Takemichi Okada

Relation between pulmonary embolus volume quantified by multidetector computed tomography and clinical status and outcome for patients with acute pulmonary embolism

PurposeThe aim of this study was to determine whether pulmonary embolus volume (PEV) obtained with multi-detector row computed tomography is related to clinical status and outcomes.Materials and methodsSubjects comprised 48 patients with acute pulmonary embolism (PTE). PEV was measured by tracing the contours manually and compared between sets of two groups divided by clinical status. Correlations of PEV to blood gases and D-dimer levels were investigated. PEV was tested as a predictor of clinical probability of acute PTE using Wells’ criteria and as a predictor of survival after PTE by logistic regression analysis.ResultsThe PEV was greater in groups with respiratory symptoms (P < 0.001), PTE as pretest clinical diagnosis (P = 0.027), and heart rate >100 beats/min (P < 0.001). It was smaller in subjects with concurrent malignancy (P = 0.02). It was correlated with PaCO2 (P = 0.04, ρ = −0.37) and the D-dimer level (P = 0.002, ρ = 0.46); it was not a predictor of clinical probability of acute PTE or survival after PTE. The survival rate did not differ between groups with PEV > 10 ml (8/9) or ≤10 ml (32/36).ConclusionThe PEV in acute PTE may relate to the presence of respiratory symptoms, hypocapnia, and tachycardia. The PEV was smaller in patients with malignancy. It did not contribute to mortality in this study.

Appendiceal diverticulitis: multidetector CT features

PurposeAppendiceal diverticulitis has been difficult to distinguish from acute appendicitis clinically and radiologically. The purpose of this study was to describe multidetector computed tomography (MDCT) features of cases of pathologically proved appendiceal diverticulitis at our institution over a 36-month period.Materials and methodsSeven of 156 patients who underwent appendectomy with the preoperative diagnosis of acute appendicitis were pathologically diagnosed with appendiceal diverticulitis. Two radiologists reviewed the MDCT images for these 7 patients.ResultsOn MDCT, a total of 8 inflamed diverticula were visualized as small fluid-filled luminal structures with thick enhanced walls or as solid enhanced masses protruding from the appendix for 6 of 7 patients. For 2 of these 6 patients, MDCT revealed a total of 5 normal diverticula visualized as small air-filled luminal structures with thin walls. For 1 of the 7 patients, neither inflamed or normal diverticula could be identified on MDCT. MDCT revealed appendiceal wall thickening with a tiny or no luminal fluid collection for 5 patients and with a moderate fluid collection for 1 patient, and a normal appendiceal wall for 1 patient.ConclusionOur results suggest that MDCT can reveal appendiceal diverticula and has potential in the preoperative diagnosis of appendiceal diverticulitis.

Multidetector CT appearance of adhesion-induced small bowel obstructions: matted adhesions versus single adhesive bands

Adhesive small bowel obstruction (SBO) is a common cause of abdominal pain after surgery or peritonitis. The role of computed tomography (CT) in the evaluation of SBO has expanded. Diagnosis of adhesive SBO, however, remains challenging. Adhesions causing SBO are classified as either matted adhesions or single adhesive bands, and both types have different mechanisms that lead to SBO. In patients with matted adhesions, SBO results from angulation and kinking or from torsion of the intestines. In patients with adhesive bands, SBO results from compression of the intestine caused by the band itself. Recent advances in spatial resolution using multidetector CT (MDCT) have enabled detailed assessment of the configuration of the SBO site. Presented in this pictorial essay are characteristic MDCT findings regarding the mechanism of the obstruction process of adhesive SBO.

Multidetector computed tomography diagnosis of primary and secondary epiploic appendagitis

PurposeThe aim of this study was to evaluate the epiploic appendages in patients with acute abdomen using multidetector computed tomography (MDCT) and to determine the incidence of primary and secondary epiploic appendagitis (EA).Materials and methodsA radiologist reviewed MDCT images from 1338 patients with acute abdomen for visible epiploic appendages. Two radiologists then reviewed the MDCT images showing inflamed epiploic appendages and diagnosed primary EA, secondary EA, or other conditions by consensus. The CT criteria for primary EA are a round or oval pericolonic fatty lesion with a hyperattenuated rim and adjacent fat stranding, without other causes of inflammation. Secondary EA is diagnosed if an epiploic appendage is found to be due to inflammation from other inflammatory entities.ResultsEpiploic appendages were identified in 19 patients. Four patients (0.3%) had a retrospective CT diagnosis of primary EA. Twelve patients (0.9%) had a retrospective CT diagnosis of secondary EA (primary condition was diverticulitis in 10 patients and inflammatory bowel disease in 2 patients). The remaining three patients had calcification of an epiploic appendage suggestive of old EA.ConclusionPrimary EA should be included in the differential diagnosis of acute abdomen. Occasionally, inflammation of the epiploic appendages is secondary to other inflammatory conditions.

Scintigraphic findings of MALT lymphoma of the thyroid

Mucosa-associated lymphoid tissue (MALT) lymphoma has been established as a distinct entity among non-Hodgkin’s lymphomas, and the most common primary site is the stomach. We describe scintigraphic findings in a patient with MALT lymphoma of the thyroid. A 71-year-old woman with Hashimoto’s thyroiditis suffered from rapid cervical swelling, and ultrasonography and CT revealed a thyroid nodule. The nodule showed accumulation of99mTc pertechnetate comparable to the surrounding thyroid tissue, mimicking a benign nodule. Both67Ga and201Tl imaging visualized the lesion as an increased uptake area. After radiotherapy, abnormally increased uptake disappeared on67Ga images, which predicted a favorable outcome. MALT lymphoma of the thyroid may be visualized as a warm nodule on99mTc pertechnetate scintigraphy.

Cystic artery bleeding due to blunt gallbladder injury: computed tomography findings and treatment with transcatheter arterial embolization

Blunt gallbladder injury is rare, and bleeding from the cystic artery due to blunt trauma is even rarer. We report herein a case of extraluminal bleeding of the gallbladder in a patient following blunt abdominal trauma. Contrast-enhanced computed tomography revealed pericholecystic fluid and extravasation of contrast material in the subcapsular liver space adjacent to the gallbladder. Abdominal digital subtraction angiography revealed pseudoaneurysm originating from a branch of the cystic artery. Successful treatment was achieved using selective transcatheter embolization, and cholecystectomy was not required.

Discrimination between ureteral stent and stone by non‐contrast helical computed tomography in the clinical setting

Objective:  In urolithiasis with indwelling ureteral stent, an adequate visualization of retained stone is often obscured by the stent. In functional solitary kidney, it is essential to detect retained fragments before stent removal. We examined the capability of non‐contrast helical computed tomography (NCHCT) in discriminating stone from stent.

Arteriovenous malformation of the gallbladder: CT and angiographic findings

We encountered a case of arteriovenous malformation (AVM) of the gallbladder in a patient with hepatocellular carcinoma (HCC). Contrast-enhanced computed tomography (CT) showed serpentine vessels around and within the gallbladder wall. Angiography showed dilated and tortuous cystic arteries, a racemose vascular network, and early-filling cystic veins. Transcatheter arterial embolization of two cystic arteries feeding the AVM was performed with platinum microcoils prior to transcatheter arterial chemoembolization for HCC to prevent embolic particles from flowing into these arteries. Follow-up contrast-enhanced CT showed blood flow in the gallbladder AVM, which appeared to be fed by the arterial collaterals.