Perianal fistula mapping at 3 T: volumetric versus conventional MRI sequences.

AIM: To evaluate volumetric contrast-enhanced three-dimensional T1-weighted (CE 3D T1) turbo spin-echo (TSE) with variable flip angle (SPACE), CE 3D T1 volumetric interpolated breath-hold examination (VIBE) sequences with conventional CE-two-dimensional (2D)-T1 and 2D-T2-weighted imaging (WI) sequences in assessing perianal fistulas. METHODS AND MATERIALS: Twenty-three patients with perianal fistula were included in this prospective study and underwent pelvic magnetic resonance imaging (MRI) at 3 T including fat-supressed CE 3D T1 SPACE, CE 3D T1 VIBE, axial and coronal 2D-T1WI together with 2D-T2WI sequences in the axial and coronal planes. Acquisition times were recorded. Performance of each sequence was evaluated in terms of image quality, presence of artefacts, lesion conspicuity, fistula type, presence of abscess, visibility of internal orifice, and number of internal orifices. Results were compared with post-surgical findings defined as the reference standard. RESULTS: Both CE 3D T1 VIBE and CE 3D T1 SPACE were the best sequences to determine fistula type and in terms of image quality, artefacts, and determining locations of internal orifices. The number of internal orifices was detected correctly in 23 (100%) patients for CE 3D T1 SPACE and CE 3D T1 VIBE sequences, in 17 (73.9%) patients on CE-T1WI, and in seven (30.4%) patients on 2D-T2WI. Lesion conspicuity was higher for CE 3D T1 SPACE and CE 3D T1 VIBE sequences compared to the 2D sequences (p<0.05). The overall acquisition time for each 3D sequence was shorter compared to the 2D sequences combined. CONCLUSION: CE 3D T1 SPACE and CE 3D T1 VIBE sequences may outperform conventional 2D sequences in the evaluation of perianal fistulas in terms of visibility and number of internal orifices with a shorter scanning time.

Hybrid seton for the treatment of high anal fistulas: results of 128 consecutive patients.

BACKGROUND: The aim of this study was to evaluate our experience in managing high anal fistulas with a simple modification of the cutting seton. METHODS: We performed a retrospective review of standardized patient charts and of prospectively collected scores and questionnaires. Surgical outcomes of 128 consecutive, well-documented patients with high anal fistulas, including anterior transsphincteric fistulas in females, treated using a hybrid seton, were analyzed. RESULTS: No significant complications occurred. The mean postoperative pain scores on a visual analog scale were 3.23 and 0.61, on days 1 and 7, respectively. Complete healing was achieved in 67 cases (52.3 %) at 1 month and in all cases (100 %) at 3 months. Recurrent fistula was noted in 2 patients (1.5 %) at 6 and 12 months. The mean postoperative incontinence scores at 3 and 12 months did not differ significantly from the preoperative score (p = 0.061, Wilcoxon's test). The depression, life style, and embarrassment item scores of the fecal incontinence quality of life index improved significantly after surgical treatment. CONCLUSIONS: The results of this series suggest that the hybrid seton might be a valid alternative for the treatment of high anal fistulas, eliminating the need for postoperative adjustments. The slow and stable cutting of the sphincter seems to have a positive effect on the maintenance of continence. The successful outcome is associated with significant improvement in quality of life.

Rosai-Dorfman disease with epidural and spinal bone marrow involvement: magnetic resonance imaging and diffusion-weighted imaging features.

Sinus histiocytosis with massive lymphadenopathy (SHML), or Rosai-Dorfman disease, is a rare histiocytic disorder that typically presents with chronic, self-limiting cervical lymphadenopathy. Although this disease mainly affects histiocytes, there are a few reports of bone marrow infiltration. Diffusion-weighted imaging (DWI) is a promising technology in differentiating between various bone marrow pathologies. We here present conventional magnetic resonance imaging and DWI features of a patient with SHML and bone marrow involvement.

Thin-section diffusion-weighted magnetic resonance imaging of the brain with parallel imaging.

BACKGROUND: Thin-section diffusion-weighted imaging (DWI) is known to improve lesion detectability, with long imaging time as a drawback. Parallel imaging (PI) is a technique that takes advantage of spatial sensitivity information inherent in an array of multiple-receiver surface coils to partially replace time-consuming spatial encoding and reduce imaging time. PURPOSE: To prospectively evaluate a 3-mm-thin-section DWI technique combined with PI by means of qualitative and quantitative measurements. MATERIAL AND METHODS: 30 patients underwent conventional echo-planar (EPI) DWI (5-mm section thickness, 1-mm intersection gap) without parallel imaging, and thin-section EPI-DWI with PI (3-mm section thickness, 0-mm intersection gap) for a b value of 1000 s/mm(2), with an imaging time of 40 and 80 s, respectively. Signal-to-noise ratio (SNR), relative signal intensity (rSI), and apparent diffusion coefficient (ADC) values were measured over a lesion-free cerebral region on both series by two radiologists. A quality score was assigned for each set of images to assess the image quality. When a brain lesion was present, contrast-to-noise ratio (CNR) and corresponding ADC were also measured. Student t-tests were used for statistical analysis. RESULTS: Mean SNR values of the normal brain were 33.61+/-4.35 and 32.98+/-7.19 for conventional and thin-slice DWI (P>0.05), respectively. Relative signal intensities were significantly higher on thin-section DWI (P<0.05). Mean ADCs of the brain obtained by both techniques were comparable (P>0.05). Quality scores and overall lesion CNR were found to be higher in thin-section DWI with parallel imaging. CONCLUSION: A thin-section technique combined with PI improves rSI, CNR, and image quality without compromising SNR and ADC measurements in an acceptable imaging time.

Diffusion-weighted imaging of the spine with a non-carr-purcell-meiboom-gill single-shot fast spin-echo sequence: initial experience.

BACKGROUND AND PURPOSE: To prospectively evaluate the signal-to-noise ratio (SNR) improvement in diffusion-weighted imaging (DWI) of the spine with the use of a newly developed non-Carr-Purcell-Meiboom-Gill (non-CPMG) single-shot fast spin-echo (SS-FSE) sequence and its effect on apparent diffusion coefficient (ADC) measurements. MATERIALS AND METHODS: Twenty-four patients were enrolled after written informed consent. DWI of the spine was obtained with an echo-planar imaging (EPI)-based sequence followed by a non-CPMG SS-FSE technique. SNR and ADC values were measured over a lesion-free vertebral corpus. A quality score was assigned for each set of images to assess the image quality. When a spinal lesion was present, contrast-to-noise ratio (CNR) and ADC were also measured. Student t tests were used for statistical analysis. RESULTS: Mean SNR values were 5.83 +/- 2.2 and 11.68 +/- 2.87 for EPI and non-CPMG SS-FSE DWI, respectively. SNR values measured in DWI using parallel imaging were found to be significantly higher (P < .01). Mean ADCs of the spine were 0.53 +/- 0.15 and 0.35 +/- 0.15 x 10(-3) mm(2)/s for EPI and non-CPMG SS-FSE DWI, respectively. Quality scores were found to be higher for the non-CPMG SS-FSE DWI technique (P < .05). Overall lesion CNR was found to be higher in DWI with non-CPMG SS-FSE. CONCLUSION: The non-CPMG SS-FSE technique provides a significant improvement to current EPI-based DWI of the spine. A study including a larger number of patients is required to determine the use of this DWI sequence as a supplementary tool to conventional MR imaging for increasing diagnostic confidence in spinal pathologic conditions.

Corpus callosum hematoma secondary to isolated inferior sagittal sinus thrombosis.

A 45-year-old female was admitted with headache and vomiting. Cranial computed tomography (CT) demonstrated a callosal hematoma. Magnetic resonance imaging (MRI) showed no venous flow and thrombus replacing the inferior sagittal sinus (ISS) lumen. Under appropriate medical treatment and close follow-up she recovered quickly and, after 2 years, was doing well with corpus callosum infarcts. Isolated inferior sagittal sinus thrombosis is an extremely rare condition with only one previously reported case in the literature. Although it is very rare, isolated inferior sagittal sinus thrombosis should be considered in the differential diagnosis of non-traumatic corpus callosum hematoma.

Persistent notochordal canal mimicking compression fracture: a case report.

A persistent notochordal canal is a rare anomaly that is generally discovered by chance. The radiographic appearance of this entity is characteristic and usually does not require further investigation. However, in some cases plain films may fail to depict this appearance, and computed tomography or magnetic resonance imaging (MRI) is required for final diagnosis. We report the MRI findings of a young woman with persistent notochordal canal who, based on plain radiographs, had first been misdiagnosed as having a compression fracture.

Single breath-hold diffusion-weighted MRI of the liver with parallel imaging: initial experience.

AIM: To evaluate prospectively the improvement in the signal:noise ratio (SNR), with the use of parallel technique in single breath-hold diffusion-weighted imaging (DWI) of the liver and its affect on apparent diffusion coefficient (ADC) measurements. MATERIALS AND METHODS: This study was approved by our institutional review board. Written informed consent was obtained from all participants. Fifteen patients underwent single breath-hold DWI of the liver with and without parallel imaging technique. SNR and ADC values were measured over a lesion-free right hepatic lobe by two radiologists in both series. When a focal hepatic lesion was present the contrast:noise ratio (CNR) and ADC were also measured. Paired Student's t-tests were used for statistical analysis. RESULTS: Mean SNR values of the liver were 20.82+/-7.54 and 15.83+/-5.95 for DWI with and without parallel imaging, respectively. SNR values measured in DWI using parallel imaging were found to be significantly higher (p<0.01). Mean ADC of the liver were 1.61+/-0.45 x 10(-3)mm(2)/s and 1.56+/-0.28 x 10(-3)mm(2)/s for DWI with and without parallel imaging, respectively. No significant difference was found between the two sequences for hepatic ADC measurement (p>0.05). Overall lesion CNR was found to be higher in DWI with parallel imaging. CONCLUSION: Parallel imaging is useful in improving SNR of single breath-hold DWI of the liver without compromising ADC measurements.

Central nervous system aspergillosis: magnetic resonance imaging, diffusion-weighted imaging, and magnetic resonance spectroscopy features.

Aspergillus infection is invasive in nature in the immunosuppressed population and disseminates throughout the body, with the brain being a common site. Conventional magnetic resonance imaging (MRI) combined with diffusion-weighted imaging (DWI) and magnetic resonance spectroscopy (MRS) play a life-saving role in the early diagnosis and treatment monitoring of this potentially fatal infection. We present MRI, DWI, and MRS findings of a case of central nervous system aspergillosis with treatment follow-up.

Gardner's syndrome: a case report.

Gardner's syndrome is characterised by polyposis coli associated with multiple hard and soft tissue tumours including osteoma and odontoma. The major significance of the condition lies in the gastrointestinal polyposis which usually undergoes malignant change by the fourth decade. Extra-intestinal components may be apparent before those in the bowel, and their early detection may lead to appropriate evaluation and life saving treatment. A case is reported to demonstrate how important it is for general dental practitioners to be aware of the clinical and radiological characteristics of Gardner's syndrome.

Is there a role for apparent diffusion coefficients in the differential diagnosis of brain tumors?

We determined the potential benefits of apparent diffusion coefficient (ADC) values of enhancing-nonenhancing solid portions, cystic-necrotic areas and surrounding edema in the differential diagnosis of brain tumors. Eighty-eight patients with brain tumors: 16 low-grade gliomas, 21 high-grade gliomas, 26 metastases and 25 meningiomas were imaged prospectively in a 1.5 Tesla magnetic resonance (MR) unit. Routine MR imaging and echo-planar diffusion-weighted imaging (DWI) with b values of 0 and 1000 mm(2)/s were performed. ADC values were obtained in different tumor parts and peritumoral edema. The ADCs of contrast-enhancing tumor regions were higher in high-grade gliomas than meningiomas (p<0.05). No significant differences were found in ADCs of contrast-enhancing regions comparing other tumor groups (p≥0.05). The ADCs in non-enhancing tumor regions did not differ between low-grade and high-grade gliomas (p≥0.05). The ADCs in cystic-necrotic regions of tumors and surrounding edema were not significantly different comparing all tumor groups (p≥0.05). There were no significant differences between ADCs of contrast-enhancing and non-enhancing regions of high-grade and low-grade gliomas (p≥0.05). No significant differences were found in ADCs of contrast-enhancing and non-enhancing areas of tumors comparing to surrounding edema (p≥0.05). ADC was not found to be useful in distinguishing different tumor types and its value in the diagnosis of brain tumors is limited due to considerable overlaps.

Polyorchidism: sonographic and magnetic resonance image findings.

Polyorchidism is a rare congenital anomaly frequently associated with maldescent testis, hernia, and torsion. Reports in the literature show an increased risk of testicular malignancy in the presence of polyorchidism. This entity has characteristic sonographic features and the diagnosis is often made on the basis of sonography. Magnetic resonance imaging might also be used for the diagnosis, but is more helpful in cases associated with cryptorchism or neoplasia. A conservative approach is the treatment of choice in uncomplicated cases.

Imaging meningiomas: is there a need for post-contrast FLAIR?

AIM: The aim of this study was to compare post-contrast fluid-attenuated inversion recovery (FLAIR) imaging with post-contrast T1-weighted images (T1WI) in depicting meningiomas. MATERIALS AND METHODS: Twenty-nine patients with 46 meningiomas were included in this study. FLAIR and T1WI were obtained before and after intravenous administration of gadopentetate dimeglumine. The contrast enhancement degree, contrast enhancement pattern, lesion conspicuity, and the detection of the dural sign were compared between post-contrast FLAIR images and post-contrast T1WI. RESULTS: The enhencement degree on FLAIR was equal or less than T1WI for all meningiomas. Among 46 meningiomas 38 (83%) enhanced homogeneously and eight (17%) inhomogeneously on T1WI. On contrast-enhanced FLAIR images, of the total 46 meningiomas 22 (48%) enhanced homogeneously, eight (17%) inhomogeneously, whereas 14 (30%) meningiomas showed a peripheral rim enhancement not observed on T1WI. Two (5%) meningiomas showed no contrast enhancement on post-contrast FLAIR images. Among the 14 meningiomas showing rim enhancement using FLAIR imaging, 12 (85%) were measured to be 2 cm or more in diameter. A dural tail sign was found in 16 (35%) and 23 (50%) meningiomas on post-contrast T1WI and FLAIR images, respectively. CONCLUSION: In contrast to other extra-axial diseases, post-contrast FLAIR sequence was not found to be a valuable adjunct to contrast-enhanced T1WI in the depiction of meningiomas.