ABSTRACT
Constraints on work extraction are fundamental to our operational understanding of the thermodynamics of both classical and quantum systems. In the quantum setting, finite-time control operations typically generate coherence in the instantaneous energy eigenbasis of the dynamical system. Thermodynamic cycles can, in principle, be designed to extract work from this nonequilibrium resource. Here, we isolate and study the quantum coherent component to the work yield in such protocols. Specifically, we identify a coherent contribution to the ergotropy (the maximum amount of unitarily extractable work via cyclical variation of Hamiltonian parameters). We show this by dividing the optimal transformation into an incoherent operation and a coherence extraction cycle. We obtain bounds for both the coherent and incoherent parts of the extractable work and discuss their saturation in specific settings. Our results are illustrated with several examples, including finite-dimensional systems and bosonic Gaussian states that describe recent experiments on quantum heat engines with a quantized load.
ABSTRACT
We discuss the thermodynamics of closed quantum systems driven out of equilibrium by a change in a control parameter and undergoing a unitary process. We compare the work actually done on the system with the one that would be performed along ideal adiabatic and isothermal transformations. The comparison with the latter leads to the introduction of irreversible work, while that with the former leads to the introduction of inner friction. We show that these two quantities can be treated on an equal footing, as both can be linked with the heat exchanged in thermalization processes and both can be expressed as relative entropies. Furthermore, we show that a specific fluctuation relation for the entropy production associated with the inner friction exists, which allows the inner friction to be written in terms of its cumulants.
ABSTRACT
Exploiting the relative entropy of coherence, we isolate the coherent contribution in the energetics of a driven nonequilibrium quantum system. We prove that a division of the irreversible work can be made into a coherent and incoherent part. This provides an operational criterion for quantifying the coherent contribution in a generic nonequilibrium transformation on a closed quantum system. We then study such a contribution in two physical models of a driven qubit and kicked rotor. In addition, we also show that coherence generation is connected to the nonadiabaticity of a processes, for which it gives the dominant contribution for slow-enough transformations. The amount of generated coherence in the energy eigenbasis is equivalent to the change in diagonal entropy, and here we show that it fulfills a fluctuation theorem.
ABSTRACT
Three cases of secondary gastric lymphoma are presented in which diagnosis was suggested by ultrasound (US) and confirmed by endoscopy and microscopical examination. Three different US patterns are illustrated and compared with endoscopy. US findings paralleled endoscopy during follow-up under antiblastic treatment: both improvement and lack of change in the gastric lesions were reliably predicted by US.
Subject(s)
Lymphoma/diagnosis , Stomach Neoplasms/diagnosis , Ultrasonography , Aged , Aged, 80 and over , Antineoplastic Agents/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Female , Gastroscopy , Humans , Lymphoma/drug therapy , Stomach Neoplasms/drug therapyABSTRACT
247 cases of patients suffering from chronic liver diseases were reviewed. These cases were divided according to "risk areas" (viral, alcoholic, viral and alcoholic, cryptogenic) and diagnosis (CAH, compensated cirrhosis, decompensated cirrhosis). Differences found in clinical and laboratory aspects of liver diseases from different risk areas are described but it is concluded that no single aetiology affects the liver functional reserve more than the others. Laboratory tests give more information in the early stages of chronic liver diseases while clinical analysis is more varied in the terminal ones. Literature on the subject is reviewed. Our data neither confirm nor disprove that HBsAg+ Alcohol+ patients display a characteristic clinical picture and this hypothesis should be further investigated.
Subject(s)
Liver Diseases/pathology , Adolescent , Adult , Aged , Chronic Disease , Female , Hepatitis, Viral, Human/pathology , Humans , Liver Cirrhosis/pathology , Liver Diseases/etiology , Liver Diseases, Alcoholic/pathology , Male , Middle Aged , Platelet Count , Prothrombin Time , Retrospective Studies , Risk , Serum Albumin/analysis , Sex Factors , gamma-Globulins/analysisABSTRACT
INTRODUCTION: The interobserver variability of the sonographic assessment of Focal Bladder Wall Abnormalities (FBWA) between two physicians with different levels of experience was evaluated prospectively. MATERIALS AND METHODS: In the same session the two operators examined independently the urinary bladder of 87 consecutive patients (Mean Age 68 yrs; range 33-80; 75 Males; 15 Females) who underwent cystoscopy within 1-2 days. Before beginning the study, the two observers standardized the process for US exam. Weighted kappa statistics were used to determine the degree of agreement as to the presence, size, location and number of FBWA detected at cystoscopy. RESULTS: the highest level of agreement (k = 1) was reached on the presence of FBWA, whereas a substantial agreement was reached on size (k = 0.78), number (k = 0.72) and location (k = 0.62) of FBWA. CONCLUSIONS: In this study the gap in US experience between two operators did not emerge in assessing FBWA, provided a standardized technical approach is pursued.
ABSTRACT
INTRODUCTION: The aim of the present study was to highlight the sonographic and clinical characteristics of large (≥30 mm in diameter) scar endometriomas near Pfannenstiel incisions, assuming that large size is a marker of delayed diagnosis. METHODS: We compared clinical, ultrasound (US) and color Doppler findings in 13 patients (mean age 31.3 years) with 13 large scar endometriomas (L-SEs) (mean lesion diameter 41.8 mm; range 30-60 mm) and 17 women (mean age 30.7 years) with 19 small scar endometriomas (S-SEs) (mean lesion size 18.3 mm; range 7-26 mm). RESULTS: Compared with the S-SE group, the L-SE group had a significantly longer mean interval between the last cesarean section and hospital admission (5.5 vs. 3.3 years; p < 0.01) and longer mean duration of symptoms before admission (43 vs. 17.4 months; p < 0.01). The L-SE group also had a significantly higher percentage of patients who had undergone at least one inconclusive diagnostic examination (Computed Tomography, Magnetic Resonance Imaging, fine needle biopsy, or laparoscopy) (39% vs. 0%; p < 0.05). As for US findings, L-SEs more frequently displayed cystic regions and fistulous tracts (p < 0.05), loss of round/oval shape (p < 0.05), and increased vascularity (p < 0.05). CONCLUSIONS: Delayed diagnosis of scar endometrioma reflected by a longer and more complex medical history results in larger than usual endometriomas with peculiar US findings, which are even more likely to be misinterpreted by physicians and radiologists.
ABSTRACT
PURPOSE: To assess factors affecting the effectiveness of percutaneous laser ablation (PLA) under ultrasound (US) guidance in terms of complete ablation achievement. MATERIAL AND METHODS: The clinical records of 86 hepatocellular carcinoma (HCC) tumors (mean diameter 23.7 mm) in 60 cirrhotic patients (mean age 68.3 years; 36 males; 57 HCV+; 53 Child's class A, seven Child's class B) treated by means of PLA were reviewed. PLA was performed with a continuous-wave Nd:YAG laser by a single operator who positioned two to four 300-microm optic fibers advanced in 21-gauge needles into target lesions under US guidance. Triphasic computed tomography (CT) studies were used to verify treatment effectiveness 1 month after PLA completion. The association between characteristics of the lesion and outcome (complete or incomplete ablation) was evaluated by logistic regression, taking into account the following predictive factors: tumor size, pattern of growth (infiltrating or not) at imaging, location, first diagnosis of HCC (naïve tumors vs. non-naïve tumors), number of sessions (1/ > 1), total delivered energy, and years of treatment in 2001-2002 (first period) vs. 2003-2004 (second period). RESULTS: Complete ablation was obtained in 62 nodules (72%). Statistically significant predictors of incomplete ablation after the first PLA course at both univariate and multivariate analysis included: infiltrating growth pattern (odds ratio (OR) 12.3, P<0.002), non-naïve tumors (OR 8.7, P<0.001), and first period of treatment (OR 10.3, P<0.002). CONCLUSION: The effectiveness of US-guided PLA for HCC tumors < or =4 cm turned out to be negatively affected by both operator-related (the beginning of the operator's experience with the technique) and tumor-related factors (non-naïve, infiltrating HCC tumors).
Subject(s)
Carcinoma, Hepatocellular/surgery , Laser Coagulation/methods , Liver Cirrhosis/complications , Liver Neoplasms/surgery , Adult , Aged , Aged, 80 and over , Carcinoma, Hepatocellular/diagnostic imaging , Female , Humans , Liver Neoplasms/diagnostic imaging , Male , Middle Aged , Multivariate Analysis , Necrosis , Retrospective Studies , Treatment Outcome , UltrasonographyABSTRACT
BACKGROUND: We describe the clinical and color Doppler ultrasound findings in a series of cases of seeding from hepatocellular carcinoma (HCC) observed in patients treated with percutaneous ablation therapy (PAT) over a 15-year period. METHODS: We reviewed the clinical and imaging records of 12 patients with cirrhosis (nine men and three women, age range 51-82 years, mean age 63 years) that showed neoplastic seeding from HCC occurring after one or more PAT procedures. Five of 12 cases of seeding were observed as a complication of 1080 PAT procedures (0.46%) performed in 545 patients (0.96%) by two of the authors (L.T., G.F.) over a long period (15 years) at different institutions. The other seven patients had been treated with PAT procedures at other institutions and had come to our attention during post-treatment follow-up. RESULTS: The 12 patients who had seeding nodules had undergone the following PAT procedures: multisession conventional percutaneous ethanol injection (PEI) without anesthesia (four patients), single-session PEI with general anesthesia (three patients), single-session PEI with general anesthesia plus multisession conventional PEI (four patients), and single-session PEI plus radiofrequency ablation (one patient). Seeding nodules ranged from 0.9 to 6.0 cm (mean 1.7 cm). Eleven of 12 seeding nodules appeared as hypervascular hypoechoic nodules with smooth and regular margins and multiple intralesional vascular signals. CONCLUSIONS: Clinical and imaging findings of seeding from HCC should be recognized by physicians who perform follow-up ultrasound examinations of patients who are treated with PAT. Early diagnosis of seeding can be reliably made by scanning the abdominal wall with small probes in the area where the previous PAT has been performed. Hypoechoic hypervascular pattern of the seeding nodule allows definitive diagnosis.
Subject(s)
Carcinoma, Hepatocellular/diagnostic imaging , Carcinoma, Hepatocellular/pathology , Catheter Ablation/adverse effects , Liver Neoplasms/diagnostic imaging , Liver Neoplasms/pathology , Neoplasm Seeding , Ultrasonography, Doppler, Color , Aged , Aged, 80 and over , Carcinoma, Hepatocellular/surgery , Female , Humans , Liver Neoplasms/surgery , Male , Middle Aged , Postoperative Period , Retrospective StudiesABSTRACT
BACKGROUND: We assessed the role of contrast-enhanced ultrasound (CEUS) in the differential diagnosis between benign and malignant portal vein thrombosis in patients who had cirrhosis with hepatocellular carcinoma (HCC). METHODS: Fifty-four consecutive patients who had cirrhosis, biopsy-proved HCC, and thrombosis of the main portal vein and/or left/right portal vein on US were prospectively studied with color Doppler US (CDUS) and CEUS. CEUS was performed at low mechanical index after intravenous administration of a second-generation contrast agent (SonoVue, Bracco, Milan, Italy). Presence or absence of CDUS signals or thrombus enhancement on CEUS were considered diagnostic for malignant or benign portal vein thrombosis. Twenty-eight patients also underwent percutaneous portal vein fine-needle biopsy (FNB) under US guidance. All patients were followed-up bimonthly by CDUS. Shrinkage of the thrombus and/or recanalization of the vessels on CDUS during follow-up were considered definitive evidence of the benign nature of the thrombosis, whereas enlargement of the thrombus, disruption of the vessel wall, and parenchymal infiltration over follow-up were considered consistent with malignancy. CDUS, CEUS, and FNB results were compared with those at follow-up. RESULTS: Follow-up (4 to 21 months) showed signs of malignant thrombosis in 34 of 54 patients. FNB produced a true-positive result for malignancy in 19 of 25 patients, a false-negative result in six of 25 patients, and a true-negative result in three of three patients. CDUS was positive in seven of 54 patients. CEUS showed enhancement of the thrombus in 30 of 54 patients. No false-positive result was observed at CDUS, CEUS, and FNB. Sensitivities of CDUS, CEUS, and FNB in detecting malignant thrombi were 20%, 88%, and 76% respectively. Three patients showed negative CDUS and CEUS and positive FNB results; follow-up confirmed malignant thrombosis in these patients. One patient showed negative CDUS, CEUS, and FNB findings. However, follow-up of the thrombus showed US signs of malignancy. Another FNB confirmed HCC infiltration of the portal vein. CONCLUSION: CEUS seems to be the most sensitive and specific test for diagnosing malignant portal vein thrombosis in patients with cirrhosis.
Subject(s)
Carcinoma, Hepatocellular/diagnostic imaging , Liver Cirrhosis/diagnostic imaging , Liver Neoplasms/diagnostic imaging , Portal Vein , Ultrasonography, Doppler, Color , Venous Thrombosis/diagnostic imaging , Aged , Aged, 80 and over , Biopsy, Fine-Needle , Carcinoma, Hepatocellular/complications , Carcinoma, Hepatocellular/pathology , Contrast Media , Diagnosis, Differential , Female , Humans , Liver Cirrhosis/complications , Liver Cirrhosis/pathology , Liver Neoplasms/complications , Liver Neoplasms/pathology , Male , Middle Aged , Phospholipids , Predictive Value of Tests , Prospective Studies , Sulfur Hexafluoride , Venous Thrombosis/complications , Venous Thrombosis/pathologyABSTRACT
OBJECTIVE: Radiofrequency hyperthermia using the newly-developed 'cooled-tip' needle has recently been proposed as a therapeutic modality for hepatocellular carcinoma (HCC). Herein we report our preliminary results on feasibility and effectiveness of the thermal ablation of mono- or pauci-focal hepatocellular carcinoma with the cooled-tip needle. MATERIALS AND METHODS: We treated 15 cirrhotic patients (mean age 68.8 years; 12 males; 14 HCV-positive; 13 in Child's Class A and 2 in Class B) with 20 hepatocellular carcinoma nodules (mean diameter 28.1 mm; range 10-43 mm; nine lesions with diameter greater than 3 cm). None of the patients had portal thrombosis and/or extrahepatic spread. We used a radiofrequency generator (100 W of power) connected to a 18 g perfusion electrode needle with an exposed tip of 2-3 cm. The circuit was closed through a dispersive electrode positioned under the patient's thighs. A peristaltic pump infused a chilled (2-5 degrees C) saline solution to guarantee the continuous cooling of the needle tip. The needle was placed into target lesions under US guidance. The interventional procedure was carried out in general anesthesia without intubation. Dynamic helical CT was carried out 15-20 days after thermal ablation to assess therapeutic efficacy. RESULTS: In all, 38 areas of coagulation necrosis (at 1000-1200 mA for 10-15 min) were generated in 24 sessions in the 20 hepatocellular carcinoma nodules (mean 1.9 lesions per nodule and 1.2 sessions per nodule). Complete necrosis as assessed at dynamic CT (lack of enhancement during the arteriographic phase) was achieved in 75% of cases in a single session; after a second RF session success rate was 90% (18 out of 20 nodules). A self-limited pleurisy along with a 5-fold increase in transaminases occurred in one patient; a 3-fold elevation of transaminases was encountered in three other patients. During the follow-up (median 15 months) five patients had recurrent hepatocellular carcinoma with a 1-year disease free interval of 64%. Of the three recorded deaths, two were due to intrahepatic tumor diffusion. CONCLUSIONS: In our experience radiofrequency hyperthermia with the cooled-tip needle afforded an effective and safe percutaneous ablative method for HCC in cirrhosis and shortened treatment time.
Subject(s)
Carcinoma, Hepatocellular/diagnostic imaging , Carcinoma, Hepatocellular/therapy , Hyperthermia, Induced/methods , Liver Neoplasms/diagnostic imaging , Liver Neoplasms/therapy , Aged , Female , Follow-Up Studies , Humans , Hyperthermia, Induced/adverse effects , Hyperthermia, Induced/instrumentation , Male , Neoplasm Recurrence, Local , UltrasonographyABSTRACT
Sensitivity and specificity of physical and laboratory findings have been evaluated for the purpose of establishing a differential diagnosis between cirrhosis and chronic active hepatitis on clinicolaboratory grounds. Data from 213 patients from southern Italy with biopsy-proven chronic active hepatitis or cirrhosis have been studied retrospectively. Splenomegaly, hypocholesterolemia, and decreased sulfobromophthalein-Ki were among the most sensitive individual findings in cirrhosis, whereas decreased platelet count, jaundice, and hypoprothrombinemia were the most specific ones. The presence in the same patient of both one of the former and one of the latter findings yields a correct diagnosis of cirrhosis with at least 90% likelihood. Advantages of the proposed diagnostic technique and comparison with data from an American series are discussed.
Subject(s)
Hepatitis, Chronic/diagnosis , Liver Cirrhosis/diagnosis , Adolescent , Adult , Aged , Cholesterol/blood , Diagnosis, Differential , Female , Humans , Hypoprothrombinemias/etiology , Italy , Male , Middle Aged , Platelet Count , Retrospective Studies , Splenomegaly/etiology , SulfobromophthaleinABSTRACT
A series of clinical steps in the severity of chronic liver disease (CLD) has been arranged to represent the case history of chronic active hepatitis and cirrhosis retrospectively. The 'steps' in such series of clinical stages have been chosen on the basis of physiopathological considerations, the state of health of the patients, and their ability to work. For every 'step' the laboratory findings were studied in order to verify the hypothesis that a laboratory case history exists, which is parallel to the clinical history of CLD. With the exception of serum albumin and, to a lesser extent, sulfobromophthalein-ki, which seem to reflect the progressive deterioration in hepatocellular function, the results suggest that most conventional tests do not seem to be of any value in monitoring a CLD patient in cases where the diagnosis is already known, whereas a physical examination provides a physician with more, and cheaper, information than laboratory tests.
Subject(s)
Hepatitis, Chronic/diagnosis , Liver Cirrhosis/diagnosis , Alanine Transaminase/blood , Ascites/diagnosis , Aspartate Aminotransferases/blood , Edema/diagnosis , Esophageal and Gastric Varices/diagnosis , Female , Hepatomegaly/diagnosis , Humans , Jaundice/diagnosis , Liver Function Tests , Male , Middle Aged , PrognosisABSTRACT
Forty-six patients with cirrhosis and 75 biopsy-proved hepatocellular carcinoma (HCC) nodules underwent percutaneous ethanol injection (PEI) regardless of number (up to five) and size (mean diameter, 3.6 cm) of tumoral lesions and clinical severity of cirrhosis (11 patients in Child's class C were included). Ethanol was injected under sonographic guidance through 20 to 22 gauge needles so as to obtain homogeneous hyperechogenicity of lesions. A total of 271 PEI sessions were carried out, delivering 2 to 14 ml per session. All nodules but one decreased in size, and seven were no longer appreciable on sonography. Recurrence was detected in two patients. The 3 year survival rate of all cases was 86%. Child's classes A and B patients fared better (3 yr survival 100%); 2 year survival of subjects with HCC < or = 3 cm was 92%. Multifocality did not affect survival. Most patients experienced mild pain at the site of injection, but only two major complications were encountered: partial chemical thrombosis of the left portal vein and cholangitis. Both cases were managed conservatively. In conclusion, PEI seems to offer a safe and valuable tool for therapy of HCC, especially in patients with good functional liver reserve and small (< or = 3 cm) tumors.
Subject(s)
Carcinoma, Hepatocellular/therapy , Ethanol/therapeutic use , Liver Cirrhosis/complications , Liver Neoplasms/therapy , Carcinoma, Hepatocellular/complications , Carcinoma, Hepatocellular/mortality , Ethanol/administration & dosage , Female , Follow-Up Studies , Humans , Liver/diagnostic imaging , Liver Neoplasms/complications , Liver Neoplasms/mortality , Male , Middle Aged , Survival Rate , Time Factors , UltrasonographyABSTRACT
Sixteen hydatid liver cysts in 14 patients were treated with a percutaneous double puncture-aspiration-injection (D-PAI) technique with alcohol used as the scolecidal agent. With ultrasound guidance, fine-needle drainage of cysts was performed, and 95% sterile alcohol was injected and left in situ to partly refill the cystic cavities. The same procedure, without reaspiration of the injected alcohol, was performed 3 days later. Viability of scoleces was assessed at each aspiration. Benzoimidazolic drugs were administered 1 week before and 3 weeks after the procedure, to reduce the risk of seeding scoleces. Follow-up ranged from 8 to 28 months (mean, 14 months). Six cysts disappeared within 40-75 days of completion of D-PAI. In the other patients, smaller liquid areas or hypo- or hyperechoic solid masses were observed. Anaphylactoid reactions did not occur. In one patient, a biliary fistula developed after the first aspiration; the second ethanol injection was postponed until 6 months later but was effective. Viable scoleces were found at the second aspiration in only two patients whose hepatic liver cysts completely healed. Serologic titers substantially decreased in seven cases and became negative in two.
Subject(s)
Alcohols/administration & dosage , Echinococcosis, Hepatic/therapy , Suction/methods , Adult , Aged , Echinococcosis, Hepatic/diagnostic imaging , Female , Humans , Male , Middle Aged , Punctures , UltrasonographyABSTRACT
Ultrasound appearance of intragallbladder haemorrhage in two patients with haemobilia is presented. Gallbladder lumina were occupied by non-shadowing, firm masses of mixed echogenicity representing blood clots. In both cases iatrogenic trauma following percutaneous transcholecystic cholangiography and blind hepatic biopsy caused bleeding in the biliary tree.
Subject(s)
Gallbladder Diseases/diagnostic imaging , Hemobilia/diagnostic imaging , Hemorrhage/diagnostic imaging , Aged , Biopsy/adverse effects , Cholangiography/adverse effects , Female , Gallbladder Diseases/etiology , Hemobilia/etiology , Hemorrhage/etiology , Humans , Male , Middle Aged , UltrasonographyABSTRACT
A 53-year-old-man underwent US-guided percutaneous thermal ablation with a cooled-tip needle of three liver metastases from gastric cancer. Six days later, the patient was re-admitted for melena, scleral jaundice, and anemia. Abdominal US disclosed echogenic material in the gallbladder lumen (hemobilia) and a focal lesion with mixed echotexture in segment III (hepatic hematoma). On day 5 portal cavernomatosis was diagnosed at US and confirmed by color Doppler and a helical CT exam. The case described emphasizes that radio-frequency interstitial hyperthermia may cause not only traumatic injury of the liver parenchyma but also thermally mediated damage of vascular structures.