Value of diffusion-weighted images in diagnosis of locoregionally recurrent rectal tumors.

INTRODUCTION: To assess the value of referring to Diffusion-weighted images in evaluation of T2-weighted images of patients clinically suspicious of locoregional rectal cancer recurrence. METHODS: After ethics committee approval and informed consent were obtained, 37 consecutive patients (male/female of 22/15; mean age 56 ± 13.5 SD) clinically suspicious of recurrent rectal tumor were prospectively included in the study over a two-year period. T2-weighted images of the patients were reviewed and the results were recorded. Right after that, the corresponding DWI images were provided for the radiologist and new ratings were given to the patients after taking into account the DWI findings. Finally, the patients underwent tissue biopsy. Receiver Operating Characteristic (ROC) analysis was performed, and Area Under the Curve (AUC) of the "T2-weighted alone" and "T2-weighted + DWI" methods were calculated and compared. RESULTS: "T2-weighted alone" and "T2-weighted + DWI" methods had an AUC of 0.64 (95% CI 0.47 to 0.79) and 0.75 (95% CI 0.58 to 0.88), respectively. The Difference between the two AUCs was 0.11 (P = 0.16). In the subgroup of patients having equivocal ratings in T2-weighted images, DWI images correctly identified 81% (13/16) of patients with true tumor recurrence and 66% (8/12) of patients without recurrence. CONCLUSION: Our results suggest that referring to DWI does not significantly change the overall diagnostic performance of T2-weighted images. However, DWI is of great value in evaluation of the subgroup of patients with equivocal findings in T2-weighted images. Studies with larger sample sizes are needed to confirm these findings. IMPLICATIONS FOR PRACTICE: When T2-weighted images are equivocal, DWI images may be helpful in evaluation of patients with suspected locoregional recurrence of rectal tumor.

Visibility of different foreign bodies in the maxillofacial region using plain radiography, CT, MRI and ultrasonography: an in vitro study.

OBJECTIVES: To compare the usefulness of four imaging modalities in visualizing various foreign bodies of different sizes. METHODS: Foreign bodies of four sizes (0.5, 1, 2 and 3 mm) including metal, tooth, wood, plastic, stone, glass and graphite were embedded in six fresh sheep heads on bone surface between the corpus mandible and muscle, and inside the tongue muscle. A human dry skull served as an air-filled space. Plain radiography, CT, MRI and ultrasonography were used, and four skilled radiologists rated the findings individually. RESULTS: All embedded foreign bodies except wood were best visualized using CT. Wood could only be detected using ultrasonography, and then only when fragments were >0.5 mm in size. Plain radiography and CT were almost equally accurate in visualizing metal and graphite. MRI was the least useful imaging technique. CONCLUSIONS: In cases with suspected foreign bodies in the maxillofacial region, CT seems to be the optimal initial imaging study. Wood, however, could only be detected using ultrasonography.

Concha bullosa, nasal septal deviation and paranasal sinusitis; a computed tomographic evaluation.

PROBLEMS/OBJECTIVES: Although concha bullosa, nasal septal deviation (NSD) and paranasal sinusitis are apparently three independent entities, some studies suggest that they are interconnected. Computed tomography (CT) is a useful and accurate imaging modality for examining this interconnection. The objective of this study is to use CT imaging to investigate the possible association between concha bullosa, NSD and paranasal sinusitis. METHODOLOGY: We reviewed 206 nasal and paranasal CT images of individuals with sinonasal symptoms/cosmetic issues and investigated the association between the presence of concha bullosa and NSD with paranasal sinusitis. RESULTS: There was no significant relation between the presence of concha bullosa and paranasal sinusitis. The mean NSD was significantly higher in the cases with frontal, maxillary, ethmoid and sphenoid sinusitis than in unaffected subjects. Similar findings were found in the patients with any involved paranasal sinus and the controls (6.49 +/- 3.060 vs. 3.31 +/- 1.99 degrees; p<0.001). An NSD > or =3.5% differentiated between the presence and absence of paranasal sinusitis, with a sensitivity and specificity of 77.8% and 76.5%, respectively. A significant positive correlation was found between NSD and the number of involved sinuses (Pearson's r=0.58, p<0.001). The laterality of sinusitis was not associated with NSD or concha bullosa. CONCLUSIONS: Nasal septal deviation, but possibly not concha bullosa, is associated with paranasal sinusitis and its extent. An NSD > or = 3.5 degrees is a useful predictor of paranasal sinusitis.

Comparison of ultrasonography with computed tomography in the diagnosis of nasal bone fractures.

OBJECTIVES: The aim of this study is to compare ultrasonography with CT in the diagnosis of nasal bone fractures. METHODS: 40 patients (9 female and 31 male) with mid-facial fractures, which were suspected nasal bone fractures, were included. All of the patients had mid-facial CT images. Ultrasonography with a 7.5 MHz transducer (Aloka 3500, Tokyo, Japan) was used to evaluate the nasal bone fractures. All of the sonograms were compared with CT findings for sensitivity, specificity and predictive values. A χ(2) test was applied to the data to assess statistical significance. RESULTS: CT diagnosed nasal bone fractures in 24 of the 40 patients (9 unilateral fractures and 15 bilateral fractures) while ultrasonography diagnosed the fractured bones in 23 patients (9 unilateral fractures and 14 bilateral fractures). Ultrasonography missed one fractured bone in a bilateral fractured case and a unilateral fracture was also missed (two false-negative results). The sensitivity and specificity of ultrasonography in assessing nasal bone fracture in comparison with CT were 94.9% and 100%, respectively. The positive predictive value (PPV) and the negative predictive value (NPV) of ultrasonographic evaluation of the nasal bone fractures were 100% and 95.3%, respectively. The χ(2) test did not show any significant difference between CT and ultrasonography in diagnosis of nasal bone fractures (P = 0.819). CONCLUSION: Ultrasonography can be used as a first line of diagnostic imaging for evaluating nasal bone fractures, especially in children and pregnant women.

Comparison of ultrasonography with submentovertex films and computed tomography scan in the diagnosis of zygomatic arch fractures.

OBJECTIVES: The aim of this study was to compare ultrasonography with CT scan and submentovertex films in the visualization of zygomatic arch fractures. METHODS: 17 patients, 10 men and 7 women, with suspected fracture of the zygomatic arch were studied. The data from CT and plain films were compared with the ultrasonographic findings (Aloka 3500 (Tokyo, Japan) ultrasound equipment with a 7.5 MHz transducer). The probe was situated over the fractured arch transversely to evaluate its whole length. All of the sonograms were taken and interpreted by the same sonologist, who was not aware of the results of the CT and the plain films. RESULTS: Ultrasound was accurate in assessing the fractured arches with sensitivity of 88.2% (15 of the 17 patients, with two false negatives) and specificity of 100% (no false positives). CONCLUSION: Ultrasound is accurate in the visualization of zygomatic arch fractures and can be used as an adjunct to plain films to reduce the overall radiation exposure.

Myocardial bridging and coronary artery anomalies detected by ECG-gated 64-row multidetector computed tomography angiography in symptomatic patients.

Advances in 64-row multidetector computed tomography have provided noninvasive imaging of coronary arteries. The aim of this study was to evaluate the prevalence of coronary artery anomalies in Iranian symptomatic patients and to determine the presence of anomalies resulting in myocardial ischaemia without atherosclerotic plaque. This study was carried out in Tabriz University of medical sciences on 534 patients with suggestive symptoms for coronary artery diseases. Original slices were reconstructed from data achieved by using a ECG-gated multidetector computed tomography scanner, and reconstructed 3-dimentional images of the heart were reviewed. Congenital angiography was performed in 36.3% of patients. The prevalence of myocardial bridging in symptomatic patients was 6.0% by multidetector computed tomography while conventional angiography could detect 20% of them. The most prevalent site was the middle portion of the left anterior descending artery. Anomalous origin or course of coronary arteries and AV fistula was detected by multidetector computed tomography coronary angiography in 2.6% of cases while conventional angiography could detect 44.4% of these anomalies. The prevalence of atherosclerotic plaques in patients with myocardial bridging was 53.1%. In 46.9% of these patients, myocardial bridging was held responsible for signs and symptoms of myocardial ischaemia as no atherosclerotic plaque was evident. This rate was 64.3% in symptomatic patients with other anomalies in origin or course of coronary arteries. This study gives the prevalence of coronary artery anomalies and myocardial bridging in the Iranian population. The results suggest multidetector computed tomography coronary angiography as the preferred utility for diagnosing such anomalies.

Brown tumor of hyperparathyroidism masquerading as central giant cell granuloma in a renal transplant recipient: a case report.

The brown tumor of hyperparathyroidism is histologically identical to the central giant cell granuloma (CGCG), but these lesions can be differentiated based on history and laboratory findings. Herein we have reported a 46-year-old renal transplant recipient in whom brown tumors of hyperparathyroidism were detected several years following renal transplantation. The lesions initially masqueraded as a CGCG with an intranasal mass and ethmoid bone involvement at 7-years posttransplantation, for which surgical resection had been performed. Six years later, she developed multiple expansile bony lesions of the chest wall with histologic features of multinucleated giant cells. A markedly elevated parathyroid hormone level led us to make a diagnosis of brown tumor of hyperparathyroidism. Hence, we propose that clinicians consider brown tumor of hyperparathyroidism to be a potential cause of giant cell lesions among renal transplant recipients. Moreover, careful follow-up examinations are required for such patients to make a timely and accurate diagnosis.