Leonhard Gruber

• MD, Priv.-Doz., PhD
• Senior consultant at Innsbruck Medical University

Background/Objectives: Large language models (LLMs), such as ChatGPT, have emerged as potential clinical support tools to enhance precision in personalized patient care, but their reliability in radiological image interpretation remains uncertain. The primary aim of our study was to evaluate the diagnostic accuracy of ChatGPT-4o in interpreting che...

Objectives: Prediction of lung function deficits following pulmonary infection is challenging and suffers from inaccuracy. We sought to develop machine-learning models for prediction of post-inflammatory lung changes based on COVID-19 recovery data. Methods: In the prospective CovILD study (n = 420 longitudinal observations from n = 140 COVID-19 su...

Germ cell tumors (GCTs) represent about 5% of urological cancers affecting mostly younger males with increasing incidence in the last decades. GCTs are very sensitive to cisplatin-based therapy and are highly curable regardless of metastatic stage, likely based on having inherited unique mechanisms of sensitivity to DNA damage and other stressors t...

Ultrasound is a highly effective imaging tool for assessing abnormalities within the breast. However, especially the identification of malignant tumors of the breast mimicking fibroadenomas (MTMF) by means of breast ultrasound can be challenging. This study aimed to identify reliable imaging characteristics of MTMF. This retrospective study was app...

Purpose Radiolabelled minigastrin (MG) analogues targeting the cholecystokinin-2 receptor (CCK2R) have proven to be a promising approach for peptide receptor radionuclide therapy (PRRT). In this study, we report on the radiopharmaceutical development and standardization of the preparation of [¹⁷⁷Lu]Lu-DOTA-MGS5 using an automated synthesis module....

Background To investigate the artifact sizes of four common breast clip-markers on a standard breast magnetic resonance imaging (MRI) protocol in an in vitro phantom model. Methods Using 1.5-T and 3-T whole-body scanners with an 18-channel breast coil, artifact dimensions of four breast biopsy markers in an agarose-gel phantom were measured by two...

Background Prostate biopsies are an invasive procedure that can lead to anxieties and fear before the examination. Prostate magnetic resonance imaging (MRI) is seen as a non-invasive test although it is known that “scanxiety” affects many patients. Transrectal ultrasound (TRUS)-guided prostate biopsies and multiparametric prostate MRI (mpMRI) are c...

The objective of this pilot study was to assess the reliability of superb microvascular ultrasound (SMI) for the measurement of the cerebrospinal fluid (CSF) flow within VPS systems as an indirect sign for shunt dysfunction. Asymptomatic hydrocephalus patients, with a VPS system implanted between 2017 and 2021, were prospectively enrolled in the st...

Background Cardiovascular risk (CV)-stratification in females is challenging, and current models miss a high proportion at-risk. Breast arterial calcifications (BAC) are independent prognosticators, but their interaction with the coronary artery disease profile by computed tomography (CT) is controverse, and the role of BAC 0 unclear. Objective to...

Background: A better understanding of the peritumoral stroma changes due to tumour invasion using non-invasive diagnostic methods may improve the differentiation between benign and malignant breast lesions. This study aimed to assess the correlation between breast lesion differentiation and intra- and peritumoral shear-wave elastography (SWE) gradi...

Introduction: Aneurysmal wall enhancement (AWE) of non-ruptured sacular intracranial aneurysms (IA) after endovascular treatment (ET) is a frequently observed imaging finding using AWE-sequences in brain magnetic resonance imaging (MRI). So far, its value remains unclear. We aimed to investigate the effect of AWE on aneurysm reperfusion rates in a...

Aneurysmal wall enhancement (AWE) of non-ruptured sacular intracranial aneurysms (IA) after endovascular treatment (ET) is a frequently observed imaging finding. So far, its value remains unclear. We aimed to investigate the effect of AWE on aneurysm reperfusion rates in a longitudinal cohort. This is a retrospective MRI study over the timespan of...

Background: Blunt traumatic aortic injury (BTAI) is a potentially fatal condition, typically resulting from high-velocity trauma. To date, little is known about this type of injury among skiers, who form the largest patient cohort with aortic injuries in the alpine region of Tyrol, Austria. Methods: This retrospective, single-center study at the Un...

One of the main causes of the dismal prognosis in patients who survive the initial bleeding after aneurysmal subarachnoidal hemorrhage is the delayed cerebral ischaemia caused by vasospasm. Studies suggest that cerebral magnesium and pH may potentially play a role in the pathophysiology of this adverse event. Using phosphorous magnetic resonance sp...

Purpose: The purpose of this study was to evaluate human interreader agreement of the PGMI (perfect good moderate inadequate) quality assessment in screening mammography and explore the role of artificial intelligence (AI) as an alternative reader. Methods: Five independent readers from three European countries (Austria, Norway, Switzerland) perfo...

One of the main causes of the dismal prognosis in patients who survive the initial bleeding after aneurysmal subarachnoidal hemorrhage is the delayed cerebral ischaemia caused by vasospasm. Studies suggest that cerebral magnesium and pH may potentially play a role in the pathophysiology of this adverse event. Using phosphorous magnetic resonance sp...

Background: Compared to conventional 2D mammography, digital breast tomosynthesis (DBT) offers greater breast lesion detection rates. Ring-like hypodense artifacts surrounding dense lesions are a common byproduct of DBT. This study’s purpose was to assess whether minuscule changes spanning this halo—termed the “broken halo sign”—could improve lesio...

To evaluate the diagnostic utility of the maximum ultrasound strain elastography (SE) halo depth in newly diagnosed and histologically confirmed breast lesions, a retrospective study approval was granted by the local Ethical Review Board. Overall, the maximum strain elastography peritumoural halos (SEPHmax)—the maximum distance between the SE stiff...

Long-term follow-up data comparing surgical and endovascular revascularization of femoropopliteal lesions is rarely reported. This study presents 4-year results of revascularization for long femoropopliteal lesions (Trans-Atlantic Inter-Society Consensus Types C and D) with vein bypass (VBP), polytetrafluorethylene bypass (PTFE), and endovascular i...

Purpose: To compare contrast-enhanced spectral mammography (CESM) with mammography (Mx), ultrasound (US), and magnetic resonance imaging (MRI) regarding breast cancer detection rate and preoperative local staging. Material and methods: This prospective observational, single-centre study included 128 female patients (mean age 55.8 ± 11.5 years) w...

Background: Discrimination between benign and atypical lipomatous tumors (ALT) is important due to potential local complications and recurrence of ALT but can be difficult due to the often-similar imaging appearance. Using a standardized MRI protocol, this study aimed to rank established and quantitative MRI features by diagnostic value in the diff...

Changes in the microvascular environment are considered crucial in the pathogenesis of compression neuropathies. Several studies have demonstrated elevated intraneural vascularity in severe neuropathy compared with healthy subjects, where intraneural vascularity is considered predominantly undetectable. The aim of this study was to assess and quant...

Purpose Vascular injuries in lower extremity trauma, especially with involvement of the popliteal artery, are associated with considerably high rates of limb loss, especially with blunt trauma mechanisms. The aim of this study was to evaluate the risk of amputation in patients with traumatic popliteal artery lesions with special focus on the validi...

Background: Gastrin-releasing peptide receptors (GRPRs) are molecular imaging targets in multiple malignancies. Recently, NeoBOMB1, a 68Ga-labelled antagonist to GRPRs, was developed for PET. Here we report the outcome of a Phase I/IIa clinical trial (EudraCT 2016-002053-38) describing diagnostic properties and covariates influencing uptake of 68G...

Conduction disorders following cardiac surgery are common complications with incidences of permanent pacemaker dependency up to 5%. However, data on pacemaker implantation rates in the long-term follow-up after Bentall operations are scarce. In a retrospective study, a mixed cohort of 260 patients including endocarditis and aortic dissection underg...

Introduction There is no uniform consensus on the gold standard therapy for acute Achilles tendon rupture. The aim of this pilot study was to compare operative and conservative treatment regarding imaging findings and clinical outcome. Materials and methods Surgically or conservatively treated patients with acute Achilles tendon rupture were retro...

Background The long-term pulmonary sequelae of coronavirus disease 2019 (COVID-19) is not well known. Purpose To characterize patterns and rates of improvement of chest CT abnormalities one year after COVID-19 pneumonia. Materials and Methods This was a secondary analysis of a prospective, multicenter observational cohort study conducted fro...

Background & objective Arterial vascular trauma bears a great risk of poor functional outcome or limb loss. The aim of this study was to analyze amputation rates of patients after vascular trauma and to perform a predictor analysis for the risk of major amputation. Methods In a single-center retrospective analysis of 119 extremities treated for ar...

Purpose: Intensive care unit-acquired weakness occurs frequently in intensive care unit patients, including critical illness myopathy (CIM) and critical illness polyneuropathy (CIPN). The authors present a prospective study to assess the ultrasound pattern sum score to differentiate between confirmed CIM, sensory neuropathy, and CIPN cases. Metho...

Introduction: Nephro- and hematotoxicity after peptide receptor radionuclide therapy (PRRT) have been described in multiple studies with heterogeneous cumulative activities, number of cycles or radiolabelled peptides. Though highly differentiated metastasized neuroendocrine tumours (NET) have long progression free survival, they may progress. We a...

Purpose Interval breast carcinomas (IBC) constitute a subgroup of malignancies in women participating in a breast cancer screening programme, yet diagnosed outside of a screening appointment. Tyrol is an Austrian screening model region with a dedicated IBC board. We analysed IBC subtype distribution, demographic and biological parameters and implic...

Backgrounds: The number of practicing female urologists is rising. The aim of this study is to evaluate the acceptance of female urologists by male patients and their partners. Methods: Men who underwent a prostate MRI or a prostate biopsy between January and December 2018 and their partners, were sent questionnaires prior to the examination. Tw...

Background Peripheral arterial disease (PAD) is accompanied by myopathy characterized by mitochondrial dysfunction. The aim of this experimental study was to investigate the effect of revascularization procedures on mitochondrial function in ischemic and non-ischemic muscle. Methods Muscle biopsies from patients with symptomatic stage IIB/III PAD...

A solely retroperitoneal mass in males in combination with elevated serum Alpha-Fetoprotein (AFP) and beta-human choriogonadotropin (β-HCG) levels is highly indicative of a metastatic testicular cancer. Although testicular cancers are rare, they represent the most common diagnosed cancer in males between 14 and 40 years. However, in cases without e...

Introduction : Compartment syndrome of the lower extremity following arterial vascular trauma can cause irreversible damage to muscle as well as nerve tissue leading to long-term functional impairment of the extremity or worse limb loss. Prompt diagnosis and treatment of compartment syndrome is mandatory to preserve muscle tissue and prevent limb l...

Purpose Nephro- and hematotoxicity after peptide receptor radionuclide therapy (PRRT) have been described in multiple studies with heterogeneous cumulative activities, number of cycles or radiolabelled peptides. Though highly differentiated metastasized neuroendocrine tumours (NET) have long progression free survival, they may progress. We analysed...

Purpose To present a safety-optimized ultrasound-guided minimal invasive carpal tunnel release (CTR) procedure. Materials and Methods 104 patients (67 female, 37 male; mean age 60.6 ± 14.3 years, 95% CI 57.9 to 63.4 years) with clinical and electrophysiological verified typical carpal tunnel syndrome were referred for a high-resolution ultrasound...

Introduction: Gastrin Releasing peptide receptors (GRPRs) are potential molecular imaging targets in a variety of tumors. Recently, a 68Ga-labelled antagonist to GRPRs, NeoBOMB1, was developed for PET. We report on the outcome of a Phase I/IIa clinical trial (EudraCT 2016-002053-38) within the EU-FP7 project Closed-loop Molecular Environment for Mi...

Background Peripheral nerve pathologies of the upper extremity are increasingly assessed by high-resolution ultrasonography (HRUS), yet rapid identification of nerve segments can be difficult due to small nerve diameters and complex regional anatomy. We propose a landmark-based approach to speed up and facilitate evaluation and intervention in this...

Purpose: 18F-Fluoro-L-dihydroxyphenylalanine (18F-DOPA) PET offers high sensitivity and specificity in the imaging of non-malignant head and neck paraganglioma (HNPGL) but lower sensitivity in metastatic disease of these neuroendocrine tumours (NET). In contrast to the radiotracer 18F-DOPA, both 123I-meta-iodo-benzylguanidine (123I-MIBG) and 68Ga-...

Objective: 18F-Fluoro-L-dihydroxyphenylalanine (18F-DOPA) PET offers high sensitivity and specificity in the imaging of non-malignant extra-adrenal paraganglioma (PGL) and pheochromocytoma (PHEO) but lower sensitivity in metastatic disease. These tumours are of neuroendocrine origin and can be detected by 68Ga-DOTA-Tyr3-octreotide (68Ga-DOTA-TOC)...

Purpose ¹⁸F-Fluoro-l-dihydroxyphenylalanine (¹⁸F-DOPA) PET offers high sensitivity and specificity in the imaging of non-malignant extra-adrenal paraganglioma (PGL) and pheochromocytoma (PHEO) but lower sensitivity in metastatic disease. These tumours are of neuroendocrine origin and can be detected by ⁶⁸Ga-DOTA-Tyr3-octreotide (⁶⁸Ga-DOTA-TOC) PET....

Objectives: To assess the diagnostic performance of median nerve (MN) flip-angle measurements, deformation during wrist flexion [transit deformation coefficient (TDC)], during compression [compression deformation coefficient (CDC)] and fascicular freedom to potentially identify fibrotic MN changes in patients with carpal tunnel syndrome (CTS). Me...

Purpose Diabetes mellitus (DM) and carpal tunnel syndrome (CTS) are common pathologies. The diagnosis of CTS can be facilitated by the use of an ultrasound-based wrist-to-forearm ratio (WFR) of the nerve diameter. However, the applicability of WFR in DM-patients is not yet clear. Materials and Methods 233 wrists of 153 patients were examined. Cross...

Purpose: Often PIRADS 3 findings are usually followed up with further MRIs of the prostate. Current guidelines do not state an optimal interval between the initial MRI and the follow-up MRI. The aim of this study was to find out if PIRADS 3 lesions evolve over time and to determine how long the optimal interval between initial MRI and follow-ups s...

Purpose: To determine whether CAIPIRINHA-Dixon-TWIST (CDT) volume-interpolated breath-hold examination (VIBE) improves image quality by reducing gadoxetate-disodium-associated transient arterial-phase motion artefacts in magnetic resonance imaging (MRI) of the liver. Materials and methods: MRI studies of the liver from 270 patients who had recei...

Objective To quantify the diagnostic utility of imaging features in soft tissue masses (STMs) and to provide a ranked list of predictors for malignancy. Subjects and methods Imaging features in 260 cases of STMs with verified histology were assessed. Diagnostic properties including sensitivity, specificity, positive and negative predictive values,...

Purpose To evaluate the diagnostic accuracy of multiparametric ultrasonography (US) consisting of gray-scale US, color Doppler US, strain elastography, and contrast agent-enhanced US in the assessment of intratesticular lesions. Materials and Methods Institutional review board approval was obtained for this retrospective study. From January 2012 to...

The soleus arcade syndrome is a rare compression neuropathy of the tibial nerve that often remains undiagnosed due to low clinical awareness and difficult diagnosis. We present the case of a female patient admitted with acute worsening of a pre-existing sensory tibial neuropathy and acute tibial nerve palsy after knee joint injection. After a knee...

Introduction: A targeted theragnostic approach based on increased expression of prostate-specific membrane antigen (PSMA) on PC cells is an attractive treatment option for patients with metastatic castration-resistant prostate cancer (mCRPC). Methods: Ten consecutive mCRPC patients were selected for (177)Lu-PSMA617 therapy on the basis of PSMA-t...

Objectives To define the diagnostic value of high-resolution ultrasound (HRUS) of the suprascapular nerve (SSN) in the diagnosis of neuralgic amyotrophy (NA). Methods The cross-section areas (CSA) of the SSN at the C5 root (CSA1) and the omohyoid muscle in the midclavicular line (CSA2) were assessed bilaterally in 15 healthy volunteers and 14 pati...

AimThe aim of this study was to compare the accuracy of 123I-MIBG SPECT/CT with that of 18F-DOPA PET/CT for staging extra-adrenal paragangliomas (PGLs) using both functional and anatomical images (i.e., combined cross-sectional imaging) as the reference standards. Methods Three men and seven women (age range 26–73 years) with anatomical and/or hist...

Clinical/methodical issue: Up to the advent of high-resolution ultrasound, interventions on the peripheral nervous system, including local anesthesia and pain treatment were performed without visual guidance, which in some cases led to treatment failure or local tissue and nerve damage. Methodical innovations: Progress in the field of ultrasound...

Anatomical variants can be found throughout the whole body. Especially in the knee region, some variability has been reported concerning the osseous, tendinous, and muscular system. Beside a few cases of patellar tendon aplasia, no anatomical variations of this tendon are known. We present a rare case of a doubled patellar tendon as an anatomical v...

Objective: The purpose of this study was to assess and compare contrast-enhanced ultrasound and MRI patterns in the diagnosis of soft-tissue masses. Materials and methods: Two hundred fifty-five consecutively registered patients with histologically confirmed soft-tissue masses were included in this retrospective study. The diagnostic properties...

Purpose To determine the correlation of the results of conventional B-mode ultrasonography (US) and compression sonoelastography with histologic results in common flexor tendons of the elbow in human cadavers. Materials and Methods Twenty-five common flexor tendons were evaluated in 16 fresh, unembalmed cadavers of 11 women with a median age of 85...

Aim Progression to androgen independence is the first cause of mortality in castration resistant (cr) prostate cancer (PC) patients. For this reason a targeted theragnostic approach based on increased expression of prostatespecific membrane antigen (PSMA) on PC cells is an attractive treatment option. Methods Ten consecutive patients with progressi...

Purpose To evaluate whether ultrasound findings of the median nerve cross-section area (CSA) and wrist-to-forearm ratio (WFR) correlate with neurophysiological and patient-reported outcome after surgery for carpal tunnel syndrome (CTS). Materials and Methods Subjective pain, CSA, WFR, postoperative scar tissue formation and nerve conduction velocit...

PurposeIn this retrospective study we examined whether size is a viable marker of tumour malignancy in soft tissue masses (STM) and if the ratio of width and length (RALD) of an STM reflects tumour biology more accurately. Methods Measurements of maximal lesion size and perpendicular diameter were performed in available MRI and ultrasonography stud...

Introduction: We report on a rare case of an atypical located aneurysmal bone cyst (ABC) in the patella presenting with pathological fracture after trauma. Materials and methods: Using all available diagnostic modalities and by means of ultrasound-guided core-needle biopsy an unclear and suspected pathological fractured cystic bone lesion in the...

Purpose High-resolution ultrasound is increasingly used in the diagnosis of carpal tunnel syndrome; yet little is known about gender differences in clinical presentation and ultrasound findings. Materials and methods In this high-resolution ultrasound-based retrospective study in 170 cases, we assessed gender influence in CTS in terms of the severi...

Aim: Novel minimally invasive techniques aimed to reposition the haemorrhoidal zone have been established for prolapsing haemorrhoids. We present a prospective randomised controlled trial to evaluate the efficacy of additional Doppler-guided ligation of submucosal haemorrhoidal arteries in patients with symptomatic grade III haemorrhoids. The tria...

Abstract INTRODUCTION: Peripheral compression neuropathy of the ulnar nerve is a frequent condition, most likely encountered at the ulnar sulcus or the Guyon's canal. High-resolution ultrasound (HRUS) can often identify the site of injury. Primarily idiopathic, compression neuropathy can stem from a punched nerve syndrome, in which direct contac...

Peripheral compression neuropathy of the ulnar nerve is a frequent condition, most likely encountered at the ulnar sulcus or the Guyon's canal. High-resolution ultrasound (HRUS) can often identify the site of injury. Primarily idiopathic, compression neuropathy can stem from a punched nerve syndrome, in which direct contact between an arterial bran...

Purpose: The axillary nerve (AN) is frequently injured during shoulder trauma and imaging is required to define the site and extent of nerve injury. However, the AN has a rather complex course through several soft tissue compartments of the shoulder and axilla. Therefore, imaging of the nerve with MRI and sonography is troublesome. Thus detection...

The formation, maintenance, and repair of epithelial barriers are of critical importance for whole-body homeostasis. However, the molecular events involved in epithelial tissue maturation are not fully established. To this end, we investigated the molecular processes involved in renal epithelial proximal-tubule monolayer maturation utilizing transc...

The glycosylated protein uromodulin is exclusively found in the thick ascending limb cells (TAL) of the kidney, where it is produced on mass and apically targeted, eventually being secreted into the urine. Recently, there has been a renewed interest in this protein due to its ability to interact with the immune system, implicating this protein as a...

There is an acknowledged need to promote and further develop in vitro techniques in order to achieve the goal of improved risk assessment of chemicals and pharmaceuticals to humans. The EU 6th framework project “PREDICTOMICS” was established in order to contribute to the further development of in vitro toxicology, with a particular focus on emergin...