Diagnostic Impact of Quantitative Dual-Energy Computed Tomography Perfusion Imaging for the Assessment of Subsegmental Pulmonary Embolism.

OBJECTIVE: The aim of this study was to investigate the quantitative differences of dual-energy computed tomography perfusion imaging measurements in subsegmental pulmonary embolism (SSPE), between normal lung parenchyma (NLP) and hypoperfused segments (HPS) with and without thrombus on computed tomography angiography (CTA). METHODS: Lung attenuation, iodine density, and normalized uptake values were measured from HPS and NLP on iodine maps of 43 patients with SSPE. Presence of pulmonary embolism (PE) on CTA was recorded. One-way repeated-measures analysis of variance and Kruskal-Wallis analyses with post hoc comparisons were conducted. RESULTS: The numbers of HPS with and without SSPE on CTA were 45 (55.6%) and 36 (44.4%), respectively. Lung attenuation of NLP was significantly different from HPS (P < 0.001). Iodine density and normalized uptake values of HPS with PE were significantly lower than those of HPS without PE, which is significantly lower than NLP (P < 0.001). CONCLUSIONS: Subsegmental pulmonary embolism causes HPS on dual-energy computed tomography perfusion imaging, which demonstrates different iodine density and normalized uptake values depending on the presence of thrombus.

Generalized q-sampling imaging fiber tractography reveals displacement and infiltration of fiber tracts in low-grade gliomas.

PURPOSE: Low-grade gliomas (LGGs) are slow growing brain tumors that often cause displacement and/or infiltration of the surrounding white matter pathways. Differentiation between infiltration and displacement of fiber tracts remains a challenge. Currently, there is no reliable noninvasive imaging method capable of revealing such white matter alteration patterns. We employed quantitative anisotropy (QA) derived from generalized q-sampling imaging (GQI) to identify patterns of fiber tract alterations by LGGs. METHODS: Sixteen patients with a neuropathological diagnosis of LGG (WHO grade II) were enrolled. Peritumoral fiber tracts underwent qualitative and quantitative evaluation. Contralateral hemisphere counterparts were used for comparison. Tracts were qualitatively classified as unaffected, displaced, infiltrated or displaced, and infiltrated at once. The average QA of whole tract (W), peritumoral tract segment (S), and their ratio (S/W) were obtained and compared to the healthy side for quantitative evaluation. RESULTS: Qualitative analysis revealed 9 (13.8%) unaffected, 24 (36.9%) displaced, 13 (20%) infiltrated, and 19 (29.2%) tracts with a combination of displacement and infiltration. There were no disrupted tracts. There was a significant increase in S/W ratio among displaced tracts in the pre-operative scans in comparison with the contralateral side. QA values of peritumoral tract segments (S) were significantly lower in infiltrated tracts. CONCLUSION: WHO grade II LGGs might displace, infiltrate, or cause a combination of displacement and infiltration of WM tracts. QA derived from GQI provides valuable information that helps to differentiate infiltration from displacement. Anisotropy changes correlate with qualitative alterations, which may serve as a potential biomarker of fiber tract integrity.

Relationship between individual payload weight and spondylolysis incidence in Turkish land forces.

OBJECTIVEThe aim of this study was to investigate the relationship between lumbar spondylolysis and payload weight between different combat units of Turkish land forces (TLF).METHODThe authors reviewed clinical and radiological data of the military personnel with low-back pain (LBP) admitted to their clinic between July 2017 and July 2018. Age, BMI, average payload weight, and military service unit were recorded. CT scans were evaluated for pars interarticularis fractures and spondylolisthesis, whereas MRI studies were evaluated for spondylolisthesis, Modic-type endplate changes, or signal loss on T2-weighted images compatible with disc degeneration.RESULTFollowing exclusion, a total of 642 all-male military personnel were included. Of these personnel, 122 were commandos, 435 were infantry, and 85 were serving in the artillery units. Bilateral pars interarticularis fracture was noted in 42 commandos (34.42%) and 2 infantrymen (0.45%). There was no spondylolysis in the artillery units. There was no multiple-level spondylolysis and the most common level of spondylolysis was L5. Commandos had a significantly higher incidence of spondylolysis and more average payload weight (p < 0.001). Twelve patients (27.2%) with spondylolysis had accompanying MRI pathologies at the same level, whereas 32 patients (72.7%) had no accompanying MRI pathologies.CONCLUSIONSIncreased payload weight in military personnel is associated with spondylolysis, and commandos in the TLF have significantly heavier payloads, which causes an increased rate of spondylolysis compared to other units. Additionally, spondylolysis without adjacent-level changes on MRI could be undiagnosed. LBP in active military personnel who have a history of carrying heavy payloads should be evaluated extensively with both MRI and CT scans.

Value of duplex Doppler ultrasonography for the evaluation of dysfunctional hemodialysis access arteriovenous fistulas prior to endovascular interventions.

PURPOSE: To demonstrate accuracy of duplex Doppler ultrasonography (DUS) for the evaluation of native-vein arteriovenous fistula (AVF) dysfunction in end-stage renal disease patients. METHODS: This retrospective study included 60 patients with dysfunctioning native-vein AVF evaluated with DUS and digital subtraction angiography (DSA) whose results were compared for detection, identification, and localization of AVF lesions. We calculated sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of DUS and evaluated the agreement between DUS and DSA by the Cohen's kappa coefficient (κ). RESULTS: DUS identified correctly 123 of 130 lesions (sensitivity 94.6%, specificity 97.5%, PPV 98.4%, NPV 92%, accuracy of 95.7%). DUS localized correctly 123 of 130 lesions (sensitivity 94.6%, specificity 98.4%, PPV 98.4%, NPV 94.6%, accuracy 96.4%). The κ value was 0.9120 for detection of all lesions (almost perfect agreement). CONCLUSION: DUS is a reliable method for the initial evaluation of dysfunctional AVFs, with high sensitivity for detecting and correctly localizing circuit problems.

Retrosternal Goiter: A couple of classification methods with computed tomograpy findings.

OBJECTIVES: The retrosternal goiter (RSG), which can be defined by different classification and its incidence between 2% and 26% of all thyroidectomized patients, is a thyroid gland disease. Our aim was to classify RSG cases with a couple of different ways, which we have detected in computed tomography (CT) imaging of the thorax. METHODS: In this retrospective study conducted at Kars Harakani State Hospital Pulmonary Medicine Polyclinic between June 2014 and June 2017 in which 176 patients were included. The age, sex, diagnostic codes, retrosternal extension of the thyroid gland (aortic upper arch, aortic reaching arch and aortic inferior arch), extension type (prevascular, paratracheal retrovascular and retrotracheal), extension amount (mm) (<50% and 50%<) of thyroid gland of the patients were assessed. RESULTS: About 56.25% (n=99) were female and the mean age was 65.9±11.4 years. The most common co-morbid disease in patients with RSG was Chronic Obstructive Pulmonary Disease (COPD) (52.3%). Thirty nine (22.2%) of the patients had associated nodule, 16 (9.1%) had accompanying tracheal pressure and one patient had nodule and tracheal pressure. 27.3% of the patients' gland's right lobe and 28.9% of the patients' left lobe were extended >50% below the thoracic entry. Left thyroid gland's (90.3%) retrosternal extension and aortic arch spread (91.2%) were more. When classified according to the trachea, the left lobe's paratracheal and retrovascular extension (50.9%) was more. Extension amounts were similar for both thyroid lobes. CONCLUSION: In patients who have retrosternal goiter, goiter spread can be defined with multiple classification with thorax CT.

A diffusion spectrum imaging-based tractographic study into the anatomical subdivision and cortical connectivity of the ventral external capsule: uncinate and inferior fronto-occipital fascicles.

PURPOSE: The inferior fronto-occipital fasciculus (IFOF) and uncinate fasciculus (UF) are major fronto-capsular white matter pathways. IFOF connects frontal areas of the brain to parieto-occipital areas. UF connects ventral frontal areas to anterior temporal areas. Both fascicles are thought to subserve higher language and emotion roles. Controversy pertaining to their connectivity and subdivision persists in the literature, however. METHODS: High-definition fiber tractography (HDFT) is a non-tensor tractographic method using diffusion spectrum imaging data. Its major advantage over tensor-based tractography is its ability to trace crossing fiber pathways. We used HDFT to investigate subdivisions and cortical connectivity of IFOF and UF in 30 single subjects and in an atlas comprising averaged data from 842 individuals. A per-subject aligned, atlas-based approach was employed to seed fiber tracts and to study cortical terminations. RESULTS: For IFOF, we observed a tripartite arrangement corresponding to ventrolateral, ventromedial, and dorsomedial frontal origins. IFOF volume was not significantly lateralized to either hemisphere. UF fibers arose from ventromedial and ventrolateral frontal areas on the left and from ventromedial frontal areas on the right. UF volume was significantly lateralized to the left hemisphere. The data from the averaged atlas was largely in concordance with subject-specific findings. IFOF connected to parietal, occipital, but not temporal, areas. UF connected predominantly to temporal poles. CONCLUSION: Both IFOF and UF possess subdivided arrangements according to their frontal origin. Our connectivity results indicate the multifunctional involvement of IFOF and UF in language tasks. We discuss our findings in context of the tractographic literature.

Evaluation of popliteal artery branching patterns and a new subclassification of the 'usual' branching pattern.

PURPOSE: To determine the frequency of popliteal artery branching variations in a wide study cohort and to investigate the relationship between these variations and infrapopliteal peripheral arterial disease (PAD). A subclassification was proposed for the most encountered type I-A, utilizing tibio-fibular trunk (TFT) length. METHODS: A total number of 1184 lower extremity digital subtraction angiography (DSA) studies of 669 patients were evaluated. Following exclusion, 863 lower extremity DSA studies (431 right, 432 left) of 545 patients were enrolled. Popliteal artery branching type, patency of anterior tibial artery (ATA), fibular artery (FA) and posterior tibial artery (PTA) in each extremity and TFT length for type I-A extremities were recorded. Percentages of branching patterns, mean length and cut-off value of TFT and incidence of PAD in different types of branching were calculated. RESULTS: Type I-A was the most common type of branching (81.3%). Frequency of branching pattern variation was 18.7%, the most common variation category was category III (12.2%) and the most common variation type was type III-A (5.6%). ATA and PTA had higher percentages of PAD in extremities with variant branching types. Cut-off value of 3 cm for TFT length was proposed in order to subclassify type I-A. CONCLUSIONS: Our study cohort presents a higher incidence of popliteal artery branching variations. Some branching variations might have effect on the involvement pattern of the infrapopliteal arteries by PAD. We propose a subclassification for type I-A; type I-A-S (TFT < 3 cm) and type I-A-L (TFT ≥ 3 cm) which might have impact on interventional procedures.

Covered stent-graft treatment of a postoperative common carotid artery pseudoaneurysm.

BACKGROUND: Extracranial carotid artery pseudoaneurysms are rare cases resulting from trauma, mycotic infection, head and neck carcinomas or complications related to their treatment. Trauma is the most common cause of carotid artery pseudoaneurysms. They can also present after surgery, most commonly following endarterectomy, which is a rare cause with an estimated incidence of 0.3-0.6%. CASE REPORT: A 26-year-old male patient was admitted with swelling in his left neck after left carotid endarterectomy. Angiography confirmed pseudoaneursym in the left carotid bulb and it was treated successfully with two heparin-bonded covered stent grafts. CONCLUSIONS: Endovascular treatment of carotid pseudoaneurysms with covered stent-grafts is a safe and efficient method providing definitive arterial reconstruction. But series with longer follow-up periods are needed to evaluate patient compatibility to lifelong antiplatelet theraphy.

Superselective arterial embolization of pseudoaneurysm and arteriovenous fistula caused by transurethral resection of the prostate.

BACKGROUND: Pelvic vascular lesions such as pseudoaneurysms and arteriovenous fistulas associated with the internal pudendal artery are uncommon. The most common cause is traumas including those of iatrogenic origin. Surgical treatment is complicated due to location of the lesions and endovascular approach is usually the first choice among the treatment options. CASE REPORT: A 79-year-old patient was admitted with massive hematuria following transurethral resection of prostate for benign prostatic hyperplasia. Doppler US and angiography revealed a pseudoaneurysm and arteriovenous fistula originating from the right internal pudendal artery. It was successfully treated with coil embolization. CONCLUSIONS: Arteriovenous fistulas and pseudoaneurysms concerning internal pudendal artery may occur as complications of prostate operations. Minimally invasive endovascular methods provide safe and efficient treatment and today should be considered as the first line of choice.

The connectivity-based parcellation of the angular gyrus: fiber dissection and MR tractography study.

The angular gyrus (AG) wraps the posterior end of the superior temporal sulcus (STS), so it is considered a continuation of the superior temporal gyrus (STG)/ middle temporal gyrus (MTG) and forms the inferior parietal lobule (IPL) with the supramarginal gyrus (SMG). The AG was functionally divided in the literature, but there is no fiber dissection study in this context. This study divided AG into superior (sAG) and inferior (iAG) parts by focusing on STS. Red, blue silicone-injected eight and four non-silicone-injected human cadaveric cerebrums were dissected via the Klingler method focusing on the AG. White matter (WM) tracts identified during dissection were then reconstructed on the Human Connectome Project 1065 individual template for validation. According to this study, superior longitudinal fasciculus (SLF) II and middle longitudinal fasciculus (MdLF) are associated with sAG; the anterior commissure (AC), optic radiation (OR) with iAG; the arcuate fasciculus (AF), inferior frontooccipital fasciculus (IFOF), and tapetum (Tp) with both parts. In cortical parcellation of AG based on STS, sAG and iAG were associated with different fiber tracts. Although it has been shown in previous studies that there are functionally different subunits with AG parcellation, here, for the first time, other functions of the subunits have been revealed with cadaveric dissection and tractography images.