighted imaging of the rectosigmoid colon: preliminary findings.

OBJECTIVES: The aims of this study were to determine and evaluate the apparent diffusion coefficient (ADC) values of the rectal wall for identifying inflammatory bowel disease (IBD) and rectosigmoid (rectum and sigmoid colon) malignancies. METHODS: Diffusion-weighted magnetic resonance imaging (DWI) findings of 23 patients (mean age, 57 years) consisting of 14 patients with rectosigmoid adenocarcinomas and 9 patients with IBD (6 with ulcerative colitis and 3 with Crohn disease) were retrospectively reviewed. In addition, 30 healthy controls (mean age, 45 years) were enrolled in the study. Diffusion-weighted imaging was performed with b factors of 0, 500, and 1000 s/mm2. RESULTS: The mean (SD) ADC values of the control, IBD, and rectosigmoid adenocarcinoma groups were 1.47 (0.19) x 10(-3) mm2/s, 1.37 (0.12) x 10(-3) mm2/s, and 0.97 (0.14) x 10(-3) mm2/s, respectively. Among the patients with IBD, 2 were in the active, and the rest were in the inactive period, with mean (SD) ADC values of 1.21 (0.08) x 10(-3) and 1.42 (0.09) x 10(-3), respectively. The ADC values of the normal rectum and rectosigmoid malignancy group and rectosigmoid carcinoma and IBD groups were significantly different (P < 0.01). A cutoff value for carcinomas of 1.14 x 10(-3) mm2/s yielded a sensitivity and specificity of 93.3% and 93.3%, respectively. CONCLUSIONS: Our preliminary findings show that quantitative DWI may be able to differentiate the normal rectum from neoplastic involvement, in addition to distinguishing between inflammatory and neoplastic involvements. However, radiologists should be aware of possible overlaps that may lead to misdiagnoses when DWI is used alone.

Diffusion-weighted MRI of urinary bladder and prostate cancers.

PURPOSE: The purpose of this study was to evaluate the feasibility of diffusion-weighted imaging in the diagnosis of the urinary bladder and prostate carcinomas. The apparent diffusion coefficient (ADC) values of the malignant and normal tissues were correlated. MATERIALS AND METHODS: A total of 23 patients with 14 urinary bladder carcinomas and 9 prostate carcinomas, and 50 healthy controls with normal ultrasonographic urinary bladder and prostate gland imaging findings were enrolled in the study. The ADC values were reported as the mean +/- standard deviation. Student's t test was performed to compare the ADC values of the normal and pathological tissues. Diffusion-weighted imaging (DWI) was performed with b factors of 0, 500, and 1000 s/mm(2), and the ADC values of the normal tissues and lesions were calculated. RESULTS: The mean ADC value of the urinary bladder wall of the control group and bladder carcinomas were (2.08 +/- 0.22 x 10(-3)mm(2)/s) and (0.94 +/- 0.18 x 10(-3)mm(2)/s), respectively. In addition, the ADC values of the normal peripheral (2.07 +/- 0.33 x 10(-3)mm(2)/s), transitional zones (1.46 +/- 0.23 x 10(-3)mm(2)/s) of the prostate, seminal vesicles (2.13 +/- 0.13 x 10(-3)mm(2)/s) and the prostate carcinomas (1.06 +/- 0.17 x 10(-3)mm(2)/s) were calculated. The comparison of mean ADC values of the peripheral-transitional zones of the prostate, normal bladder wall-bladder carcinomas, and peripheral zone prostate carcinomas were statistically significant (P < 0.01). CONCLUSION: The present study demonstrated that ADC measurement has a potential ability to differentiate carcinomas from normal bladder wall and prostate gland.

Do the manipulations in pediatric inguinal hernia operations affect the vascularization of testes?

PURPOSE: The aim of this study is to evaluate the effect of manipulations performed in inguinal hernia operations on testicular perfusion, in pediatric age group using Doppler ultrasonography (DUS). METHODS: In this prospective clinical trial, 51 boys who underwent elective inguinal hernia repair were examined before the operation and in early-late postoperative periods. Blood flow indices of centripetal and capsular arteries including peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistivity index (RI) were examined by DUS. RESULTS: There was a statistically significant increase in early postoperative PSV and RI values compared with preoperative findings. These values turned to normal in late postoperative period. The increase in early and decrease in late postoperative EDV values were not statistically significant compared to preoperative findings. CONCLUSIONS: The surgical manipulations performed in inguinal hernia operations in children cause transient changes in testes vascularization in early postoperative period but turns to normal late postoperatively.

Non-breath-hold high b-value diffusion-weighted MRI with parallel imaging technique: apparent diffusion coefficient determination in normal abdominal organs.

PURPOSE: To detect apparent diffusion coefficient (ADC) values in normal abdominal organs using non-breath-hold high b-value diffusion-weighted magnetic resonance imaging (DW-MRI) with a parallel imaging technique. MATERIALS AND METHODS: A total of 50 patients with normal abdominal MRI findings were retrospectively enrolled. DW-MRI was performed with b-factors of 0, 500, and 1000 s/mm(2). Mean ADC measurements were calculated. RESULTS: There were statistically significant differences (P < 0.001) between the ADC values of four liver segments (left lobe lateral segment: 1.77 +/- 0.21 x10(-3) mm(2)/s, left lobe medial segment: 1.59 +/- 0.21 x 10(-3) mm(2)/s, right lobe anterior segment: 1.46 +/- 0.18 x 10(-3) mm(2)/ s, right lobe posterior segment: 1.34 +/- 0.20 x 10(-3) mm(2)/s). The ADC value for the left lobe lateral segment was significantly higher than the values for the other segments. The calculated ADC values for cortex and medulla of kidney were 2.08 +/- 0.22 x 10(-3) mm(2)/ s, 1.94 +/- 0.18 x 10(-3) mm(2)/s, respectively; (P < 0.001), for pancreas tail 1.59 +/- 0.38 x 10(-3) mm(2)/s, for pancreas body 1.68 +/- 0.26 x 10(-3) mm(2)/s, pancreas head 1.65 +/- 0.29 x 10(-3) mm(2)/s, stomach wall 1.84 +/- 0.22 x 10(-3) mm(2)/s, and spleen 1.28 +/- 0.38 x 10(-3) mm(2)/s. CONCLUSION: Knowledge of ADC values for normal abdominal organs will be required during quantitative evaluation of DW-MR images in diseases in accordance with the technique used. We believe that further studies investigating the effect of diseases on normal ADC values are necessary and would be helpful in quantitative DWI.

The correlation between root canal patterns and interorificial distance in mandibular first molars.

OBJECTIVES: The aim of this study was to investigate the relationship of the distance between mesiobuccal (MB) and mesiolingual (ML) orifices (interorificial distances) in the pulp chamber floor and the degree of canal curvature in the mandibular first molars. STUDY DESIGN: In this in vitro study, 102 extracted teeth were radiographed in both buccolingual (CV) and mesiodistal (PV) directions and then grouped according to the Vertucci classification. The interorificial distance was measured by the stereomicroscope method. RESULTS: The interorificial distance was significantly higher in type IV compared to type II (P= .016). In the logistic regression analysis, the increase in the degree of primary canal curvature of the ML in CV was a predictive factor for increase in the primary curvature of ML in PV (P = .01). CONCLUSION: The interorificial distance in the pulp chamber floor and primary curvatures in CV were found to be key factors for evaluation of root canal patterns in PV.

The role of HRCT versus CXR in children with recurrent pulmonary infections.

The purpose of this study is to evaluate the role of high-resolution computed tomography (HRCT) versus chest radiography (CXR) in children with recurrent respiratory infections. Fifty-one cases, aged 2 months-13 years, who had a history of recurrent respiratory infections, were examined with CXR and HRCT. HRCT showed that 16/51 of the cases had bronchiectasis. CXR revealed findings of bronchiectasis only in 5 of the 16 cases. HRCT showed peribronchial thickening in 18 cases, whereas CXR showed the same finding in 5 patients. Overall, HRCT showed the underlying pathology and sequel of pulmonary lesions in 22 out of 51 cases, and linear densities in 12. Compared with the CXR, HRCT gives much more information.