Brain MR findings in patients with systemic lupus erythematosus with and without antiphospholipid antibody syndrome.

BACKGROUND AND PURPOSE: Antiphospholipid syndrome may affect the incidence and pathogenesis of cerebrovascular diseases in patients with systemic lupus erythematosus. We compared the spectrum of MR findings in patients with systemic lupus erythematosus with and without antiphospholipid syndrome. MATERIALS AND METHODS: We identified 256 patients with systemic lupus erythematosus (45 with, 211 without antiphospholipid syndrome) who underwent MR studies; in 145 (57%), we detected abnormalities. These were categorized as large territorial, lacunar, localized cortical, and borderzone infarctions and as microembolisms, basal ganglia lesions, callosal lesions, hemorrhages, and white matter hyperintensity on T2-weighted and/or FLAIR images, and as stenotic arterial lesions on MR angiograms. Logistic regression analysis was performed to compare the MR findings in patients with systemic lupus erythematosus with and without antiphospholipid syndrome, with patient age and antiphospholipid syndrome as the covariates. RESULTS: Abnormal MR findings were more common in patients with systemic lupus erythematosus with antiphospholipid syndrome (73% versus 53%). Large territorial (P = .01), lacunar (P = .01), localized cortical (P < .01), borderzone infarcts (P < .01), basal ganglia lesions (P = .03), stenotic arterial lesions (P = .04), and the rate of positive findings on MR imaging (P = .01) were significantly associated with antiphospholipid syndrome. Irrespective of age, significantly more patients with antiphospholipid syndrome manifested lacunar infarcts in the deep white matter (P < .01), localized cortical infarcts in the territory of the MCA (P < .01), bilateral borderzone infarcts (P < .01), and anterior basal ganglia lesions (P = .01). CONCLUSIONS: Abnormal MR findings were more common in patients with systemic lupus erythematosus with than in those without antiphospholipid syndrome. Large territorial infarctions, lacunar infarctions in the deep white matter, localized cortical infarctions in the MCA territory, bilateral borderzone infarctions, anterior basal ganglia lesions, and stenotic arterial lesions are common MR findings in patients with systemic lupus erythematosus with antiphospholipid syndrome.

Ecchordosis physaliphora and its variants: proposed new classification based on high-resolution fast MR imaging employing steady-state acquisition.

OBJECTIVES: To propose a new classification for ecchordosis physaliphora (EP) using fast imaging employing steady-state acquisition (FIESTA). METHODS: We evaluated 974 consecutive patients and selected for further study 78 (8.0 %) who manifested an excrescence on the dorsal surface of the clivus (DSC) and/or clivus lesions. Lesions were defined as "classical EP" when they appeared as a hyperintense excrescence (cyst-like component) on DSC. Other lesions were defined as "possible EP". RESULTS: Of the 78 patients, 17 (22 %) were diagnosed with classical EP, the other 61 with possible EP. The 61 patients with possible EP were further classified into "incomplete EP = EP bud" (n = 55, 90.2 %), characterised by a T2 hypointense protrusion of the clivus, and into "EP variant" (n = 6, 9.8 %), characterised by hyperintense lesions within only clivus. FIESTA findings of incomplete EP were similar to those of classical EP except for lack of the hyperintense excrescence on DSC. Most lesions were located at the level of the Dorello canal at the midline of the craniospinal axis. CONCLUSION: Our results suggest that the magnetic resonance imaging appearance of EP is diverse. Based on our FIESTA results we propose a new classification for EP, i.e. classical EP, incomplete EP (EP bud) and EP variant. KEY POINTS: • Ecchordosis physaliphora (EP) is a rare benign cystic congenital lesion arising from notochord. • The classical type of EP is frequently associated with a T2 hypointense protrusion. • T2 hypointense protrusions without clivus cysts may represent an incomplete type of EP. • Third type of EP variant only harbours lesions within the clivus.

Normal flow signal of the pterygoid plexus on 3T MRA in patients without DAVF of the cavernous sinus.

BACKGROUND AND PURPOSE: Cavernous sinuses and draining dural sinuses or veins are often visualized on 3D TOF MRA images in patients with dural arteriovenous fistulas involving the CS. Flow signals may be seen in the jugular vein and dural sinuses at the skull base on MRA images in healthy participants, however, because of reverse flow. Our purpose was to investigate the prevalence of flow signals in the pterygoid plexus and CS on 3T MRA images in a cohort of participants without DAVFs. MATERIALS AND METHODS: Two radiologists evaluated the flow signals of the PP and CS on 3T MRA images obtained from 406 consecutive participants by using a 5-point scale. In addition, the findings on 3T MRA images were compared with those on digital subtraction angiography images in an additional 171 participants who underwent both examinations. RESULTS: The radiologists identified 110 participants (27.1%; 108 left, 10 right, 8 bilateral) with evidence of flow signals in the PP alone (n = 67) or in both the PP and CS (n = 43). Flow signals were significantly more common in the left PP than in the right PP. In 171 patients who underwent both MRA and DSA, the MRA images showed flow signals in the PP with or without CS in 60 patients; no DAVFs were identified on DSA in any of these patients. CONCLUSIONS: Flow signals are frequently seen in the left PP on 3T MRA images in healthy participants. This finding may be the result of flow reversal and should not be considered to indicate occult DAVF.

Effect of tube voltage on image quality in 64-section multidetector 3D CT angiography: Evaluation with a vascular phantom with superimposed bone skull structures.

BACKGROUND AND PURPOSE: Optimal tube voltage and tube current settings are not well established. The purpose of our study was to investigate the image quality on 3D CT angiograms of the brain at various kilovoltage settings by evaluating the depiction of simulated intracranial lesions by using a vascular phantom. MATERIALS AND METHODS: An anthropomorphic vascular phantom with superimposed bone skull structures was designed to simulate various intracranial aneurysms with aneurysmal blebs. We performed CT angiography by using a 64-detector row CT scanner for various effective tube currents with 4 tube voltages of 80, 100, 120, and 135 kV(p). Simulated aneurysm enhancement and image noise were quantified; SNR and CNR were calculated. The depiction of the simulated aneurysms and blebs on 3D CT angiograms obtained with the volume-rendering technique was subjectively assessed. The effective dose was calculated on the basis of a CTDIw. The results of several protocols were compared by using the Student t test. RESULTS: At identical doses levels (CTDIw), the mean SNR and CNR at 100 kV(p) were significantly higher than those at 80, 120, and 135 kV(p); and the mean qualitative image score at 100 kV(p) was significantly superior to those at 80 and 135 kV(p). CONCLUSIONS: Our phantom study suggests that the tube voltage of 100 kV(p) is desirable for cerebral 3D CT angiograms, and the higher or lower kilovoltage settings may result in the degradation in diagnostic image quality.

Signal intensity of the motor cortex on phase-weighted imaging at 3T.

BACKGROUND AND PURPOSE: It is known that the motor cortex shows hypointensity on T2-weighted images in older patients. The goal of this study was to assess the signal intensity of the motor cortices on the phase-weighted imaging performed with a Windows-based software program that we developed ourselves. MATERIALS AND METHODS: All studies were performed at 3T MR imaging. First, the TE for the phase-weighted image was optimized; the best contrast between the motor and other cortices was obtained with a TE of 40 ms. The study population consisted of 45 healthy subjects (23 females, 22 males; mean age, 32.1 years). The signal intensity of the motor cortices was divided into 3 grades by 2 neuroradiologists in comparison with that of the superior frontal cortex (SFC): In grade I, the motor cortex was isointense to the SFC; in grade II, the motor cortex was slightly hypointense to the SFC; and in grade III, the motor cortex was markedly hypointense to the SFC. RESULTS: The motor cortex was classified as either grade II or III in all subjects older than 20 years of age on the phase-weighted images. Even at 10-19 years of age, the grade II or III appearance was found in 14 (88%) of 16 motor cortices (8 subjects) on the phase-weighted images. CONCLUSION: In adolescents, the motor cortex is hypointense to other cerebral cortices on phase-weighted MR imaging, which probably reflects differences in the concentration of nonheme iron and/or in the tissue architecture.

A cone-beam volume CT using a 3D angiography system with a flat panel detector of direct conversion type: usefulness for superselective intra-arterial chemotherapy for head and neck tumors.

BACKGROUND AND PURPOSE: The development of flat panel detectors (FPDs) has made cone-beam CT feasible for practical use in a clinical setting. Our purpose was to assess the usefulness of cone-beam CT using the FPD in conjunction with conventional digital subtraction angiography (DSA) for performing superselective intra-arterial chemotherapy for head and neck tumors. MATERIALS AND METHODS: Twenty-three consecutive patients (43 feeding arteries) were prospectively examined. All of the patients underwent intra-arterial rotational angiography using an FPD system, and the cone-beam CT was reconstructed from the volume dataset. Two radiologists evaluated the quality of the cone-beam CT and then evaluated whether the additional information provided by the cone-beam CT was useful for the interventional procedures. RESULTS: In 41 (95%) of 43 arteries, the extent of contrast material perfusion was sufficiently visualized on cone-beam CT. In 20 (47%) of 43 arteries, the DSA plus cone-beam CT was superior to the DSA alone regarding the precise understanding of vascular territory of each artery. This information was helpful for predicting the drug delivery for superselective intra-arterial chemotherapy, especially in deeply invasive tumors with multiple feeding arteries. CONCLUSION: In superselective intra-arterial chemotherapy for head and neck tumors, cone-beam CT with FPD provides useful additional information, which allows interventional radiologists to determine the feeders, as well as the dose of antitumor agent for each feeder.

3D digital subtraction angiography of intracranial aneurysms: comparison of flat panel detector with conventional image intensifier TV system using a vascular phantom.

BACKGROUND AND PURPOSE: Compared with the image intensifier (I.I.)-TV system, the flat panel detector (FPD) system of direct conversion type has several theoretic advantages, such as higher spatial resolution, wide dynamic range, and no image distortion. The purpose of this study was to compare the image quality of 3D digital subtraction angiography (DSA) in the FPD and conventional I.I.-TV systems using a vascular phantom. MATERIALS AND METHODS: An anthropomorphic vascular phantom was designed to simulate the various intracranial aneurysms with aneurysmal bleb. The tubes of this vascular phantom were filled with 2 concentrations of contrast material (300 and 150 mg I/mL), and we obtained 3D DSA using the FPD and I.I.-TV systems. First, 2 blinded radiologists compared the volume-rendering images for 3D DSA on the FPD and I.I.-TV systems, looking for pseudostenosis artifacts. Then, 2 other radiologists independently evaluated both systems for the depiction of the simulated aneurysm and aneurysmal bleb using a 5-point scale. RESULTS: For the degree of the pseudostenosis artifacts at the M1 segment of the middle cerebral artery at 300 mg I/mL, 3D DSA with FPD system showed mild stenoses, whereas severe stenoses were observed at 3D DSA with I.I.-TV system. At both concentrations, the FPD system was significantly superior to I.I.-TV system regarding the depiction of aneurysm and aneurysmal bleb. CONCLUSION: Compared with the I.I.-TV system, the FPD system could create high-resolution 3D DSA combined with a reduction of the pseudostenosis artifacts.

Reduction of radiation dose for cerebral angiography using flat panel detector of direct conversion type: a vascular phantom study.

BACKGROUND AND PURPOSE: Compared with image intensifier television (I.I.-TV) system, an angiography system using the flat panel detector (FPD) of direct conversion type has a high spatial resolution, which may improve image quality, reduce patient exposure, or both. Our purpose was to evaluate the detection of simulated aneurysmal blebs under dose reduction with the FPD system in comparison with the I.I.-TV system. MATERIALS AND METHODS: A vascular phantom was designed to simulate various intracranial aneurysms with and without blebs, and this phantom was filled with 3 different concentrations of contrast material (300, 150, and 100 mg I/mL). 2D digital subtraction angiography (DSA) at low-dose mode of FPD system was compared with 2D DSA at a standard-dose mode of FPD system and a conventional mode of I.I.-TV system. Data analysis was based on 171 observations (57 aneurysms [20 with bleb and 37 without bleb] x 3 contrast material concentrations) by each of 7 radiologists, and the detection performances of blebs were compared using a receiver operating characteristic (ROC) analysis. RESULTS: The mean dose measurements with a phantom during 2D DSA were 0.36 mGy/frame with low-dose mode of FPD system, 0.72 mGy/frame with standard-dose mode of FPD system and 0.76 mGy/frame with I.I.-TV system. The mean Az at 100 mg I/mL was significantly higher for low-dose mode of FPD than for conventional-dose mode of I.I.-TV mean Az, 0.85 versus 0.56; P < .01), though differences were not significant with 150 and 300 mg I/mL between both systems. CONCLUSION: The FPD system allows a considerable dose reduction during 2D DSA without loss of the image quality.

Hepatic inflow vessels caliber as an index for liver function.

BACKGROUND/AIMS: Little is known about the serial change of the hepatic inflow vessels' caliber in the chronically diseased liver. We have analyzed the caliber change in patients with esophageal varices and examined relationship between hepatic inflow vessels diameter and age of patients who had no liver disease. MATERIALS AND METHODS: (i) Diameters of the hepatic inflow vessels was measured on angiogram in five patients with chronic liver disease. They underwent liver angiography twice with an interval of more than 10 months. The caliber change was analyzed. (ii) Thirty-nine patients without chronic liver disease were analyzed to examine vessel diameter change with aging. RESULTS: (i) The left hepatic artery diameter increased in size during the follow-up periods. On the other hand, the portal vein caliber increased in three cases excluding two cases whose Child grade did not change from A. (ii) The hepatic artery and the portal vein diameter had a tendency to become smaller with aging in thirty-nine patients who underwent hepatic angiography and had no liver disease. CONCLUSIONS: Hepatic inflow vessels' caliber change, particularly increase in hepatic artery diameter, has a potential of suggesting the liver function to some extent.

[The efficacy of bone scintigraphy screening in postoperative follow-up of breast cancer patients].

Discussed are 110 breast cancer patients given surgery, totaling 70 stage 1 cases, 22 stage II cases, 15 stage III cases, and 3 stage IV cases, that were routinely followed-up postoperatively at 6 or 12-month intervals, said follow-ups including bone scintigraphy screening. Among 394 bone scintigrams taken of these 100 patients, 15 new cases of a bone metastasis were detected, 9 of which had either a local recurrence or an associated metastasis at the time that their bone metastasis was detected. In only 1 case, at more than five years after surgery, was a bone metastasis detected by bone scintigraphy, and even this case had another metastasis at that time. Therefore, the value of bone scintigraphy screening as part of the follow-up of postoperative breast cancer patients is questioned.

Asymptomatic Bochdalek hernia diagnosed by magnetic resonance imaging.

An asymptomatic mass at the base of the left lung was examined by computed tomography (CT) and magnetic resonance (MR) imaging. Coronal and sagittal T1-weighted MR images provided a definitive diagnosis of Bochdalek hernia.

[MR imaging of acute hemorrhagic brain infarction].

Six patients with acute hemorrhagic brain infarct were imaged using spin-echo (SE) pulse sequences on a 1.5 Tesla MR scanner. Including two patients with repeated MR imaging, a total of eight examinations, all performed within 15 days after stroke, were analyzed retrospectively. Four patients revealed massive hemorrhages in the basal ganglia or cerebellum and three cases demonstrated multiple linear hemorrhages in the cerebral cortex. On T1-weighted images, hemorrhages were either mildly or definitely hyperintense relative to gray matter, while varied from mildly hypointense to hyperintense on T2-weighted images. T1-weighted images were superior to T2-weighted images in detection of hemorrhage. CT failed to detect hemorrhages in two of five cases: indicative of MR superiority to CT in the diagnosis of acute hemorrhagic infarcts.

[MRI of middle cerebral artery occlusion].

Magnetic resonance imagings (MRIs) of ten patients with angiographically proved middle cerebral artery (MCA) occlusion were retrospectively reviewed. Eight of the ten patients had cerebral infarcts, one had an intraventricular hemorrhage, and the remaining one had no significant abnormalities. All patients were examined by the 1.5 Tesla SIGNA (GE), using spin-echo pulse sequences. In all patients, occluded MCA could be detected by MRI. All occluded arteries showed absence of flow void and were demonstrated as iso- or hyperintense structures relative to gray matter on T1-weighted images, iso- or hypointense on T2-weighted images. In eight of the ten patients, absence of flow void in the sylvian fissure was observed on T2-weighted images. Thus, MRI was proved to be a pertinent diagnostic modality for evaluating MCA occlusions.

[MRI of internal carotid occlusion and high-grade carotid stenosis].

Magnetic resonance imaging (MRI) of twelve patients with angiographically proved internal carotid artery (ICA) occlusions and a patient with high-grade ICA stenosis was retrospectively reviewed. In one of the occluded ICA cases, the bilateral ICAs were involved. All patients were examined by a 1.5 Tesla system, using spin-echo pulse sequences. Both absence of normal flow void and decreased caliber of the cavernous portion of the ICA were detected in all patients. In ten of the thirteen occluded ICAs, flow void was completely absent. Most of the occluded arteries were isointense relative to gray matter on T1-weighted images, and were mildly hypointense on T2-weighted images. "Partial flow void" was observed in four cases, including the high-grade stenosis patient. So-called "border zone infarcts" were detected in seven patients (eight hemispheres). In three of the thirteen cases, however, cerebral infarcts relating to the ICA occlusions or high-grade stenosis were not observed. Since detection of abnormal ICA before cerebral infarct has occurred is extremely significant, we want to stress that abnormal ICA must be routinely searched for in the routine review of MRI of the head.

[Acute hypertensive intracranial hemorrhage: MR imaging at 1.5T].

Twelve patients with acute hypertensive intracranial hemorrhage underwent magnetic resonance (MR) imaging within 7 days after the ictus. T1-weighted (TR = 400 msec; TE = 20 msec) and T2-weighted (TR = 2000 msec; TE = 80 msec) images were obtained on a 1.5 Tesla MR system. Signal intensities of hematomas were carefully evaluated and were compared with white matter intensity. A 9-hour-old hematoma was mildly hypointense on T1-weighted images, and was mildly hyperintense on T2-weighted images, suggesting a reflection of the high water content. On T2-weighted images, thin peripheral hypointense rim, probably due to deoxyhemoglobin, was also observed. Both of 15-hour-old hematoma and 21-hour-old hematoma had peripheral hypointensity on T2-weighted images. Both of 39-hour-old hematoma and 43-hour-old hematoma had central hyper-intensity on T1-weighted images and iso-to-mild central hypointensity on T2-weighted images, suggesting a reflection of decreased water content. A 3-day-old hematoma had thin peripheral iso-to-mild hyperintense rim on T1-weighted images, presumably due to intracellular methomoglobin. A 5-day-old hematoma had thin peripheral hyperintense rim on T2-weighted images, probably due to free methemoglobin. A 7-day-old hematoma was hyperintense on T1-weighted images and was mildly hypointense to hyperintense on T2-weighted images, presumably due to mixed intracellular methemoglobin and free methemoglobin.

MR imaging of intracranial vertebral artery occlusion.

Magnetic resonance (MR) images of nine patients with intracranial vertebral artery occlusion (five proved, four presumed) have been reviewed. In two of nine, both vertebral arteries were occluded and in five of the nine, the basilar artery was also blocked. All occluded arteries showed absence of flow void and were clearly demonstrated as mildly hypo- approximately mildly hyperintense structures to brainstem parenchyma on the T1-weighted images. In two of five patients with basilar artery occlusion, retrograde filling of the distal basilar artery was detected. Thus, MR imaging, in particular the T1-weighted image, is a pertinent diagnostic modality for evaluating intracranial vertebral artery occlusion. Angiography does not seem to be required for confirmation.