Two Cases of Mechanical Thrombectomy in Patients with Fenestration of the M1 Segment of the Middle Cerebral Artery.

M1 fenestration of the middle cerebral artery is rare. We present two patterns of acute thromboembolic conditions in M1 fenestrations treated with mechanical thrombectomy. Case 1 was a male in his 60s presenting with right hemiparesis and aphasia. Angiography showed acute left M1 proximal occlusion; the first direct aspiration revealed two parallel routes, and the second aspiration achieved complete recanalization of the left M1 fenestration. Case 2 was a male in his 70s presenting right hemiparesis and aphasia. Angiography revealed a sudden stair-like narrowing of the left M1 in the intermediate part, and a retrograde blood flow cavity was observed on the upper side of the distal part. Mechanical thrombectomy was performed to diagnose the upper limb occlusion of the left M1 fenestration, and successful recanalization was achieved through direct aspiration. Anatomical variations, such as fenestration, should be considered to reduce complication risks.

Orbitofrontal artery arising from a hairpin turn in type 1 persistent primitive olfactory artery: a possible new variant (type 6).

PURPOSE: To describe a case of a possible new variant of persistent primitive olfactory artery (PPOA). CASE REPORT: A 93-year-old man with left hemiparesis and dysarthria underwent cranial magnetic resonance (MR) imaging and MR angiography using a 3-T scanner. MR imaging showed an acute infarction at the right precentral gyrus. MR angiography showed no steno-occlusive lesions, but the distal A1 segment of the left anterior cerebral artery (ACA) took an extreme anterior course and made a hairpin turn, connecting to the A2 segment, which is indicative of type 1 PPOA. In addition, there was a faintly visualized small artery arising from the hairpin turn. Subsequent computed tomography (CT) angiography showed that the hairpin turn had a mildly dilated arterial lumen, and an extremely tortuous orbitofrontal artery arose from the hairpin turn. DISCUSSION: There are five types of PPOA. Type 1 is most common, and usually no arterial branch arises from the hairpin turn, except for in type 3 PPOA, which has a branch continuing to the anterior ethmoidal artery arising from the hairpin turn. Using MR and CT angiography, we diagnosed a case of type 1 PPOA associated with the orbitofrontal artery arising from a hairpin turn. A similar previously reported case was diagnosed using catheter angiography. CONCLUSION: The present case may be a new variant (type 6) of PPOA. Because the orbitofrontal artery was relatively small in caliber and its proximal segment extremely tortuous, CT angiography had superior utility to MR angiography for demonstrating this variation.

Multiple cerebral arterial variations incidentally detected by magnetic resonance angiography: a case report.

We herein report a case of multiple variations, including (1) anterior communicating artery duplication, (2) accessory anterior cerebral artery (ACA), (3) distal origin right accessory middle cerebral artery (MCA) with bifurcation, (4) proximal origin left accessory MCA with bifurcation, (5) right superior cerebellar artery (SCA) duplication, and (6) left SCA early bifurcation. These variations were found incidentally by magnetic resonance (MR) angiography. Volume-rendering images of MR angiography were more useful than maximum-intensity-projection images for identifying these variations, especially bilateral accessory MCAs, which were superimposed with the A1 segment of the ACAs and the M1 segment of the MCAs.

Endovascular Treatment for Acute Ischaemic Stroke Caused by Vertebral Artery Dissection: A Report of Three Cases and Literature Review.

Vertebrobasilar artery dissection is an uncommon cause of acute ischaemic stroke (AIS). Optimal endovascular management has not been established. This study aimed to share our experience with endovascular reperfusion therapy for vertebrobasilar artery occlusion due to vertebral artery dissection (VAD). We retrospectively reviewed 134 consecutive patients with AIS who received urgent endovascular reperfusion therapy between November 2017 and November 2019. Three patients diagnosed with VAD were investigated. The evaluation included mechanisms of vertebrobasilar artery occlusion due to VAD, variations in endovascular procedures, and functional outcomes. Dissections at the V3, V4 and extension of V3 to V4 segments were seen in one patient each. The mechanism of AIS was different in each patient: occlusion of the distal non-dissected artery due to an embolus from the dissection site (distal occlusion), haemodynamic collapse of the entire vertebrobasilar artery system due to the arterial dissection itself (local occlusion), or coexistence of distal occlusion and local occlusion (tandem occlusion). The endovascular reperfusion therapy was performed corresponding to the abovementioned mechanisms: mechanical thrombectomy for distal occlusion, stenting for local occlusion, and a combination of thrombectomy and stenting for tandem occlusion. In all three patients, effective recanalization and functional independence (modified Rankin Scale scores of 0-2 at 90 days after the onset) were achieved. Endovascular treatment corresponding to the individual mechanism of AIS may improve patient outcomes.

Clinical Usefulness of 18F-FDG PET/CT for Staging Cancer of the External Auditory Canal.

OBJECTIVE: Our objective was to evaluate the clinical usefulness of positron emission tomography/computed tomography using 2-deoxy-2-[F-18]fluoro-D-glucose (FDG-PET/CT) for staging cancer of the external auditory canal (EAC). STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. PATIENTS: Twenty-three patients (seven men, 16 women, mean age of 59.6-year-old) who underwent FDG-PET/CT and high-resolution CT within 1 month for staging cancer of the EAC between July 2006 and December 2014 were enrolled in this study. INTERVENTION: FDG-PET/CT, high-resolution CT. MAIN OUTCOME MEASURES: Sensitivity, specificity, and accuracy for diagnosing nodal metastases. RESULTS: Most primary tumors were FDG-avid and maximum standardized uptake values were 7.72 ±â€Š3.04 and 9.06 ±â€Š3.94 for the early (60 min) and delayed (120 min) phases of FDG-PET/CT, respectively. FDG-PET/CT was capable of detecting small nodal metastases (short axis <10 mm), and patient-based sensitivity, specificity, and accuracy of FDG-PET/CT for the N staging were 71.4, 81.3, and 78.3%, respectively. There were no patients with distant metastases in our cohort. Compared with the combination of clinical examination and conventional imaging methods, additional FDG-PET/CT resulted in a change in the surgical strategy in five patients (21.7%). CONCLUSIONS: Most primary cancers of the EAC are FDG-avid, and FDG-PET/CT is useful for detecting small nodal metastases, followed by the change in the surgical strategy.

Predictors of primary lung cancer in a solitary pulmonary lesion after a previous malignancy.

OBJECTIVE: A solitary pulmonary lesion in patients with a history of malignancy may be either primary lung cancer or a metastatic lung tumor or benign nodule. We retrospectively examined the preoperative predictive factors for determining the type of pathology. METHODS: We used an exact logistic regression analysis to identify radiological and clinical predictors of primary lung cancer. The study included 187 patients who underwent pulmonary resection for a solitary pulmonary lesion and had received previous treatment for a malignancy. RESULTS: There were 107 patients with primary lung cancer, 74 with metastatic lung tumors, and 6 with benign lesions. The previous malignancy included colorectal cancer in 71 patients. A disease-free interval exceeding 5 years and ground-glass opacity were found in 27.0% (20/74) and 1.4% (1/74) of metastatic lung tumors, respectively. Multivariate logistic regression analysis demonstrated that spiculation [adjusted odds ratio (a-OR), 1.74; 95% confidence interval (CI), 1.09-2.86], pleural indentation (a-OR 1.99, 95% CI 1.24-3.29), and ground-glass opacity (a-OR 5.28, 95% CI 2.61-13.1) on high-resolution computed tomography, maximum standardized uptake value (a-OR 1.14, 95% CI 1.02-1.29), current and former smokers (a-OR 1.96, 95% CI 1.21-3.30), and previous malignancy other than colorectal cancer (a-OR 2.02, 95% CI 1.26-3.37) were associated with primary lung cancer. CONCLUSIONS: A combination of radiological findings, smoking history, and type of previous malignancy can improve the ability to predict primary lung cancer in the presence of a solitary pulmonary lesion that appears after previous treatment for a malignancy.

Detection of unexpected emergency diseases using FDG-PET/CT in oncology patients.

PURPOSE: To evaluate the frequency of emergency diseases that were detected unexpectedly using FDG-PET/CT. MATERIALS AND METHODS: Interpretation reports for 11,663 FDG-PET/CT studies in our hospital were retrospectively reviewed. Patients with major emergency diseases were extracted according to the following exclusion criteria: (1) relevant findings had been recognized prior to the PET/CT; (2) an intervention or operation that may have been relevant to the present findings was performed within 1 month prior to the PET/CT; and (3) the clinical course could not be investigated sufficiently (e.g., in cases where the patients were introduced from other hospitals). RESULTS: Forty-one patients (0.35%) with unexpected emergency diseases were identified. The most frequent disease was pneumothorax (8 patients), followed by chronic subdural hematoma (CSH) (7 patients), ureteral stone (7 patients), and abdominal aortic aneurysm (AAA) with a dirty fat sign or a high-attenuation crescent sign visualized on CT (4 patients). Nine patients (2 pneumothorax, 3 CSH, 1 cerebral hemorrhage, 1 acute cholecystitis, 1 acute pancreatitis, and 1 acute appendicitis) were hospitalized and/or underwent therapeutic intervention within 1 week after the PET/CT. CONCLUSION: Although rare, an unexpected emergency disease requiring urgent management can be detected using FDG-PET/CT in oncology patients.

Seventy FDG-PET/CT Cases in Which Nuclear Medicine Physicians Suspected Lymphoma: How Reliable Are We?

OBJECTIVES: To validate the reliability of nuclear medicine physicians in diagnosing lymphoma using positron emission tomography/computed tomography using 2-deoxy-2-[18F]fluoro-D-glucose (FDG-PET/CT) and to determine findings that reliably suggest lymphoma. METHODS: Seventy patients suspected of having lymphoma using FDG-PET/CT were enrolled in this retrospective study. Two nuclear medicine physicians read all the interpretation reports and graded the degree of suspicion by consensus (3: definitely suspicious, 2: probably suspicious, and 1: possibly suspicious). The following factors were also investigated for each patient: maximum standardized uptake value (SUVmax) of the lesions, serum level of soluble interleukin-2 receptor (sIL-2R), and the presence of splenic FDG uptake higher than that of the liver. RESULTS: The study group consisted of 34 lymphomas, 18 other malignancies, and 18 benign lesions according to histopathological diagnosis. No patient with a Grade 1 degree of suspicion was diagnosed as lymphoma. SUVmax and the serum level of sIL-2R could not distinguish lymphoma from other diseases. Of the 11 patients who presented with elevated splenic FDG uptake, 10 were diagnosed as having lymphoma. CONCLUSION: When the degree of suspicion by nuclear medicine physicians is low, the possibility of lymphoma is also low. On the other hand, elevated splenic FDG uptake may suggest lymphoma.

Pathogenesis and FDG-PET/CT findings of Epstein-Barr virus-related lymphoid neoplasms.

Epstein-Barr virus (EBV) is one of the most common viruses, infecting more than 90% of the adult population worldwide. EBV genome is detected in some lymphoid neoplasms. Not only their histopathological subtypes, but also their backgrounds and their clinical courses are variable. A number of B-cell lymphoproliferative disorders associated with the immunocompromised state are related to EBV infection. The incidences of these disorders have been increasing along with generalization of organ transplantations and use of immunosuppressive treatments. Furthermore, some EBV-positive lymphoma can also occur in immunocompetent patients. While evaluating patients with generalized lymphadenopathy of unknown cause by positron emission tomography/computed tomography with 2-deoxy-2-[18F]fluoro-D-glucose (FDG-PET/CT), the possibility of lymphoid neoplasms should be considered in some patients, and a careful review of the background and previous history of the patients is necessary. In this review article, we describe the pathogenesis of EBV-related lymphoid neoplasms and then present FDG-PET/CT images of representative diseases. In addition, we also present a review of other EBV-related diseases, such as infectious mononucleosis and nasopharyngeal carcinoma.

Optimization of left adrenal vein sampling in primary aldosteronism: Coping with asymmetrical cortisol secretion.

We evaluated the influence of catheter sampling position and size on left adrenal venous sampling (AVS) in patients with primary aldosteronism (PA) and analyzed their relationship to cortisol secretion. This retrospective study included 111 patients with a diagnosis of primary aldosteronism who underwent tetracosactide-stimulated AVS. Left AVS was obtained from two catheter positions - the central adrenal vein (CAV) and the common trunk. For common trunk sampling, 5-French catheters were used in 51 patients, and microcatheters were used in 60 patients. Autonomous cortisol secretion was evaluated with a low-dose dexamethasone suppression test in 87 patients. The adrenal/inferior vena cava cortisol concentration ratio [selectivity index (SI)] was significantly lower in samples from the left common trunk than those of the left CAV and right adrenal veins, but this difference was reduced when a microcatheter was used for common trunk sampling. Sample dilution in the common trunk of the left adrenal vein can be decreased by limiting sampling speed with the use of a microcatheter. Meanwhile, there was no significant difference in SI between the left CAV and right adrenal veins. Laterality, determined according to aldosterone/cortisol ratio (A/C ratio) based criteria, showed good reproducibility regardless of sampling position, unlike the absolute aldosterone value based criteria. However, in 11 cases with autonomous cortisol co-secretion, the cortisol hypersecreting side tended to be underestimated when using A/C ratio based criteria. Left CAV sampling enables symmetrical sampling, and may be essential when using absolute aldosterone value based criteria in cases where symmetrical cortisol secretion is uncertain.

Residual FDG uptake of primary thyroid lymphoma after treatment may overestimate residual lymphoma.

OBJECTIVE: To assess 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) images in primary thyroid lymphoma (PTL) patients before and after treatment. METHODS: We conducted a retrospective review of data for ten patients (four men, six women) of mean age 65 (range 48-88) years, with histopathologically confirmed malignant thyroid lymphoma who underwent pre-treatment and post-treatment 18F-FDG PET between January 2005 and December 2014. Thyroid uptake was assessed by the 5-point scale score based on maximum intensity projection images. RESULTS: Four of the ten patients were judged to have a complete metabolic response (scores 1-3) and four to have a partial metabolic response (PMR; scores 4-5). Three of the four PMR patients had a good outcome with a treatment-free interval and overall survival of at least 53.0 months, although two of these three patients showed residual FDG uptake in the thyroid for more than 2 years after completion of treatment. Two of the ten patients were considered to have progressive metabolic disease. CONCLUSIONS: In patients with PTL, residual FDG uptake in the thyroid after treatment that corresponds to a PMR may not always indicate a poor outcome.

Embolosclerotherapy by the Transvenous Approach for Lower Extremity Arteriovenous Malformation in Cowden Syndrome: A Case Report.

A 69-year-old female with Cowden syndrome presented with pain at rest in the right leg. Arteriovenous malformations (AVMs) of the right lower extremity were detected by computed tomography and magnetic resonance imaging. Angiography indicated arteriolovenous fistulae, which were initially treated using a transarterial approach with minimal therapeutic effect. In contrast, excellent outcomes were achieved with a transvenous approach using coil embolization and liquid sclerotherapy for the venous component of the nidus. At 15 months after embolosclerotherapy, no angiographic evidence of AVM recurrence was noted. Embolosclerotherapy by the transvenous approach for AVM in Cowden syndrome was a useful therapeutic strategy for arteriolovenous fistulae.

Anterograde Degeneration of the Nigrostriatal Pathway Visualized by 123I-FP-CIT SPECT in a Patient With Artery of Percheron Infarction.

I-FP-CIT SPECT is widely used for diagnosis in patients with parkinsonism. Vascular parkinsonism usually has nonspecific findings from normal uptake to radiotracer decrease in the infarcted region. Infarction of the substantia nigra has been reported as a rare cause of vascular parkinsonism. We present a case of artery of Percheron infarction involving the substantia nigra unilaterally with ipsilateral reduction of striatal uptake on I-FP-CIT SPECT, suggesting anterograde degeneration of the nigrostriatal pathway. Infarction of the substantia nigra should be considered in cases of decreased striatal uptake with marked laterality on I-FP-CIT SPECT.

Breast Shape Change Associated with Aging: A Study Using Prone Breast Magnetic Resonance Imaging.

BACKGROUND: Objective assessments of the shapes of various parts of the body can be made using images acquired with multidetector row computed tomography or magnetic resonance imaging. These images can be useful for understanding the changes in body shape that accompany aging. METHODS: Data from our previous bilateral prone breast magnetic resonance imaging studies between March and August 2013 were analyzed. Breast size and volume were measured using these images. All the patients included in the study were divided into a younger group (54 years or younger) and an older group (55 years or older). The values were compared between the 2 groups using paired t tests. Regarding variables that were shown to have a significant difference between the 2 groups, the relationships between age and the values of the variables were evaluated using the Pearson correlation coefficient. RESULTS: A total of 90 breasts, 45 breasts in the younger group and 45 breasts in the older group, were used for analysis. There was a significant correlation between age and craniocaudal nipple deviation (R = -0.38; P < 0.001) and between age and the measured breast volume (R = 0.26; P < 0.05). There was also a significant correlation between the measured breast volume and the craniocaudal nipple deviation (R = -0.48; P < 0.001). CONCLUSIONS: A caudal deviation of the nipple and an increase in volume were age-related changes in breast shape. These 2 variables were also correlated.

Comparison of FDG-PET/CT images between chronic renal failure patients on hemodialysis and controls.

The whole-body 2-deoxy-2-[(18)F]fluoro-D-glucose (FDG) distribution in chronic renal failure (CRF) patients on hemodialysis would be different from that in subjects with normal renal function, because they lack urinary FDG excretion and remain in a constant volume overload. We evaluated the difference in the physiological uptake pattern of FDG between chronic renal failure patients on hemodialysis and control subjects. The subjects for this retrospective study consisted of 24 chronic renal failure patients on hemodialysis (HD group) and 24 age- and sex-matched control subjects (NC group). Standardized uptake values normalized by the body weight (SUVbw), ideal body weight (SUVibw), lean body mass (SUVlbm), and body surface area (SUVbsa) in the cerebellum, lungs, liver, gluteal muscles and subcutaneous fat, spleen, thoracolumbar spine, thoracic and abdominal aorta, and right atrium were calculated in positron emission tomography/computed tomography (PET/CT) images. SUVbw in the gluteal muscles, subcutaneous fat, spleen and right atrium was significantly higher in the HD group as compared to that in the NC group (p < 0.05; unpaired t test). In addition, SUVibm, SUVlbm, as well as SUVbsa in the abdominal aorta were significantly higher in the HD group as compared to those in the NC group (p < 0.05; unpaired t test). In conclusion, as compared to normal subjects, chronic renal failure patients on hemodialysis show significantly higher physiological FDG uptake in the soft tissues, spleen and blood pool.

Is 18F-FDG PET/CT useful for distinguishing between primary thyroid lymphoma and chronic thyroiditis?

PURPOSE: This study aims to investigate the usefulness of (18)F-FDG PET/CT for distinguishing between primary thyroid lymphoma (PTL) and chronic thyroiditis. METHODS: We retrospectively reviewed the data of 196 patients with diffuse (18)F-FDG uptake of the thyroid gland and enrolled patients who were diagnosed as having PTL or chronic thyroiditis based on the medical records, pathological findings, and laboratory data. The enrolled patients comprised 10 PTL patients (M/F = 4:6) and 51 chronic thyroiditis patients (M/F = 8:43). Images had been acquired on a PET/CT scanner at 100 minutes after intravenous injection of (18)F-FDG. RESULTS: The PTL group consisted of 7 patients with diffuse large B-cell lymphoma (DLBCL) and 3 with mucosa-associated lymphoid tissue (MALT) lymphoma. The maximum standardized uptake value (SUV(max)) was significantly higher in the PTL group than that in the chronic thyroiditis group (25.3 ± 8.0 and 7.4 ± 3.2, P < 0.001). On the other hand, the CT density (Hounsfield unit: HU) was significantly lower in the PTL group than that in the chronic thyroiditis group (46.1 ± 7.0 HU and 62.1 ± 6.9 HU, P < 0.001). Within the PTL group, the SUV(max) was significantly higher in the cases of DLBCL than in those of MALT lymphoma (29.0 ± 6.4 and 16.7 ± 2.3, P = 0.017). CONCLUSIONS: The SUV(max) was significantly higher and the CT density was significantly lower in PTL as compared with those in chronic thyroiditis. Thus, (18)F-FDG PET/CT may be useful for distinguishing between PTL and chronic thyroiditis.

Long-term changes of aortic 18F-FDG uptake and calcification in health-screening subjects.

BACKGROUND: We investigated long-term changes in aortic (18)F-fluorodeoxyglucose ((18)F-FDG) uptake and calcification in health-screening subjects and their relation with atherogenic risk factors. METHODS AND RESULTS: A total of 94 consecutive subjects (72 men, 22 women; age 47-85 years, mean 57.9 years) participating in a health-screening protocol were evaluated retrospectively. All subjects had follow-up PET/CT scans 3.0-5.8 years (mean 4.1 years) later. We measured (18)F-FDG uptake (maximum SUV) and calcium score (Agatston score) of the ascending, descending thoracic and infrarenal abdominal aorta on PET/CT images. (18)F-FDG uptake and calcium score of the whole aorta (FUWA and CSWA) increased significantly in the follow-up study compared with the initial study (p = 0.02 and p < 0.0001, respectively). Multiple regression analysis showed that the change in FUWA per year was significantly associated with visceral fat area, while the change of CSWA per year was significantly associated with age and smoking habit. The degrees of (18)F-FDG uptake and calcium score increases were significantly greater in the abdominal aorta than in the thoracic aorta (p = 0.05 and p < 0.0001, respectively). CONCLUSIONS: Our data demonstrated the longitudinal progressions of vascular inflammation and calcification of health-screening subjects. Inflammation and calcification were observed to progress significantly faster in the abdominal aorta than in the thoracic aorta. The progressions of vascular inflammation and calcification may be associated with different atherogenic risk factors.