Retinal Thickness and Its Interocular Asymmetry Between Parkinson's Disease and Drug-Induced Parkinsonism.

BACKGROUND: Drug-induced parkinsonism (DIP) is common, but diagnosis is challenging. Although dopamine transporter imaging is useful, the cost and inconvenience are problematic, and an easily accessible screening technique is needed. We aimed to determine whether optical coherence tomography (OCT) findings could differentiate DIP from Parkinson's disease (PD). METHODS: We investigated 97 de novo PD patients and 27 DIP patients using OCT and [18F] N-(3-fluoropropyl)-2b-carbon ethoxy-3b-(4-iodophenyl) nortropane (FP-CIT) positron emission tomography. We compared peripapillary retinal nerve fiber layer thickness (pRNFLT) and macular retinal thickness (mRT) between PD and DIP patients as well as interocular differences in the pRNFLT and the mRT. Asymmetric index (%) for retinal thickness (AIRT) was calculated to measure the interocular differences between pRNFLT and mRT. The correlation between AIRT and total striatal specific/non-specific binding ratio asymmetry index (SNBRAI) was investigated in PD and DIP patients. RESULTS: No significant differences in pRNFLT and mRT values were observed between PD and DIP patients (all P values > 0.090). The mean SNBRAI was significantly higher in PD than in DIP (P = 0.008) patients; however, AIRT did not differ between PD and DIP patients in pRNFLT and mRT (all P values > 0.100). SNBRAI did not correlate with AIRT of pRNFL or mRT in PD and DIP patients (all P values > 0.060). CONCLUSION: Our study showed no benefit of retinal thickness and interocular asymmetry measurements using OCT for distinguishing PD from DIP in the early stages. Additional investigations are needed for confirmation.

Neural and dopaminergic correlates of fatigue in Parkinson's disease.

Fatigue is one of the most common non-motor symptoms in Parkinson's disease (PD). Despite its clinical importance, there are few studies on the cause or mechanism of fatigue. Our aim was to find brain areas related to fatigue and to explore the association between striatal dopaminergic dysfunction and fatigue. We consecutively screened forty-seven patients with de novo PD from 2012 to 2017 and enrolled 32 patients. The gray matter volumes, white matter tracts, and striatal dopaminergic activity between PD without fatigue and with fatigue were compared. The correlation between fatigue and striatal dopaminergic activity was also analyzed. Our data did not show any significant difference in gray matter volume between PD without fatigue and with fatigue (familywise error [FWE] corrected p > 0.05) but revealed significantly higher mean fractional anisotropy (FA) values for all analyzed white matter tracts in PD with fatigue (false discovery rate [FDR] corrected p < 0.05), except left cingulum-hippocampus (CH), right superior longitudinal fasciculus, and right longitudinal fasciculus temporal part (FDR corrected p > 0.06); lower mean diffusivity (MD) values for all analyzed white matter tracts in PD with fatigue (FDR corrected p < 0.05), except in the left CH and uncinate fasciculus (FDR corrected p > 0.05). The mean radial diffusivity (RD) values, except for the left CH (FDR corrected p = 0.0576), were also significantly lower (FDR corrected p < 0.05). There was no difference in dopaminergic deficits between PD without fatigue and PD with fatigue (p > 0.50). The alteration of the white matter tract may reflect the degree of fatigue in PD. This is not true of the gray matter and striatal dopaminergic activity. These results show the possibility that white matter changes can be used as a biomarker for fatigue.

Detection of loco-regional recurrence in malignant head and neck tumors: a comparison of CT, MRI, and FDG PET-CT.

BACKGROUND: The early and accurate detection of local or regional recurrence of head and neck tumor is critically important. PURPOSE: To compare the diagnostic accuracy of contrast-enhanced computed tomography (CT), contrast-enhanced magnetic resonance imaging (MRI), and fluorodeoxyglucose (FDG) positron emission tomography (PET)-CT, alone and in combination, in detecting the locoregional recurrence of malignant head and neck tumor. MATERIAL AND METHODS: A total of 93 patients with loco-regional recurrence of malignant head and neck tumors underwent CT, MRI, and PET-CT within 30 days before surgery. CT, MRI, and PET-CT for each patient were retrospectively reviewed to determine the presence of recurrent tumors in the primary site on a patient-by-patient basis and that of regional lymph nodes on a level-by-level basis. The diagnostic accuracy of CT, MRI, and PET-CT, alone and combined, were accessed with the postoperative histopathological findings or with 12-month follow-up results as the standard of reference. RESULTS: The sensitivity/specificity/and accuracy of CT, MRI, and PET-CT for the detection of primary site recurrence was 89.9/85.7/89.3%, 94.9/85.7/93.6%, and 97.5/92.9/96.8%, respectively. The sensitivity/specificity/accuracy of CT, MRI, and PET-CT for the detection of nodal recurrence was 66.3/99.4/92.4%, 74.7/99.4/94.2%, and 85.5/94.9/93.0%, respectively. MRI + PET-CT achieved the best performance in the receiver operating characteristics curve analysis (Az value = 0.958 for primary site recurrence and 0.929 for nodal recurrence). CONCLUSION: MRI + PET-CT offered the highest diagnostic performance in the detection of loco-regional recurrence of malignant head and neck tumor, compared with CT, MRI, PET-CT, and other combinations including CT.

Scaling problem in Parkinson's disease patients with pain.

INTRODUCTION: Although pain is common in Parkinson's disease (PD), the underlying mechanism remains unknown. Scaling function and dopaminergic hypofunction may contribute to pain development because increased pain sensitivity is observed in PD and is normalized after levodopa administration. We aimed to determine whether spatial discrimination (SD) and striatal dopaminergic activity (DA) differed between PD patients with and without pain. METHODS: We divided 90 patients with drug-naïve PD into two groups based on the presence or absence of pain and compared the SD threshold (SDT). We evaluated the correlation of the SDT with pain severity in PD with pain. We also compared the DA of 48 patients and analyzed the correlation with pain severity in PD patients with pain. RESULTS: The SDTs did not differ between the two groups, but unmeasurable SDT was more frequent in PD with pain. There was a positive correlation of pain severity with the SDT of the more affected hand but no correlation with the SDT of the less affected hand. The DA did not differ between the groups. There was a negative trend of pain severity with the DA of the ventral striatum (VS) but no correlation with the other striatal subregions. CONCLUSIONS: Pain in PD may be associated with scaling dysfunction in the sensory system. The abnormal scaling function would render the PD patient hypersensitive to even mild pain. The dopamine in the VS appears to be associated with pain severity; however, the relationship of striatal dopaminergic deficits with pain occurrence requires further investigation.

Role of 18F-FDG PET/CT in the diagnosis of clinically suspected Marjolin ulcer.

OBJECTIVE: The purpose of our study is to retrospectively determine the diagnostic role of (18)F-FDG PET/CT at the primary lesion site in burned patients with chronic nonhealing ulcers who are suspected of having Marjolin ulcers. MATERIALS AND METHODS: Thirty-three burn scar contractures with nonhealing chronic ulcer in 28 patients were included in this study. The lesions were sorted into two groups: 22 squamous cell carcinomas and one basal cell carcinoma were assigned to group 1 (Marjolin ulcer), and 10 lesions of chronic ulcer with inflammation and fibrosis were assigned to group 2. The maximum standardized uptake value (SUV(max)) and the lesion thickness and size for the two groups were evaluated. To determine the utility of PET/CT in the evaluation of invasion depth, we compared the imaging findings of PET/CT with surgical or pathologic results and the findings of additional imaging modalities, such as CT or MRI. RESULTS: The SUV(max) and the lesion thickness for group 1 were significantly higher than those for group 2 (p < 0.01 and p = 0.03, respectively). The sensitivity, specificity, and area under the receiver operating characteristic curve were 82.6%, 90%, and 0.900, respectively, for SUV(max) and 65.2%, 80%, and 0.741, respectively, for lesion thickness. PET/CT was helpful and showed quite good correlation with surgical or pathologic results in determining invasion depth. CONCLUSION: PET/CT is useful in differentiating Marjolin ulcer from benign inflammatory conditions of chronic nonhealing ulcer in burn scars. It is also useful in the evaluation of the depth of invasion in Marjolin ulcer cases.

MR imaging findings of high-voltage electrical burns in the upper extremities: correlation with angiographic findings.

BACKGROUND: A high-voltage electrical burn is often associated with deep muscle injuries. Hidden, undetected deep muscle injuries have a tendency for progressive tissue necrosis, and this can lead to major amputations or sepsis. MRI has excellent soft tissue contrast and it may aid in differentiating the areas of viable deep muscle from the areas of non-viable deep muscle. PURPOSE: To describe the MR imaging findings of a high-voltage electrical burn in the upper extremity with emphasis on the usefulness of the gadolinium-enhanced MRI and to compare the MR imaging findings with angiography. MATERIAL AND METHODS: We retrospectively reviewed the imaging studies of six patients with high-voltage electrical burns who underwent both MRI and angiography at the burn center of our hospital from January 2005 to December 2009. The imaging features were evaluated for the involved locations, the MR signal intensity of the affected muscles, the MR enhancement pattern, the involved arteries and the angiographic findings (classified as normal, sluggish flow, stenosis or occlusion) of the angiography of the upper extremity. We assessed the relationship between the MR imaging findings and the angiographic findings. RESULTS: The signal intensities of affected muscles were isointense or of slightly high signal intensity as compared with the adjacent unaffected skeletal muscle on the T1-weighted MR images. Affected muscles showed heterogenous high signal intensity relative to the adjacent unaffected skeletal muscle on the T2-weighted images. The gadolinium-enhanced T1-weighted images showed diffuse inhomogeneous enhancement or peripheral rim enhancement of the affected muscles. The angiographic findings of the arterial injuries showed complete occlusion in three patients, severe stenosis in two patients and sluggish flow in one patient. Of these, the five patients with complete occlusion or severe stenosis on angiography showed non-perfused and non-viable areas of edematous muscle on MRI. On the other hand, one patient with sluggish flow on angiography showed a perfused and viable area of edematous muscle on MRI. CONCLUSION: Gadolinium-enhanced MRI is a useful non-invasive imaging modality to detect the site and extent of hidden, undetected deep muscle injuries in a group of patients with high-voltage electrical burns of the upper extremities.

Diagnostic value of CT density in patients with diffusely increased FDG uptake in the thyroid gland on PET/CT images.

OBJECTIVE: The purpose of this article is to determine the diagnostic significance of thyroid density as determined by CT in patients with a diffuse hypermetabolic thyroid on PET/CT images. SUBJECTS AND METHODS: One hundred twelve patients were enrolled in this study, and all underwent PET/CT and a thyroid function test between August 2007 and December 2008. The 56 study patients enrolled had visible (18)F-FDG uptake in the thyroid, whereas the 56 control subjects had no visible FDG uptake. Maximum standardized uptake values (SUV(max)), Hounsfield units, thyroid-stimulating hormone levels, free thyroxine levels, and visual assessments of thyroid CT densities (grades 0-2) were evaluated. Analyses were performed to identify variables that differed between patients and control subjects and to examine relationships between Hounsfield unit and SUV(max) values, free thyroxine level, or thyroid-stimulating hormone level. RESULTS: Mean Hounsfield unit and SUV(max) values were significantly different between the two groups (p < 0.001), and SUV(max) values were found to be significantly different between grades. Free thyroxine and thyroid-stimulating hormone levels were also significantly different between thyroid density grades 0 and 2 (p < 0.001). A strongly negative relationship was found between Hounsfield units and SUV(max) values (r = 0.75), whereas Hounsfield units were found to be weakly correlated with free thyroxine level (r = 0.36) and thyroid-stimulating hormone level (r = -0.33). CONCLUSION: CT density is closely related to FDG uptake, and low CT density coupled with high FDG uptake suggests a change in thyroid tissue composition and is probably helpful for assessing the disease process and thyroid function of patients whose thyroid show diffuse FDG uptake on FDG PET/CT.

Visual and quantitative comparison of (18)F-fluorodeoxyglucose PET/CT findings in the detection of pelvic tumor recurrence in colorectal cancer.

OBJECTIVE: This study aimed to visually and quantitatively compare (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) imaging in determining postoperative pelvic recurrence in colorectal cancer (CRC). MATERIALS AND METHODS: This retrospective analysis focused on 96 patients (age: mean 62.6 ± 10.5) with surgically resected CRC (time interval after surgery: 19.2 ± 20.4 months). The standard of reference was histopathologic confirmation (n = 27) or imaging follow-up (n = 69). For visual analysis, three independent nuclear physicians interpreted the PET/CT findings. For the quantitative analysis, the normalized standardized uptake values (nSUVs: nSUVmax, nSUVpeak, nSUVmean) were calculated by applying the mean SUV of a normal liver. We evaluated the areas under the receiver operating characteristic curves (AUCs) for all the quantitative parameters. RESULTS: Of the 96 patients, 49 showed pelvic recurrence and 47 revealed no tumor recurrence. Sensitivity and specificity were 85.7 and 80.9 %, respectively, for visual analysis, and 65.3 and 83.0 %, respectively, for quantitative analysis. The AUC (0.766, CI: 0.668-0.846) of nSUVmax was largest comparing nSUVpeak and nSUVmean values, without significant difference (p value >0.316). Sensitivity of lesion detection was superior in visual analysis (p value = 0.02), but specificity was not significantly different (p = 0.80). After inclusive and exclusive combinations, sensitivity and specificity were slightly increased to 89.8 % (p = 0.54) and 91.5 % (p = 0.14), respectively. CONCLUSIONS: Visual interpretation was superior to quantitative analysis in pelvic tumor recurrence in CRC. Though it was possible to improve diagnostic performance through combinatory analysis, the effect was not statistically significant.

Usefulness of stent implantation for treatment of intracranial atherosclerotic stenoses.

PURPOSE: We evaluated the usefulness of intracranial stent implantation for treating patients with atherosclerotic stenosis and with recurrent, ischemic, neurological symptoms despite having undergone medical therapy. MATERIALS AND METHODS: Between March 2004 and April 2010, we attempted intracranial, stent-assisted angioplasty in 77 patients with 85 lesions (anterior circulation 73 cases, posterior circulation 12 cases) and who had ischemic neurological symptoms with more than 50% major cerebral artery stenosis. We analyzed the results regarding the technical success rate, complication rate, and restenosis rate during the mean 29.4 month follow-up period. RESULTS: Intracranial stent implantation was successfully performed in 74 cases (87.1%). In nine cases among the 11, failed cases, stent implantation failure was due to the tortuosity of the target vessel. One patient experienced middle cerebral artery rupture during the procedure, and we embolized the vessel using a microcoil. Five patients developed cerebral infarction in three weeks after the procedure, three of whom improved using conservative management, although the other, two patients expired. The mean number of residual stenoses decreased from 72.3% to 14.7%. Three patients demonstrated significant in-stent restenosis, i.e. more than 50%, during the follow-up period. CONCLUSION: As stent-assisted angioplasty in intracranial, atherosclerotic stenosis is effective and relatively safe, it can be considered as an alternative treatment for patients with recurrent, ischemic, neurologic symptoms despite having undergone medical therapy.

Usefulness of Bremsstrahlung Images after Intra-arterial Y-90 Resin Microphere Radioembolization for Hepatic Tumors.

PURPOSE: Y-90 resin microsphere radioembolization is used to treat inoperable hepatic tumors. After injection of Y-90 resin microsphere, the only method to visualize the distribution of Y-90 is the scintigraphic imaging of bremsstrahlung radiation. The purpose of this study was to evaluate the characteristics and usefulness of bremsstrahlung imaging in Y-90 resin microsphere treatment. METHODS: Twenty patients (22 administrations) underwent intra-arterial Y-90 resin microsphere treatment. For pre-treatment planning, images of Tc-99m albumin macroaggregate (MAA) arterial injection and hepatic contrast angiography were obtained. Post-treatment bremsstrahlung images were taken and compared with pre-treatment images. The extrahepatic activity was evaluated on bremsstrahlung images. To correlate the size and vascularity of the tumors with tumor visualization on bremsstrahlung images, the individual tumors were grouped according to visualization on each image and compared with one another by size and tumor-to-normal ratio. RESULTS: All post-therapeutic bremsstrahlung images showed similar contours of the liver with pre-treatment angiography. No extrahepatic activity was seen in all cases. The visualized tumors on bremsstrahlung images were significantly larger than the non-visualized tumors. Tumor-to-normal ratios of the visualized tumors on bremsstrahlung images were significantly higher than those of the non-visualized tumors. CONCLUSIONS: Bremsstrahlung images after intra-arterial Y-90 resin microsphere treatment are useful in evaluating the intrahepatic distribution of radioisotope and detecting possible extrahepatic activity.

[Analysis of patients with positive acid-fast bacilli culture and negative T-SPOT.TB results].

BACKGROUND: T-SPOT.TB is a sensitive test that detects interferon-gamma producing T-cells in tuberculosis patients following stimulation with tuberculosis-specific antigens. Our study was aimed to investigate the possible causes of false negative results of the test by analyzing the patients with positive acid-fast bacilli (AFB) culture and negative T-SPOT.TB results. METHODS: We investigated 138 patients with positive AFB culture results reported between January 2009 and April 2010. Medical records of these patients were reviewed for the results of T-SPOT.TB test, AFB culture, PCR for Mycobacterium tuberculosis (TB-PCR), chest X-ray, drug treatment, etc. Diagnosis of tuberculosis was confirmed by positive TB-PCR or identification of Mycobacterium tuberculosis (MTB). Sensitivity of T-SPOT.TB test was calculated and the possible causes of AFB culture positive and T-SPOT.TB negative results were analyzed. RESULTS: T-SPOT.TB test was performed in 63 of the 138 patients with AFB culture positive results. Fifty-six (88.9%) were positive and 7 patients (11.1%) were negative on T-SPOT.TB test. Of these 7 negative cases, 4 were confirmed as nontuberculous mycobacteria (NTM), 2 were suspected as NTM and diagnosis could not be confirmed in 1. Six of these 7 patients were over 70 yr old and 6 patients had lymphocytopenia. T-SPOT.TB negative results were not observed in any of the 44 patients confirmed to have active tuberculosis (sensitivity 100%). CONCLUSIONS: Our results suggest that T-SPOT.TB test is very sensitive for diagnosing active tuberculosis. NTM may be the main cause of AFB culture positive and T-SPOT.TB negative results, but MTB infection in immunocompromised patients also has to be considered.

Sonographic appearance of a tear of the lateral internal oblique muscle resulting from cough.

During forced respiratory movement such as coughing, complications can occur, including abdominal muscle rupture. We report a case of spontaneous tear of the internal oblique muscle resulting from violent cough diagnosed by sonography. The physiology of cough and the possible pathophysiologic mechanism of this case is discussed.