Extratesticular masses focusing on MRI findings.

Scrotal masses, whether cystic or solid lesions, are routinely evaluated using ultrasonography. Magnetic resonance imaging (MRI) may be used for further investigation in cases with atypical findings, difficult diagnoses, large masses, and/or unclear relationships with the surrounding tissues. Scrotal solid masses are divided into intra- and extra-testicular masses. A staggering 90% of the intratesticular masses are malignant, whereas 75% of extratesticular masses are benign. Extratesticular masses are less common than intratesticular masses; however, some extratesticular masses present characteristic MRI findings. Familiarity with these specific MRI features of extratesticular masses is beneficial to radiologists, as appropriate diagnoses can help avoid unnecessary invasive treatments such as orchiectomy. In this review, we describe fibrous pseudotumors, polyorchidism, adenomatoid tumors, and scrotal leiomyoma as benign paratesticular masses, focusing on their characteristic imaging features on MRI. Although these tumors are extremely rare, their MRI findings are distinctive, and accurate diagnoses can prevent unnecessary orchiectomy. In addition, to demonstrate the pitfalls of diagnosing extratesticular masses, we present a case of seminoma misidentified as extratesticular masses due to large extensions outside the testis. Spermatic cord sarcoma, including rhabdomyosarcoma, leiomyosarcoma, and liposarcoma, and metastasis to the spermatic cord are described as malignant extratesticular masses. This review focused on extratesticular masses and elaborates the imaging findings that can aid in the accurate diagnosis using MRI.

Perihepatic caudate lobe haematoma originating from a pancreatic pseudoaneurysm: a diagnostic dilemma.

Despite advances in diagnostic imaging and interventional techniques, pancreatic pseudoaneurysms remain a life-threatening complication of pancreatitis. Presentation varies among patients and may include intra-abdominal, retroperitoneal, or gastrointestinal bleeding and bleeding into the pancreatic or common bile duct. We present a unique case of a 74-year-old man with a history of heavy alcohol consumption who presented with a haematoma surrounding the caudate lobe of the liver. Initially, alcoholic cirrhosis and a ruptured hepatocellular carcinoma were suspected. Therefore, transarterial embolization (TAE) of the caudate branch of the hepatic artery was performed. However, 3 months later, the patient experienced abdominal pain with a lesser sac haematoma and a seemingly interconnected pancreatic cyst. One month later, a pseudoaneurysm appeared in the pancreatic cyst. TAE was successfully performed for the pseudoaneurysm, and the patient showed no signs of recurrence during the 1-year follow-up.

Transarterial embolization for an infected internal iliac artery aneurysm without recurrence for a long period: A case report.

We report an 85-year-old man who underwent transarterial embolization (TAE) for an infected internal iliac artery aneurysm. The patient presented with fever and left lower abdominal pain. Computed tomography (CT) revealed the expansion of a left internal iliac artery aneurysm. We planned surgical treatment for an infected internal iliac artery aneurysm; however, the patient's age and general condition made the surgery high-risk. Therefore, we performed emergency TAE. The patient was administered antibiotics for 4 weeks and discharged on day 33 after the procedure with good progression. A 3-year follow-up CT scan showed aneurysm reduction and no recurrent infections. This case report highlights that TAE can be a treatment option for patients with an infected artery aneurysm.

Idiopathic myointimal hyperplasia of mesenteric veins: radiological evaluation using CT angiography.

A 44-year-old man presented with a chief complaint of constipation. Initial contrast-enhanced CT showed extensive bowel wall thickening, mainly in the left colon, with a thin cord-like inferior mesenteric vein (IMV), in contrast to ectatic mesenteric venous branches, suggesting bowel ischaemia owing to venous stasis. One month later, at the time of symptom exacerbation, CT angiography showed a cord-like IMV and ectatic mesenteric venous branches with early enhancement, suggesting the presence of an arteriovenous fistula (AVF). Owing to the progression of bowel ischaemia and necrosis with peritonitis, emergency surgery was performed. Surgical specimens showed focal myointimal hyperplasia of the proximal mesenteric veins in both ischaemic and non-ischaemic lesions of the resected colon, thus leading to the diagnosis of idiopathic myointimal hyperplasia of mesenteric veins (IMHMV) when combined with the clinical and imaging findings. IMHMV is a bowel ischaemic disease caused by non-thrombotic venous obstruction that requires bowel resection and has been suggested to be associated with AVF. Cord-like IMV and AVF in the mesentery are important CT findings that characterize IMHMV. CT angiography is useful in diagnosing IMHMV.

A case of low-grade endometrial stromal sarcoma presented as an intramyometrial mass mimicking uterine leiomyoma on MRI.

A low-grade endometrial stromal sarcoma (ESS) has a pattern of presenting as an intramyometrial mass and is often misdiagnosed as cellular leiomyoma or degenerative uterine leiomyoma. A low-grade ESS is a malignant tumour that requires total hysterectomy with bilateral salpingo-oophorectomy; while a leiomyoma is a benign tumour and could be acceptable for enucleation. As the treatment strategies differ between a low-grade ESS and leiomyoma, radiologists should be familiar with the characteristic MRI findings of a low-grade ESS. A 51-year-old woman with abnormal uterine bleeding had been observed for 2 years at a previous hospital for a uterine leiomyoma based on MRI findings. A contrast-enhanced MRI demonstrated an intramyometrial mass composed of three components with the hypointense rim on T2-weighted images (T2WI): the first component was a homogeneous solid structure with mild hyperintensity on T2WI with a low apparent diffusion coefficient value; the second component was cystic; the third component was a structure of low signal intensity on T2WI similar to the muscle. Although a degenerative uterine leiomyoma was a differential diagnosis, these MRI findings were suggestive of a low-grade ESS. A total abdominal hysterectomy, bilateral salpingo-oophorectomy, pelvic lymphadenectomy, and partial omentectomy were performed. The pathological diagnosis was a low-grade ESS. In a low-grade ESS, there are three major patterns of MRI findings: one of these patterns is the less popular but clinically important intramyometrial mass pattern, which can be misdiagnosed as a leiomyoma, and this case conformed to this pattern.

Histological parameters and stromal desmoplastic status affecting accurate diagnosis of extraprostatic extension of prostate cancer using multi-parametric magnetic resonance imaging.

OBJECTIVE: To investigate the clinicopathological factors affecting discrepancies between multi-parametric magnetic resonance imaging (mpMRI) and histopathological evaluation for diagnosis of extraprostatic extension (EPE) of prostate cancer. METHODS: One hundred-and-three lesions from 96 cases with suspected EPE on preoperative mpMRI, of which 60 and 43 showed bulging and frank capsular breach, respectively, were grouped according to pathological (p)EPE in radical prostatectomy specimens. Additionally, clinicopathological/immunohistochemical findings for periostin reflecting a desmoplastic stromal reaction were compared between these groups. RESULTS: pEPE was detected in 49 (48%) of the 103 lesions. Of these, 25 (42%) showed bulging and 24 (56%) showed frank capsular breach on MRI. In the total cohort, the absence of pEPE was significantly associated with a lower Gleason Grade Group (GG) (p < 0.0001), anterior location (p = 0.003), absence of intraductal carcinoma of the prostate (IDC-P) (p = 0.026), and high stromal periostin expression (p < 0.0001). These trends were preserved in subgroups defined by MRI findings, except for anterior location/IDC-P in the bulging subgroup. CONCLUSIONS: GG, anterior location, and periostin expression may cause mpMRI-pathological discrepancies regarding EPE. Periostin expression was a significant pEPE-negative factor in all subgroup analyses. Our results indicate that patients with suspected EPE on MRI, regardless of their pEPE results, should be followed as carefully as those with definite pEPE.

A case of emphysematous intrascrotal abscess secondary to sigmoid coloseminal fistula.

A 54-year-old male patient presented with pneumaturia. Right scrotal swelling was observed. CT showed an intrascrotal abscess with gas formation. MRI showed a fistula extending from the sigmoid colon to the seminal vesicles. Since there are many diverticula in the sigmoid colon, an abscess caused by diverticulitis may have formed a fistula. The scrotal abscess was drained; however, the pus discharge did not decrease. A colostomy was then performed, and the scrotal infection rapidly improved. Sigmoidectomy and fistula transection were performed 11 months after the colostomy. Prompt diagnosis of a sigmoid coloseminal fistula using imaging has led to optimal treatment.

Use of Imaging and Biopsy in Prostate Cancer Diagnosis: A Survey From the Asian Prostate Imaging Working Group.

OBJECTIVE: To elucidate the use of radiological studies, including nuclear medicine, and biopsy for the diagnosis and staging of prostate cancer (PCA) in clinical practice and understand the current status of PCA in Asian countries via an international survey. MATERIALS AND METHODS: The Asian Prostate Imaging Working Group designed a survey questionnaire with four domains focused on prostate magnetic resonance imaging (MRI), other prostate imaging, prostate biopsy, and PCA backgrounds. The questionnaire was sent to 111 members of professional affiliations in Korea, Japan, Singapore, and Taiwan who were representatives of their working hospitals, and their responses were analyzed. RESULTS: This survey had a response rate of 97.3% (108/111). The rates of using 3T scanners, antispasmodic agents, laxative drugs, and prostate imaging-reporting and data system reporting for prostate MRI were 21.6%-78.9%, 22.2%-84.2%, 2.3%-26.3%, and 59.5%-100%, respectively. Respondents reported using the highest b-values of 800-2000 sec/mm² and fields of view of 9-30 cm. The prostate MRI examinations per month ranged from 1 to 600, and they were most commonly indicated for biopsy-naïve patients suspected of PCA in Japan and Singapore and staging of proven PCA in Korea and Taiwan. The most commonly used radiotracers for prostate positron emission tomography are prostate-specific membrane antigen in Singapore and fluorodeoxyglucose in three other countries. The most common timing for prostate MRI was before biopsy (29.9%). Prostate-targeted biopsies were performed in 63.8% of hospitals, usually by MRI-ultrasound fusion approach. The most common presentation was localized PCA in all four countries, and it was usually treated with radical prostatectomy. CONCLUSION: This survey showed the diverse technical details and the availability of imaging and biopsy in the evaluation of PCA. This suggests the need for an educational program for Asian radiologists to promote standardized evidence-based imaging approaches for the diagnosis and staging of PCA.

Invasive candidiasis presenting bronchiectatic cavity as chest radiological findings: A case report.

Invasive candidiasis is rare but is associated with high mortality in immunocompromised or critically ill patients. Here, we present a case of a 55-year-old man with untreated diabetes who was diagnosed with coronavirus disease 2019 and subsequently developed invasive candidiasis. The patient presented with fever, tachycardia, and tachypnea. Chest computed tomography revealed multiple consolidations mainly distributed around the bronchovascular bundles with bronchiectatic cavity formation, which initially raised suspicion for invasive pulmonary aspergillosis. However, subsequent testing confirmed Candida albicans infection; hence, we changed the antifungal agents effective for invasive candidiasis. This improved the patient's respiratory status, and he was then successfully weaned from mechanical ventilation. This case report highlights the importance of considering invasive candidiasis in the differential diagnosis of patients with bronchiectatic cavities on chest computed tomography, particularly in immunocompromised or critically ill patients with risk factors for invasive candidiasis.

Longitudinal changes in radiographic features of pulmonary Mycobacterium avium complex diseases.

Background: The radiographic features of Mycobacterium avium complex pulmonary disease (MAC-PD), a major component of nontuberculous mycobacteria, consist of a variety of lesions; however, the responsiveness of each type of radiographic factor to treatment is unclear. Thus, we evaluated the longitudinal changes of each factor in serial computed tomography (CT) images using a mixed-effects model, and investigated the radiographic transition in patients with MAC-PD whose progress could be followed. Methods: In this retrospective study, eighty-four patients diagnosed with MAC-PD and with yearly CT records were recruited after a review of 328 medical records with culture-positive MAC in respiratory specimens. The study participants were divided into two groups: treatment (n = 43) and no-treatment (n = 41) groups. Radiographic images were scored using the nodule (N), infiltration (I), cavity (C), ectasis (E) scoring system. Longitudinal changes in each radiographic lesion factor were analyzed using a mixed-effects model in treated and untreated patients. Results: All factors tended to progress without treatment, and significant longitudinal changes were observed in the N, I, and E factors (N: p = 0.010, I: p = 0.004, E: p < 0.001). Although treatment tended to improve N and I in radiographic images (N: p = 0.006, I: p = 0.203), cavities and ectasis progressed, regardless of treatment (C: p = 0.057 and E: p = 0.033). Conclusion: Radiographic changes of MAC-PD can be categorized into reversible (nodules and infiltrations) and irreversible (cavities and ectasis) lesions. Early treatment may prevent the accumulation of irreversible factors.

Initial experience of coaxial percutaneous liver biopsy with tract embolization using N-Butyl cyanoacrylate.

OBJECTIVE: Bleeding occurs after liver biopsy in up to 10.9% cases, and patients with impaired hemostasis or ascites are considered to have absolute or relative contraindications. N-butyl cyanoacrylate enables immediate hemostasis, even in lethal situations. Therefore, percutaneous liver biopsy combined with tract embolization using N-butyl cyanoacrylate is expected to enable safe biopsy, even in patients for whom conventional biopsy is contraindicated. Here we describe our initial experience with coaxial percutaneous biopsy with tract embolization using N-butyl cyanoacrylate. MATERIALS AND METHODS: Eighty-six patients who underwent tract embolization using N-butyl cyanoacrylate between October 2014 and July 2020, including 21 patients who had absolute or relative contraindications for liver biopsy, were retrospectively analyzed. Tract embolization using N-butyl cyanoacrylate comprised two steps: (1) liver biopsy with a biopsy needle inserted via a coaxial introducer needle and (2) embolization of the puncture route by injecting N-butyl cyanoacrylate via the coaxial needle. RESULTS: No complications occurred in any patient. The mean number of biopsies per patient was 3.30 (range, 1-7). Histologically adequate samples were acquired in all cases, and pathological diagnoses were obtained. The mean time required for tract embolization was 52.8 s (range, 6-132 s). The mean peak skin dose was 9.97 mGy (range, 2-68 mGy), which is far below the 3-Gy threshold dose for temporary erythema. CONCLUSIONS: This proposed technique may be a promising and straightforward alternative to improve the management of patients with severe liver disease by allowing safer biopsy, including patients for whom conventional liver biopsy is contraindicated.

Ultra-short Echo-time MR Angiography Combined with a Modified Signal Targeting Alternating Radio Frequency with Asymmetric Inversion Slabs Technique to Assess Visceral Artery Aneurysm after Coil Embolization.

Contrast-enhanced CT and MR angiography are widely used for follow-up of visceral artery aneurysms after coil embolization. However, potential adverse reactions to contrast agents and image deterioration due to susceptibility artifacts from the coils are major drawbacks of these modalities. Herein, we introduced a novel non-contrast-enhanced MR angiography technique using ultra-short TE combined with a modified signal targeting alternating radio frequency with asymmetric inversion slabs, which could provide a serial hemodynamic vascular image with fewer susceptibility artifacts for follow-up after coil embolization.

Composite pheochromocytoma-ganglioneuroma: a case with two distinct components radiographically.

Composite pheochromocytoma is an extremely rare tumor that comprises a pheochromocytoma and an embryologically related neurogenic tumor, such as ganglioneuroma, ganglioneuroblastoma, neuroblastoma, or peripheral nerve sheath tumor. A 46-year-old male with hypertension, elevated plasma catecholamine levels, and suspected pheochromocytoma presented to the National Defense Medical College Hospital. CT and MRI showed two adjacent masses in the left adrenal gland; one was a 6 cm cephalic lesion and the other was a 1.5 cm caudal lesion. Only the 1.5 cm caudal mass showed uptake on 123I-metaiodobenzylguanisine single photon emission CT/CT. Pheochromocytoma was suspected and a left adrenalectomy was performed. Pathology confirmed that the 6 cm mass was a ganglioneuroma and the 1.5 cm mass a pheochromocytoma, with cellular intermingling at their border. The two masses were diagnosed as a composite pheochromocytoma-ganglioneuroma. This is the first report in which the two components of a composite pheochromocytoma can be clearly distinguished in the pre-operative images. If a patient with clinically suspected pheochromocytoma has different components from a typical pheochromocytoma, composite pheochromocytoma should be considered.

Successful Closure of External Iliac Artery Perforation with Super-selective Transcatheter Coil Embolization.

We present two cases of external iliac artery perforation occurring after endovascular interventions successfully treated with direct closure using super-selective transcatheter coil embolization. Two patients, one 78-year-old man and one 78-year-old woman, underwent cardiac catheterization via the right femoral approach for coronary artery disease and atrial fibrillation. Following the procedures, both patients suffered severe acute hypotension, and contrast-enhanced computed tomography revealed a massive retroperitoneal hematoma due to perforation of the right external iliac artery. We attempted direct perforation site closure with super-selective transcatheter embolization using microcoils and achieved complete hemostasis in both cases. Our technique could be an alternative treatment option for external iliac artery perforations associated with the endovascular intervention.

Successful Treatment of Subcapsular Hepatic Hemorrhage Concomitant with Diffuse Arterioportal Shunt by Transcatheter Arterial Embolization.

We present a case of subcapsular hepatic hemorrhage with a concomitant diffuse arterioportal shunt successfully treated with transcatheter arterial embolization. An 85-year-old man with duodenal carcinoma developed hemorrhagic shock three days after pancreaticoduodenectomy. Contrast-enhanced computed tomography revealed an extensive subcapsular hepatic hematoma with extravasation. At the same time, diagnostic angiography showed innumerable foci of petechial extravasation from disrupted isolated arteries and the right inferior phrenic artery. In addition, a comorbid diffuse arterioportal shunt in the hematoma area was detected. We performed transcatheter arterial embolization on the peripheral side of the hepatic artery while preserving the proximal portion. Subsequently, the transcatheter arterial embolization for the right inferior phrenic artery was also performed. Complete hemostasis and occlusion of the arterioportal shunt were successful without fulminant liver failure.

Effect of Ultra-High-Resolution CT on Pseudoenhancement in Renal Cysts: A Phantom Experiment and Clinical Study.

BACKGROUND. Ultra-high-resolution CT (UHRCT) allows acquisition using a small detector element size, in turn allowing very high spatial resolutions. The high resolution may reduce partial-volume averaging and thereby renal cyst pseudoenhancement. OBJECTIVE. The purpose of this article was to assess the impact of UHRCT on renal cyst pseudoenhancement. METHODS. A phantom was constructed that contained 7-, 15-, and 25-mm simulated cysts within compartments simulating unenhanced and nephrographic phase renal parenchyma. The phantom underwent two UHRCT acquisitions using 0.25- and 0.5-mm detector elements, with reconstruction at varying matrices and slice thicknesses. A retrospective study was performed of 36 patients (24 men, 12 women; mean age, 75.7 ± 9.4 [SD] years) with 118 renal cysts who underwent renal-mass protocol CT using UHRCT and the 0.25-mm detector element, with reconstruction at varying matrices and slice thicknesses; detector element size could not be retrospectively adjusted. ROIs were placed to measure cysts' attenuation increase from unenhanced to nephrographic phases (to reflect pseudoenhancement) and SD of unenhanced phase attenuation (to reflect image noise). RESULTS. In the phantom, attenuation increase was lower for the 0.25- than 0.5-mm detector element for the 15-mm cyst (4.6 ± 2.7 HU vs 6.8 ± 2.9 HU, p = .03) and 25-mm cyst (2.3 ± 1.4 HU vs 3.8 ± 1.2 HU, p = .02), but not the 7-mm cyst (p = .72). Attenuation increase was not different between 512 × 512 and 1024 × 1024 matrices for any cyst size in the phantom or patients (p > .05). Attenuation increase was not associated with slice thickness for any cyst size in the phantom or in patients for cysts that were between 5 mm and less than 10 mm and those that were 10 mm and larger (p > .05). For cysts smaller than 5 mm in patients, attenuation increase showed decreases with thinner slices, though there was no significant difference between 0.5-mm and 0.25-mm (3-mm slice: 23.7 ± 22.5 HU; 2-mm slice: 20.2 ± 22.7 HU; 0.5-mm slice: 11.6 ± 17.5 HU; 0.25-mm slice: 12.6 ± 19.7 HU; p < .001). Smaller detector element size, increased matrix size, and thinner slices all increased image noise for cysts of all sizes in the phantom and patients (p < .05). CONCLUSION. UHRCT may reduce renal cyst pseudoenhancement through a smaller detector element size and, for cysts smaller than 5 mm, very thin slices; however, these adjustments result in increased noise. CLINICAL IMPACT. Although requiring further clinical evaluation, UHRCT may facilitate characterization of small cystic renal lesions, thereby reducing equivocal interpretations and follow-up recommendations.

Treatment of massive hemoptysis after thoracic aortic aneurysm repair.

BACKGROUND: Massive hemoptysis after thoracic aortic aneurysm (TAA) repair is a rare but potentially lethal condition. Endovascular management is a challenging treatment option due to the complexity of culprit vessel access. CASE PRESENTATION: An 81-year-old woman was referred to our hospital with massive hemoptysis. She had a history of graft replacement and thoracic endovascular aortic repair (TEVAR) for dissecting TAA. Computed tomography (CT) showed massive atelectasis with hematoma in the left lower lung lobe adjacent to the descending aortic aneurysm treated with TEVAR. Contrast-enhanced CT revealed a pseudoaneurysm and proliferation of abnormal vessels at the peripheral side of the left pulmonary ligament artery (PLA) in the atelectasis. The PLA continued to the right subscapular artery via a complex collateral pathway. Diagnostic angiography of the right subcapsular artery revealed a pseudoaneurysm and abnormal vessels at the peripheral side of the left PLA with a systemic-pulmonary artery shunt. Transcatheter arterial embolization (TAE) for the left PLA via the collateral pathway with N-butyl cyanoacrylate achieved complete embolization. The patient's hemoptysis was controlled and she was discharged. CONCLUSIONS: Here we presented a case of massive hemoptysis due to PLA disruption that occurred after TAA repair. TAE via a complex collateral pathway is a feasible and effective treatment for hemoptysis, even in patients who have undergone surgical or endovascular TAA repair.

Laryngeal schwannoma with extralaryngeal extension mimicking a thyroid tumour.

Objective: A schwannoma is a common benign tumour that can arise anywhere in the body. When it occurs in an unusual location such as the larynx, its differentiation from other tumours can be challenging. Herein, we report a case of a laryngeal schwannoma with extralaryngeal extension that mimicked a thyroid tumour, focusing on its characteristic features on MRI. Methods: A 19-year-old male presented with a mass in the left side of the neck and hoarseness for 2 years. Endoscopy showed a submucosal mass in the laryngeal region. MRI found a well-defined solid mass in the thyroid gland, extending to the larynx through the lower edge of the thyroid cartilage. T 2 weighted MRI showed slightly low signal intensity at the central part of the tumour and high signal intensity at the peripheral part of the tumour. Pre-operative imaging suggested that the tumour originated in the thyroid gland. Left thyroidectomy with tumour excision was performed; the tumour was diagnosed as a laryngeal schwannoma with extralaryngeal extension, compressing the thyroid gland. In retrospect, features such as the dumbbell-shape and known as 'target sign' on T 2 weighted MRI were typical features of schwannoma. Additionally, the tumour's extension pattern was similar to previous reports of laryngeal schwannomas with extralaryngeal extension. Conclusion: A large laryngeal schwannoma may extend outside the larynx with significant compression of the thyroid gland. Understanding the pattern of extension and familiarity with the features on MRI can improve the preoperative diagnosis accuracy.

Magnetic resonance imaging findings of pure prostatic ductal adenocarcinomas: a case series.

PURPOSE: This study aimed to investigate the characteristics of magnetic resonance imaging (MRI) findings in pure prostatic ductal adenocarcinoma. METHODS: From January 2009 to February 2020, seven patients who were diagnosed with pure prostatic ductal adenocarcinoma and had a referable preoperative MRI scan were included in the study. We evaluated the following MRI findings for each tumor: size, location, presence of multi-cystic component, and apparent diffusion coefficient (ADC) value. RESULTS: The median maximum diameter of the tumors was 22 mm (range 19-70 mm). Regarding transverse distribution, five tumors were located in the periurethral area and two were located peripherally apart from the urethra. Two of the seven tumors had cystic components. The median ADC value of the tumors was 0.754 × 10-3 mm2/s (range 0.570-0.963 × 10-3 mm2/s). Based on the transverse distribution and components of the tumors on MRI, ductal adenocarcinomas were classified into three types: type I as a non-cystic tumor located peripherally apart from the urethra (29%, two cases); type II as a non-cystic tumor located in the periurethral area (43%, three cases); and type III as a tumor with a multi-cystic component (29%, two cases). CONCLUSION: The non-cystic mass with periurethral distribution (type II) and multi-cystic mass (type III) may be characteristic features that differentiate pure ductal adenocarcinoma from ordinary acinar adenocarcinoma on MRI.

Assessment of pulmonary arteriovenous malformation with ultra-short echo time magnetic resonance imaging.

PURPOSE: The purpose of this study was to evaluate the diagnostic performance of ultra-short echo time magnetic resonance imaging (UTE MRI) in the assessment of pulmonary arteriovenous malformation (PAVM). METHODS: Eighteen consecutive patients (mean [± standard deviation] age, 48.6 ± 16.8 years) with 46 untreated PAVMs who underwent and thin-section computed tomography (CT) and UTE MRI with a 1.5-Tesla and 3-Tesla unit were retrospectively assessed. Two radiologists evaluated the diagnostic capabilities of UTE MRI for the detection and classification of PAVMs with reference to CT. Sensitivity, specificity, and kappa statistics were calculated with reference to CT. We also compared the differences in PAVM measurements between CT and MRI. RESULTS: The sensitivity and specificity of UTE-MRI for the detection of PAVMs were 89.1% and 100%, respectively, for reader 1 and 87.0% and 100%, respectively, for reader 2. In the classification of PAVMs, inter-modality agreement in reader 1 and 2 were both substantial (κ = 0.78 and 0.69, respectively). The measurements of the PAVM feeding artery and sac on CT and MRI were strongly correlated in both readers 1 and 2 (R2 = 0.981 and 0.983, respectively). Both readers 1 and 2 slightly underestimated the diameter of the PAVM feeding artery and sac on UTE MRI (p < 0.001). CONCLUSION: This study indicates that UTE MRI is a feasible and promising modality for noninvasive assessment of PAVMs.