Pembrolizumab-Associated Pneumonitis Resembling Lymphangitic Carcinomatosis in a Melanoma Patient.

ABSTRACT: In recent years, many articles have described the adverse events associated with immune checkpoint inhibitors. We report the case of a 63-year-old woman with bilateral lung shadows after 1-year pembrolizumab immunotherapy following surgery for the right-foot melanoma because of positive sentinel lymph nodes. Follow-up 18 F-FDG PET/CT demonstrated bilateral diffuse mass-like peribronchovascular opacities with marked FDG uptake. Clinically, melanoma metastases with lymphangitic spread were suspected, and bronchoscopy was performed, although no evidence of malignancy was found. The lung shadow was mostly resolved after steroid treatment. Pembrolizumab-induced pneumonitis can be a mimicker of melanoma metastasis with lymphangitic spread.

Steroids May Be Associated With Extensive Skeletal Muscle Uptake of 18 F-FDG.

PURPOSE: The possibility of steroid administration inducing the extensive skeletal muscle uptake (ESMU) of FDG in PET scans was investigated. METHODS: From 8923 consecutive 18 F-FDG PET/CT scans taken at our hospital, 23 scans (15 patients) met adult age and ESMU-positive inclusion criteria. Among the 15 patients, 13 with both ESMU-positive and -negative scans were examined for association with steroid administration. RESULTS: Extensive skeletal muscle uptake was associated with a history of steroid administration ( χ2 test: P = 0.001). Notably, 20 ESMU-positive scans and 11 ESMU-negative scans were significantly different, with 0 to 95 days (median, 18.5 days) and 0 to 708 days (median, 319.0 days) since the last steroid administration, respectively (Mann-Whitney U test, P = 0.003). A significant correlation was observed between mean skeletal muscle SUV max and the number of days since the last steroid administration (Spearman rank correlation coefficient, ρ = -0.501, P = 0.004). Specifically, the degree of ESMU tended to decrease over time, after steroid administration. From multiple regression analysis, the number of days since the last steroid administration was significantly associated with mean SUV max ( P = 0.007), but the blood glucose level was not significant ( P = 0.204), revealing that the number of days since the last steroid administration was an independent risk factor. Multicollinearity was low (the variance inflation factor was 1.007 for both the number of days since the last steroid administration and blood glucose levels). CONCLUSIONS: Steroid administration within months before PET may be one cause of ESMU.

Dynamic contrast-enhanced MRI and sequential CT findings of metaplastic breast carcinoma in neurofibromatosis type 1: A case report.

Metaplastic breast carcinoma in neurofibromatosis type 1 is extremely rare. There are few reports about dynamic contrast-enhanced MRI findings and sequential CT findings of metaplastic breast carcinoma in neurofibromatosis type 1. Herein, we report imaging findings, including dynamic contrast-enhanced MRI and sequential CT, of metaplastic breast carcinoma in an 82-year-old woman with neurofibromatosis type 1. Short tau inversion recovery image revealed an oval mass with a circumscribed margin that exhibited moderate intensity with partially hyperintense area inside, and T1-weighted imaging revealed a spotty hyperintense area. The solid component of the mass showed heterogeneous enhancement and the time-intensity curve had a fast/washout pattern with restricted diffusion. In addition, multiple neurofibromas were observed. Sequential CT revealed that the diameter of the mass doubled in 3 months without apparent lymph node metastasis. Because detection of metaplastic breast carcinoma in neurofibromatosis type 1 tends to be delayed due to multiple neurofibromas, characteristic MRI findings suggestive of metaplastic breast carcinoma and sequential CT findings are important for early treatment of metaplastic breast carcinoma in patients with neurofibromatosis type 1.

Vessel wall MR imaging in neuroradiology.

Vessel wall MR imaging (VW-MRI) has been introduced into clinical practice and applied to a variety of diseases, and its usefulness has been reported. High-resolution VW-MRI is essential in the diagnostic workup and provides more information than other routine MR imaging protocols. VW-MRI is useful in assessing lesion location, morphology, and severity. Additional information, such as vessel wall enhancement, which is useful in the differential diagnosis of atherosclerotic disease and vasculitis could be assessed by this special imaging technique. This review describes the VW-MRI technique and its clinical applications in arterial disease, venous disease, vasculitis, and leptomeningeal disease.

Cerebral proliferative angiopathy depicted by four-dimensional computed tomographic angiography: A case report.

Cerebral proliferative angiopathy is a rare cerebrovascular disorder characterized by diffuse abnormal vessels with intermingled brain parenchyma fed by many arteries and draining into many veins without high-flow arteriovenous shunts, which is usually confirmed by conventional digital subtraction angiography. However, dilution of the contrast medium due to the markedly increased blood flow and volume in cerebral proliferative angiopathy leads to low-contrast angiography. We report a 53-year-old man with cerebral proliferative angiopathy who underwent CT, MR imaging, MR angiography, digital subtraction angiography and 4D-CTA. The 4D-CTA exhibited abnormal vessels without early venous filling between the atrophic brain parenchyma in higher contrast than the angiography due to high spatial and time resolution, whereas the left external carotid angiography visualized the characteristic transdural supply more clearly than the 4D-CTA due to high vascular selectivity. Therefore, novel 4D-CTA and conventional angiography plays a complementary role in the accurate diagnosis of cerebral proliferative angiopathy. Taking invasiveness into account, 4D-CTA may be advantageous for the diagnosis of cerebral proliferative angiopathy based on the characteristic imaging findings.

Neonatal subpial hemorrhage along the medial side of the temporal lobe: Two case reports.

Neonatal subpial hemorrhage has been underrecognized until recently and its pathophysiology remains unclear. Advances in magnetic resonance imaging have facilitated the identification of hemorrhage within the subpial space and cohort studies recently reported its imaging and clinical features. We encountered two cases of neonatal subpial hemorrhage along the medial side of the temporal lobe. Case 1: A 1-day-old boy had repeated apneic attacks with cyanosis from 2 hours after birth at 39 weeks of gestation by vacuum extraction delivery. Computed tomography and magnetic resonance imaging showed subpial hemorrhage from the medial to caudal side of the right temporal lobe with T2 prolongation in the underlying cerebral parenchyma. Case 2: A 0-day-old boy had repeated apneic attacks with cyanosis from 3 hours after birth at 39 weeks of gestation by vaginal delivery. Subpial hemorrhage was observed from the anterior to medial side of the left temporal lobe on computed tomography and magnetic resonance imaging. On magnetic resonance imaging, the adjacent brain parenchyma showed a hyperintense signal on T2-weighted imaging. No abnormalities or signs of fetal distress were noted in the course of delivery. A mildly prolonged activated partial thromboplastin clotting time, an elevated D-dimer level, and low fibrinogen level were detected in a blood examination after birth in both cases. Both cases had subpial hemorrhage along the medial side of the temporal lobe, which suggested that an external mechanical force with fetal head molding during delivery caused subpial hemorrhage; however, other factors, including coagulopathy, may be involved in its pathophysiology.

A case of pleomorphic adenoma of the breast on dynamic contrast-enhanced MR imaging.

Pleomorphic adenoma commonly develops in the salivary gland, but rarely in the breast. The dynamic contrast-enhanced MR imaging findings of pleomorphic adenoma of the breast have not been well described. We report a 43-year-old woman with pleomorphic adenoma of the left breast. The imaging findings, including those on dynamic contrast-enhanced MR imaging, included an oval mass with a smooth margin, which consisted of solid and cystic components. The solid component was hypo-intense on T1-weighted imaging, hyper-intense on short tau inversion recovery imaging, with no apparent restricted diffusion, and had heterogeneous enhancement with dark internal septation and a fast/plateau dynamic contrast enhancement pattern. The cystic component was slightly hyper-intense on T1-weighted imaging, slightly hypo-intense on short tau inversion recovery imaging and had no apparent restricted diffusion or contrast enhancement. Together with its rarity, the similarities of imaging findings and the pathologic findings of pleomorphic adenoma of the breast to those of other tumors make accurate preoperative diagnosis difficult. Therefore, through this case report, awareness of pleomorphic adenoma of the breast on dynamic contrast-enhanced MR imaging will facilitate appropriate surgery and postoperative observation based on an accurate diagnosis.

Inverted papilloma originating from the lacrimal sac and the nasolacrimal duct with marked FDG accumulation.

Inverted papilloma originating from the lacrimal sac and the nasolacrimal duct is rare, although that in the sinonasal region is a relatively common lesion with local invasion, malignant potential and high recurrence rates after surgery. We report a 52-year-old woman with inverted papilloma of the right lacrimal sac and the nasolacrimal duct, who underwent CT, MR imaging and FDG-PET/CT preoperatively. In addition to CT and MR imaging features similar to those in previous reports, the inverted papilloma exhibited marked FDG accumulation with a maximum standardized uptake value of 7.34 and no other significant FDG accumulation was detected. In summary, our case of inverted papilloma originating from the right lacrimal sac and the nasolacrimal duct noted marked FDG accumulation on PET/CT, which enabled visualization of the localized tumor extension with no metastases.

Transportal embolization for pancreatic arteriovenous malformation via a recanalized paraumbilical vein: A case report.

A 62-year-old man with liver cirrhosis presented with deterioration of liver function. Imaging studies revealed an arteriovenous malformation (AVM), with a dilated venous space, at the pancreatic head. Transarterial embolization of the AVM, using microcoils, was performed, although many feeding arteries remained. As the transarterial embolization was incomplete, further liver function deterioration was a possibility. In fact, 1 year after the procedure, the patient was referred back to our hospital for treatment of massive ascites and liver function deterioration. Transportal embolization of the dilated venous space was performed, using microcoils via the recanalized paraumbilical vein, with no enhancement of the AVM. No complications occurred. Based on our experience, we propose transportal embolization as an effective treatment option for pancreatic AVM.

Granulocyte Colony-Stimulating Factor Administration at 1 Hour Before 18F-FDG PET Does Not Increase Bone Marrow FDG Accumulation.

ABSTRACT: A 74-year-old man with diffuse large B-cell lymphoma underwent 18F-FDG PET/CT to evaluate the response to chemotherapy. Although granulocyte colony-stimulating factor was incidentally administered 1 hour before FDG administration, bone marrow FDG accumulation did not increase compared with the previous 18F-FDG PET/CT examination without granulocyte colony-stimulating factor administration. The mean SUVmax of 12 thoracic and 5 lumbar vertebrae was 2.55 (range, 2.14-3.36) and 3.19 (range, 2.49-4.28) in the present and previous examinations, respectively.

A case of cardiac amyloidosis incidentally detected by bone scintigraphy.

A 73-year-old man with lung cancer underwent bone scintigraphy for disease staging. Diffuse myocardial technetium hydroxymethylene diphosphonate (99mTc-HMDP) uptake was incidentally found. A diagnosis of amyloid transthyretin (ATTR) cardiac amyloidosis was suspected, although the patient had no symptoms at this time. Single-photon emission computed tomography (SPECT) showed particularly strong uptake in the ventricular septum. Cardiac magnetic resonance imaging (CMR) showed widespread subendocardial and partly transmural enhancement of the left ventricular myocardium on delayed postcontrast T1-weighted images. These findings were consistent with ATTR cardiac amyloidosis. 18F-FDG uptake in the left ventricle wall was observed on PET/CT. He was finally diagnosed with ATTR by endomyocardial biopsy. There are two major subtypes of cardiac amyloidosis: ATTR amyloidosis and amyloid light-chain (AL) amyloidosis. Endomyocardial biopsy is the gold standard for diagnosis. Recently, however, several reports have shown that bone scintigraphy using a 99mTc-labelled bone-seeking agent can detect ATTR cardiac amyloidosis and differentiate it from AL amyloidosis. Bone scintigraphy may play an important role in the detection and differentiation of ATTR cardiac amyloidosis.

A case report of fetus in fetu with an aorta-like structure visualized by contrast-enhanced CT.

Fetus in fetu (FIF) is a rare congenital anomaly resulting from abnormal embyogenesis in monochorionic diamniotic twins and appears as a cystic mass containing fetus-like structures mainly in the retroperitoneum of infants. Although there is a theory that FIF is a highly differentiated teratoma, it is commonly distinguished from teratoma as a mass containing a vertebral axis with appropriate arrangement of limbs or other organs around this axis. Here we present a case of FIF with aorta-like structure visualized by contrast-enhanced computed tomography. A 5-day-old girl was pointed out a cystic mass in the abdomen by ultrasound examination. Abdominal contrast-enhanced computed tomography revealed a retroperitoneal cystic mass with spine- and limb-like bone structures and blood vessel-like elongated structures and it was confirmed as FIF by surgery. The presence of major vascular structures along the skeletal axis is clearly different from teratoma and suggests that it occurred as an embryo and underwent some stage of development. Our findings strongly support the monozygotic twin theory.

Intraabdominal Hemorrhage from Ruptured Ectopic Varices Treated by Antegrade Embolization via a Recanalized Paraumbilical Vein.

A 49-year-old man with alcoholic liver cirrhosis was admitted to our hospital with abdominal pain. Contrast-enhanced CT demonstrated massive hemorrhagic ascites and ectopic varices fed by right colic and ileocolic veins. The varices were treated with selective embolization via a recanalized paraumbilical vein using N-butyl cyanoacrylate. Currently, no complications and rebleeding have occurred for 7 months. Antegrade embolization via a recanalized paraumbilical vein is feasible and less-invasive in a patient with massive ascites. Flow reduction may be effective for intraabdominal hemorrhage from ruptured ectopic varices. LEVEL OF EVIDENCE: Level 5, case report.

Placement of a Viabahn stent-graft for hepatic artery pseudoaneurysm complicated by arterial dissection caused by a guiding sheath.

A 69-year-old man was transferred to our hospital for massive hemorrhage from a right hepatic artery pseudoaneurysm 5 months after surgery for gastric cancer. Stent-graft placement was planned to avoid fatal hepatic infarction, and a guiding sheath was advanced deeply into the tortuous and stenotic right hepatic artery beyond the pseudoaneurysm for safe deployment of a stent-graft. However, this advancement caused arterial dissection of the right hepatic artery. After the guiding sheath was pulled back, a Viabahn stent-graft was successfully advanced over a guidewire to exclude the pseudoaneurysm. We consider that a Viabahn stent-graft is more flexible than a guiding sheath and that advancing a Viabahn stent-graft directly from a proximally placed guiding sheath is safer than advancing a guiding sheath into a tortuous and stenotic abdominal artery.

Evaluation and Optimization of a New PET Reconstruction Algorithm, Bayesian Penalized Likelihood Reconstruction, for Lung Cancer Assessment According to Lesion Size.

OBJECTIVE. The purpose of this study was to characterize the Bayesian penalized likelihood (BPL) reconstruction algorithm in comparison with an ordered subset expectation maximization (OSEM) reconstruction algorithm and to determine its optimal penalization factor (expressed as a beta value) for clinical use. MATERIALS AND METHODS. FDG PET/CT scans of 46 patients with lung cancer were reconstructed using OSEM and BPL with beta values of 200, 300, 400, 500, and 1000. The liver signal-to-noise ratio, mean standardized uptake value (SUVmean) of the liver, and maximum standardized uptake value (SUVmax) and SUVmean of the cancers were measured. Tumors were categorized into three size groups, and the percentage difference in the tumor SUVmax between OSEM and BPL with a beta value of 200 as well as the percentage difference in the SUVmax between BPL with a beta value of 200 and BPL with a beta value of 1000 were calculated. Image quality was assessed by visual scoring. RESULTS. BPL showed a significantly higher liver signal-to-noise ratio than OSEM, except for BPL with a beta value of 200. The liver SUVmean showed no statistical difference among all algorithms. The SUVmax and SUVmean of tumors decreased as the beta value increased. BPL with a beta value of 200 produced a significantly higher tumor SUVmax than did OSEM (p < 0.01), and BPL with a beta value of 400, 500, or 1000 produced a significantly lower tumor SUVmax than did OSEM (p < 0.01). Visual analysis showed the highest and lowest scores for BPL with beta values of 500 and 200, respectively. In the small size group, the percentage difference in the SUVmax between OSEM and BPL with a beta value of 200 and the percentage difference in the SUVmax between BPL with a beta value of 200 and BPL with a beta value of 1000 were significantly larger than that in the other size groups (p < 0.01). CONCLUSION. The BPL algorithm improves image quality without compromising image quantification. A beta value of 500 appeared to be optimal in this study. Smaller tumors were more influenced by BPL.

Usefulness of a distal access catheter in embolization of a short gastric artery pseudoaneurysm.

A 59-year-old man was admitted to our hospital for hematemesis. A hematoma was found in the posterior wall of the stomach, but the source of bleeding was not identified. One month later, contrast-enhanced computed tomography revealed a pseudoaneurysm in the short gastric artery. Embolization of the pseudoaneurysm was difficult due to vessel tortuosity. Usage of a distal access catheter improved catheter stability and enabled successful embolization. We consider a distal access catheter to be useful for embolization of an aneurysm beyond a tortuous artery.

Loop formation by an aortic occlusion balloon catheter during resuscitative endovascular balloon occlusion of the aorta (REBOA).

A 77-year-old man was transferred to our hospital for endoscopically uncontrollable active bleeding from a duodenal ulcer. Soon after his arrival, he became hemodynamically unstable and resuscitative endovascular balloon occlusion of the aorta was performed using a 7-F aortic occlusion balloon catheter (Rescue Balloon; Tokai Medical Products, Aichi, Japan). He became hemodynamically stable and was transferred to the CT room. CT demonstrated that the distal part of the catheter shaft had made a loop in the aorta and the balloon was located at the level of the upper abdomen. We consider the low-profile occlusion balloon catheter to be less rigid than large ones, and care should be taken to prevent balloon migration and catheter shaft bending.

Successful embolization of ileal conduit stomal varices with N-butyl cyanoacrylate via a recanalized paraumbilical vein.

A 77-year-old woman with liver cirrhosis was admitted to our hospital for marked hemorrhage in her ileal conduit stoma. She had a history of cystectomy and urinary diversion for bladder carcinoma 2 years ago. Contrast-enhanced CT demonstrated varices in the ileal conduit stoma. We accessed the varices via a recanalized paraumbilical vein to avoid pain from the transhepatic approach, and selectively embolized the varices with N-butyl cyanoacrylate (NBCA). We consider antegrade embolization of ileal conduit stomal varices with NBCA to be effective and feasible. Access via a paraumbilical vein is a useful alternative to the transhepatic approach.

Possibility of Interstitial Lung Disease as a Phlebosclerotic Colitis Manifestation.

Phlebosclerotic colitis presents with ischemic bowels and calcification of the mesenteric veins. Owing to its rarity, we have little information on the complications of this disease. Herein, we report on a 77-year-old woman with phlebosclerotic colitis and interstitial lung disease. She was diagnosed as having phlebosclerotic colitis by CT and colonoscopy. At the same time, chest CT also showed interstitial lung disease. After 4 years, she experienced exacerbation of interstitial lung disease. She recovered without treatment. The occurrence of interstitial lung disease may have been associated with her phlebosclerotic colitis.