Diffusion-weighted magnetic resonance imaging in the assessment of choroid plexus aging

Recent studies have pointed out dysfunction and histopathological changes of the choroid plexuses (CPs) with aging. This paper reviews apparent diffusion coefficient (ADC) values of the CPs for age-related changes. All the brain MR images of the patients between January 2013 and June 2014 in our Radiology Department were retrospectively investigated. Patients with major cranial abnormalities (brain tumors, hyperacute or acute ischemia, developmental anomalies, hemorrhage, hydrocephaly) were excluded. Diffusion-weighted images were obtained at the parameter values of b = 1000 s/mm² in the axial plane. The transverse diameters of the lateral ventricles (LVs) and ADC values of both CPs were measured. Brain MRIs of 202 individuals, 97 men (48%), 105 women (52%), were studied. There were statistically significant positive correlations between the ADC values of CP and patient ages. (Right CP: r = 0.623; p < 0.05. Left CP: r = 0.654; p < 0.05). There were positive correlations between LV diameters and age ( r = 0.624, p < 0.05 for the right LV; r = 0.621, p < 0.05 for the left LV). The ADC values of age groups significantly differed ( p < 0.05); the ≥61-year-old group was significantly higher compared to younger individuals. There is a progressive increase of water diffusivity in the CPs during aging. ADC values should be considered as a neuroimaging quantitative biomarker in normal aging-dementia syndromes.

Efficacy of in vivo31Phosphorus Magnetic Resonance Spectroscopy in Differentiation and Staging of Adult Human Brain Tumors

The aim of this study was to evaluate the efficacy of 31P magnetic resonance spectroscopy (31P-MRS) in the differentiation and staging of brain tumors. Fifteen volunteers and 44 patients with brain tumors (14 meningiomas, 13 low- and 17 high-grade gliomas) were prospectively evaluated by 31P-MRS. The pH (r=0.493, p<0.001), [Mg+2] (r=0.850, p<0.001) PME/α-ATP (r=0.776, p<0.001), PDE/α-ATP (r=-0.569, p<0.001) and (PCr+β-ATP)/Pi ratios were well correlated with tumor differentiation. High-grade gliomas had significantly higher pH (r=0.912, p<0.001) and [Mg+2] (r=0.855, p<0.001) and PME/α-ATP (r=0.894, p<0.001) ratio, and lower PCr/α-ATP (r= −0.959, p<0.001), Pi/α-ATP (r= −0.788, p<0.001) and PDE/α-ATP ratios (r=−0.968, p<0.001) than those of low-grade gliomas. Changes in 31P-MRS parameters by the degree of malignancy are good indicators of increased anaerobic metabolism and hypoxia of tumoral tissue to compensate intratumoral energy deficiency. 31P-MRS parameters are very useful for grading and differentiation of brain tumors.

The middle interhemispheric variant of holoprosencephaly: magnetic resonance and diffusion tensor imaging findings

OBJECTIVE

The middle interhemispheric (MIH) variant of holoprosencephaly (HPE) is the incomplete separation of midline cerebral hemispheres with the absence of callosal body. We aimed to describe the additional knowledge of diffusion tensor imaging (DTI) over conventional MRI in the evaluation of patients with MIH variant of HPE.

METHODS

Conventional MRI and DTI data of five patients were retrospectively evaluated. The parenchymal anomalies as well as changes at white matter tracts were systematically reviewed.

RESULTS

Except the callosal body and central cingulum fibres, which were missing in all patients, all other major white matter tracts (superior and inferior longitudinal, superior and inferior fronto-occipital, subcallosal and uncinate fasciculi and anterior commissure) had a normal course, thickness and integrity on diffusion tensor images. The genial and splenial callosal fibres were altered and rarefied on tractography. All patients had a central ventricular notch extending into the non-cleaved heterotopic grey matter involving the body of the corpus callosum, which is very typical for the MIH variant of HPE. The remnant traversing white matter fibres above the non-cleaved heterotopic grey matter and incomplete partition of the interhemispheric fissure were also identified. No Probst bundles were detected. A single common ventricle without the septum pellucidum was noted in all patients. One patient had incomplete partition of the thalami, and two patients had abnormally oriented thalami without any prominent interthalamic connection. Vertically oriented hippocampi were detected in four out of five patients. Three patients had relatively flat and vertically oriented Sylvian fissures and in two patients, fissures were abnormally connected over the vertex.

CONCLUSION

Additional DTI findings can not only clearly reveal the white matter alterations better than conventional MRI but also provide a better understanding of the aetiological changes that cause the MIH variant of HPE.

ADVANCES IN KNOWLEDGE

DTI can provide a better analysis of cerebral white matter connectivity and promotes understanding of the underlying microstructural changes that occur in patients with the MIH variant of HPE.

Interrelationship between liver hemodynamics and tumor metabolism in liver metastases: diagnostic value of Doppler perfusion index revisited

It should be expected that the hepatic blood flow increase in the cases with liver metastasis. We aimed to find out if there is a correlation between Doppler parameters and hepatic metabolic activity in oncology patients. 35 patients with hepatic metastases who were identified by 18F-fluorodeoxyglucose positron emission tomography scan and assessed with Doppler ultrasound were included in this prospective study. Patients with hepatic disease, cardiac dysfunction, dehydration, history of alcoholism, intake of antihypertensive or vasoactive medication were excluded. Volume flow of the proper hepatic artery and the portal vein were measured in the hepatoduodenal ligament by Doppler sonography. Doppler perfusion index (the ratio of the hepatic artery flow to the total liver blood flow) and flow volumes of 31 age matched subjects were compared. Both flow of the proper hepatic artery and portal vein were found to be significantly higher in patients with liver metastasis. The mean Doppler perfusion index value was 0.2 ± 0.13 in hepatic metastases whereas 0.13 ± 0.05 in control group. Doppler perfusion index was significantly higher in liver metastases (p=0.008). A positive correlation was found between the maximum standardized uptake value of the liver and flow volume of the proper hepatic artery (r=0.774, p=0). Blood flow of the proper hepatic artery and Doppler perfusion index correlates with hepatic standardized uptake value. Flow measurements of the liver may become an important parameter for selecting patients for further positron emission tomography scan and following-up the response after systemic and local therapeutic procedures.

Effect of complete denture wearing on deglutition time: a cine-magnetic resonance imaging study

Purpose of the study was to evaluate the effect of complete denture wearing on deglutition time (DT), hyoid bone and larynx movements in edentulous patients with real-time balanced turbo field echo cine-magnetic resonance imaging. Subjects were examined by cine-magnetic resonance imaging in supine position during swallowing water. Two sets of images for 23 edentulous (with/without wearing complete dentures) and one for 23 dentulous patients were obtained. Radiographic outputs representing three consecutive deglutition stages (oral, pharyngeal and oesophageal) were provided to perform measurements. Deglutition time significantly increased when edentulous patients wore their dentures (mean 0·75 s increased to 1·17 s), whereas dentulous patients' DT was about 0·91 s (P ≤ 0.05). The duration of deglutition is crucial because prolonged pharyngeal transit times increases the risk of aspiration. Within the limitations of the study, complete denture wearing could increase the shortened DT of the edentulous patients.

Cerebrospinal fluid flow imaging by using phase-contrast MR technique

Cerebrospinal fluid (CSF) spaces include ventricles and cerebral and spinal subarachnoid spaces. CSF motion is a combined effect of CSF production rate and superimposed cardiac pulsations. Knowledge of CSF dynamics has benefited considerably from the development of phase-contrast (PC) MRI. There are several disorders such as communicating and non-communicating hydrocephalus, Chiari malformation, syringomyelic cyst and arachnoid cyst that can change the CSF dynamics. The aims of this pictorial review are to outline the PC MRI technique, CSF physiology and cerebrospinal space anatomy, to describe a group of congenital and acquired disorders that can alter the CSF dynamics, and to assess the use of PC MRI in the assessment of various central nervous system abnormalities.

Corpus callosum: normal imaging appearance, variants and pathologic conditions

Various types of lesions can occur within the corpus callosum (CC) which is a white matter tract communicating corresponding regions of the cerebral hemispheres. Magnetic resonance imaging is the modality of choice for the evaluation of the CC. In addition, diffusion weighted imaging and diffusion tensor imaging can provide additional information about the CC. The aim of this study is to illustrate the imaging features of the corpus callosum and its pathologies.

Multifocal peliosis hepatis: MR and diffusion-weighted MR-imaging findings of an atypical case

Peliosis is a rare benign disorder that is characterized by the presence of diffuse blood-filled cystic spaces and can occur in the liver, spleen, bone-marrow, and lungs. We present a 10-year-old boy with Fanconi anemia who presented with peliosis hepatis due to androgen treatment. Magnetic resonance (MR) imaging revealed multiple non-enhancing masses. Some of the lesions revealed fluid-fluid levels and extrahepatic extension on MR images. Diffusion-weighted (DW) imaging showed restricted diffusion. Fluid-fluid levels and extrahepatic extensions are unusual findings for hepatic peliotic lesions. In addition, DW imaging findings of peliosis hepatis have not been reported previously.

Multifocal peliosis hepatis: MR and diffusion-weighted MR-imaging findings of an atypical case

Peliosis is a rare benign disorder that is characterized by the presence of diffuse blood-filled cystic spaces and can occur in the liver, spleen, bone-marrow, and lungs. We present a 10-year-old boy with Fanconi anemia who presented with peliosis hepatis due to androgen treatment. Magnetic resonance (MR) imaging revealed multiple non-enhancing masses. Some of the lesions revealed fluid-fluid levels and extrahepatic extension on MR images. Diffusion-weighted (DW) imaging showed restricted diffusion. Fluid-fluid levels and extrahepatic extensions are unusual findings for hepatic peliotic lesions. In addition, DW imaging findings of peliosis hepatis have not been reported previously.

Case report. Isolated complete congenital sternal cleft in an adult: MDCT imaging findings

Sternal cleft is a very rare midline defect. Incomplete forms are more common than complete ones. In this challenging anomaly, the underlying mediastinal structures (especially the heart and great vessels) can easily be injured by external trauma. In addition, the deformity is cosmetically unpleasant and quite alarming to the young patient and the patient's family. In this report, we describe the multidetector CT (MDCT) images that demonstrate the complete sternal cleft.

Central neurocytoma: proton MR spectroscopy and diffusion weighted MR imaging findings

PURPOSE

To present proton magnetic resonance spectroscopy and diffusion-weighted imaging (DWI) findings of central neurocytoma (CN).

METHODS AND MATERIALS

Imaging findings of seven patients with the histopathological diagnosis of CN (five male and two female; age range, 21-28 years of age) were evaluated retrospectively. In addition to conventional magnetic resonance imaging features, we also assessed the metabolite ratios and tumor normalized apparent diffusion coefficient (NADC), which was calculated by dividing the tumor apparent diffusion coefficient (ADC) values by normal ADC. Approval from our institutional review board was obtained for this review.

RESULTS

The tumor choline/creatine ratios were 5.17+/-2.38, while N-acetyl aspartate/choline and N-acetyl aspartate/creatine ratios were 0.33+/-0.15 and 1.84+/-1.38, respectively. On DWI, tumors had heterogeneous hyperintense appearances when compared with the contralateral parietal lobe white matter and tumor NADC values were 0.63+/-0.05.

CONCLUSION

Significantly increased choline/creatine and decreased N-acetyl aspartate/choline ratios with lower NADC values in CN resemble high-grade gliomas and complicate the diagnosis. Familiarity its physiologic features would help to presurgical diagnosis of ventricular and exraventricular CNs.

Giant infantile gliosarcoma: magnetic resonance imaging findings

Gliosarcoma is an uncommon variant of glioblastoma multiforme, which is composed of gliomatous and sarcomatous elements. The tumor is rarely encountered in childhood. This case report presents the magnetic resonance imaging characteristics of a giant gliosarcoma in a 3-year-old girl. Size and location of the tumor are described.

Central nervous system infections of herpesvirus family

Herpesviruses are one of the most common groups of pathogens causing central nervous system infections in humans. They mostly cause encephalitis, meningitis, or myelitis in immunocompetent and immunocompromised patients. Children, adults, and the elderly can all be affected. Although contrast-enhanced CT is more widely used for diagnosis, contrast-enhanced MR imaging combined with diffusion-weighted imaging is superior to CT in the detection of early changes and the real extent of the disease, and in assessing prognosis and monitoring response to antiviral treatment. More sophisticated techniques, such as MR spectroscopy and perfusion imaging, can aid in the differential diagnosis of herpesvirus infections from other tumoral, demyelinating, and ischemic processes.

Pelvic hydatid disease: CT and MRI findings causing sciatica

Pelvic masses, especially hydatid disease, rarely present with sciatica (1, 2). We present the computed tomography (CT) and the magnetic resonance imaging (MRI) findings of a 49-year-old female patient with presacral hydatid disease, who was evaluated for her sciatica. We also want to emphasize the importance of assessing the pelvis of patients with symptoms and clinical findings that are inconsistent and that cannot be satisfactorily explained by the spinal imaging findings.

Dysembryoplastic neuroepithelial tumors: proton MR spectroscopy, diffusion and perfusion characteristics

INTRODUCTION

We describe the magnetic resonance (MR) imaging characteristics of dysembryoplastic neuroepithelial tumors (DNT) and discuss their differential diagnosis.

MATERIAL AND METHODS

Proton MR spectroscopy (TE 30 and 136 ms), diffusion-weighted and perfusion images were retrospectively evaluated in 22 patients with pathologically proven DNT (17 male and 5 female, mean age 18.7 years) and 14 control subjects (10 male and 4 female, mean age 16.9 years). The results from the DNT patients and from the control subjects were compared using an independent sample t-test and the degree of correlation was tested by Pearson's correlation.

RESULTS

All DNTs were solitary and in a supratentorial cortical or subcortical location (ten temporal, eight frontal and four parietal). They had low-signal on T1-weighted images and high-signal on T2-weighted images without a prominent mass effect. Additionally a cystic appearance (six patients, 27.3%), cortical dysplasia (six patients, 27.3%) and contrast enhancement (four patients, 18.2%) were also noted. No significant differences were detected in NAA/Cho, NAA/Cr, NAA/Cho+Cr or Cho/Cr ratios between DNT and normal brain. DNTs had a significantly higher mI/Cr ratio and apparent diffusion coefficient (ADC) values and lower cerebral blood values than normal parenchyma (P < 0.001). ADC had the highest correlation with the diagnosis of DNT (r = 0.996) followed by relative cerebral blood volume (rCBV) (r = -0.883) and mI/Cr ratio (r = 0.663).

CONCLUSION

Proton MR spectroscopy, diffusion-weighted and perfusion imaging characteristics of DNTs provide additional information to their MR imaging findings. The MR spectrum showing a slight increase in mI/Cr ratio, and higher ADC and lower rCBV values than normal parenchyma help to differentiate DNTs from other cortical tumors, which had higher rCBV and lower ADC values than DNTs.

Craniospinal Involvement in a Patient with Isolated Bone Marrow Mastocytosis

Central nervous system involvement in systemic mastocytosis (SM) is very rare. This case report describes the computed tomography and magnetic resonance (MR) imaging findings of central nervous system involvement in a patient with isolated bone marrow mastocystosis. Bone marrow infiltration in SM caused cranial nerve dysfunction and meningeal irritation secondary to narrowing of cranial apertures and meningeal involvement, respectively. MR imaging is the modality of choice in both detection and follow-up of SM and also useful for differential diagnosis and detection of complications.

Behçet's Disease Presenting with Acute Transverse Myelitis: MRI Findings and Review of the Nosology

Spinal cord involvement, either isolated or together with brain, in Behçet's disease (BD) has been reported. In these cases the existence of the disease was previously known or the classical triad of disease such as oral and genital ulcers with uveitis/iritis was present. Here we describe a 22-year-old man in whom acute transverse myelitis diagnosed with MRI was the first finding of BD.

MRI in long-term evaluation of reconstructed hind-feet of land-mine trauma patients

INTRODUCTION

The purpose of this study was to assess the flap reconstructed hind feet of patients with MRI who were traumatized by land-mine.

MATERIALS AND METHODS

T1 and T2 weighted images were obtained in 7 patients, 12 months later the reconstruction of their hind feet by myocutaneous flaps after land-mine trauma.

RESULTS

In all patients T2 signal intensities of the myocutaneous flaps were slightly high compared to normal undisturbed muscle. Slight vascular engorgement was noted in the vicinity of the flaps in all cases. There were ankle joint ankylose (n=1), tarsal coalition (n=3), sklerosis within the calcaneus (n=1), bone cortex irregularities (n=3), absence of calcaneus (n=4), deformity in talus and bone marrow edema (n=1), navicular edema (n=2), remodeling in the superior aspect of talus neck (n=2), absence of talus (n=2), talocalcaneal ankylose (n=1), small collection in the superior aspect of flap (n=1), drenage canules (n=1).

CONCLUSION

In reconstructed hind feet by myocutaneus flaps done for land-mine traumas, MRI presents useful information by displaying detailed anatomy of the flaps, bones, joints, soft tissues and associated complications.

Transient splenial lesion of the corpus callosum in clinically mild influenza-associated encephalitis/encephalopathy

BACKGROUND

Reversible lesions in the splenium of the corpus callosum (SCC), caused by various agents such as influenza, rotavirus, Escherichia coli, mumps, and adenovirus, were previously defined in a handful of cases. We present 5 cases with transient diffusion restriction of the SCC associated with influenza A virus infection.

MATERIALS AND METHODS

Five patients with influenza-associated encephalitis/encephalopathy and sudden-onset neurologic symptoms following a prodromal flulike episode were examined by MR and diffusion-weighted imaging (DWI).

RESULTS

Three patients, who had drowsiness and new-onset convulsions, recovered spontaneously without any medication. In the other 2 seizure-free patients, 1 had trigeminal neuralgia and headache and the other had facial numbness and left upper monoparesis. All patients had round well-defined ovoid hyperintense splenial lesions (14.94 +/- 1.87 mm) on DWI with a significantly low apparent diffusion coefficient (ADC) of 0.41 +/- 0.05 x 10(-3) mm(2)/s compared with 0.84 +/- 0.01 x 10(-3) mm(2)/s of normal-appearing white matter. In the patient with a motor deficit, additional lesions were found in the cerebral deep white matter. The high signal intensity of the splenial and deep white matter lesions on DWI completely disappeared on follow-up studies, and ADC values also improved, returning to those of normal-appearing white matter on days 8-11. Clinically, all patients completely recovered on days 4-9.

CONCLUSION

A transient lesion of the SCC is a significant but nonspecific finding. It is probably due to edematous and/or inflammatory changes of the SCC. It may be the only detectable change in patients with good prognosis, indicating a clinically mild form of encephalitis/encephalopathy.

An unusual complication of the use of stapler after Hartmann's procedure

BACKGROUND

Circular anastomotic staplers have been used in colorectal surgery for several years with low complication rates. We report here an extremely rare case of direct colovaginal anastomosis and rectovaginal fistula occurred by using a 31 end-to-end anastomosis stapler after reversal of Hartmann's Procedure.

STUDY DESIGN

A 33-year-old woman with complaint of rectal bleeding had undergone low anterior resection and end colostomy for rectal adenocarcinoma in 1995. In spite of making recommendation for colostomy closure, she had postponed the operation until 2003 due to afraid of incontinence. After reversal of Hartmann's procedure achieved by using circular stapler and diverting ileostomy, she developed complaints of vaginal gas and minimal vaginal fecal discharge.

RESULT

Endoscopic examination and imaging methods revealed a rectovaginal fistula with a blind Hartmann's pouch. After a certain verification of complexity of the case, a reoperation which comprises true intestinal anastomosis and repair of fistula was performed. Postoperative period was uneventful except an incisional infection, and ileostomy was closed subsequently.

CONCLUSION

A rectovaginal fistula, though encountered rarely, must be taken into account in cases with suspicious complaints after using circular stapler for pelvic intestinal anastomosis. Careful placement of stapler in accurate direction has a great importance to avoid stapling related complications.

A rare cause of flank mass: psoas abscess due to extensive primary thoracolumbar tuberculous spondylodiskitis

Psoas abscess secondary to tuberculous spondylodiskitis is usually a complication of thoracolumbar vertebrae disease. The psoas abscess may be difficult clinically to diagnose because of its rarity, insidious onset of the disease, and nonspecific clinical presentation. We report multidetector CT and MR imaging findings of a psoas abscess secondary to primary tuberculous spondylodiskitis of the spine from the T3 to L2 vertebrae, which presented as a flank mass.

Thin-section axial multidetector computed tomography and multiplanar reformatted imaging of children with suspected foreign-body aspiration: Is virtual bronchoscopy overemphasized?

PURPOSE

To determine the added value of multidetector computed tomography (MDCT)-assisted virtual bronchoscopy (VB) to axial MDCT and multiplanar reformatted (MPR) imaging with respect to conventional bronchoscopy in the evaluation of children with suspected foreign-body aspiration (FBA).

MATERIAL AND METHODS

Twenty-one consecutive children (14 male, seven female, age 8 months-7 years, mean age 3.5 years) presenting with the suspicion of FBA were examined with 16-slice MDCT using 100-120 kV, 30-50 mA, 1-mm section thickness, 1.2 pitch ratio, and 0.6-1.0-mm reconstruction interval. Before CT examinations, chest radiographies were also obtained in all cases. VB and MPR imaging were carried out after MDCT examinations.

RESULTS

Nine foreign bodies were identified by gold-standard conventional bronchoscopy. VB, thin-section axial MDCT, and MPR images identified eight of nine foreign bodies. CT scans with MPR images and VB did not reveal a chronic foreign body; and, in one patient, endobronchial mucous was diagnosed as the foreign body. The sensitivity, specificity, and accuracy of thin-section axial MDCT and MPR images alone in the diagnosis of FBA were 88.9%, 91.7%, and 90.5%, respectively. Results were the same as those obtained when VB was also included.

CONCLUSION

MDCT with VB and axial/MPR images provide equally valuable information in children with suspected foreign-body aspiration and prevent unnecessary conventional bronchoscopic examinations. However, VB increases total examination time and cost, and it does not provide additional information over MPR images in the evaluation of foreign-body aspiration.

Symptomatic epidural gas after open diskectomy: CT and MR imaging findings

We report a case of symptomatic epidural gas accumulation after open diskectomy, causing lumbar radiculopathy. Surgery had been performed in a 44-year-old man for disk extrusion; however, he was readmitted to the hospital with increased lower back pain 5 months after the operation. CT and MR studies demonstrated accumulation of gas in the lumbar epidural space compressing the dural sac and nerve root. Symptoms disappeared after surgical removal of the gas.

Intravenous contrast-enhanced dynamic MR urography: Diagnosis of vesicoureteral reflux during bladder filling with time-signal intensity curves

PURPOSE

To evaluate the time-signal intensity (SI) curves generated from intravenous (IV) gadodiamide-enhanced dynamic magnetic resonance (MR) urographic scans for identifying vesicoureteral reflux (VUR) during bladder filling.

MATERIALS AND METHODS

MR urographic studies of children were retrospectively reviewed, and 52 ureterorenal units of 26 patients (15 females and 11 males, mean age = 5.5 years) who had also undergone voiding cystourethrographic (VCUG) examination were included in this study. The patients were examined on a 1.5T scanner. For functional MR urography and to generate time-SI curves, we used a post IV contrast-enhanced two-dimensional (2D) fast field echo (FFE) sequence (TR = 17 msec, TE = 3.2 msec, flip angle (FA) = 90 degrees ) in the coronal plane. MR urographic time-SI curves that demonstrated a prompt and concave fall of the initial third phase followed by intermittent or constantly increasing SI peaks above the baseline from which the second phase starts were considered to have VUR. We compared the differences in time-SI curves between the control group and patients with VUR during bladder filling.

RESULTS

Twelve ureterorenal units of eight patients (four bilateral and four unilateral) had VUR during bladder filling on VCUG. The time-SI curves of these patients showed intermittent (N = 8 ureterorenal units), and constantly increasing (N = 4 ureterorenal units) SI peaks consistent with VUR. One patient also had bilateral abnormal time-SI curves suggesting VUR despite the normal VCUG study. In the control group, 25 units had normal triphase time-SI curves, six renal units had urinary dilatation with good washout after diuretic injection, and four renal units had upper urinary dilatation without contrast washout, while five renal units did not show any function. None of the patients in the control group revealed distortion in the time-SI curve. The differences in time-SI curves patterns between the control group and patients with VUR during bladder filling were statistically significant (P < 0.001).

CONCLUSION

After a prompt and concave decrease of the initial third phase of the time-SI curve, intermittent spikes or a constant rise in SI above the baseline suggest the existence of VUR.

Univentricular heart and supramitral ring: an unusual association

Univentricular heart, which is rarely seen cardiac anomaly, is associated with various cardiac anomalies. The presence of supramitral ring and univentricular heart in the same patient is very interesting association which, to the best of our knowledge, was not reported previously.

MRI findings of renal lymphangiectasia

We present the case of a 20-year-old male with renal lymphangiectasia who presented with hypertension and hematuria. We discuss the role of magnetic resonance imaging (MRI) with gadolinium-enhanced MR urography in confirming the diagnosis, extensions of this rare benign entity, and associated conditions.

Assessment of diagnostic accuracy of perfusion MR imaging in primary and metastatic solitary malignant brain tumors

PURPOSE

The purpose of this study was to estimate the diagnostic accuracy of relative cerebral blood volume (rCBV) measurement in preoperative grading and differentiation of solitary intra-axial malignant brain tumors.

METHODS

Thirty-six low-grade glial tumors (LGGTs), 22 high-grade glial tumors (HGGTs), and 17 metastases (METs) were prospectively evaluated by MR imaging and standard dynamic susceptibility contrast-enhanced gradient echo, echoplanar imaging during first pass of a bolus injection of contrast material. Normalized rCBV values from tumoral (rCBV(T)) and peritumoral (rCBV(P)) areas were calculated by standard software and statistically tested independently.

RESULTS

The mean differences of rCBV(T) and rCBV(P) values between LGGT (2.30 +/- 1.12 and 1.18 +/- 0.24) and HGGT (5.42 +/- 1.52 and 2.17 +/- 0.82) (P < .001); HGGTs and METs (3.21 +/- 0.98 and 0.97 +/- 0.09) (P < .001); and LGGTs and METs (P < .05 and P < .001, respectively) were significant. No clear cutoff value was present. A clear rCBV(T) cutoff value of 2.6 was detected for differentiation of low- (1.75 +/- 0.38; LGA) versus high-grade (4.78 +/- 0.99; HGA) astrocytomas when nonastrocytic glial tumors were excluded. The rCBV(T) values were linearly correlated with degree of malignancy (r = 0.869; P < .001). Cutoff rCBV(P) values of 1.1 and 1.2 were quite effective in differentiation of METs from LGGTs and HGGTs, respectively. The overall efficacy of rCBV was higher in grading than in differentiation.

CONCLUSION

The diagnostic accuracy of rCBV measurement is higher in grading of glial brain tumors than in differentiation of HGGTs from solitary intra-axial METs. The astrocytic and nonastrocytic glial tumors have to be evaluated separately for precise grading.

The Added Value of the Apparent Diffusion Coefficient Calculation to Magnetic Resonance Imaging in the Differentiation and Grading of Malignant Brain Tumors

OBJECTIVE

ADC calculation can improve the diagnostic efficacy of MR imaging in brain tumor grading and differentiation.

METHODS

Apparent diffusion coefficient (ADC) values and ratios of 33 low-grade (23 astrocytomas, 10 oligodendrogliomas) and 40 high-grade (25 metastases and 15 high-grade astrocytomas) malignant tumors were prospectively evaluated.

RESULTS

Tumoral ADC values (r=-0.738, P <0.000) and ratios (r=-0.746, P < 0.000) were well correlated with higher degree of malignancy and quite effective in grading of malignant brain tumors (P < 0.000). By using cutoff values of 0.99 for tumoral ADC value and 1.22 for normalized ADC ratio, the sensitivity of MR imaging could be increased from 72.22% to 93.75% and 90.63%, the specificity from 81.08% to 92.68% and 90.24%, PPV from 78.79% to 90.91% and 87.88%, and NPV from 75.00% to 95.00% and 92.50%, respectively.

CONCLUSION

ADC calculation was quite effective in grading of malignant brain tumors but not in differentiation of them and added more information to conventional contrast-enhanced MR imaging.

Imaging Findings in Idiopathic Granulomatous Mastitis

OBJECTIVE

To describe magnetic resonance (MR) imaging features of patients with a histologic diagnosis of idiopathic granulomatous mastitis (IGM).

METHODS

Dynamic contrast-enhanced MR imaging was performed with a 1.5-T MR unit. Postprocessing of images included subtraction and calculation of time-intensity curves of the enhancing regions at several points in all patients.

RESULTS

In addition to granulomatous inflammation, biopsy slides of 5 patients demonstrated abscess formation without a specific organism (aseptic abscess). One patient had a fibrotic tissue component. Magnetic resonance imaging findings were heterogeneously enhancing areas with (n = 5) and without (n = 1) multiple ring-like enhanced abscesses and a circumscribed lesion with heterogeneous contrast enhancement (n = 1). Time-intensity curves showed a benign pattern in all but 1 patient.

CONCLUSION

Idiopathic granulomatous mastitis has a number of appearances on MR imaging. Magnetic resonance imaging with measurement of time-signal intensity curves may support the findings of ultrasonography and mammography in distinguishing benign inflammatory breast disorders from malignant ones; however, biopsy still remains the only method of definite diagnosis.

A different approach to missile induced head injuries

Missile induced head injuries can be influenced by the anatomical location of the injury, i.e. type of tissue and by the ballistic properties such as the design of the weapon and the mass, shape and construction of the projectile, as well as its velocity characteristics and trajectory angle. In the diagnostic work up of the patients with missile induced head injuries, every available modality can be used. It is important, however, to recognize that CT scan is the primary and most efficacious diagnostic tool in such patients. In this article we have identified risk factors for both morbidity and mortality in patients with missile induced head injury with excluding the patients who had also extracranial serious trauma and systemic disease.

Comparison of contrast-enhanced T1-weighted and 3D constructive interference in steady state images for predicting outcome after hearing-preservation surgery for vestibular schwannoma

We compared contrast-enhanced T1-weighted and 3D constructive interference in steady state (CISS) sequences for demonstrating possible prognostic factors in hearing-preservation surgery for vestibular schwannoma. We studied 22 patients with vestibular schwannomas having hearing-preservation surgery. Postoperatively six (27%) had a facial palsy and eight (36%) had hearing loss. There was a significant correlation between the size of the tumour and facial palsy (r=-0.72). Both techniques adequately demonstrated all tumours. Involvement of the fundus of the internal auditory canal (IAC) and a small distance between the lateral border of the tumour and the fundus were correlated significantly with hearing loss (r=-0.81 and -0.75, respectively). The 3D-CISS sequence, by virtue of its high contrast resolution was superior to T1-weighted images ( P<0.05) for detection of the fundal involvement. The direction of displacement of the facial nerve did not correlate with facial palsy or hearing loss. We think that 3D-CISS images better show the features influencing surgical outcome, but that contrast-enhanced T1-weighted images are required for diagnosis.

Value of magnetic resonance imaging in the depiction of intravenous leiomyomatosis extending to the heart

Intravenous leiomyomatosis is a seldom neoplasia characterized by invasion of venous channels by a benign smooth muscle tumor originating either from a uterine myoma or from vessel wall. Extension to the heart may cause mechanical obstruction and is frequently misdiagnosed as a right-atrial myxoma. We present a case of recurrent intravenous leiomyomatosis with previous hysterectomy because of uterine leiomyoma which have different magnetic resonance characteristics than that of the former reports.

Spoiled gradient recalled acquisition in the steady state technique is superior to conventional postcontrast spin echo technique for magnetic resonance imaging detection of adrenocorticotropin-secreting pituitary tumors

Recent studies show that the standard T1-weighted spin echo (SE) technique for magnetic resonance imaging (MRI) fails to identify 40% of corticotrope adenomas. We hypothesized that the superior soft tissue contrast and thinner sections obtained with spoiled gradient recalled acquisition in the steady state (SPGR) would improve tumor detection. We compared the performance of SE and SPGR MRI in 50 patients (age, 7-67 yr) with surgically confirmed corticotrope adenoma. Coronal SE and SPGR MR images were obtained before and after administration of gadolinium contrast, using a 1.5 T scanner. SE scans were obtained over 5.1 min (12-cm field of view; interleaved sections, 3 mm). SPGR scans were obtained over 3.45 min (12- or 18-cm field of view, contiguous 1- or 2-mm slices). The MRI interpretations of two radiologists were compared with findings at surgical resection. Compared with SE for detection of tumor, SPGR had superior sensitivity (80%; confidence interval, 68-91; vs. 49%; confidence interval, 34-63%), but a higher false positive rate (2% vs. 4%). We recommend the addition of SPGR to SE sequences using pituitary-specific technical parameters to improve the MRI detection of ACTH-secreting pituitary tumors.

Schwannoma of the lateral ventricle: eight-year follow-up and literature review

Intracerebral and intramedullary schwannomas are uncommon; but, in general, spinal intramedullary schwannomas are more frequent than intracerebral schwanomas. We present a case of right lateral ventricle schwannoma in a 21-year-old man and review the associated literature. The 21-year-old right-handed man presented with loss of the left-eye vision approximately 8 months before referral to an ophthalmologist. The patient was immediately subjected to computed tomography (CT) scan, which showed an enhanced lesion with cystic component in the right occipital horn of the lateral ventricle. And consecutively, he was admitted to our department. The tumor was evacuated via craniotomy with marked improvement in his clinical state. The postoperative course was uneventful and postoperative CT control showed no residue. On MRI control no recurrence was noted after a follow-up period of 8 years. Intracerebral schwannoma is a rare, benign neoplasm. It is usually located superficially or adjacent to a ventricle. Characteristic imaging features include cyst formation, calcification, and evidence of peritumoral edema or gliosis. The recognition of this benign and potentially curable neoplasm and its differentiation from other neoplasms, some of which have less favourable outcomes, is of obvious importance.

Combination of single-voxel proton MR spectroscopy and apparent diffusion coefficient calculation in the evaluation of common brain tumors

BACKGROUND AND PURPOSE

MR spectroscopy and apparent diffusion coefficient (ADC) calculation have been used frequently for tumor grading and differentiation during the last decade. We evaluated whether the combination of these two techniques can improve the diagnostic effectiveness of MR imaging in patients with brain tumors.

METHODS

Forty-nine patients with histologically proved brain tumors (eight high- and 12 low-grade astrocytomas, eight metastases, eight nonastrocytic gliomas, seven meningiomas, three dysembryoplastic neuroepithelial tumors (DNETs), and three tuberculomas) were prospectively evaluated with contrast material-enhanced MR imaging, single-voxel proton MR spectroscopy (TE = 135 ms), and diffusion-weighted imaging (b = 0, 500, and 1000 s/mm(2)) before surgery.

RESULTS

MR spectroscopy could differentiate benign from malignant tumors but was not useful in grading malignant tumors. In the differentiation of malignant from benign tumors, N-acetylaspartate (NAA)/choline (Cho), NAA/Cho + creatine (Cr), lactate/Cr, and alanin/Cr ratios (P <.001) were statistically more significant than NAA/Cr and lactate/lipid ratios (P <.05). Increase in lipid/Cr and alanin/Cr ratios could distinguish metastasis and meningiomas from other tumors, respectively (P <.001). DNETs could be diagnosed by their normal spectra and high ADC values (116.25 +/- 6.93 x 10(-3) mm(2)/s). Increase in lactate/Cr ratio correlated with degree of malignancy (r = -0.71). ADCs were effective for grading malignant tumors (P <.001) but not for distinguishing different tumor types with the same grade. High-grade malignant tumors (87.16 +/- 10.41 x 10(-3) mm(2)/s) had significantly lower ADC values than did low-grade malignant (115.33 +/- 11.67 x 10(-3) mm(2)/s) and benign (107.69 +/- 8.05 x 10(-3) mm(2)/s) tumors. Peritumoral ADCs were significantly higher in low-grade than in high-grade astrocytomas (P <.05).

CONCLUSION

Combination of calculated ADC values from tumoral core and specific relative metabolite ratios acquired by MR spectroscopy added more information to MR imaging in the differentiation and grading of brain tumors and were more useful together than each alone.

Walker-Warburg syndrome variant

A Turkish patient with cobblestone lissencephaly and eye involvement without characteristic muscular changes for congenital muscular dystrophy died at the age of 3 months presented with neonatal apneic periods and generalized seizures. Serum creatine kinase level, electromyography, chromosome analysis and blood biochemistry were normal. Unilateral microphthalmia, retinal dysplasia and internal strabismus were the ocular findings. Magnetic resonance imaging clearly demonstrated the thickened, irregular, nearly agyric cobblestone cerebral cortex with underlying unmyelinated white matter, hydrocephalus, hypoplastic corpus callosum, brain stem and cerebellum with retrocerebellar cyst and posterior cephalocele.

The value of ultrasonography in interrupted inferior vena cava with azygos continuation

The cardiosplenic syndromes represent a complex set of abnormalities of the thorax and viscera resulting from abnormal folding of the embryo during early development. Anomalies of venous development include interruption of inferior vena cava (IVC), and in combination with situs inversus referred to as the polysplenia syndrome. We present a 23-year-old male previously diagnosed as having a persistent left IVC on venography whereas ultrasonographic examination clearly demonstrated interrupted IVC with azygos continuation along with situs inversus.

Comparison of In-111 octreotide and Tc-99m (V) DMSA scintigraphy in the detection of medullary thyroid tumor foci in patients with elevated levels of tumor markers after surgery

PURPOSE

In this retrospective study, the authors evaluated the utility of In-111 octreotide (OctreoScan) and Tc-99m (V) DMSA scintigraphy for the localization of recurrent metastatic tumor foci in patients with medullary thyroid cancer (MTC) and compared the findings with those of conventional radiologic imaging methods.

METHODS

The scintigraphic images were compared with computed tomography (CT) and magnetic resonance imaging (MRI) and ultrasonography (US) in 14 patients (8 men, 6 women; age range, 22 to 74 years) with elevated calcitonin and carcinoembryonic antigen levels after total thyroidectomy. All scintigraphic image findings were evaluated qualitatively as mild uptake (+) and moderate to marked uptake (++).

RESULTS

In-111 octreotide may be superior to Tc-99m (V) DMSA for the detection of tumor foci of patients with MTC on a patient basis (78.5% versus 57.1%) and on a lesion basis (44.1% versus 30.2%). The sensitivity rate for In-111 octreotide (78.5%) was also similar to that of CT and MRI on a patient basis. Conversely, the combined use of Tc-99m (V) DMSA and In-111 octreotide revealed the best sensitivity rate (85.7%) on a patient basis, whereas the combined use of CT and MRI showed the best sensitivity rate (81.3%) on a lesion basis.

CONCLUSIONS

These findings suggest that In-111 octreotide is superior to Tc-99m (V) DMSA and has a similar sensitivity rate to CT and MRI for the diagnosis of recurrent or metastatic MTC. Although the combined use of In-111 octreotide and Tc-99m (V) DMSA was most sensitive, the combined use of CT and MRI with radionuclide imaging methods may better detect more metastatic tumor foci.