Comparison of 201Tl-chloride SPECT with 99mtc-MIBI SPECT in the depiction of malignant head and neck tumors.

OBJECTIVE: Comparison of 201Tl chloride SPECT (TI-SPECT) with 99mTc-MIBI SPECT (MIBI-SPECT) in the depiction of malignant head and neck tumors was prospectively studied. METHODS: Forty-one patients with various tumors of the head and neck were included in this prospective study. Histologically, 36 patients had squamous cell carcinomas, 3 undifferentiated carcinomas, 1 transitional cell carcinoma, and 1 MALT lymphoma. All patients underwent a simultaneous dual-isotope SPECT of the head and neck with 201Tl and 99mTc-MIBI. Dual-isotope SPECT for early (n=41) and delayed acquisition (n=21) was performed. Qualitatively, 3 observers evaluated both TI-SPECT and MIBI-SPECT individually. The interpretation criteria were graded as grade 1 (no abnormal increased uptake) to 5 (definitely increased uptake of a degree equal to or greater than that of normal salivary gland). Statistical analysis of the comparison of Tl-SPECT and MIBI-SPECT was performed. The interobserver difference was evaluated using the kappa-coefficient. Quantitatively, T/N ratio (the ratio of the counts in the tumor divided by that in the normal nuchal muscles) and retention index were compared between TI-SPECT and MIBI-SPECT. RESULTS: On both the early and delayed images, the grades of uptake of the tumor in TI-SPECT were significantly higher than those in MIBI-SPECT by three observers. The grade of Tl-uptake of the tumor on the delayed images was 5 for all observers (kappa-coefficient=1); however, the kappa-coefficient varied from 0.39 to 0.84 in early T1-SPECT, and in early and delayed MIBI-SPECT. Statistical differences in T/N ratio were noted between early TI-SPECT (2.87 +/- 1.19) and MIBI-SPECT (2.48 +/- 1.06), and between delayed Tl-SPECT (2.11 +/- 0.70) and MIBI-SPECT (1.20 +/- 0.48). The retention index or Tl-SPECT (0.81 +/- 0.24) was significantly higher than that of MIBI-SPECT (0.52 +/- 0.15). CONCLUSIONS: The present study qualitatively and quantitatively showed that 201Tl had higher accumulation in the tumor than 99mTc-MIBI in both early and delayed images.

Comparison of technetium Tc 99m hexamethylpropyleneamine oxime single-photon emission tomograph with stump pressure during the balloon occlusion test of the internal carotid artery.

BACKGROUND AND PURPOSE: Measuring blood pressure (stump pressure) in the distal internal carotid artery during occlusion of the internal carotid artery is reportedly a reliable safety index with which to predict ischemia following permanent occlusion of the internal carotid artery. We compared the stump pressure during occlusion of the internal carotid artery with single-photon emission CT (SPECT) using technetium Tc 99m hexamethylpropyleneamine oxime (HMPAO). METHODS: Twenty-seven patients underwent the balloon occlusion test. After occlusion of the internal carotid artery was performed by a balloon catheter, technetium Tc 99m HMPAO was injected, and then the balloon remained inflated for 15 minutes. The stump pressure was continuously monitored for those 15 minutes. After the balloon catheter was deflated and removed, SPECT was performed. Sixty-four symmetric pairs of regions of interest were set on both sides of the cerebral hemisphere. The radioactivity count ratio (L/n ratio) of the occluded side to the contralateral normal side was calculated. We defined hypoperfusion as an area with an L/n ratio <0.8. The minimum mean stump pressure (minMSP) during the balloon occlusion test and the pressure ratio of the minMSP to the mean systemic pressure were compared with the hypoperfusion area on SPECT. RESULTS: The number of regions of interest with hypoperfusion was significantly (P < .001) greater in patients with a minMSP <40 mm Hg (mean [+/-SD] = 31.5 +/- 13.7) than in patients with a minMSP > or =40 mm Hg (5.1 +/- 4.0). The number of regions of interest with hypoperfusion was also significantly (P < .001) greater in patients with a pressure ratio <0.5 (26.7 +/- 15.8) than in patients with a pressure ratio > or =0.5 (4.5 +/- 3.5). CONCLUSION: The minMSP during the balloon test occlusion reflects the extent of the hypoperfused area measured by SPECT using technetium Tc 99m HMPAO.

Thallium-201 SPECT in the evaluation of early effects on brain tumors treated with stereotactic irradiation.

PURPOSE: To determine whether thallium-201 SPECT can predict response to stereotactic irradiation (STI) earlier than magnetic resonance imaging (MRI), the change in tumor size measured by MRI was compared with the change in tumor activity measured by Tl-201 SPECT before and after STI. MATERIALS AND METHODS: Twenty-one tumors in 16 patients with intracranial tumors were treated by STI. Tl-201 SPECT was performed within 1 week before the beginning of STI and within 1 week after the end of STI in all patients. All patients underwent MRI within 1 week before the beginning of STI, and 14 patients (19 tumors) underwent MRI within 1 week after the end of STI. Follow-up MRI was performed 1 to 2 months after the end of STI in 14 patients (16 tumors). The activity of Tl-201 in the tumor divided by that of the uninvolved symmetric area was defined as the Tl-index. The change in tumor size immediately and 1 to 2 months after STI was compared with the change in Tl-index immediately after STI. RESULTS: No significant relationship between the ratio of tumor size immediately after STI and the ratio of Tl-index immediately after STI was found. A significant correlation (r = 0.69, P <0.05) between the ratio of tumor size 1 to 2 months after STI and the ratio of Tl-index immediately after STI was found. CONCLUSIONS: This study suggests that Tl-201 SPECT immediately after STI can predict treatment response 1 to 2 months after STI, and that Tl-201 SPECT can be an early indicator of treatment response.

[Three-dimensional surface anatomical scanning with 3D-FSPGR: anatomical conformity with surgical findings].

Three-dimensional imaging with MRI is a useful method for neurosurgical simulations. As in our previous study, we have constructed three-dimensional surface anatomical scanning (3D-SAS) from the data of contrast enhanced 3D fast spoiled gradient recalled acquisition in the steady state (3D-FSPGR) sequence. Using this technique, it is possible to generate 3D images from the data of only one acquisition, without using the fusion function. In our previous study, we did not compare the 3D images with the operative views at surgery. In the present study, two radiologists and one neurosurgeon assessed the 3D images in comparison with the operative views. There were problems in some cases, including unclear cortical sulci owing to brain swelling, lack of depiction of the cortical veins owing to meningeal enhancement, inadequate distinction between pial veins and meningeal veins, and so forth. However, in the majority of cases, 3D-SAS with 3D-FSPGR was able to demonstrate good anatomical conformity with the operative views, indicating the clinical usefulness of this technique.

[A case of astrocytoma with extracranial extension after malignant transformation].

A case of astrocytoma with extracranial extension after malignant transformation is presented. The patient was a 58-year-old female who suffered from headache. The initial magnetic resonance imaging (MRI) demonstrated a slightly hyperintense tumor on T 2-weighted images in the tip of the left temporal lobe, and no contrast enhancement on gadolinium-enhanced T 1-weighted images(Gd-T 1 WI). On digital subtraction angiography, there was no tumor staining. The initial diagnosis was made as low-grade astrocytoma. However two months later, her symptoms aggravated suddenly. MRI revealed a remarkably growing tumor with ring-like enhancement on Gd-T 1 WI. She underwent a temporal lobectomy, which pathologically demonstrated a glioblastoma. After surgery, chemotherapy and radiotherapy were performed. The tumor invades the skull base and extended into the infratemporal fossa 25 months after surgery.

Diffuse large B-cell lymphoma with mass lesions of skull vault and ileocecum.

We report a rare case of non-Hodgkin lymphoma with mass lesions of skull vault and ileocecum. The patient was an 82-year-old Japanese woman who exhibited a painless subcutaneous scalp tumor in the right parietal region associated with no neurological abnormalities. Magnetic resonance imaging of the head demonstrated a mass in the skull vault with iso- to hypointense signals on both T1- and T2-weighted imaging. Biopsy of the mass revealed that the tumor comprised large cells that were immunoreactive for CD20 (L-26) and CD79a. Diffuse large B-cell lymphoma (DLBCL) was therefore diagnosed. Further investigation could not identify any other evidence of systemic lymphoma other than ileocecal lesions. She was treated by irradiation (45 Gy) of the mass on the parietal bone and with rituximab, pirarubicin, cyclophosphamide, and vincristine. The patient achieved complete remission after 3 cycles of systemic chemotherapy. As of 30 months after presentation, no signs of lymphoma have been found.

Hepatitis B reactivation in a multiple myeloma patient with resolved hepatitis B infection during bortezomib therapy : case report.

It has recently been reported that hepatitis B virus (HBV) reactivation in patients with hepatitis B surface antigen (HBsAg)-negative lymphoma during or after cytotoxic therapy occurs after the use of rituximab and stem cell transplantation for hematologic malignancies. However, clinical data on HBV reactivation in multiple myeloma patients have not been extensively reported. This is the first reported case of HBV reactivation in an HBsAg-negative myeloma patient treated with bortezomib (BOR) as salvage therapy and not stem cell transplantation. By closely monitoring HBV-DNA and early administration of entecavir, severe hepatitis was avoided and BOR therapy was continued. We suggest the importance of close monitoring of HBV-DNA for transplant-ineligible myeloma patients treated with BOR as salvage therapy.

Evaluation of postoperative status after clipping surgery in patients with cerebral aneurysm on 3-dimensional-CT angiography with elimination of clips.

BACKGROUND AND PURPOSE: the use of 3-dimensional computed tomography angiography (3D-CTA) for clipped aneurysms is limited. Usefulness of 3D-CTA with elimination of bone and clips was evaluated in patients with clipped cerebral aneurysms. METHODS: forty-three clipped cerebral aneurysms were included. As review of digital subtraction angiography after surgery is the current gold standard, the presence or absence of remnant necks on 3D-CTA with elimination of bone and clips was compared with that on conventional CTA, using receiver operating characteristic analysis (5, definitely absent; 1, definitely present). RESULTS: in the ROC analysis, the Az (.949) in CTA with clip elimination significantly (P < .05) differed from that (.751) of conventional 3D-CTA. If a score of 1 or 2 is considered to represent positive detection of remnant necks, then the sensitivity of 3D-CTA with clip elimination and of conventional 3D-CTA is 73% and 36%, respectively. If a score of 5 or 4 is considered to represent negative detection of remnant necks, then the specificity of 3D-CTA with clip elimination and of conventional 3D-CTA is 88% and 78%, respectively. CONCLUSIONS: 3D-CTA with elimination of bone and clips can improve the accuracy of detection of remnant necks after clipping surgery for cerebral aneurysms.

Three-dimensional bone-free computed tomographic angiography of aneurysms near the skull base using a new bone-removal application.

PURPOSE: Bone elimination is needed for computed tomography angiography (CTA) because bone structures obscure aneurysms located at the skull base. The purpose of our study was to evaluate the efficacy of three-dimensional (3D)-CTA using an application for bone elimination. MATERIALS AND METHODS: A total of 27 patients with 32 angiographically confirmed aneurysms near the skull base were investigated. The 3D maximum intensity projection (MIP) images were initially obtained using the application. Further postprocessing was performed to obtain the MIP and volume-rendered (VR) images. The quality of the initial MIP images by the application was analyzed. Visualization of aneurysms after further processing was also reviewed. RESULTS: The initial MIP images by the application showed almost bone-free images in 23 of the 27 patients. In 8 patients, the image of the internal carotid artery (ICA) was segmentally removed in the initial MIP images by the application. Further postprocessing was able to recover all loss of the ICA image in these eight patients. For visualizing aneurysms and their necks, VR images with the application were significantly superior to VR images without the application. CONCLUSION: The application for bone elimination allows fast, selective elimination of bony structures and can improve the interpretation of aneurysms near the skull base.

Visualization of anterior disc displacement in temporomandibular disorders on contrast-enhanced magnetic resonance imaging: comparison with T2-weighted, proton density-weighted, and precontrast T1-weighted imaging.

OBJECTIVE: To compare postcontrast T1-weighted imaging (T1WI+) with precontrast T1-weighted (T1WI-), T2-weighted (T2WI), and proton density-weighted imaging (ProWI) in depiction of the anterior disc displacement (ADD) in temporomandibular disorders (TMDs). STUDY DESIGN: A total of 120 joints with TMD were included in this study. Qualitatively, Receiver operating characteristic analysis was performed. Quantitatively, the ratio of the intensity in the retrodiscal tissue to intensity in the disc (intensity ratio) was measured. RESULTS: One reader achieved superior performance in visualization of ADD with T1WI+ than with the other sequences. The other reader showed superiority with T1WI+ rather than T2WI or T1WI-. The intensity ratio on T1WI+ was significantly higher than the intensity ratio on other sequences. On T1WI,+ the intensity ratio in the joints with ADD was significantly higher than that in the joints without ADD. CONCLUSION: Postcontrast T1-weighted imaging can improve the visualization of ADD in TMDs.

Reduced perfusion reserve in Leukoaraiosis demonstrated using acetazolamide challenge 123I-IMP SPECT.

OBJECTIVE: We examined the relationship between the perfusion reserve as measured by acetazolamide (ACZ)-challenge N-isopropyl-I-123-p-iodoamphetamine (IMP)-single-photon emission computed tomography (SPECT) and the degree of leukoaraiosis (LA) as estimated using magnetic resonance imaging. METHODS: In 51 patients receiving IMP-SPECT with the resting state and ACZ challenge, the unaffected cerebral hemispheres were included in the present study. Mean cerebral blood flow (CBF) in the resting state and ACZ reactivity were acquired. Absolute CBF value and ACZ reactivity were compared among patients with LA grades 0, 1, and 2. The relationship between mean age and LA grade was also assessed. RESULTS: No significant difference in the absolute CBF value in the resting state was observed among the 3 LA groups. Although vasoreactivity in LA grade 0 did not differ from that in grade 1, vasoreactivity in LA grade 2 was significantly lower (P < 0.05) than that in grades 0 or 1. CONCLUSIONS: The perfusion reserve is impaired in advanced LA.

Diffusion changes in a tumor and peritumoral tissue after stereotactic irradiation for brain tumors: possible prediction of treatment response.

OBJECTIVE: Changes in apparent diffusion coefficient (ADC) in a tumor and peritumoral tissue after stereotactic irradiation (STI) were evaluated, and then the therapeutic efficacy of ADC measurement was assessed. METHODS: In 20 tumors, diffusion-weighted imaging within 1 week before and 2-4 weeks after STI was performed. The normalized ADC (nADC) was measured. The nADCs in the tumor and peritumoral region before STI were compared with those after STI and the change in tumor nADC compared with the change in tumor size. RESULTS: The nADC of the tumors was significantly higher 2-4 weeks after STI compared with that before STI. The nADC of the peritumoral regions 2-4 weeks after STI did not differ significantly from that before STI. A significant difference in the nADC at 2-4 weeks after STI was observed between the responder and nonresponder groups. CONCLUSIONS: Changes in nADC as measured by diffusion-weighted imaging can predict response to STI.

Craniocervical junction venous anatomy around the suboccipital cavernous sinus: evaluation by MR imaging.

The present study evaluated the venous anatomy of the craniocervical junction, focusing on the suboccipital cavernous sinus (SCS), a vertebral venous plexus surrounding the horizontal portion of the vertebral artery at the skull base. MR imaging was reviewed to clarify the venous anatomy of the SCS in 33 patients. Multiplanar reconstruction MR images were obtained using contrast-enhanced three-dimensional fast spoiled gradient-recalled acquisition in the steady state (3-D fast SPGR) with fat suppression. Connections with the SCS were evaluated for the following venous structures: anterior condylar vein (ACV); posterior condylar vein (PCV); lateral condylar vein (LCV); vertebral artery venous plexus (VAVP); and anterior internal vertebral venous plexus (AVVP). The SCS connected with the ACV superomedially, with the VAVP inferolaterally, and with the AVVP medially. The LCV connected with the external orifice of the ACV and superoanterior aspect of the SCS. The PCV connected with the posteromedial aspect of the jugular bulb and superoposterior aspect of the SCS. The findings of craniocervical junction venography performed in eight patients corresponded with those on MR imaging, other than with regard to the PCV. Contrast-enhanced 3-D fast SPGR allows visualization of the detailed anatomy of these venous structures, and this technique facilitates interventions and description of pathologies occurring in this area.

Dynamic contrast-enhanced magnetic resonance imaging in radiotherapeutic efficacy in the head and neck tumors.

PURPOSE: The purpose to this study is to identify correlations between pathology and dynamic contrast-enhanced magnetic resonance imaging (MRI) and to assess the utility of this technique in the evaluation of radiation response for head and neck cancer. MATERIALS AND METHODS: MRI was prospectively performed after radiotherapy in 27 patients with various head and neck tumors. After bolus injection of contrast material, a dynamic study was performed using a spoiled gradient-recalled imaging sequence. The maximum slope of increase (MSI) on the time-intensity curve was displayed as a color-coded image. The ratio of MSI (MSIR) was obtained for tumor and normal muscles. Pathological specimens were obtained after MRI in all cases. Histological grading of irradiation changes was classified into 5 grades (0-4). Correlations between MSIR and histological grade were examined. RESULTS: Histologically, 18 tumors were classified as grade 2 (presence of viable tumor cells), 4 were grade 3 (nonviable tumor cells), and 5 were grade 4 (no tumor cells). Although the mean +/- SD of MSIR in patients with histological grade 2 or 3 was 7.4 +/- 7.9, MSIR in patients with grade 4 was 1.8 +/- 0.73, representing a significant difference ( P < .05). Every patient with grade 4 displayed an MSIR of 2.5 or less, although 5 of 22 patients with grade 2 or 3 had an MSIR of 2.5 or less. CONCLUSIONS: MSI quantitatively reflects response to radiotherapy for head and neck cancer. Color-coded MSI display is feasible for depicting permeability changes after radiotherapy.

Ischemic lesions related to cerebral angiography: Evaluation by diffusion weighted MR imaging.

We examined the incidence of ischemic lesions occurring after cerebral angiography by means of diffusion weighted MR imaging (DWI). Fifty patients were included in this study. Balloon occlusion tests of the internal carotid artery were performed in 9 of the 50 patients. DWI was performed on the same day as the cerebral angiography or on the following day. No new neurological deficits were found after cerebral angiography. However, 13 of the 50 cases revealed new ischemic lesions after cerebral angiography. The incidence of ischemic lesions was significantly different between patients who underwent balloon occlusion tests and patients who did not. The incidence of ischemic lesions was not influenced by the duration of the procedure, use of additional catheters, total amount of contrast material or the type of contrast material. The incidence of clinically silent ischemic lesions related to cerebral angiography is greater than the incidence of neurological complications. In patients who underwent occlusion tests of the internal carotid artery, the incidence of silent lesions was significantly higher than in patients who did not.

Comparison of multishot echo-planar fluid-attenuated inversion-recovery imaging with fast spin-echo fluid-attenuated inversion-recovery and T2-weighted imaging in depiction of white matter lesions.

PURPOSE: To compare a multishot echo-planar fluid-attenuated inversion-recovery (EPI-FLAIR) sequence with fast spin-echo FLAIR (F-FLAIR) and fast spin-echo T2-weighted (FSE-T2W) sequences in depiction of white matter lesions. METHODS: Thirty-five patients with various white matter lesions were included in this prospective study. Two independent readers for lesion detection (lesion size, >2 mm) compared sequences quantitatively. In 22 patients, contrast was calculated between periventricular hyperintensity (PVH) and the cerebrospinal fluid (CSF). RESULTS: EPI-FLAIR revealed more lesions than FSE-T2W (p < 0.01). However, F-FLAIR revealed more lesions than EPI-FLAIR (p < 0.01). For PVH-to-CSF contrast, EPI-FLAIR demonstrated significantly higher contrast than FSE-T2W. There were no differences in PVH-to-CSF contrast between EPI-FLAIR and F-FLAIR. CONCLUSIONS: This study shows that EPI-FLAIR has distinct advantages over FSE-T2W in the depiction of white matter lesions. Although EPI-FLAIR reduces imaging time by more than 60% relative to F-FLAIR, it cannot replace F-FLAIR for the detection of lesions in the cerebral white matter.

Image fusion of thallium-201 SPECT and MR imaging for the assessment of recurrent head and neck tumors following flap reconstructive surgery.

The aim of this study was to assess the value of fused MR and Tl-201 single photon emission computed tomography (SPECT) images in the diagnosis of recurrent head and neck tumors in patients after flap reconstruction surgery. Twenty-four patients after resection of primary head and neck tumors with flap reconstruction were suspected of having recurrent tumor by follow-up MR examination. Both MR examination and Tl-201 SPECT were prospectively performed to produce fused images. For qualitative analysis, two independent readers separately evaluated the existence of tumor recurrence in the fused images. The Tl-201 uptake of the lesion (Tl index) was also quantitatively compared with that of the normal nuchal muscles. Eighteen patients were histologically proved as having recurrence. The remaining 6 patients, false positive on MRI alone, had non-recurrence. Using the fused images, false positive was found in 1 case for one reader and 2 cases for the other reader. The Tl index of recurrent tumors was significantly higher (p < 0.001) than that of non-recurrent mass lesions. In the assessment of recurrent tumors following flap reconstruction surgery in the head and neck, the use of fused MRI and Tl-201 SPECT images can reduce the number of false positives.

[Feasibility of early ambulation three hours after transfemoral angiography using a 4 French sheath].

PURPOSE: Our objective was to evaluate the feasibility of early resumption of ambulation 3 hours after transfemoral angiography using a 4 French sheath. SUBJECTS AND METHODS: This prospective study was carried out in a selected group of men and women without impaired blood clotting (prothrombin time > 15 sec) or thrombocytopenia (platelet < 55,000/mm3). The subjects consisted of 66 men and 34 women with a mean age of 62.3 years (range 27-90 years). Incidences of rebleeding or hematoma at the site of femoral catheter insertion were investigated before and after ambulation. Rebleeding was defined as bleeding that required recompression. Hematoma was defined as a palpable, firm collection of subcutaneous blood. RESULTS: Of 100 patients who resumed full ambulation after three hours of bed rest, none (0%) had acute groin hematoma and only three (3%) showed rebleeding that had to be manually compressed. The remaining 97 patients (97%) had no problem after ambulation. CONCLUSION: Supervised resumption of ambulation 3 hours after angiography with a 4 French sheath is safe and feasible in most ambulatory patients undergoing transfemoral angiography.