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.

Imaging Features of Uncommon Entities That Manifest with Torsion.

Torsion is the twisting of an object along the axis, and various structures (organs and tumors) in the body can twist. Torsion causes initial lymphatic and venous outflow obstruction, leading to congestive edema, enlargement, venous hemorrhagic infarction, and surrounding edema. It can also cause subsequent arterial obstruction depending on the degree of torsion, leading to ischemia, infarction, necrosis, gangrene, and surrounding inflammation. Therefore, in several cases of torsion, immediate surgical intervention is required to improve blood flow and prevent serious complications. Clinical manifestations of torsion are often nonspecific and can affect individuals of varying ages and sex. Imaging plays an important role in the early diagnosis and management of torsion. Multiple imaging modalities, including US, radiography, CT, and MRI, are used to evaluate torsion, and each modality has its specific characteristics. The imaging findings reflect the pathophysiologic mechanism: a twisted pedicle (whirlpool sign), enlargement of the torsed structures, reduced blood flow, internal heterogeneity, and surrounding reactive changes. The whirlpool sign is a definitive characteristic of torsion. In some cases, despite poor internal enhancement, capsular enhancement is observed on contrast-enhanced CT and MR images and is considered to be associated with preserved capsular arterial flow or capsular neovascularization due to inflammation. Radiologists should be familiar with the pathophysiologic mechanisms, clinical characteristics, and imaging characteristics of torsion in various structures in the body. Since other articles about common organ torsions already exist, the authors of this article focus on the uncommon entities that manifest with torsion. ©RSNA, 2024.

Unveiling the mille-feuille sign: a key to diagnosing ovarian carcinosarcoma in addition to ovarian metastasis from colorectal carcinoma on MRI.

PURPOSE: To clarify the diagnostic utility and formation of the Mille-feuille sign for ovarian carcinosarcoma (OCS) on MRI, and to evaluate the other MRI findings and serum markers compared to ovarian metastases from colorectal carcinoma (OMCRC). METHOD: Three blinded radiologists retrospectively reviewed MR images of 12 patients with OCS, 18 with OMCRC, and 40 with primary ovarian carcinoma (POC) identified by the electronic database of radiology reports. The interobserver agreement was analyzed using Fleiss' kappa test. Their MRI characteristics and tumor markers were compared using Fisher's exact test and Mann-Whitney's U test. Receiver operating characteristic curve analyses were used to determine the cutoff points for the ADC value. This study was approved by the institutional ethics committee. RESULTS: Interobserver agreement analysis was moderate or higher for all MRI characteristics. The frequency of Mille-feuille sign was comparable for both OCS and OMCRC groups, and predominantly higher than that of the POC group (p < 0.001, p < 0.001), respectively. Pathologically, the Mille-feuille sign in OCS reflected alternating layers of tumor cells with stroma and necrosis or intraluminal necrotic debris. Compared to OMCRC, intratumoral hemorrhage (p = 0.02), margin irregularity (p = 0.048), unilateral adnexal mass (p = 0.02), and low ADC values (p < 0.01) were more frequently observed and serum CEA levels was significantly lower (p = 0.007) in the OCS group. Under setting of the cutoff value of ADC at 0.871 × 10-3mm2/s, the discriminative ability for OCS showed 66.7% sensitivity, 94.4% specificity, and 81.0% accuracy, respectively. CONCLUSIONS: The Mille-feuille sign was seen in both OCS and OMCRC. MR findings of intratumoral hemorrhage, margin irregularity, unilateral adnexal mass, low ADC values, and low serum CEA levels can be useful in differentiating OCS from OMCRC.

Asymmetric genetic population structures at the range edges of a mangrove whelk.

Many marine species are distributed across incredibly wide geographical ranges spanning thousands of kilometers often due to movement along prevailing ocean currents. However, data are lacking on genetic connectivity among populations of such widespread species within or among ecoregions, possibly due to the lack of appropriate datasets. In this study, we investigated the genetic structure of populations of the mangrove whelk, Terebralia palustris, using mitochondrial cytochrome oxidase subunit I (COI) sequences. Sequences generated for this study from Okinawa, Japan, were compared to samples from the coast of East Africa analyzed in a previous study. Interestingly, despite considerable distance separating them, the African and Japanese populations share major haplotypes and do not show clear genetic differentiation. At lower latitudes, core African populations exhibited higher genetic diversity than either the more southerly African and Japanese populations. Genetic ß-diversity revealed that the northern edge population in Japan has a greater proportion of ßSNE (the nestedness-resultant component), indicating contemporary migration, whereas the southern edge population in Africa is characterized by a predominant ßSIM (the turnover component), suggesting historical demography. A potential cause of this dissimilarity could be due to the strong Kuroshio Current along the Ryukyu Islands, which may promote larval dispersal. These differing patterns suggest that there may be divergent responses to future climate change at the population level at the periphery of the range of T. palustris.

Magnetic resonance imaging features of complete androgen insensitivity syndrome in comparison to Mayer-Rokitansky-Küster-Hauser syndrome.

PURPOSE: Complete androgen insensitivity syndrome (CAIS) and Mayer-Rokitansky-Küster-Hauser syndrome (MRKHS) share common clinical features such as female phenotype, vaginal hypoplasia, and primary amenorrhea. Magnetic resonance imaging (MRI) is performed to investigate the cause of primary amenorrhea. However, the MRI features are also similar in both disorders. They are ultimately diagnosed by chromosome testing, but there is a possibility of misdiagnosis if chromosome testing is not performed. This study aimed to identify MRI features that are useful for differentiating CAIS from MRKHS. METHOD: This multicenter retrospective study included 12 patients with CAIS and 19 patients with MRKHS. Three radiologists blindly evaluated the following features: (1) detection of vagina, (2) detection of nodular and cystic structures in the lateral pelvis; undescended testicles and paratesticular cysts in CAIS and rudimentary uteri and ovaries in MRKHS, (3) their location, (4) number of cysts in the cystic structures, and (5) signal intensity on diffusion-weighted images (DWI) and apparent diffusion coefficient (ADC) values of the nodular structures. Statistical comparisons were performed using Mann-Whitney U and Fisher's exact tests. RESULTS: Compared with MRKHS, the CAIS group showed significantly detectable vagina, more ventrally located nodular and cystic structures, fewer cysts within the cystic structures, and nodular structures with higher signal intensity on DWI and lower ADC values. CONCLUSIONS: MRI features of detectable vagina, location of nodular and cystic structures, number of cysts within the cystic structures, signal intensity on DWI and ADC values of the nodular structures were useful in differentiating CAIS from MRKHS.

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.

Lymphoscintigraphy with single-photon emission computerized tomography/computed tomography for evaluating lymphatic leakage following pelvic and para-aortic lymphadenectomy.

Lymphatic ascites following pelvic and para-aortic lymphadenectomy is a well-known complication. Surgical treatment and interventional radiology are required in a few cases. To determine the appropriate treatment strategy, it is important to preoperatively detect the presence and location of lymphatic leakage. However, the methods have yet to be established. We report a case in which lymphoscintigraphy with single-photon emission computerized tomography/computed tomography (SPECT/CT) was performed to evaluate pelvic lymphorrhea that occurred following total hysterectomy with pelvic and para-aortic lymphadenectomy for stage IIIA uterine sarcoma. Lymphoscintigraphy with SPECT/CT showed leakage of radioisotopes into the pelvic space, and intranodal lymphangiography was performed based on these findings. Following the procedure, the pelvic lymphorrhea improved, and no radioisotope leakage was confirmed by re-evaluation with lymphoscintigraphy with SPECT/CT. Our case indicates that lymphoscintigraphy with SPECT/CT may be useful for detecting the precise site of lymphatic leakage before interventional radiology or surgery.

Recurrent bicycle falls by an elderly man who developed multiple intramuscular abscesses associated with urine leakage secondary to posterior urethral injury caused by pelvic ring disruption.

Key Clinical Message: With the aging of the population, physicians need to pay more attention to assessing the presence or absence of pelvic fractures and urinary retention associated with urethral injury due to such fractures in the elderly when falling from bicycles. Abstract: Walking ability does not rule out the presence of pelvic fractures. Many geriatric patients are likely to fall off bicycles. Physicians should pay more attention when assessing complications related to urethral trauma caused by pelvic fractures in the elderly after falling from bicycles.

Double inversion recovery MRI of subcortical band heterotopia and its variations.

BACKGROUND AND PURPOSE: Subcortical band heterotopia (SBH) is a malformation of cortical development diagnosed via MRI. Currently, patients with SBH are classified according to Di Donato's classification. We aimed to show a variation of SBH and the usefulness of double inversion recovery (DIR) images. METHODS: We retrospectively reviewed the MRI findings of 28 patients with SBH. The patients were classified according to Donato's classification by using conventional MR images, and their DIR findings were reviewed. RESULTS: Of 28 patients, 20 were grade 1 and 8 were grade 2 according to Di Donato's classification. In 15 of 28 patients, the following four types of atypical MRI findings were detected: asymmetry distribution (four cases), coexistence of thin and thick SBH (five cases), and DIR faint abnormal signal intensity in subcortical white matter (five cases) and in deep white matter (five cases). The latter two types were detected on DIR alone and have not been reported. Additionally, these were identified only in the mild group (Di Donato's classification 1-1 or 1-2). CONCLUSION: DIR is a useful MRI sequence for detecting faint white matter signal abnormalities, and it can aid in the accurate classification of SBH and identification of its variations, which may reflect the pathology of SBH.

Malignancy-related Hypercalcemia Caused by Metameric Cutaneous Metastasis of Parathyroid Hormone-related Protein-producing Bladder Carcinoma with Squamous Cell Differentiation: An Autopsy Case of Cobb Syndrome.

A 74-year-old woman was admitted with hypercalcemia and prolonged disturbance of consciousness. The left buttock to the anterior aspect of the left thigh was swollen and erythematous, with a collection of 1.0-cm large, firm, elastic nodules distributed in a zosteriform pattern in the L1-L4 region. Based on autopsy findings, a very rare case of Cobb syndrome was diagnosed due to a spinal vascular malformation at the Th12-L4 level and L5 vertebral hemangioma. Cobb syndrome-associated cutaneous metastasis extending along the same metamere was complicated by immunohistochemically proven parathyroid hormone-related protein-producing advanced bladder carcinoma in this case.

Ultra-short Echo-time MR Angiography Combined with a Subtraction Method to Assess Intracranial Aneurysms Treated with a Flow-diverter Device.

A flow-diverter (FD) device is a well-established tool for the treatment of unruptured intracranial aneurysms. Time-of-flight (TOF) MR angiography (MRA) is widely used for postoperative assessment after the treatment with FD; however, it cannot fully visualize intra-aneurysmal and intrastent flow signals due to the magnetic susceptibility from the FD. Recently, the utility of MRA with ultra-short TE (UTE) sequence and arterial spin labeling technique in assessing the therapeutic efficacy of intracranial aneurysms treated with metallic devices has been reported, but long image acquisition time is one of the drawbacks of this method. Herein, we introduce a novel UTE MRA using the subtraction method that enables the reduction in susceptibility artifacts with a short image acquisition time.

Diagnostic imaging and histopathologic features of rounded atelectasis in four cats and one dog: A descriptive case series study.

In humans, rounded atelectasis is defined as focal lung collapse that radiologically appears as a round mass-like lesion in the periphery of the lung. In general, human patients with rounded atelectasis have a history of pleural effusion and abnormal pleura and characteristic CT findings help to distinguish rounded atelectasis from pulmonary neoplasia without the need for invasive surgical biopsy. This retrospective multi-center case series describes rounded atelectasis in four cats and one dog. Chylothorax was seen in four patients and an eosinophilic and lymphoplasmacytic effusion was seen in one patient. All patients had solitary or multifocal subpleural pulmonary masses (26 masses total in 5 patients) with diffuse, multifocal, or focal visceral and parietal pleural thickening. All the masses but one were broad-based towards the visceral pleura. Masses were most common in the ventral or lateral aspect of the lungs. Indistinctness at the hilar aspect of the lesion was seen in all masses; a "comet tail" sign was seen in 14 of 26 masses. On postcontrast images, the lesions were homogeneously enhanced in 24 of 26 masses and heterogeneous in two of 26 masses. Other findings include ground glass opacities (n = 5), parenchymal bands (n = 4), mild to moderate lymphadenopathy (n = 4), and compensatory hyperinflation of the lung lobes not affected by atelectasis (n = 2). Histopathology of four cases revealed atelectasis with fixed pleural folds, chronic pleuritis, and mild to moderate pleural fibrosis. Awareness of rounded atelectasis in veterinary species will enable inclusion of a benign etiology into the differential diagnosis for subpleural masses in cases with pleural abnormalities.

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.

Shallow epifaunal sea cucumber densities and their relationship with the benthic community in the Okinawa Islands.

Sea cucumbers are important ecological engineers in marine ecosystems. However, the fishery demand of some species, especially large-epifaunal and commercially used (LEC) sea cucumbers, has risen drastically, resulting in serious depletion of local populations for many species. Despite this problem, basic ecological data on sea cucumbers, such as population densities and preferred habitats, are often still insufficient. Here, we report on the population densities of multiple LEC sea cucumber species, and their ambient benthic communities at eight sites around Okinawa Islands. Further, we discuss the correspondence between sea cucumber densities and the surrounding coral communities. Our results show two sites within national or quasi-national parks, Aka and Manza, where stricter rules have been placed on fisheries and land reclamation compared to other areas, had the highest and third highest sea cucumber population densities among sites, respectively. Holothuria atra was observed at all survey sites and made up the majority of sea cucumber populations at all sites except for Chatan and Sesoko, where Holothuria leucospilota and Stichopus chloronotus were most abundant, respectively. Regarding the relationships between benthic composition and LEC sea cucumber species, S. chloronotus was significantly correlated with dead corals, scleractinian corals, and coralline algae. As well, H. leucospilota had significant correlations with rubble. Although there were no significant correlations between any specific scleractinian coral genus and sea cucumber densities, S. chloronotus was marginally insignificant with Platygyra and Psammocora. Notably, medium- to highly valued species were sparse in our surveys, and most of them appeared at only one site. Additionally, at one site (Odo), only three LEC sea cucumber individuals were observed. Combining these facts with relatively low population densities around the Okinawa Islands compared to densities reported in previous research from the Indo-West Pacific Ocean region, we conclude that Okinawan LEC sea cucumber populations have been and are being impacted by high levels of direct (e.g., overexploitation, as well as coastal development) and indirect anthropogenic pressure (e.g., decreasing water quality). To address the current situation, repeated monitoring and more detailed investigations to reveal the drivers that determine LEC sea cucumber species aggregations and population densities are urgently needed, along with more robust management of remaining LEC sea cucumber populations.

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.

A new infaunal species of the genus Enosteoides Johnson, 1970 (Crustacea: Decapoda: Anomura: Porcellanidae) from Okinawa, southwestern Japan.

A new porcellanid species of the genus Enosteoides Johnson, 1970 is described on the basis of a single specimen collected from the burrow of an unidentified snapping shrimp of the genus Alpheus Fabricius, 1798, on the subtidal coarse sediment in Okinawa Island, Ryukyu Islands, southwestern Japan. Enosteoides lapis n. sp. is similar to E. melissa (Miyake, 1942) and E. philippinensis Dolorosa Werding, 2014 in the general morphology of the frontal region of the carapace, third thoracic sternite, and ambulatory legs, but is distinguished from both by the dorsal surface of the carapace being more strongly uneven, as well as by the absence of dense plumose setae on the lateral margins of the carapace, anterodorsal surfaces of the chelae, and anterior and posterior margins of the ambulatory meri.

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.

A preliminary animal study on the prediction of nerve block success using ultrasonographic parameters.

This study aimed to evaluate the diagnostic value of ultrasonographic parameters as an indicator for predicting regional nerve block success. Ultrasound-guided sciatic nerve block was performed in seven dogs using either 2% mepivacaine (nerve-block group) or saline (sham-block group). The cross-sectional area (CSA), nerve blood flow (NBF), and shear wave velocity (SWV) of the sciatic nerve (SWVN), SWV of the biceps femoris muscle (SWVM), and their ratio (SWVNMR) were measured at 0, 30, 60, and 90 min after the nerve block as well as the change rate of each parameter from the baseline. A receiver operating characteristic (ROC) curve analysis was performed to determine the diagnostic value of each parameter in the prediction of nerve block success. No significant changes were observed in the CSA or NBF in association with the nerve block. The SWVN and SWVNMR in the nerve-block group were significantly higher than those in the sham-block group at 90 min and at 30, 60, and 90 min, respectively (p < 0.05). The change rates of SWVN and SWVNMR in the nerve-block group were significantly higher than those in the sham-block group at all time points (p < 0.05). The ROC curve analysis showed that SWVN had a moderate diagnostic accuracy (area under the curve [AUC], 0.779), whereas SWVNMR and change rates of SWVN and SWVNMR had a high diagnostic accuracy (AUC, 0.947, 0.998, and 1.000, respectively). Ultrasonographic evaluation of the SWVN and SWVNMR could be used as indicators for predicting nerve block success.