Added value of diffusion-weighted magnetic resonance imaging for the diagnosis of perianal fistula.

PURPOSE: To evaluate the added value of diffusion-weighted (DWI) magnetic resonance imaging (MRI) by comparison with T2-weighted images alone in the diagnosis of perianal fistula. MATERIAL AND METHODS: MRI examinations of 123 patients (97 men, 26 women; mean age, 41.9 years) with suspected perianal fistula were retrospectively evaluated by two radiologists. Fat-suppressed T2-weighted fast spin echo images, DWI (b values, 0 and 1000s/mm2) and fat-suppressed gadolinium chelate-enhanced T1-weighted images were evaluated for each patient by using a four-point scale. Confidence scores and sensitivities were calculated for T2-weighted images alone, the combination of DWI and T2-weighted images and the combination of gadolinium chelate-enhanced T1-weighted images and T2-weighted images. The combination of gadolinium chelate-enhanced and T2-weighted images was used as reference standard. RESULTS: Perianal fistulas were present in 92/123 patients (74.8%). An almost perfect interobserver agreement was found for T2-weighted images (kappa=0.868), the combination of gadolinium chelate-enhanced T1-weighted images and T2-weighted images (kappa=0.96) and the combination of DWI and T2-weighted images (kappa=0.90). The confidence scores for the diagnosis of perianal fistula for the combination of gadolinium chelate-enhanced T1-weighted images and T2-weighted images were greater than those of T2-weighted images alone for observer 1 (P<0.001) and observer 2 (P=0.009). The confidence scores of the combination of DWI and T2-weighted images were greater than those of T2-weighted images alone for observer 1 (P<0.001) and observer 2 (P=0.032). Sensitivity and specificity of the combination of DWI and T2-weighted images were greater than those of T2-weighted images alone for both observers. CONCLUSION: DWI has a significant added value compared to T2-weighted imaging alone in the diagnosis of perianal fistula.

Temporal bone MRI with 3D-FIESTA in the evaluation of facial and audiovestibular dysfunction.

PURPOSE: To evaluate the clinical usefulness of magnetic resonance imaging (MRI) of the temporal bone using three-dimensional fast imaging employing steady-state acquisition (3D-FIESTA) sequences in patients with facial and audiovestibular dysfunction. METHODS: We retrospectively reviewed the MR images of 1263 patients who presented with hearing loss (n=429), peripheral facial palsy (n=96), tinnitus (n=341) or vertigo (n=397). There were 605 men and 658 women, with a mean age of 46.97±16.95 (SD) years (range: 2-83 years). Positive MRI findings that were responsible for clinical manifestations in individual patients were categorized according to the anatomic sites and etiologies of the lesions. RESULTS: Positive MRI findings possibly responsible for clinical manifestations were found in 232/1263 (18.37%) patients, including 86/429 (20.05%) patients with hearing loss, 21/96 (21.88%) patients with facial palsy, 62/341 (18.18%) patients with tinnitus, and 63/397 (15.87%) patients with vertigo. CONCLUSION: Although the use of MRI of the temporal bone using 3D-FIESTA shows positive findings in only 18.37% of patients, it provides important information in those with facial and audiovestibular dysfunction. However, for patients with normal MRI of the temporal bone, other etiological factors should be investigated in order to clarify or elucidate the cause of clinical manifestations.

Petrous apex cephalocoele: contribution of coexisting intracranial pathologies to the aetiopathogenesis.

OBJECTIVE: The aim of this study was to show the MRI findings of petrous apex cephalocoele (PAC) and the other intracranial pathologies that coexist with PAC, and to discuss the contribution of the co-existing pathologies to aetiopathogenesis. METHODS: A retrospective analysis of our imaging archive for the period from January 2012 to October 2013 revealed 13 patients with PAC (12 females and 1 male; age range, 26-69 years). 11 patients underwent MRI examination of the cranium, and 2 patients underwent MRI examination of the sellar region. We evaluated the lesions for content, signal intensity, enhancement, relation to petrous apex and Meckel's cave. Images were also evaluated for coexisting pathologies. RESULTS: The presenting symptoms included headache, vertigo, cerebrospinal fluid (CSF) leak and trigeminal neuropathy. All patients had PAC. All lesions were located posterolateral to the Meckel's cave and were isointense with CSF signal on all pulse sequences. All lesions were continuous with Meckel's cave. Coexisting pathologies included intracranial aneurysmal dilatation, empty sella, mass in hypophysis, arachnoid cyst, inferior herniation of parahippocampal gyrus and optic nerve sheath CSF distension. CONCLUSION: Coexistence with other intracranial pathologies supports the possibility of CSF imbalance and/or intracranial hypertension in the aetiopathogenesis of PAC. ADVANCES IN KNOWLEDGE: This study examined the contribution of the co-existing intracranial pathologies to the aetiopathogenesis of PAC.

Clinical presentation of Von Hippel Lindau syndrome type 2B associated with VHL p.A149S mutation in a large Turkish family.

Von Hippel Lindau (VHL) syndrome is an autosomal dominant disorder characterized by benign and malignant tumors. This study presents the clinical and genetic features of VHL syndrome in a Turkish family. For the diagnosis of pheochromocytoma-related diseases, 49 family members from three generations were evaluated between March 2008 and January 2013. Family members were examined to identify components of pheochromocytoma-related genetic syndromes through physical examination, laboratory tests, and imaging methods. For the causative mutation, sequence analysis of VHL gene was performed. Nine patients were diagnosed with pheochromocytoma. Lumbal spinal hemangioblastoma and pancreatic neuroendocrine tumor without pheochromocytoma were detected in one patient. In patients with pheochromocytoma, additional tumors, such as retinal angioma, renal cell carcinoma, pancreatic serous cystadenoma, and pancreatic neuroendocrine tumors were detected. All patients were diagnosed as VHL syndrome type 2B. Sequence analysis of VHL gene revealed heterozygous p.A149S mutation in all symptomatic patients and in seven of the asymptomatic family members. This is the first study that identified VHL p.A149S mutation in a Turkish family with VHL syndrome. However, VHL p.A149S mutation was identified in an American family by Atuk et al. (J Clin Endocrinol Metab, 83:117-120, 14) and the family was defined as VHL type 2A. In our study, the family was identified as VHL type 2B. This variability in the phenotypic features suggests that further studies are required to beter assess the genotype-phenotype correlation in such cases.

Intramedullary lipoma of the cervico-thoracic spinal cord.

Most of the spinal cord lipomas reported in the literature are intradural extramedullary, and true intramedullary lipomas are very rare. We present a case of intramedullary spinal cord lipoma of the cervico-thoracic region with extensions over many spinal segments. Magnetic resonance (MR) examination showed an intramedullary lipoma of the cervico-thoracic spinal cord of both high T1 and T2-weighted signal intensity and suppression on fat saturation sequence. MR imaging assessment is critical in the detection of intramedullary lipomas which may present without any neurological deficit at an early stage. Early diagnosis may lead to prevention of the irreversible deterioration of neurological functions.

The Correlation between Diffusion-Weighted Imaging and Histopathological Evaluation of 356 Prostate Biopsy Sites in Patients with Prostatic Diseases.

Purpose. The aim of this study is to investigate the reliability of diffusion MRI for detection of cancer foci by comparing diffusion-weighted imaging (DWI) results and pathology results of prostate biopsy sites. Methods. Of the patients who applied with lower urinary tract symptoms, 36 patients who had suspected DRE and/or PSA ≥2.5 ng/mL were included in the study. Patients underwent DWI prior to 10 cores-prostate biopsy. 356 biopsy cores were obtained from the patients. Foci from the patients with prostate cancer were labeled as malignant or benign foci, likewise foci from the patients with benign pathology were grouped as BPH and inflammation foci. Apparent diffusion coefficients (ADCs) of biopsy groups were compared with each other in order to measure the reliability of DWI in detection of PCa foci. Results. When ADC values of adenocarcinoma foci and BPH foci were compared, a statistically significant difference was found (P < 0.001). When ADC values obtained from adenocarcinoma foci and chronic inflammation foci are compared, the difference between two groups is statistically significant, too (P < 0.001). Conclusions. Biopsies focused on suspected regions after formation of ADC maps by means of DWI would provide to start definitive treatment immediately as well as being beneficial to prevent morbidity related to repeated prostate biopsies.

A comparative study of pre-operative imaging methods in patients with primary hyperparathyroidism: ultrasonography, 99mTc sestamibi, single photon emission computed tomography, and magnetic resonance imaging.

AIM: This study compares the accuracy rates achieved in ultrasonography (US), 99mTc-sestamibi (MIBI), single photon emission computed tomography (SPECT), and magnetic resonance imaging (MRI) as imaging methods used in the pre-operative localization of the enlarged parathyroid glands. SUBJECTS AND METHODS: For the purposes of this study, US, MIBI, SPECT, and MRI were performed on 98 patients with primary hyperparathyroidism (pHPT). All patients underwent parathyroidectomy. RESULTS: Pre-operative localization of an abnormal parathyroid gland was successfully performed in 82 of the cases scanned with US (83.7%), while the result was 66 in the cases scanned with MIBI (67.3%), 71 of the cases were successfully localized with SPECT (72.4%), while MRI revealed the diseased gland in only 60 of the total cases (61.2%). In MIBI-positive and -negative patients there was a statistically significant difference among cases in terms of adenoma volume (1.30±1.51 vs 0.58±0.91, p<0.05). Sensitivity, specificity and diagnostic accuracy values were 87.2%, 25.0%, and 83.0%; 70.2%, 50.0%, and 69.4%; 75.5%, 50.0%, and 74.5%; 63.8%, 50.0%, and 63.3% for US, MIBI, SPECT, and MRI, respectively. The respective values for sensitivity, specificity, and diagnostic accuracy were 94.9%, 25.0%, and 91.1% when US was combined with MIBI. CONCLUSIONS: Combining US and MIBI as imaging methods for pre-operative imaging of pHPT often produces more satisfactory results. While the accuracy of US is relatively low in the ectopic localizations, the size of the lesion can be an important factor in the accuracy achieved with MIBI.

Quantitative and diffusion MR imaging as a new method to assess osteoporosis.

BACKGROUND AND PURPOSE: The role of advanced MR imaging techniques in demonstrating the microarchitectural changes in osteoporosis has been recently investigated. Our aim was to determine the role of quantitative and diffusion MR imaging in the diagnosis of osteoporosis compared with dual-energy x-ray absorptiometry (DEXA). MATERIALS AND METHODS: Fifty-one subjects underwent both DEXA and conventional MR imaging with diffusion and apparent diffusion coefficient (ADC) mapping. T1, T2, diffusion signal intensity, and ADC values were calculated and compared with bone mineral attenuation (BMD). Results were obtained from L1 to L4 of each patient with a total of 204 lumbar vertebrae. RESULTS: Both T1 and T2 signal intensities tended to increase when both diffusion and ADC values decreased with reducing BMD. CONCLUSIONS: An inverse relationship between BMD and T1 and T2 signal intensities and a direct relationship between diffusion and ADC values were present in this pilot group. The T1/diffusion signal-intensity ratio could be a reliable diagnostic indicator of osteoporosis.