Distinguishing Pituitary Metastasis and Pituitary Neuroendocrine Tumors through Conventional MR Imaging and Clinical Features.

BACKGROUND AND PURPOSE: Given their overlapping features, pituitary metastases frequently imitate pituitary neuroendocrine tumors in neuroimaging studies. This study aimed to distinguish pituitary metastases from pituitary neuroendocrine tumors on the basis of conventional MR imaging and clinical features as a practical approach. MATERIALS AND METHODS: In this 2-center retrospective study, backward from January 2024, preoperative pituitary MR imaging examinations of 22 pituitary metastases and 74 pituitary neuroendocrine tumors were analyzed. Exclusion criteria were as follows: absence of a definitive histopathologic diagnosis, history of pituitary surgery or radiation therapy before MR imaging, and pituitary neuroendocrine tumors treated with medical therapy. Two radiologists systematically evaluated 13 conventional MR imaging features that have been reported more commonly as indicative of pituitary metastases and pituitary neuroendocrine tumors in the literature. Age, sex, history of cancer, and maximum tumor size constituted the clinical/epidemiologic features. The primary cancer origin for this study was also noted. Univariable and multivariable logistic regression was used for the selection of variables, determining independent predictors, and modeling. Interobserver agreement was evaluated for all imaging parameters using the Cohen κ statistic or intraclass correlation coefficient. RESULTS: A total of 22 patients with pituitary metastases (8 women; mean age, 49.5 [SD, 13] years) and 74 patients with pituitary neuroendocrine tumors (36 women; mean age, 50.1 [SD, 11] years) were enrolled. There was no statistically significant distributional difference in age, sex, or maximum tumor size between the 2 groups. Lung cancer (9/22; 41%) was the most commonly reported primary tumor, followed by breast (3/22; 13.6%) and unknown cancer (3/22; 13.6%). Logistic regression revealed 3 independent predictors: rapid growth on control MR imaging, masslike or nodular expansion of the pituitary stalk, and a history of cancer. The model based on these 3 features achieved an area under the curve, accuracy, sensitivity, specificity, and Brier score of 0.987 (95% CI, 0.964-1), 97.9% (95% CI, 92.7%-99.8%), 95.5% (95% CI, 77.2%-99.9%), 98.6% (95% CI, 92.7%-100%), and 0.025, respectively. CONCLUSIONS: Two conventional features based on pituitary MR imaging with the clinical variable of history of cancer had satisfying predictive performance, making them potential discriminators between pituitary metastases and pituitary neuroendocrine tumors. In cases in which differentiation between pituitary metastases and pituitary neuroendocrine tumors poses a challenge, the results of this study may help with the diagnosis.

Diffusion tensor imaging in anorectal malformations: a pilot study for the evaluation of lumbosacral plexus.

INTRODUCTION: Neurogenic bladder with anorectal malformations (ARM) is a well-known yet understudied topic. Diffusion tensor imaging (DTI) is a special usage of MRI that can evaluate peripheric nerves. The aim of this study is to evaluate the lumbosacral plexuses of patients with ARM using DTI. PATIENTS AND METHODS: Patients with ARM willing to participate were included. Patient files were reviewed, a questionnaire was made, and DTI was performed. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) were computed for the right and left lumbosacral plexuses. RESULTS: There were 18 patients and 12 controls. Groups were similar in terms of sex (p = 0.232) and age (p = 0.853). There was a significant difference only for ADC of the left plexus. There was visible asymmetry in tractographies and DTI parameters of two patients with severely deformed pelvises (image 1) but also in another patient with a normal sacrum. In addition, despite asymmetry, FA and ADC were similar to controls also in these patients. CONCLUSION: This is the first study presenting quantitative data about the lumbosacral plexus in ARM. We think the most interesting finding of this study was observing the normal values even in the patients with severely malformed sacrum which is yet to be validated with further studies.

Aneurysmal bone cysts of the spine.

PURPOSE: Aneurysmal bone cyst is a benign, relatively uncommon lesion, representing 1.4 % of primary bone tumors. The vertebral column is involved in 3-30 % of cases. This report describes clinical characteristics and treatment results of 18 patients with aneurysmal bone cyst of the spine. METHODS: Between 1991 and 2008, 18 patients with aneurysmal bone cyst of the spine were surgically treated in our department. The clinical records, radiographs, histologic sections, and operative reports were analyzed. RESULTS: There were 11 male and 7 female patients; mean age was 22.1 years (range 7-46 years). Localizations were cervical (3), cervicothoracic (2), thoracic (3), lumbar (4), and sacrum (6). Tumor was localized on the left side in 11 cases, on the right side in 2 and at midline in 5 patients. The two most common clinical features were axial pain (14 patients) and radicular pain (8 patients). Neurological signs were paraparesis in 3, monoparesis in 6. Mean duration of symptoms was 9 months (range 3 months-3 years). All patients underwent surgery: total removal was performed in 13 patients and subtotal resection in 5. Posterior (11), anterolateral (1), or combined anterior-posterior (6) approaches were used. Mean follow-up duration was 112.3 months (range 4-21 years). We detected four recurrences in subtotal excision group (4/5), and one recurrence in total excision group (1/13). CONCLUSION: Treatment options for aneurysmal bone cysts are simple curettage with or without bone grafting, complete excision, embolization, radiation therapy, or a combination of these modalities. Radical surgical excision should be the goal of surgery to decrease the recurrence rate. Recurrence rate is significantly lower in case of total excision.

Neurobrucellosis.

Brucellosis is a multisystem infection with a broad spectrum of clinical presentations. Its nervous system involvement is known as neurobrucellosis. Neurobrucellosis (NB) has neither a typical clinical picture nor specific cerebrospinal fluid (CSF) findings. Its diagnosis is based on the existence of a neurologic picture not explained by any other neurologic disease, evidenced by systemic brucellar infection and the presence of inflammatory alteration in CSF. Imaging findings of NB is divided into four categories: (1) normal, (2) inflammation (recognized by granulomas, abnormal enhancement of the meninges, perivascular space, or lumbar nerve roots), (3) white matter changes, and (4) vascular changes.

Reliability of diffusion weighted MR imaging in differentiating degenerative and infectious end plate changes.

BACKGROUND: The aim of the study was to investigate the value of diffusion weighted MR imaging in the diagnosis of Modic type 1 change, which may be confused with the acute infectious spondylodiscitis on conventional MR imaging. PATIENTS AND METHODS: Twenty-seven patients with erosive intervertebral osteochondrosis, Modic type 1 and 18 patients with spondylodiscitis were included in this retrospective study. All images were acquired using on 1.5 Tesla MR units. Lumbar spinal MR imaging of 45 patients were retrieved from a digital database of a radiology record system and evaluated by one experienced radiologist. Patients with Modic type 1 change had CT slices obtained from the diseased disc space and the affected vertebrae. RESULTS: Bone marrow adjacent to the vertebral end plate in both Modic type 1 change and acute spondylodiscitis were hypointense on T1-weighted images. On T2-weighted images corresponding levels of vertebral end-plates showed hyperintense signal intensity in both group. All the patients with spondylodiscitis and Modic type 1 change were hyperintense and hypointense on diffusion-weighted MR images, respectively. CONCLUSIONS: Our findings suggest that diffusion weighted MR imaging is an useful method in differentiating Modic type 1 changes from acute spondylodiscitis, both of which may mimic each other, either on clinical or conventional MRI findings.

Intracranial calcifications on CT.

Computed tomography (CT) is very sensitive for detection and localization of intracranial calcifications. We reviewed in this pictorial essay the diseases associated with intracranial calcifications and emphasized the utility of CT for the differential diagnosis.

Developmental venous anomaly (DVA) with arterial component: a rare cause of intracranial haemorrhage.

INTRODUCTION: To examine the clinical and radiologic findings of patients with developmental venous anomaly (DVA) associated with intracranial haemorrhage but unrelated to cavernoma. METHODS: Computed tomography (CT) was used to obtain intracranial images from seven patients ranging in age from 6 to 51 years. Magnetic resonance imaging (MRI) was then performed on six patients, and two patients were further examined via CT angiography. Finally, digital subtraction angiography (DSA) was performed to confirm the initial diagnosis. RESULTS: CT showed intraparenchymal supratentorial haemorrhage in all patients. The combined imaging modalities eventually confirmed a diagnosis of arterialized DVA in four patients and arterialized DVA associated with arteriovenus malformation (AVM) in three. Two patients were managed symptomatically, two underwent radiosurgery, one underwent surgery, one underwent combined embolisation plus radiosurgery and the remaining patient underwent combined embolisation plus surgery. Two patients died, one as a result of re-bleeding, and the other due to radiation necrosis. The mean follow-up period was 33 months (6 months to 6 years) for the remaining five patients with favourable outcome. CONCLUSION: DVA associated with intraparenchymal haemorrhage, but not related to cavernoma, was confirmed. Though very rare, DVA may present with non-cavernoma-related haemorrhage in the form of arterialized DVA or DVA with AVM.

Carotid endarterectomy versus carotid artery stenting: findings in regard to neuroclinical outcomes and diffusion-weighted imaging.

The purpose of our study was to evaluate prospectively the frequency and significance of brain lesions after elective carotid endarterectomy (CAE) and carotid artery stenting (CAS) by using diffusion-weighted magnetic resonance imaging (DW MRI) and then to correlate imaging findings with neuroclinical outcomes. From February 2003 through March 2005, 95 consecutive patients underwent surgical endarterectomy or CAS (with a cerebral protection device) at our institution. A total of 59 CAE procedures were performed in 46 consecutive patients (mean age, 65.8 +/- 9 yr), and 56 CAS procedures were performed in 49 consecutive patients (mean age, 66.3 +/- 9 yr). Diffusion-weighted magnetic resonance imaging of the brain was performed in all patients within 24 hours of the procedure, both before and after. The post-procedural stroke rate was slightly higher in the CAS group, but this difference was not significant (5.4% vs 0). One early and 1 late death occurred in the stent group. Although the incidence of ischemic lesions was similar in both groups (surgery group, 12.5%; stent group, 13.5%), new DW MRI lesions were higher in the endarterectomy group (27.1% vs 12.5%, P=0.041). This difference was due chiefly to nonischemic lesions such as hemorrhage and watershed ischemia. In the analysis of patients with embolic ischemia, incidences of symptomatic stroke (P=0.046) and large infarct (P=0.013) were higher in the stent group. When we used protective devices during CAS, the incidence of embolic complications was similar to that of surgical enarterectomy. On the other hand, the clinical results of CAS need improvement.

A spinal dermoid tumor that ruptured into the subarachnoidal space and syrinx cavity.

The widespread use of computed tomography (CT) and magnetic resonance (MR) imaging has increased the preoperative diagnosis of dermoid tumors and detection of their complications. In particular, cases of ruptured dermoid tumors, which may manifest as emergent conditions with variable clinical pictures, have typical CT and MR imaging findings. In this report, we present a case of a spinal dermoid tumor, which ruptured into the syrinx cavity and subarachnoidal space.

Perfusion and diffusion MR imaging in enhancing malignant cerebral tumors.

OBJECTIVE: Common contrast-enhancing malignant tumors of the brain are glioblastoma multiforme (GBMs), anaplastic astrocytomas (AAs), metastases, and lymphomas, all of which have sometimes similar conventional MRI findings. Our aim was to evaluate the role of perfusion MR imaging (PWI) and diffusion-weighted imaging (DWI) in the differentiation of these contrast-enhancing malignant cerebral tumors. MATERIALS AND METHODS: Forty-eight patients with contrast-enhancing and histologically proven brain tumors, 14 AAs, 17 GBMs, nine metastases, and eight lymphomas, were included in the study. All patients have undergone routine MR examination where DWI and PWI were performed in the same session. DWI was performed with b values of 0, 500, and 1000 mm(2)/s. Minimum ADC values (ADC(min)) of each tumor was later calculated from ADC map images. PWI was applied using dynamic susceptibility contrast technique and maximum relative cerebral blood volume (rCBV(max)) was calculated from each tumor, given in ratio with contralateral normal white matter. Comparisons of ADC(min) and rCBV(max) values with the histological types of the enhancing tumors were made with a one-way analysis of variance and Bonferroni test. A P value less than 0.05 indicated a statistically significant difference. RESULTS: The ADC(min) values (mean+/-S.D.) in GBMs, AAs, lymphomas, and metastases were 0.79+/-0.21 (x10(-3)mm(2)/s), 0.75+/-0.21 (x10(-3)mm(2)/s), 0.51+/-0.09 (x10(-3)mm(2)/s), and 0.68+/-0.11 (x10(-3)mm(2)/s), respectively. The difference in ADC(min) values were statistically significant between lymphomas and GBMs (P<0.05). It was also statistically significant between lymphomas and AAs (P<0.03). However, there were no differences between lymphomas and metastasis, and between GBMs, AAs, and metastasis. The rCBV(max) ratio (mean+/-S.D.) in GBMs were 6.33+/-2.03, whereas it was 3.66+/-1.79 in AAs, 2.33+/-0.68 in lymphomas, and 4.45+/-1.87 in metastases. These values were statistically different between GBMs and AAs (P<0.001), GBMs and lymphoma (P<0.0001). Although there seemed to be difference between GBMs and metastases, it was not statistically significant (P<0.083). CONCLUSION: Combination of DWI and PWI, with ADC(min) and rCBV(max) calculations, may aid routine MR imaging in the differentiation of common cerebral contrast-enhancing malignant tumors.

Dural plasmacytoma mimicking meningioma in a patient with multiple myeloma.

Apart from calvarial infiltration, intracranial involvement in multiple myeloma is uncommon. Diffuse leptomeningeal invasion with or without parenchymal involvement is most common. Dural infiltration without involvement of the parenchyma, leptomeninges or skull is rare. The differential diagnosis of a dural plasmacytoma includes meningioma, which has a similar MRI appearance, metastasis, lymphoma and sarcoma of the dura mater. We present a patient with multiple myeloma presenting with an intracerebral mass mimicking a meningioma on MRI. Multiple myeloma had been diagnosed seven years previously. The patient presented with headache and speech disturbance 12 months after autologous peripheral stem cell transplantation for recurrence of multiple myeloma. MRI revealed a left temporal extra-axial mass with a dural tail mimicking meningioma. Histopathological examination of the mass after excision showed multiple myeloma immunopositive for IgG, kappa light chain and CD38. There was no recurrence after postoperative radiotherapy. Plasmacytoma should be considered in the differential diagnosis of a solitary dural mass, particularly in a patient with multiple myeloma.

Minimum apparent diffusion coefficients in the evaluation of brain tumors.

OBJECTIVE: To determine whether diffusion-weighted imaging by using minimum apparent diffusion coefficient (ADC(min)) values could differentiate various brain tumors including gliomas, metastases, and lymphomas. MATERIALS AND METHODS: We examined 65 patients with histologically or clinically diagnosed brain tumors (12 low-grade gliomas, 31 high-grade gliomas, 14 metastatic tumors, and 8 lymphomas) using a 1.5 T MR unit. On diffusion-weighted imaging, the ADC(min) values were measured within the tumors and mean values were evaluated regarding statistical differences between groups. RESULTS: The ADC(min) values of low-grade gliomas (1.09+/-0.20 x 10(-3)mm(2)/s) were significantly higher (p<.001) than those of other tumors. There were no statistical significant differences between glioblastomas (0.70+/-0.16 mm(2)/s), anaplastic astrocytomas (0.77+/-0.21 mm(2)/s), metastases (0.78+/-0.21 mm(2)/s), and lymphomas. But, lymphomas had lower mean ADC(min) values (0.54+/-0.10mm(2)/s) than high-grade gliomas and metastases. CONCLUSION: The ADC measurements may help to differentiate low-grade gliomas from high-grade gliomas, metastases, and lymphomas. Although there is no statistical difference, lymphomas seem to have marked restriction in diffusion coefficients.